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/" A' T& /f. /K /Z. J>MApy TsCAj*-- &cjsa*6#J> Mb 23 2-3J y ENVIRONMENTAL HEALTH PERSPECTIVES Volume 41, October 1981 m UCC 084108 SUBSCRIPTION INFORMATION Subscription rates are as follows: Single copies $7.00, foreign $8.75, domestic $41.00 per year, foreign $51.25 per year. The yearly subscription is for 6 regular issues. Please send check or money order, in advance to the Superintendent of Docu ments, U.S. Government Printing Office, Washing ton, D.C. 20402. The Secretary of Health and Human Services has determined that the publication of this periodical is necessary in the transaction of the public business required by law of this Department. Use of funds for printing this periodical has been approved by the Director of the Office of Management and Budget through January 31,1983. ENVIRONMENTAL HEALTH PERSPECTIVES is a publication of the National Institute of Environmental Health Sciences, National Institutes of Health, Department of Health and Human Services. 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Executive Order 1141 prohibits discrimination on the basis of age by contractors and subcontractors in the performance of Federal contracts, and Executive Order 11246 states that no federally funded contractor may discriminate against any employee or applicant for employment because of race, color, religion, sex, or national origin. Therefore, the National Institute of Environmental Health Sciences must be operated in compliance with these laws and Executive Orders. UCC 084110 -#gr ;T David P. Rail, Director, National Institute of Environmental Health Sciences George W. Lucier Richard Bates Colin F. Chignell Robert L. Dixon Hans L. Falk Lawrence Fishbein Robert Goyer Larry Hart Joseph Haseman David Hoel EDITORS Gary E. R. Hook BOARD OF EDITORS James Huff Heinrich Mailing H. B. Matthews Ernest E. McConnell James D.. McKinney Clifford L. Mitchell John A. Moore Warren Piver Robert Staples Ray Tennant EDITORIAL STAFF Martha H. Dockery, Assistant Managing Editor Ruth Krigman, Copy Editor Sharon Barber [ I ENVIRONMENTAL HEALTH PERSPECTIVES I Volume 41, October 1981 U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES Public Health Service b National Institutes of Health V CONTENTS Conference to Reevaluate the Toxicity of Vinyl Chloride, Poly(vinyl Chloride) and Structural Analogs R. 1. Waxweiler, P. J. Landrigan, P. Infante and R. Shapiro. Introduction......... 1 C. Maltoni, G. Lefemine, A. Clliberti, G. Cotti and D. Carretti. Carcinogenicity bioassays of vinyl chloride monomer a model of risk assessment on an experimental basis .......................................................... ............................................................................ 3 Y. Suzuki. Neoplastic and nonneoplastic effects of vinyl chloride in mouse lung ...... 31 D. H. Groth, W. B. Coate, B. M. Ulland and R. W. Homung. Effects of aging on the induction of angiosarcoma ................................................................................................ 53 M. J. Radike, K. L. Stemmer and E. Bingham. Effect of ethanol on vinyl chloride carcinogenesis........................................................................................................................ . 59 R. M. Hehir, B. P. McNamara, J. McLaughlin, Jr., D. A. Willipn, G. Bierbower and J. F. Hardisty. Cancer induction following single and multiple exposures to a constant amount of vinyl chloride monomer .......................................................... ....... 63 D. H. Groth, D. W. Lynch, W. J. Moorman, L. E. Stettler, T. R. Lewis, W. D. Wagner and C. Kommineni. Pneumoconiosis in animals exposed to poly(vinyl chloride) dust......................................................................................................................... '" 73 J. C. Wagner and N. F. Johnson. Preliminary observations of the effect of inhalation of PVC in man>and experimental gnimals ...................................................................... 83 C. Maltoni and P. Lodi. Results of sputum cytology among workers exposed to vinyl chloride monomer and to poly(vinyl chloride) ................................................................ . 85 P. F. Infante. Observations of the site-specific carcinogenicity of vinyl chloride to humans................................................... 89 H. Weber, W. Reinl and E. Greiser. German investigations on morbidity and mortality of workers exposed to vinyl chloride ............................................................. 95 W. C. Cooper. Epidemiologic study of vinyl chloride workers: mortality through December 31, 1972 .............................................................................................................. 101 H. Falk, J. Herbert, S. Crowley, K. G. Ishak, L. B. Thomas, H. Popper and G. G. Caldwell. Epidemiology ofhepatic angiosarcoma in the United States: 1964-1974 .... P. J. Baxter. The British Hepatic Angiosarcoma Register............................................ 107 115 C. H. Tamburro and R. Greenberg. Effectiveness of federally required medical laboratory screening in the detection of chemical liver injury.................................... 117 R. N. Wheeler, Jr. Poly(vinyl chloride) processes and products ................................... 123 J. H. Jones. Worker exposure to vinyl chloride and poly(vinyl chloride).................... 129 L. Chiazze, Jr., and L. D. Ference. Mortality among PVC-fabricating employees .... 137 G. Molina, B. Holmberg, S. Elofsson, L. Holmlund, R. Moosing and P. Westerholm. Mortality and cancer rates among workers in the Swedish PVC processing industry.............................................................................................................. 145 G. Mastrangelo, B. Saia, G. Marcer and G. Piazza. Epidemiological study of pneumoconiosis in the Italian poly(vinyl chloride) industry ........................................ 153 R. J. Waxweiler, A. H. Smith, H. Falk and H. A. Tyroler. Excess lung cancer risk in a synthetic chemicals plant................................................................................................. 159 R. Lilis. Review of pulmonary effects of polyfvinyl chloride) and vinyl chloride exposure ................................................................................................................................. 167 w '!v, . UCC 084112 r ** i* J. A. John, F. A. Smith and B. A. Schwetz. Vinyl chloride: inhalation teratology study in mice, rats and rabbits ........................................................................................ J. M. Rice. Prenatal susceptibility to carcinogenesis by xenobiotic substances including vinyl chloride....................................................................................................... J. D. Fabricant and M. S. Legator. Mutagenicity studies of vinyl chloride ............. M. Hatch, J. Kline and Z. Stein. Power considerations in studies of reproductive effects of vinyl chloride and some structural analogs .................................................. W. F. Dimmick. EPA programs of vinyl chloride monitoring in ambient air............ N. J. Vianna, J. Brady and P. Harper. Angiosarcoma of the liver: a signal lesion of vinyl chloride exposure....................................................................................................... K. C. Chu and H. A. Miiman. Review of experimental carcinogenesis by compounds related to vinyl chloride...................................................................................................... < R. Apfeldorf and P. J. Infante. Review of epidemiologic study results of vinyl chloride-related compounds ............................................................................................... D. Hattis. Needs for public health intervention and needs for new research on vinyl halides and their polymers: a public policy perspective .............................................. 171 179 189 195 203 207 211 222 227 Contributed Articles R. M. Stern. Process-dependent risk of delayed health effects for welders ............... J, H. Ware, L. A Thibodeau, F. . Speizer, S. Colome and B. G. Ferris, Jr. Assessment of the health effects of atmospheric sulfur oxides and particulate matter: evidence from observational studies.................................................................. R. Jourmard, M. Chiron, R. Vidon, M. Maurin and J.-M. Rouzioux. Mathematical models of the uptake of carbon monoxide on hemoglobin at low carbon monoxide levels ....................................... J. C. Westman and J. R. Walters. Noise and stress: a comprehensive approach .... 235 255 277 291 Erratum................................................. Previous volumes ofEHP .......................................................................................................... 311 312 Ucc 084113 IN THE NEXT ISSUE A Symposium on Environmental Epidemiology N. A. Esmen. Limitations on dose estimation. Y. Alarie. Dose response analysis in animal studies: prediction of human responses. C. E. Land. Statistical limitations in relation to sample size. B. Altshuler. Modeling of dose-response relationships. H. E. Griffen. Discussion: Detection of health effects of exposure to low doses of agents--epidemiologic problems. M. A. Schneiderman. Extrapolation from incomplete data to total or lifetime risks at low doses. P. E. Enterline. Extrapolation from occupational studies--a substitute for environmental epidemiology. E. P. Radford. Sensitivity of health end points: effect on conclusions of studies. R. J. Waxweiler. Epidemiologic problems associated with exposure to several agents. P. E. Enterline. Discussion: Policy issues in applying epidemiologic evidence. V. R. Hunt. Epidemiological studies for regulatory agencies. M. Bundy. When are studies adequate for regulatory purposes: view of one regulated. I. H. Billick. Lead: a case study in interagency policy-making. L. H. Kuller. Who should provide research initiative and support? J. H. Turner Discussion: New approaches to detecting low-dose effects. N. L. Petrakis. Genetic-environmental interactions in relation to low dose stud ies. A possible model from breast cancer. J. C. Christian. Use of twins to study environmental effects. M. K. Conner. Chromosomal methods in population studies. V. Hunt. Discussion: Epidemiologic investigation of special groups. E. A. Murphy. Detection of genetic effects of environmental agents. J. Kline. Epidemiologic detection of low dose effects on the developing fetus. C. K. Redmond. Sensitive population subsets in relation to effects of low doses. Contributed Articles J. I. Rader. Comparative toxicity and tissue distribution of lead acetate in weanling and adult rats. B. E. Vaughan. Problems in evaluating radiation dose via terrestrial and aquatic pathways. F. Perera. The carcinogenicity of airborne fine particulate benzo(a)pyrene: an appraisal of the evidence and the need for control. UCC 084114 M, J.11,,M U f J. Miller. Cadmium, lead and zinc in growing rats fed com leaf tissue grown on soil amended with sewage sludge or heavy metal salts. S. Lan. Effect of air pollution on chronic respiratory disease in the New York City metropolitan area, 1972. -WrV* i. UCC 084U5 . t A*'-.- Conference to Reevaluate the Toxicity of Vinyl Chloride Monomer, Poly(vinyl Chloride) and Structural Analogs National Institutes of Health, Bethesda, MD March 20-21,1980 Sponsored by National Institute of Environmental Health Sciences, National Institute for Occupational Safety and Health and Occupational Safety and Health Administration UCC 084116 Environmental Health I'rnpeetire* Vol. il, p. 1, 19*1 Introduction It has been over 30 years since the first sugges tive evidence was published by Tribukh to indicate that vinyl chloride monomer (VCM) is acutely toxic in man. Chronic toxicity in animals was subse quently demonstrated by Torkelson in 1961, but it was an outbreak to VCM-induced acroosteolysis in the 1960's that focused attention for the first time on the occupational toxicity of this important indus trial chemical. The carcinogenicity of VCM was recognized in 1974 following the nearly simulta neous reports of an association between exposure to VCM and angiosarcoma of the liver (ASL) in man (reported by Creech and Johnson) and in animals (reported by Maltoni). These reports precipitated a thorough international review of the toxicity of VCM at the New York Academy of Sciences. Since then, enormous research efforts have been under taken to expand our knowledge of the toxicity of vinyl chloride. Many of the research efforts stimu lated by the events of the 1970's have now come to fruition, and are appropriately brought together in these proceedings. The proceedings begin with a presentation of the most extensive animal research on the carcinoge nicity of VCM ever published. In these data, dose-response curves can be examined by site and type of tumor, by route and schedule of exposure, and by species and strain of animal. This study and other research on the carcinogenicity of VCM reported in this volume indicate the importance of cofactors such-as age at exposure and simultaneous exposure to ethyl alcohol in VCM toxicity. Evi dence that even a single exposure to VCM induces experimental neoplasia is significant from the stand point of both occupational and nonoccupational exposures. The updated epidemiologic studies presented in this volume of mortality among workers exposed to vinyl chloride reinforce the laboratory findings of multisite carcinogenicity. Data demonstrating the mutagenic and transplacental effects of VCM are also updated and summarized. The lack of predictivitv of one prospective liver screening program sug gests the need for further work in identifying effective medical surveillance techniques for early recognition of liver abnormalities. While thousands of workers are exposed to VCM vapor, many more are exposed to its polymer, poly(vinyl chloride) (PVC). The carcinogenicity of PVC dust is evaluated both experimentally and epidemiologically in these proceedings. The results are not definitive. Nonmalignant respiratory sys tem effects from PVC dust are suggested by a number of papers at this conference. Finally, the extension of the findings of carcino genicity of VCM to its structural analogs, vinylidene chloride, trichloroethylene and tetrachloroethylene, and its brominated equivalent, vinyl bromide, serves as another lead in our effort to understand some fundamental concepts of chemical carcinogenesis. Richard J. Waxwhileh Philip J. Lanukican Peter Infante Raymond Shapjro October 1981 1 Environmental Health Perspective) Vol. it, pp. J-M, Mi Carcinogenicity Bioassays of Vinyl Chloride Monomer: A Model of Risk Assessment on an Experimental Basis by Cesare Maltoni,* Giuseppe Lefemine,* Adriano Ciliberti,* Giuliano Cotti* and Donata Carretti* Data ar pmcntcd regarding the Anal rciulta of the Bentivoglio (Bologna) project on long-term carcinogenicity bioaitayi of vinyl chloride (VC). The experimental project itudied the effect! of the monomer, adminittcrcd by different route*, concentration* and ichedule* of treatment, to animal* (near 7000) of different tpecici, (train*. *cx and age. To our knowledge thi* it the largett experimental carcinogenicity itudy perforated on a tingle compound by a (Ingle inctitution. The recult* indicate that VC i* a multipotential carcinogen, affecting a variety of organa and tiuuet. In the experimental condition* ttudied, the neoplaatic effect* of the monomer were alto detected at low do*c*. The experimental and biological factor* greatly affect the neoplaatic retponce to VC. Long-term carcinogenicity bioastay* are, at present, a unique tool for the identification and quantification of environmental and occupational ritk*. Preciie and highly standardized experimental procedure* are needed to obtain data for risk assessment. Introduction The present report deals with the presentation of the final results of our project on the long-term carcinogenicity bioassays of vinyl chloride (VC) (BT project). To our knowledge this project is the most exten sive experimental carcinogenesis study ever per formed on one industrial compound by a single institution. Planning, Materials, Methods and Performance of the Experiment Planning The experiments of the project were planned (a) to test the carcinogenicity of the compound; Institute of Oncology and Tumor Center; Bologrij, July. (b) to obtain information on the site and type of tumors; (c) to evaluate the possible effects of the routes of administration, with particular regard to the ones reproducing potential human exposure; (d) to assess, in quantitative terms, the level of risk. The planning of the experiments was aimed at achieving these goals. The compound was tested on animals of different species, Btrain, sex and age (Table 1), since it is known that these factors may modify the neoplastic response qualitatively and quantitatively. The choice of the animals was made with the intention of having an integrated system of complementary biological models which could express a range, as wide as possible, of neoplastic responses. VC was administered by different routes: intraperitoneal (IP) injection, subcutaneous (SC) injec tion, inhalation and ingestion (by stomach tube), the latter two being the major routes of potential human exposure. The monomer was administered at different concentrations: 14 by inhalation levels and 6 inges tion levels for various periods of time, by continu ous or intermittent treatment (Table 2). October 1981 3 UCC 084118 Table 1. BT project on VC: animate used. Specie* Strain Rat SpragueDawley Rat Mouse Hamster Wi*tar Swiss Golden Sex Age M, F M M. F M Adult (10-21 wk) Newborn (1 day) Embryo (12 day* pregnancy) Adult Adult Adult The plan of the project is presented in Tables 3-9. Material VC was supplied from the same source in all cases, and it contained very low amounts of impuri ties (Table 10). The oil employed as a vehicle in the ingestion and injection experiments was pure vir gin olive oil from Tuscany. The animals (except for the golden hamsters) were breeds which have been routinely employed in our laboratory for many years. It should be pointed out that, whatever their use, all the animals of our colony undergo periodic examination and complete autopsy, giving us extensive information concern ing their pathology. The chambers for inhalation exposure were built basically of stainless steel and glass. For the ingestion treatment glass syringes and stainless steel needles with round tips were used. To control the level of exposure in the inhalation experiments, an automatic gas chromatography system was used. Route Inhalation Ingestion IP injection SC injection Table 2. BT project on VC: route*, concentration! and ichedule*. Concentration Schedule 30,000, 10,000, 6000, 2300, 500. 250, 200, 150, 100, 50, 25, 10, 5, 1 ppm 10,000. 6000, 2500, 500, 250, 50 ppm 10,000, 6000 ppm . 10,000, 6000 ppm 10,000, 6000 ppm 10,000, 6000 ppm 50, 16.65, 3.33, 1.0, 0.3, 0.03, mg/kg body weight 4.25 mg 4.25 mg 4.25 mg 4 hr/day, 5 d*y$/wk, 52 wk 4 hr/day, 5 day*/wk, 17 wk 4 hr/day. 5 days/wk, 5 wk 4 hr/day, 1 day/wk, 25 wk 1 hr/day, 4 days/wk, 25 wk 4 hr/day, 7 days 5 times/wk, 52 wk 4, 3, or 2 times at 2 month intervals Once only Once only Table S. Plan of lonf-term experiment* on the effect* of expoture by inhalation for 1 year to different doae* of VC on adult Sprague-Dawley rat* (baaic experiment*). ExpL no. BTl BT2 BT6 BT9 BT15 Route Treatment____________________ VC doae Duration _________________________ Animal* Age, Species Strain week* No. 9 No. d Inhalation 10,000, 6000, 2500, 500 250, 50 ppm Untreated controls Treated controls VA, 2500 ppm Inhalation 200, 150, 100 ppm Untreated controls Inhalation 30,000 ppm Inhalation 50 ppm Untreated control* Inhalation 25, 10, 5, 1 ppm Untreated controls 4 hr/day, 5 days/wk, 52 wk 4 hr/day, 5 days/wk, 52 wk 4 hr/day, 5 days/wk, 52 wk 4 hr/day, 5 d*yt/wk, 52 wk 4 hr/day, 5 days/wk, 52 wk Rat Sprague- 13 Dawley Rat SpragueDawley Rat SpragueDawley Rat SpragueDawley Rat SpragueDawley 13 17 11 13 240 240 280 265 30 30 200 200 300 300 Total 480 545 60 400 600 No. per group 60 120-185 60 100 (c) 300 (t) 120 4 Environmental Health Perspectives UCC 084119 milt Table 4. Plan of long-term experiment! on the effect! of length of VC expoeure on VC carcinogenicity. Expt. no. Treatment Route VC doae BT3 BTJO Inhalation 10,000,6000,2500, GOO, 250, GO ppm Untreated control! Inhalation 10.000, 6000, ppm Untreated control! Duration Spedea Strain Animala Age. wceki No. 9 No. 4 hr/day, 8 daya/wk, 17 wk 4 hr/day, 5 daya/ wk, 5 wk: 4 hr/ day, 1 day/wk, 25 wk; 1 hr/day, 4 daya/wk, 25 wk Rat SpragueDawley Rat SpragueDawley 12 11 262 288 420 420 No. per Total group 550 60-190 840 120 Table S. Plan of long-term experiment! on the effect! of age on rinyl chloride carcinogenicity. Expt, no. Treatment Route VC doae Duration Spedea Strain Animala Age, weeka No. 9 No. No. per Total group BT5 Transpla- 10,000, 6000 ppm cental 4- BT14 Inhalation 10,000, 6000 ppm 4 hr/day, 7 dayi Rat Sprague- 19 110 36 146 30-54 (from 12th to 18th Dawley (breed- day ot pregnancy) era) 12 daya (em bryo!) 4 hr/day, 5 Rat Sprague- 1 day 45 44 89 43-46 days/wk, 5 wk Dawley idult Table 6. Plan of long-term experiment! on the effect! of itrain on vinyl chloride carcinogenicity. Expt. noBT7 BT17 Treatment Route VC doae Duration Inhalation 10,000,6000,2500,500, 250, 50 ppm Untreated control! Inhalation 1 ppm Untreated control! 4 hr/day, 5 daya/wk. 52 wk 4 hr/day, 5 daya/wk, 52 wk Species Strain Animala Age, weeka No. 9 No. Rat Wiatar 11 0 220 Rat Wiatar 13 0 250 No. per Total group 220 30-40 250 120-130 Table 7. Plan of long-term experiment! on the effect! of ipeciet on vinyl chloride carcinogenicity. Expt. no- Treatment Route VC doae Duration Specie! Strain Animala Age, week! No. 9 No. No. per Total group BT4 Inhalation 10,000, 6000, 2500, 250, 50 ppm Untreated control! BT8 Inhalation 10.000.6000,2500, 500, 250, 50 ppm Untreated control! 4 hr/day, 5 daya/wk, 30 wk 4 hr/day, 5 daya/wk. 30 wk Mouae Swiaa 11 500. 250 260 510 60-150 Hamater Golden 11 10 268 268 30-62 October 1981 tJCC 084120 Table S. Plan of lonf-term infection experiment! on rinyl chloride carcinoftnicity. Expt. no. BTll BT27 Treatment Route VC dose Duration Specie* Strain Animals Age, weeks No. 9 No. $ g 1 Ingestion SO, 16.65, 3.33 mg/kg body weight in olive oil Controls, olive oil 1, 0.3, 0.03 mg/kg body weight in olive oil Controls, olive oil 5 timea/wk, 62 wk 5 timewVk, 52 wk or 59 wk* Rat SpragueDawley Rat SpragueDawley 13 10 160 160 300 300 No. per Total group 320 80 600 ISO *For 10 animals of each of the three exposed and control groups the treatment was planned to last 104 weeks. but it had to be topped bectutt of tninuU intolerance. Expt. no. BT12 BT13 Table 9. Plan of long-term injection experiments on rinyl chloride carcinogenicity. Treatment Route VC dose Duration Species Strain Animals Age, weeks No. 9 No. $ IP injection SC injection 4.25 mg in 1.0 cc olive oil Controls, 1.0 ec olive oil 4.25 mg in 1.0 cc olive oil Controls, 1.0 cc olive oil 4. 3, 2, or 1 times; two month intervals 1 injection Rat SpragueDawley Rat SpragueDawley 13 21 150 150 80 70 No. per Total group 300 60 150 75 Table 10. Maximum level of impuritiei in the VC uacd. Impurity Concn, ppm H*0 Acetic aldehyde Acetylene Allene Butane 1.3-Butadiene Chiorophene Diacetyiene Vinyl acetylene Propine Methyl chloride 10 5 2 5 8 10 10 4 10 3 100 Methods and Procedures For the experiment on VC, as well as for any other long-term experimental bioassays performed in our laboratory, the procedure has been always the same highly standardized and controlled one. In particular, the following points in our laboratory standard procedures, should be emphasized. Compounds. All shipments of VC used were examined in order to determine whether they meet the required standards. Concentrations. The concentrations, particularly when VC was given by inhalation, were controlled by continuous gas chromatographic monitoring. Modalities of Treatment. Treatment was al ways performed by the same people. This is par ticularly important for gavage, since the animals become accustomed to the same operator. Control of the Animals. The conditions of the animals was checked three times daily. Every two weeks the animals were examined to detect any gross changes. Weight of the Animals. The animals were weighed every two weeks during treatment and every eight weeks after the end of treatment. Duration of the Experiments. In the VC pro ject, as in any other long-term bioassays performed in our laboratory, the animals were kept alive until spontaneous death. Autopsy. Full autopsy was performed on each animal. All parts of the body were explored, including the centra] nervous system. Specimens for histology included the brain, Zymbal glands, interscapular brown fat, salivary glands, tongue, lungs, liver, kidneys, adrenals, spleen, pancreas, stomach, intestine, bladder, uterus, gonads and any other organ with pathological lesions. Histology. Specimens were trimmed in the standard way. Sections were routinely stained with Haematoxylin-Eosin and, when necessary, with special techniques. Histopathological Examination. All sides were screened by a junior pathologist and then reviewed Environmental Health Perspectives UCC 084121 Cc Codt Octob No. per (roup ISO had to be No. per group 60 76 was al'arlals mof the ery two ect any s were ent and snt. VC prorformed ve until on each \plored, ecimens glands, tongue, ncreas, Js and in the ed with y, with "s were viewed by a senior pathologist. The same classification of the lesions were used by all pathologists. Classification ofData, All the anatomical sites and the gross and microscopic observations were classified and coded following our laboratory codes (Tables 11-13). Table 11. Codei of organ* comidered (eequence). 1 ode Organ Code Organ 1 Skin (epidermi* and dermia) 2 Epidermal appendage* 3 ZvmbaJ gland* 4 Subcutaneous tiaauea 5 Mammary gland* 6 Parotid gland* 1 Submaxillary gland* P Naaai and paranasal cavitiea 9 Oral cavity 10 Tongue 11 Lung 12 Pleura and pleural cavity 13 Eaophtgu* 14 Forettomach 15 Glandular stomach 16 Intestine 17 Liver le Panereaa 19 Peritoneum and peritoneal cavity 20 Kidneys 21 Pelves . 22 Ureter* 23 Bladder 24 Ovarie* 25 Uterus 26 Seminal vesicles 27 Prostate 28 Testicles 29 Epididymis 30 Hypophysis 31 Thyroid 32 33 34 35 36 37 38 39 40 41 42 43 44 46 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 . 61 62 Adrenal* Cerebrum Cerebellum Spinal marrow Peripheral nervous system: ganglia Peripheral nervous system: nerves Eyes Harderian glands Skeletal muadet (diaphragm not included) Diaphragm Bones Articulations Heart Pericardium and pericardial cavity Large veaaela Thymua Spleen Axillary and inguinal lymph node* Head-neck lymph nodes Interthoradc and parathymic lymph nodes Intrabdominal lymph nodes Lymph nodes of other sites Bone marrow Soft tiaauea of support Interscspular 1st pad Trachea Ear Female external sex organs Male external sex organs Odontogenic apparatus Gall bladder Table 12. Code* of macroscopic change*. Code Change Code Change 1 No change 2 Alopecia 3 Keratosis 4 Degenerative pathosi* 5 Ulceration Hyperemia, edema and hemorrhage 7 Phlogosii (including of abaceaa) 8 Pulmonary hepatization 9 Pulmonary emphysema 10 Irregular surface 11 Granulation* and plaque* 12 Simple thickening 13 Thickening of capsule 14 Fibroaia 15 In toto reduction 16 Atrophy 17 In toto enlargement 18 Augmentation in consistency 19 Dilatation of organ with cavity 20 Protrusion of eyeball 21 Simple eyst 22 Hemorrhagic cyst 23 Multiple simple eyst 24 Multiple hemorrhagic cyst 25 Polypoid formation 26 Papillomatous formation and horn 27 Solid nodule 28 Hemorrhagic nodule 29 Cystic mass 30 Solid mass 31 Solid necrotic mass 32 Hemorrhagic mass 33 Ossifying mass 34 Serous effusion 35 Fibrinous-purulent effusion 36 Hemorrhagic effusion October 1981 7 UCC 084122 i Table 13. Code* of microscopic change*. Code Change 1 No change* 2 Mild regressive changes 3 Serious regressive change* 4 Necrosis 5 Ulcer 6 Amyloidosis 7 Hyalinosis 8 Colloid-cystic degeneration 9 Calcifications 10 Emphysema 11 Vascular changes (hyperemia, dilatation of sinusoids and other vessels, edema and hemorrhage) 12 Hematic cyst 13 Organized fibrinous coagulum 14 Hemorrhagic effusion 15 Acute phlogistic changes (including abscess) 16 Chronic phlogistic changes (also reactive) 17 Particular granulomatous changes 18 Phlogistic efTuaion 19 Thickening of capsule 20 Thickening of submesothelial tissues 21 Fibrosis ,s 22 Post necrotic fibrosis (comprehensive of drThosis) 23 Fibrous thickening of vessels 24 Cystic ectasia of blood vessels with fibrosis 25 Cystic ectasia of blood vessels with fibrosis and hyperplasia of perithelial cells 26 Cystic ectasia of blood vessels with fibrosis and dysplasia of perithelial cells 27 Cellular'depletion and atrophy (with or without fibrosis) 28 Simple cyst 29 Hemorrhagic cyst 30 Multiple simple cyst 31 Multiple hemorrhagic cyst 32 Dilatation of organs with cavity (including hydronephrosis) 33 Hyperplasia and squamous metaplasia 34 Glandular simple and cystic hyperplasia 35 Diffused parenchyma] hyperplasia 36 Nodular parenchymal hyperplasia 37 Cortical hyperplasia 38 Medullary hyperplasia ........... 39 Hyperplasia of stroma 40 Reactive hyperplasia 41 Simple proliferation of lymphoreticular cells with myelopoieais 42 Proliferation of angioblastic cell* 43 Fibroangioblaatic proliferation 44 Proliferation of lipocytes 45 Proliferation of biliary ducta 46 Proliferation of renal tubules and/or of nephroblastoma 47 Adenomatous hyperplasia 48 Cholangiofibrosis 49 Dysplasia (comprehensive of neoplastic parenchymal nodule of liver) 50 Simple and cystic glandular dysplasia 51 Cortical dysplasia 52 Medullary dysplasia 53 Dysplasia of angioblastic cells 54 Papillomatosis 55 Acanthomatoeis 56 Angiomatosis . -- ------ Code Change 57 Fibroangiomatosis 58 Simple polyp 59 Polyp with cellular distypias 60 Papilloma 61 Fibropapilloma 62 Acanthoma 63 Trichoepithelioma 64 Simple adenoma 65 Muciparous adenoma 66 Colloid-cystic adenoma 67 Exocrine pancreas adenoma 68 Endocrine pancreas adenoma (Islet cell adenoma) 69 Chromophobe adenoma 70 Chromophilic adenoma 71 Cortical adenoma 72 Medullary adenoma 73 Cholangioma 74 Hepatocellular adenoma or hepatoma 75 Tumor of granulosa and of theca 76 Leydig cell tumor 77 Other epithelial benign tumors 78 Fibroma 79 Mixoma 80 Lipoma 81 Leiomyoma 82 Rhabdomyoma 83 Chondroma 84 Osteoma 85 Angioma 86 Fibroangioma 87 Ossifying angioma 88 Other benign tumors of connective tissue 89 Fibroadenoma 90 Adenomyoma 91 Benign tumors of nervous ganglia (ganglioneuroma) and benign sympathetic tumors of adrenal medulla 92 Benign tumors of peripheral nerves (neurilemoma) 93 Carcinoma 94 Carcinoma with metastases 95 Basocellular carcinoma 96 Basocellular carcinoma with metastases 97 Squamocellular carcinoma 98 Squamocellular carcinoma with metastases 99 Transitional cell carcinoma 100 Transitional cell carcinoma with metastases 101 Adenocarcinoma 102 Adenocarcinoma with metastases 103 Biliary duct adenocarcinoma 104 Biliary duct adenocarcinoma with metastases 105 Hepatocellular carcinoma or hepatocareinoma 106 Hepatocareinoma with metastases 107 Exocrine pancreas adenocarcinoma 108 Exocrine pancreas adenocarcinoma with metastases 109 Conical adenocarcinoma 110 Conical adenocarcinoma with metastases 111 Pheochromoblastoma 112 Pheochromoblastoma with metastases 113 Nephroblastoma 114 Nephroblastoma with metastases 115 Seminoma 116 Seminoma with metastases 117 Melanoma 118 Melanoma with metastases 119 Other malignant epithelial turnon Environmental Health Perspectives c i i i i i i i i i i i l l i l l l i i i i l l l F prep fact and shot P of al exp pres sam t; by * anin pro? Si amo sanv stud In subj anal; inter bioa; smal grou whil> front the anin- Octc UCC 084123 ( .-If Change 1-"' Other malignant epithelial turnon with metaataaes 1:1 Mesothelioma l ii Mesothelioma with metaataaes Fibrosarcoma i." Fibrosarcoma with metaataaes ij'i Mixosarcoma i." Mixosarcoma with metaataaes Liposarcoma u* Liposarcoma with metaataaes Leiomyosarcoma i i Leiomvosarcoma with metaataaes Rhabdomyosarcoma : Rhabdomvosarcoma with metaataaes Chondrosarcoma * Chondrosarcoma with metaataaes Osteosarcoma : Osteosarcoma with metaataaes Angiosarcoma ! Angiosarcoma with metaataaes * (|s Ossifying angiosarcoma 14" Ossifying angiosarcoma with metaataaes ` 1 Angiopericytosarcoma ! iJ Angiopericytosarcoma with metaataaes Other malignant tumors of connective tissue 1 t * Other malignant tumors of connective tissue with metaataaes <- Code Change 145 Carcinosarcoma 146 Carcinosarcoma with metaataaes 147 Neuroblastoma 148 Neuroblastoma with metaataaes 149 Glioma (astrocytoma, oligodendroglioma, microglioma) 150 Ependymoma 151 Meningioma 152 Malignant tumors of nervous ganglia and malignant sympathetic turnon of adrenal medulla 153 Malignant turnon of nervous ganglia and malignant sympathetic turnon of adrenal medulla with metaataaes 154 Malignant turnon of peripheral nerves (malignant schwannoma) 155 Malignant turnon of peripheral nerves (malignant schwannoma) with metaataaes 156 Characteristic turnon of eyes 157 Lymphoreticular neoplastic localizations 158 Secondary localizations of turnon from other anatomical districts 159 Neoplastic effusions 160 Odontoma 161 Chondromatosis 162 Histiocytosis and benign histiocytoma 163 Mesothelisl hyperplasia M>r each animal an individual final card was I'tv.iared, which included data on experimental h; nr.', survival, weight at 6,12,18 and 24 months, ;>\ i any gross and microscopic lesions. Samples are u n in Figures 1 and 2. Presentation of Pathological Data. The results ..i; VC experiments, as well as those of any other *-\j. nment performed in our laboratory, will be i M-med in the final report (now in press) with the .. types of tables, in the same sequence. 'I'm- type of presentation has been made possible 1'. 'ne knowledge of the basic pathology of the a:.. vial used, which enabled us to make an apI' simated census of the expected lesions. s ii h a procedure permits a quick comparison a::. the results of different experiments of the project and possibly of the results of projects mg different compounds. Ink rpretation of the Data. The data were i-.. .-ctwl to statistical analysis. Although statistical -is provides an extremely important tool for i: *i iivting the meaning ofthe results of long-term h: ..--ays. it should be stressed that there may be .'.vy differences between exposed and control *which do not reach statistical significance, these differences could still have meaning :r an oncological point of view (particularly in of tumors which are infrequent in the a:.:::;;tl colony). October 1981 Therefore, the most important data should be commented on both in the light of the statistical analysis performed and from a biological point of view. The methodological protocol adopted meets the requirements of the recent Good Laboratory Practice Act. Results Part of these results, namely those dealing with seven basic experiments on the effects of long-term exposure to a range of 14 doses by inhalation (from 30,000 to 1 ppm) and of six doses by ingestion (from 50 mg to 0.03 mg/kg bw), on Sprague-Dawley rates, were presented previously (f, 2). A report, for limited circulation, dealing with part of the results has also appeared (3). The results of the whole project, with detailed tables, will appear in a monograph which will encompass data on survival rate, body weight, regressive and inflammatory changes, benign and malignant tumors, neoplastic precursors, and the most important proliferative changes. With this report we are presenting only tables summarizing the most outstanding results and information, and what we do believe to be the integrative documentation and strictly necessary comments. 9 UCC 084124 Agent: Vinyl chloride Experiment So.: BT 6 Group So.: I No. animal: 10 Type of exposure Inhalation Concentration; 30,000 ppm Treatment protocol: 4 hr'day, 5 daytl week. 52 weeki Specie*; Rat Strain; Sprague-Dawley Sex: Female Age at start of experiment (weeks): 17 Total dose received: Code XVIII, 1 I. 1 II. 1 VI. 5 X, 1 XI, 1 XII. 1 XIII. 10 Age at death (weeks): 85 Period from start of treatment (weeks): 68 Weight (g) 6 months: 247 IS months: 278 IS months: 290 Si months: Figure 1. Sample treatment protocol card. Tables 15*31 presented data on the incidence of the tumors which have been considered as depen dent or possibly correlated to VC exposure, in 17 different experiments on the effects of VC in different animal systems, by different routes, at different doses and with various schedules of treat ment. Explanations of abbreviations used in the tables are given in Table 14. The possible leukemogenic effect of VC in golden hamsters is expressed both by the slight increase in incidence but more by the decrease in latency time (from 16 weeks in animals treated at 10,000 ppm to 36 weeks in control animals). Examples of the most characteristic microscopic features of these tumors were given in a previous publication U). The data on dose-response relationship in long term treatment experiments, by inhalation and by ingestion, in Sprague-Dawley rats, Wistar rats and Swiss mice, with reference to the incidence of total malignant and benign tumors, and the most impor- tant neoplasias observed, are shown in Tables 32-63. The striking effect of the influence of scheduled treatment is pointed out by the results shown in Table 64. Examples of the marked influence of the animals used in determining the neoplastic response are shown in Tables 65*67, which point out the effects of species, strain and age. Conclusions VC-dependent tumors are identified on the basis of one or more of the following parameters: (a) sharply enhanced incidence; (b) rare or excep tional occurrence in the colony of the animal used: (c) dose-response relationship; (d) association of precursor lesions. From the presented data the following conclu sions may be drawn. (1) VC causes tumors in all the different animal systems tested. (2) VC is a multipotential carcinogen, since it causes tumors of different types in different sites (Table 68). (3) Some types of tumors are observed in all the animals studied, i.e., liver angiosarcoma, whereas others are observed in only one animal system. (4) The degree of evidence of correlation be tween VC treatment and the tumors considered as VC-dependent varies from tumor to tumor. (5) VC shows carinogenic effects both when given by inhalation and ingestion and possibly byinjection. (6) Both through inhalation and ingestion exper iments there is a clear-cut dose-response relation ship. (7) The duration of treatment and schedule of treatment greatly affects the neoplastic response. (8) The neoplastic response, in qualitative and quantitative terms, is greatly affected by the spe cies, the strain and the sex of the animals studied. (9) Newborn animals appear to be extremely responsive and easily develop liver tumors, both hepatocarcinomas and angiosarcomas. (10) VC produces carcinogenic effects on em bryos via the placenta. (11) With the above criteria for identifying VCdependent tumors, VC shows carcinogenic effects even at low doses, namely down to 50 ppm and less. (12) The results of the seven basic experiments studying the effects of doses of VC as given by inhalation (BTl, 2, 6, 9, 15), and ingestion (BT11. 27), have been subject to statistical analysis follow ing the Fisher exact probability test (p < 0.05). The total cancer-bearing animals and the tumors :S 'f L F F L iF A 1H I> M S I S: : L' 1 P! F. I Li Pt I Ai Hi In I Ficc Abbr. T ca EpT p Ac Ad Adt MT BT LAS LA ELA5 ELA Nephr Neurt A At N'cop. Nod. 1 Dif. h; *Th< utl* beer rr the tit tumor The animal live 10 * Environmental Health Perspective* Octol UCC 084125 I d in al> ire cts sis .*r$: "p. *d; of Ju lia) f it tee the eas i as nen by *?r- on- of se. and -pe* id. iely oth an* VC- cCtB ess. ;nta by m, owThe i: v I ,W'-,copif changes: < t. >jt- j-.aneous tissues Lur.y fteura and pleural cavity Ki.r.-: omsch Lnir p, neum and peritonei) esvity Adr-t-nsl* H.' Ivrisn glands Ii `rsthoraeie and psrmthymie !;. mph node Type Hemorrhagic nodule Hemorrhagic nodule Hemorrhagic effusion No changes Hemorrhage No changes Hemorrhagic mass No changes In toto enlargement M rmttapie changes: 'cutaneous tissues Lui>p Pit ura and pleural cavity P '-eMomach Liver ivntoneum and l*ntoneal cavity Adrenals Hunterian glands lr.trathoracic and parathymic lymph node Type Fibroangioma Secondary neoplastic localization (liver angiosarcoma) Secondary neoplastic localization (liver angiosarcoma) Papilloma Hepatocareinoma Angiosarcoma with metastases Secondary neoplaatic localization (liver angiosarcoma) Cortical adenoma Abscess t Ho change* Side Sn Sn Side Sn Sn No. Code 1 4, 28, D1 11, 28, D12 12, 38 14. 1 17,6 19, 1 1 32. 32. Cl, D1 38. 1. Cl 51, 17 No. Code 4. 86 11, 158 (17, 138) 12, 158 (17, 138) 14, to 17, 105 17, 136 19, 158 (17, 138) 32. 71, Cl 39. 16, Cl 51, 1 Ki'.i ke 2. Sample record of macroscopic and microscopic changes. Table 14. Abbreviation* used in table*.* Al-hreviation T Tumor A Carcinoma l.!> T Epithelioma !',, Papilloma Ac Acanthoma A.) Adenoma a.) r Adenoma in malignant transformation MT Malignant tumors (total if not otherwise specified) XT Benign tumors (total if not otherwise specified) LAS Liver angiosarcoma LA Liver angioma KLAS Extra-liver angiosarcoma KLA Extra-liver angioma Ncphro-BL Nephroblastoma Neuro-BL Neuroblastoma A Angioblastic hyperplasia in liver AT Angioblastk dysplasia in liver Ncop. nod. Neoplastic nodules of liver .VkJ. hyp. Nodular hyperplasia of liver Liif. hyp. Diffused hyperplasia of liver - * Marked -- 4- Very marked `The incidence of total malignant and benign tumour* i* given a- the total number of tumors per 100 animal* (one animal may k-ar more than one malignant or benign tumor) on the basis of '.re turnon observed among the animals alive, when the first :jmor was observed in the experiment. The incidence of specific tumour is given, as percent of the animal* bearing the tumor considered, referred to the animals alive when the first tumor was observed (in parentheses). October 1981 significantly in excess in these experiments, in relation to dose, are given in Tables 69 and 70. The Fisher exact probability test at 95% confidence is, in relation to the above, not "sensitive" enough, in our experimental conditions. Biologically, in our opinion, the following results, although not statistically significant according to the test used, should be given proper attention. Extrahepatic angiosarcomas of different sites are observed at a very low incidence dose in untreated Sprague-Dawley rats of our colony. Results of experiments BT1 and particularly BT9, however, strongly suggest a relationship between these tu mors and VC exposure. This relationship is sup ported by the excessive incidence of extrahepatic vascular tumors in mice treated with VC (BT4). Few cases of hepatomas have been observed in treated groups, particularly in BT1. This tumor is exceptionally rare in our colony of animals, and none have been observed in the control group of the 17 experiments. Moreover the relationship with treatment is supported by the fact that a high incidence of hepatomas has been observed in Sprague-Dawley rats, following neonatal exposure to a high dose for a short period (BT14). In view of their rareness or nonobservation in the colony of animal used, for the following tumors it should be stressed that attention should be paid to 11 ucc 084126 Table 15. Experiment BTl.* Group and concentration I 10,000 ppm II 6000 ppm III 2500 ppm IV 500 ppm V 250 ppm VI 50 ppm VII No treatment (control) Tumora/100 animals MT BT 81.7 23.3 60.0 38.3 63.3 20.0 51.7 13.3 30.0 25.0 15.0 36.7 13.3 43.3 Animals with tumors. * LAS Fore- Mam Hepa Nephro- Neuro- Zymbal Skin stomach mary LA ELAS ELA tomas BL BL Gl.Ca EpT Pa&Ac MT 11.7 (7/60) 22.0 (13/59) 21.7 (13/60) 10.0 (6/60) 5.1 (3/59) 1.7 (1/60) - 3.4 (2/59) * - 1.7 (1/59) 5.0 (3/60) 5.1 (3/59) 5.0 (3/60) 1.7 (1/60) 3.4 (2/59) 1.7 (1/60) 5.0 (3/60) 6.8 (4/59) 3.3 (2/60) 1.7 (1/60) - 3.3 (2/60) 1.7 (1/60) 1.7 (1/59) 3.3 (2/60) 8.3 (5/60) 1.7 (1/59) - 8.3 (5/60) 8.5 (5/59) 10.0 (6/60) 10.0 (6/60) 8.5 (5/59) 1.7 (1/60) 11.7 (7/60) 5.1 (3/59) 6.7 (4/60) - * 26.7 (16/60) 11.9 a/59) 3.3 (2/60) 6.7 (4/60) -- 5.0 (3/60) 3.4 (2/59) 1.7 (1/60) 1.7 (1/60) 3.4 (2/59) 1.7 (1/60) 1.7 (1/59) - * - 1.7 (1/60) 5.0 (3/60) - 3.3 (2'60) 1.7 (160) 3.4 (2 59) 3.3 (2 60) - - 3.4 - - * - 1.7 (2/58) (1/68) . Exposure by inhalation to VC in air at 10.000. 6000. 2500, 500, 250, and 50 ppm: 4 hr/day, 5 days/week, for 52 weeks. Sprague-Dawley rats, M and F, 13 weeks old. Results after 135 weeks (end of experiment). t s. Table 16. Experiment BT2. i Group and concentration I 200 ppm II 150 ppm III 100 ppm IV No treatment (control) Tumors/100 animals MT BT LAS Animals with tumors, % Fore- MamHeps- Nephro- Neuro- Zymbal Skin stomach marv LA ELAS ELA tomas BL BL Gl.Ca EpT Pt&Ac MT 35.0 21.7 10.0 3.3 0.8 0.8 2.5 5.8 3.3 4.2 - 5.0 (12/120) (4/120) (1/120) (1/120) (3/120) (7/120) (4/120) (5/120) (6 120) 35.0 25.0 5.0 - - 0.8 - 9.2 - 3.4 3.4 1.7 5.0 (6/119) (1/119) (11/119) (4/119) (4/119) (2/119) (6 119) 21.7 27.5 0.8 0.8 - - - 8.3 - 0.8 0.8 3.3 3.3 (1/120) (1/120) (10/120) (1/120) (1/120) (4/120) (4 120) 15.7 21.6 - ' - 1.1 - - * - 1.1 1.1 1.6 1.0 (2/185) (2/185) (2/185) (3/185) (2 185) `Exposure by inhalation to VC in air at 200,150,100 ppm; 4 hr/day, 5 days/week, for 52 weeks. Sprague-Dawley rats, M and F, 13 weeks old. Results after 143 weeks (end of experiment). F Table 17. Experiment BTC.* Group and concentration I 30,000 ppm Tumora/100 animals MT BT 100.0 50.0 Animals with tumors. % LAS Fore- Mam- Hepa Nephro- Neuro- Zymbal Skin stomach mary LA ELAS ELA tomas BL BL Gl.Ca EpT PaAAc MT 30.0 1.7 1.7 5.0 1.7 (18/60) (1/60) (1/60) (3/60) (1/601 -- 17 Cfi O 1.7 18.3 3.3 am (3&/Go> (1/60) (11/60) (2 60) Exposure by inhalation to VC in air at 30,000 ppm; 4 hr/day, 5 days/week, for 52 weeks. Sprague-Dawley rats, M and F, 17 w eeks old. Results after 68 weeks (end of experiment). 12 Environmental Health Perspective* i Spr Oc UCC 084127 T Table IS. Experiment BT9.* Group and rortentration Tumon/100 animals MT BT LAS Animals with turnon, % Fore- MamHepa Nephro- Neuro- Zymbal Skin stomachi mary LA ELAS ELA tomas BL BL Gl.Ca EpT PaAAc MT 1 ppm il N<` treatment (control) 44.3 41.7 4.8 2.7 3.1 3.7 0.3 (14/294) (8/294) (9/294) (11/294) (1/294)l 3.1 1.0 0.4 21.7 (9/294) (3/294) (1/294) (62294) 23.0 24.0 * - - -- _ _ 1.0 10.2 - (1/98) (10/98) *K vi~- ure bv inhalation to VC in air at 50 ppm; 4 hr/day, 5 days/week, for 52 weeks. Spngue-Dawley rats, M and F, 13 weeks old. after 142 weeks (end of experiment). Table 19. Experiment BT15.11 Group and cneem ration I 25 ppm II 10 ppm III 5 ppm IV 1 ppm Y No treatment (control) Animals with turnon. % Tumon/100 animals MT BT LAS Fore- MamHeps- Nephro- Neuro- Zymbal Skin stomach miry LA ELAS ELA tomas BL BL Gl.Ca EpT PaAAc MT 33.3 58.3 4.2 0.8 2.5 0.8 (5/120) (1/120) (3/120) (1/120) 31.7 53.3 0.8 - 1.7 2.5 - - * a (1/119) (2/119) (3/119) 35.8 55.0 -- - - 22.5 44.2 -- -- 3.3 (4/120) 1.7 (2/119) 0.8 (1/119) 0.8 (1/118) _ - 0.8 (1/119) 0.8 (1/118) _ 15.0 (17/120) * 17.6 (21/119) - 18.5 (22/119) - 12.7 (15/118) 23.3 37,5 _ 0.8 (1/120) 1.7 (2/120) 5.8 (7/120) K\;*ure by inhalation to VC in air at 25, 10, 5,1 ppm; 4 hr dav, 5 daysweek, for 52 weeks. Sprague-Dawley rats. M and F, 13 < old. Results after 147 weeks (end of experiment). ' Table 20. Experiment BT3.1 Group and ivncentntion i 10.000 ppm II 6000 ppm III 2500 ppm IV 500 ppm V 250 ppm VI 50 ppm VII No treatment (control) Tumon/100 animals MT BT 45.0 20.0 S3.S 26.0 41.7 36.0 15.0 35.0 21.7 25.0 18.3 25.0 14.7 20.0 Animals with turnon, % LAS ' Fore- Mam- Hepa- Nephro- Neuro- Zymbal Skin atomach miry LA ELAS. ELA tomas BL BL .GLCa EpT PaAAc MT 1.7 1.7 1.7 15.5 15.5 8.6 1.7 1.7 (1/58) (1/58) (1/58) (9/58) (9/58) (5/58) (1/58) (1/58) 1.7 - 3.3 1.7 1.7 20.0 15.0 8.3 3.3 1.7 (1/60) (2/60) (1/60) (1/60) (12/60) (9/60) (5/60) (2/60) (1/60) 1.7 - - - 3.3 3.3 8.3 11.7 3.3 6.7 (1/60) (2/60) (2/60) (5/60) (7/60) (2/60) (4/60) 1.7 -- _ -- _ _ 1.7 - _ 5.0 (1/60) (1/60) (3/60) 1.7 1.7 - 10.2 1.7 * 5.1 1.7 (1/59) (1/59) (6/59) (1/59) (3/59) (1/59) 1.7 1.7 5.2 - 1.7 - 1.7 (1/58) (1/58) (3/58) (1/58) (1/68) 0.5 (1/190) 1.0 0.5 (2/190) (1/190) 2.6 (5/190) , `Exposure by inhalation to VC in air at 10,000, 6000, 2500, 500. 250, and 50 ppm; 4 hr/day, 5 dayc/week. for 17 weeks. rprague-Dawley rats, M and F, 12 weeks old. Results after 156 weeks (end of experiment). October 1981 13 ucc 084128 Table 21. Experiment BT10.* Group end concentration Tumor*/100 animals MT BT US Animal* with tumor*. % Fore- MamHepa-. Nephro- Neuro- Zymbal Skin atomach mary u ELAS EU tomaa BL BL Gl.Ca EpT Pa&Ac MT I 10,000 ppm II 6000 ppm III 10,000 ppm IV 6000 ppm V 10,000 ppm VI 6000 ppm VII No treatment (control) 33.3 41.7 0.8 _ 0.8 0.8 _ 7.6 _ 2.5 11.0 (1/118) 30.0 45.0 0.8 (1/118) (1/118) - 1.7 - 0.8 (9/118) (3/118) (13/118) 0.8 7.5 - 1.7 10.8 (1/120) (2/120) (1/120) (1/120) (9/120) (2/120) (13/120) 86.8 45.0 0.8 1.7 - 0.8 - 7.6 2.5 2.5 .13.4 (1/119) (2/119) (1/119) (9/119) (3/119) (3/119) (16.119) 30.8 39.2 2.5 - 1.7 - - 4.2 3.4 1.7 9.3 (3/118) (2/118) (5/118) (4/118) (2/118) (11118) 41.7 45.0 0.8 1.7 0.8 * 0.8 0.8 6.7 0.8 0.8 16.8 (1/119) (2/119) (1/119) (1/119) (1/119) (8/119) (1/119) (1/119) (20.119) 33.3 50.8 0.8 1.7 0.8 - 1.7 0.8 7.5 * 0.8 10.0 (1/120) (2/120) (1/120) (2/120) (1/120) (9/120) (1/120) (12120) 16.6 41.0 4 - 0.4 - * - - 0.9 2.2 7.5 (1/227) (2/227) (5/227) (17/227) Exposure by inhalation to VC in air at 10,000, 6000, ppm; 4 hr/day, 5 days/week, for 5 weeks (groups I and II) or 1 hr'day. 4 days/week. for 25 weeks (groups III and IV) or 4 hr/day, once weekly, for 25 weeks (groups V and VI) (100 hr). Sprague-Dawley rats, M and F. 13 weeks old. Results after 154 weeks (end of experiment). Group and concentration Tumors/100 animals MT BT US Table 22. Experiment BT5.* Animals with tumor*. 41 Hepa- Nephro- Neuro- Zymbal U EUS EU tomas BL BL Gl.Ca Fore Mam Skin stomach mary EpT Pa&Ac MT I 10.000 ppm 11 6000 ppm III 10,000 ppm IV 6000 ppm 6.7 6.7 29.6 21.9 36.7 23.3 22.2 46.9 __ _ __ 3.3 - - (1/30) --* 5.9 - 9.8 * 2.0 2.0 (3/51) (5/51) (1/51) <1 51) 3.1 - - 9.4 3.1 3.1 6.2 (1/32) (3/32) (1/32) (1/32) (232) `Exposure by inhalation to VC in air at 10.000, and 6000 ppm of breeders; 4 hr/day for 1 week (from 12th to 18th day of pregnancy). Sprague-Dawley rats, M and F, 19 weeks old (breeders). Breeders (groups 1 and II) and offsprings (groups III and IV). Results after 143 weeks (end of experiment). Table 23. Experiment BT14.` Group and concentration Tumor*/100 animal* MT BT ______________________________ Animals with tumors, 41 US Hepa- Nephro- Neuro- Zymbal U ELAS EU tomaa BL BL Gl.Ca Fore- MamSkin stomach man* EpT PaiAc MT I 10.000 ppm (breeder*) II 6000 ppm (breeder*) III 10,000 ppm (newborn) IV 6000 ppm (newborn) 16.7 66.7 100.0 109.3 55.5 34.1 (15/44) - - 6.8 45.4 (3/44) (20/44) 58.1 40.5 2.4 2.4 2.4 47.6 (17/42) (1/42) (1/42) (1/42) (20/42) - - 2.3 2.3 (1/44) (1/44) - - 4.8 4.8 (242) (242) 2.4 (1/42) 'Exposure by inhalation to VC in air at 10,000 and 6000 ppm, 4 hr/day, 5 days/week, for 5 weeks (from 1 day to 5 weeks of age). Sprague-Dawley rats, M and F, 21 weclu old (breeders) (groups I and II) and newborn (groups III and IV). Results after 124 weeks (end of experiment). 14 Environmental Health Perspective* UCC 084129 mUmimJ*T' a Wiry ' MT 11 A (13/118) 10.8 (13/120) 13.4 (16/119) 9.3 (11/118) 16.8 '20/119) 10.0 12/120) 7.5 17/227) day. i yratt, lamtarv XT 0 51) 2 (2) ey). 'ter 1 i Table 34. Experiment 8T7.* i inup and c '.rentration I ppm II ppm HI i'eei ppm IV ppm V iVi ppm VI Vi ppm VII treatment i control) Tumon/100 animals MT BT 50.0 10.0 S3-.3 20.0 26.7 13.3 30.0 10.0 133 16.7 16.7 6.7 15.0 16.0 LAS Animals with tumors. Fore- Hepa wepnro- wturo- Zymbal Skin stomach LA ELAS ELA tomas BL BL Gl.Ca EpT Pa&Ac 29.6 (8/27) 11.5 (3/26) 12.0 (3/25) 10.7 (3/28) 3.7 (1/27) 7.7 (2/26) " 3.6 (1/28) 3.8 (1/26) 4.0 (1/25) " 3.7 (1/27) 3.8 (1/26) * 3.7 (1/27) * 7.7 (2/26) 4.0 (1/25) * " 3.7 (1/27) 7.7 (2/26) 7.1 (228) 3.6 (1/28) 11.1 (3/27) 3.8 (1/26) 4.0 (1/25) " * 7.4 (2/27) 7.7 (2/26) * -- * - - 4.0 (1/25) 3.7 (1/27) * * 2.6 (li38) " 1) > :.-ure by inhalation to VC in air at 10.000,6000,2500,500.250, and 50 ppm; 4 hr/day, 5 days-week, for 52 weeks. Wiatar rats, M, 1: old. Results after 165 weeks (end of experiment). Table 25. Experiment BT17.* * iroup and uentration 1 1 ppm il N' treatment control) Tumon/100 animals MT BT 24.2 29.2 20.0 18.5 LAS LA 1.0 (1/99) ELAS 3.0 (3.99) Animals with tumors, % Hepa- Nephro- Neuro- Zymbal ELA tomas BL BL Gl.Ca 5.0 1.0 (5/99) (1/99) 2.0 (2/99) ForeSkin stomach EpT Fa&Ac -" "- 3.2 - 1.1 (3/94) (1/94) Kvi.. .sure by inhalation to VC in air at 1 ppm; 4 hr/day, 5 days/week.'for 52 weeks. Wiatar rata, M, 13 week* old. Reaults after 134 w - - lend of experiment). iroup and (."uentration Tumors'100 animala MT BT Table 26. Experiment BT4.* Animaia with turnon, ** LAS Mammary Skin LA ELAS ELA Lung T Ca EpT Foretomach PaftAe I lp.OOO ppm 11 iV"X) ppm 111 2500 ppm IV 5< ppm V 250 ppm VI 50 ppm VII No treatment (control) 50.0 96.3 17.8 10.7 1.8 7.1 82.1 23.2 7.1 1.8 (10/56) (6/56) (1/56) (4/56) (46/56) (13/56) (4/56) (1/56) 56.7 100.0 21.7 11.7 1.7 5.0 78.8 13.3 11.7 1.7 (13/60) (7/60) (1/60) (3/60) (47/60) (8/60) (7/60) (1/60) 58.3 90.0 27.1 8.5 13.5 1.7 67.8 13.5 6.8 1.7 (16/59) (5/59) (8/59) (1/59) (40/59) (8/59) (4/59) (1/59) 58.3 108.3 23.3 8.3 11.7 6.0 83.3 13.3 3.3 * (14/60) (5/60) (7/60) (3/60) (50/60) (8/60) (2/60) 63.3 96.8 30.0 18.3 5.0 5.0 68.3 20.0 1.7 1.7 (18/60) (11/60) (3/60) (3/60) (41/60) (12/60) (1/60) (1/60) 28.3 23.3 1.7 1.7 1.7 8.3 10.0 20.0 * 1.7 (1/60) (1/60) (1/60) (5/60) (6/60) (12/60) - (1/60) 14.7 14.7 _ 0.7 (1/150) 0.7 10.0 (1/150) (15/150) 0.7 1.3 (1/150) (2/150) 'Exposure by inhalation to VC in air at 10,000,6000,2500, 500.250, and 50 ppm; 4 hr/day, 5 days/week. for 30 weeka. Sanaa mice, M and F. 11 weeks old. Results after 81 weeks (end of experiment). October 1981 15 UCC 084130 A Tabic 27. Experiment BT8.* Group and concentration I 10,000 ppm II 6000 ppm III 2500 ppm IV 500 ppm V 250 ppm VI 50 ppm VII No treatment (control) Tumort/100 animals MT BT ________________________________ Animals with tumors, * Acoustic Hepa Cholan- Cholan- Duct LAS LA ELA tomas gio-Ca giomat EpT Skin EpT Fore Mela stomach Leuksenomas PaAAc miss11 50.0 40.0 43.3 53.3 30.0 50.0 73.3 63.3 103.3 63.3 43.3 40.0 3.3 (1/30) * 6.7 (2/30) - - 3.3 (1/30) 3.3 (1/30) 6.7 (2/30) - - - 6.7 (2/30) - - 3.3 (1/30) 3.3 (1/30) - - 3.3 (1/30) - * * * 6.7 (2/30) 6.7 (2/30) - - - - 13.3 (4/30) 16.7 (5/30) 26.7 (8/30) 20.0 (6/30) 20.0 (6/30) 23.3 (7/30) 3.3 (1/30) -6.7 (2/30) 3.3 (1/30) 10.0 (3/30) - - 23.3 (7/30) 3.3 (130) 10.0 (330) 23.3 (730) 10.0 (330) 30.0 (930) 3.3 (130) 6.7 (230) 3.3 (130) 3.3 (130) 3.3 (130) 33.3 (1030) 33.3 (1030) 56.7 (1730) 30.0 (930) 13.3 (430) 10.0 (330) 16.7 ' (530) 20.0 (630) 30.0 (9.30) 16.7 (530) 20.0 (630) 20.0 (630) 20.0 46.7 - - - - * 36.7 5.0 (22/60) (3/60) 5.0 13.3 (3/60) (8/60) 'Exposure by inhalation to VC in air at 10.000, 6000, 2500, 500, 250. and 50 ppm; 4 hr/day, 5 days/week, for 30 weeks. Golden hamsters, M, 11 weeks old. Results after 109 weeks (end of experiment). bLatency time in weeks: Group 1,16.7; Group II, 27.2; Group III, 30.8; Group IV, 19.0; Group V, 22.5; Group VI, 35.3; Group VII, 36.5. I* Table 28. Experiment BT11.' Group and concentration I 50.00 mg/kg II 16.65 mg/kg III 3.33 mg/kg IV Olive oil (control) Tumors.'100 animals MT BT LAS . LA ELAS Animals with tumors. ** Hepa Nephro- Neuro- Zymbal ELA tomas BL BL Gl.Ca Fore Mam Skin stomach mary EpT Pa&Ac MT 38.7 35.0 21.2 3.7 2.5 2.3 - 2.5 - 1.2 1.2 2.5 5.0 (17/80) (330) (230) (230) (2/80) (130) (1/80) (2/80) 1430) 30.0 17.5 12.5 - - " 3.7 " 2.5 - 1.2 7.5 (10/80) (330) (2/80) (130) (6/80) 10.0 25.0 2.5 1.2 (2/80) (130) ' 3.7 " (330) 13.7 22.5 " " . -- * " " 1.2 1.2 " 5.0 (130) (130) (4/80) `Exposure by ingestion (stomach tube) of VC in olive oil at 50.00,16.65 and 3.33 mgkg body weight, once daily, 4-5 days/week, for 52 weeks. Sprague-Dawley rata, M and F, 13 weeks old. Results after 136 weeks (end of experiment). Table 29. Experiment BT27.* Group and concentration I 1.0 mg/kg II 0.3 mg/kg III 0.03 mg/kg IV Olive oil (control) Tumors/100 animals MT BT LAS Animals with tumors. % Fore- MamHeps- Nephro- Neuro- ZymbaJ Skin stomach mary LA ELAS ELA tomas BL BL Gl.Ca EpT PaAAc MT 24.7 35.8 20 0.7 0.7 (3/149) (1/149) (1/149) 18.3 28.0 0.7 0.7 , - 0.7 - (1/146) (1/148) (1/148) 18.0 31.3 3.3 2.0 8.0 (5/149) (3/149) (12/149) - * 0.7 1.3 2.7 (1/148) (2/148) (4^148) 0.7 0.7 9.3 (1/150) (1/150) (14/150) 16.0 28.7 * * 0.7 (1/150) 1.3 4.7 (2/150) (7 150) 'Exposure by ingestion (stomach tube) of VC in olive oil at 1.0.0.3,0.03 mg/kg body weight, once daily, 4-5 days/week, for 59 weeks. Sprague-Dawley rats, M and F, 10 weeks old. Results after 136 weeks (end of experiment). IS Environmental Health Perspective* UCC 084131 \ : i LcuJu^. mitik (530) 20.0 (6 30) 30.0 (030) 16.7 . (6 30) 20.0 (6 30) 20.0 (6 30) 13.3 (8)60) Golden ap VIJ. lamnarv MT '80) 1.7 80) 0 80) ar52 11 H TJ T ) 49) 46) 50) 0) -- -Cl. Tabic 30* Experiment BT12.* Gr jf and d"*e 4 mg1 11 4 mg *3- III 4 J mg *2 IV j* mg * 1 V olive oil '("Mrol) minors'iw animals MT BT 13.8 25.0 16.7 28.3 11.7 18.3 20.0 35.0 LAS _ -- _ 8.3 31.7 _ Fore- Mam Hepa- Nephro- Neuro- Zymbal Skin stomach mary LA ELAS ELA tomaa BL BL Gl.Ca EpT PadAc MT --- - - - 1.8 1.8 (1/56) (1/56) - 1.9 * - - - - 1.9 1.9 (1/53) (1/53) (1/53) - 1.8 - - - - - 1.8 - 5.3 (1/56) _ - 1.8 _ (1/56) (3/56) - 1.8 - 3.6 3.6 (1/55) (1/55) (2/55) (2/55) _ __ we _ 3.6 . -- (2/55) .jre bv intrapcritoneal injection of VC, 4.25 mg in olive oil (1 ml), 4, 3, 2 timet, at two month interval* or once only. , .Hawley rats, M and F, 17 week* old. Results after 144 weeks (end of experiment). Table 31. Experiment BT13.* ijrujp and duse I 4.25 mg II Oliv e oil i control) Tumora/100 animals MT BT 16.0 lt.3 LAS 13.3 26.7 Animals with tumors. 1 Fore Mam Hepa Nephro- Neuro- Zymbal Skin stomach mary LA ELAS ELA tomas BL BL GLCa EpT PaAAc MT - - - 1.3 (1/75) " 4.0 (3)75) 1.3 (175) - 1.3 (1/75) " - 1.3 (1.75) Ky^ure by subcutaneous injection of VC, 4.25 mg, in olive oil (1 ml), single dose. Sprague-Dawley rats, M and F, 21 weeks old. !. after 145 weeks (end of experiment). T.itile 32. Incidence of total MT and BT in Sprague-Dawley rats, in relation to concentration of VC administered by inhalation for 52 weeks. hyvnments ___________________________Tumors'100 animals __________ MT______________ BT Concentration (ppm) M F Total M F Total 1 'i ii BT 1 l;T 2 HT 1 BT 9 BT 15 Controls BT 1 BT2 BT9 BT 15 30,000 10,000 6,000 2,500 500 250 200 160 100 50 50 25 10 6 1 0 0 0 0 76.7 80.0 46.7 53.3 23.3 23.3 40.0 21.7 23.3 6.7 20.7 20.0 18.3 25.0 15.0 . 15.3 16.0 18.3 123.3 83.3 73.3 73.8 80.0 36.7 30.0 48.3 20.0 23.3 68.0 46.7 45.0 46.7 30.0 26.7 16.0 30.0 28.3 100.0 81.7 60.0 63.3 51.7 80.0 85.0 35.0 21.7 15.0 44.3 33.3 31.7 35.8 22.5 13.3 15.7 23.0 23.3 40.0 26.7 13.3 16.7 13.3 23.3 10.0 21.7 20.0 23.3 23.3 31.7 30.0 28.3 18.3 23.3 21.2 4.0 20.0 60.0 20.0 63.3 23.3 13.3 26.7 33.3 28.3 35.0 50.0 60.0 85.0 76.7 81.7 70.0 63.3 22.0 44.0 55.0 50.0 23.3 38.3 20.0 13.3 25.0 21.7 25.0 27.5 36.7 41.7 58.3 53.3 55.0 44.2 43.3 21.6 24.0 37.5 October 1981 17 UCC 084132 Tabic S3. Incidence of LAS. LA. A + */+ + T and A+ >/+ + + in Sprafue>Dawley rate in relation to concentration of VC adminiitered by inhalation for 52 weeke. Experiments BT 8 BT1 BT 2 BT 1. BT 9 BT 15 Control BT 1, BT 2. BT 9, BT 15 Concentration, ppm 30,000 10,000 6,000 2,500 GOO 250 200 150 100 50 25 10 5 1 0 Animele with tumor* end correlated changes, ft LAS M F Total U LA A+ +/* 4- + T A+ + /+ + + F Total M F Total M F Total 16.6 43.3 30.0 _ 3.3 1.7 6.7 6.7 6.7 6.7 13.3 10.0 10.0 13.3 11.7 - 3.3 1.7 3.3 6.7 5.0 10.3 33.3 22.0 - 6.7 3.4 - _ _ 20.0 16.7 18.3 20.0 23.3 21.7 - _ 13.3 13.3 13.3 - 20.0 10.0 - - 3.3 _ 1.7 13.3 6.7 10.0 3.4 6.7 5.1 - 3.3 1.7 -- -. 20.0 10.0 15.0 11.7 8.3 10.0 3.3 3.3 3,3 6.6 5.0 5.8 18.3 10.0 14.1 1.7 8.3 5.0 - - 8.3 10.0 9.2 18.3 6.6 12.5 * 1.7 0.8 1.7 _ 0.8 1.7 6.6 4.2 8.3 5.0 6.6 1.1 7.2 4.2 1.1 3.3 2.2 1.7 1.1 1.4 5.5 15.5 10.5 1.7 6.7 4.2 * 1.7 0.8 1.7 _ 0.8 3.3 5.0 4.2 - 1.7 0.8 * - - 1.7 - 0.8 1.7 1.7 1.7 * 2.5 1.3 Table 34. Incidence of ELAS, ani ELA in Sprafue-Dawley rate in relation to concentration of VC administered by inhalation for 52 weeke. Experiments BT 6 BT 1 BT 2 BT 1. BT 9 BT 15 Controls BT 1. BT 2, BT 9, BT 15 Concentration, ppm 30,000 10,000 6,000 2,500 GOO 250 200 150 100 50 25 10 5 1 0 M _ 6.7 3.4 6.7 3.4 1.7 2.3 3.3 0.9 ELAS F 3.3 3.3 6.7 3.3 3.3 3.3 " Animals with tumors. ft Total 1.7 5.0 5.1 5.0 1.7 3.4 0.8 M 3.3 6.7 6.9 3.3 3.3 3.3 2.8 4.6 _ -- 5.0 " 1.7 3.3 ELA F 6.7 3.3 6.7 3.3 _ _ 1.7 1.7 2.8 _ 1.7 - 0.4 0.4 0.8 Total 5.0 5.0 6.6 3.3 1.7 _ 0.6 0.8 3.7 25 25 0.6 Table 35. Incidence of hepatomaa, neoplastic liver nodulee, nodular hyperplasia of the liver and diffuse hyperplaeia of the liver in Spracue-Dawley rate in relation to concentration of VC administered by inhalation for 52 weeks. Experiments BT 6 BT 1 18 Concentration, ppm 30.000 10.000 6,000 2,500 GOO 250 Animals with tumors snd corrected chances. ft Hepatomift Neopl. nod. Nod. hyp. Dili. hyp. M F Total M F Total M F Total M F Total - 3.3 1.7 3.3 * 1.7 - 3.3 1.7 * 6.7 3.3 - 16.7 8.3 3.3 7 1.7 3.3 13.3 8.3 13.3 10.0 11.7 . 3.3 3.3 3.3 3.3 3.3 - 1.7 13.3 6.7 10.0 3.3 . 3.3 1.7 67 13.3 10.0 , - -- w _ 10.0 5.0 13.3 - - - 23.3 - 11.7 8.3 _ 6.7 5.0 3.3 3.3 3.3 1.7 6.7 10.0 - 1.7 Environmental Health Perapectivei UCC 084133 Exper BT 2 BT 1* BT 15 Centro BT l BT S Table Exper BT 6 DT 1 BT 2 BT 1, BT 15 Contro BT 1 BT S " Table: ExpertBT 6 BT 1 BT2 BT 1, E BT IS Control BT 1, Octobc Experiments BT 2 BT 1. BT 9 BT 15 Controls BT 1, BT 2, BT 9, BT 15 Concentration, ppm 200 150 100 50 25 10 5 1 0 Animals with turnon and correlated changes, % Hepatomas Neopl. nod. Nod, hm_______ pjff, hm M F Total U F Total M F Total M F Total 1.7 3.3 2.5 3.3 1.7 2.5 20.0 13.3 16.7 38.3 18.3 28.3 - - * 1.7 - 0.8 8.3 13.3 10.8 16.7 25.3 20.8 - * - - - - 5.0 23.3 14.2 26.7 13.3 20.0 - - - 0.5 - 0.3 13.3 9.4 11.4 2.8 3.3 3.0 - - - - 15.0 8.3 11.7 5.0 10.0 7.5 - - - * - 20.0 5.0 12.5 10.0 6.7 8,3 - -- - .* * 1.7 - 0.8 _ _ - *- - - - 3.3 - 1.7 1.7 _ 0.8 - -* * 0.4 0.2 0.4 0.8 0.6 0.9 2.9 1.9 Table 36. Incidence of nephroblastoma in Spracue>Dawiey rats in rotation to concentration of VC administered by inhalation for 52 weeks. Experiment BT 6 BT 1 BT 2 BT 1. BT 9 BT 15 Controls BT 1. BT 2, BT 9. BT 15 Concentration, ppm 30,000 10,000 * - 6.000 2,500 500 250 200 150 100 50 25 10 5 1 0 Animals with NEPHRO-BL, % M F Total __ 10.0 6.7 8.3 13.8 3.3 8.5 16.7 3.3 10.0 6.7 13.3 10.0 3.4 13.3 8.5 8.3 3.3 5.8 13.3 5.0 9.2 13.3 3.3 8.3 - 1.1 0.6 1.7 * 0.8 "- -** Table 37. Incidence of neuroblastoma in Sprague>Dawley rats in relation to concentration of VC administered by inhalation for 52 weeks. Animals with NEURO-BL, *k Experiments Concentration, ppm M F Total BT 6 30,000 3.3 * BT 1 10,000 6.7 16.7 6,000 6.9 3.3 2,500 6.7 6.7 500 _ * 250 _- BT2 200 _ - 150 - * 100 -- - BT 1, BT 9 50 - - BT 15 25 - 10 * ** 5 1 -* Controls 0 BT 1. BT 2, BT 9. BT 15_______________________________________________________________________ 1.7 11.7 5.1 6.7 * _ - -- - October 1981 19 UCC 084134 Table 38. Incidence of symbol eland carcinoma In Sprafue-Dewley rats In relation to concentration of VC administered bt inhalation for 52 weeks. Experiment BT6 BT 1 BT 2 BT 1, BT 9 BT 16 Controls BT 1. BT 2, BT 9. BT 15 Concentration, ppm 30,000 10,000 6,000 2,500 500 250 200 150 100 50 25 10 5 1 0 Animals with ZvmbaJ eland CA. % M F Total 56.6 33.3 10.3 3.3 10.0 _ 60.0 20.0 13.3 3.3 3.3 _ 58.3 26.7 11.9 3.3 6.7 _ 5.0 1.7 3.3 -- 6.7 3.4 _ 1.7 0.8 2.3 2.8 2.5 5.0 1.7 3.3 1.7 1.7 1.7 - 1.7 0.8 1.7 0.8 0.9 0.8 0.9 Table 39. Incidence of forestomach papilloma and acanthoma in Spratue-Dawley rats In relation to concentration of VC administered by inhalation for 52 weeks. Experiment BT 6 BT 1 BT2 BT 1. BT 9 BT 15 Controls BT 1, BT 2, BT 8, BT 15 Concentration, ppm 30.000 10.000 6,000 2,500 500 250 200 150 100 50 25 10 5 1 0 Animals with forestomach Pa and Ac. % M F Total 16.7 20.0 18.3 - 3.3 1.7 " *-- 3.3 -- 1.7 3.3 3.3 3.3 1.1 * 0.6 --- "*- " 1.3 0.4 0.9 their onset, even st doses below the ones with statistically significant results. An excess of Zymbal gland carcinomas is ob served down to 50 and 25 ppm. Liver angiosarcomas are extremely rare in the colony used (4 cases over several thousand un treated animals). Therefore, one must consider the onset of these tumors as important even at doses not shown by statistical analysis, and particularly below 50 ppm (5 liver angiosarcomas out of 120 animals at 25 ppm, and 1 liver angiosarcoma out of 20 120 animals at 10 ppm), and at 1 mg/kg (3 liver angiosarcomas out of 150 animals), and at 0.3 mg/kg (1 liver angiosarcoma out of 150 animals). The onset of a few nephroblastomas observed after inhalation treatment at doses below 100 ppm and in groups treated by ingestion with 50 and 16.65 mg/kg, is not casual in our opinion, given the extreme rarity of these tumors in rats. Neuroblastomas have never been observed by us, up to the present, in the Sprague-Dawley rats used in our laboratory as control or otherwise Environmental Health Perspectives Table Spras BT 6 BT 1 BT 2 BT 1 BT 9 BT 15 Conor BT BT. BT BT Table relatic Exper BT7 BT 17 Contro BT 7 BT 1 Ti Expert BT 7 BT 17 Contro BT 7 Octob UCC 084135 '"Ik) 6.7 1.9 3.3 7 1.3 1.4 >.8 .'.5 .3 .7 1 .8 .9 . rve , Inndrnc* of mammary malitnsnt tumor in female rau In rtiation to concentration of VC administered by inhalation for 52 wooka. Concentration, ppm Animals with Mammary MT, % KT * KT 1 KT.' KT I f'T * kt r. t r*r . HI 1 KT.' KT HT 1` 30,000 10,000 6.000 2,500 500 250 200 160 100 50 50 25 10 5 1 0 0 0 0 6.7 10.0 6.7 3.3 6.7 8.3 10.0 6.7 6.7 40.7 28.3 35.0 38.3 23.3 2.0 18.0 10.0 *a Tahli ti I m idi'ntt of total MT and BT in male Wiitar rati in rrlaiHin ........ nerntration of VC administered by inhalation for 52 weeks. 1V' KT T l'T :* KT T KT :* Concentration. ppm 10.000 6,000 2.500 500 250 50 1 0 0 Tumora'lCO Animals MT BT 50.0 10.0 53.3 20.0 26.7 13.3 30.0 10.0 13.3 16.7 16.7 6.7 24.2 29.2 15.0 15.0 20.0 18.5 Table 43. Incidence of ELAS and ELA in male Wiatar rata in relation to concentration of VC adminietcred by inhalation for 52 weeka. Experiment Concentration, ppm BT 7 BT 17 Controls BT 7, BT 17 10,000 6,000 2,500 600 250 50 1 0 Animals with tumors. % ELAS ELA _ 3.8 4.0 - 3.7 --, 3.0 0.7 _ 3.8 _ -- 3.7 6.0. _ treated. Therefore we consider as dependent on treatment the onset of these tumors, even at doses below 10,000 ppm, i.e., 6000 and 2500 ppm. The meaning in oncological terms of the results at the lowest doses may be better evaluated in consid ering, not singly, but together, the tumors found to be VC-dependent (Table 71). None (or no increase) of the specifically VC related tumors shown in Table 71, observed in the seven basic experiments, was found at doses of 5 and 1 ppm (by inhalation) and 0.03 mg/kg (by ingestion). General Comments VC long-term experimental study led to the discovery of VC carcinogenicity, and as a direct consequence, to what probably has been the great est effort ever made at controlling the exposure to an industrial carcinogen in the workplace (Table 72). Moreover, long-term carcinogenicity bioassays on VC are a crucial step in the field of environmen tal and occupational carcinogenesis which, in turn, liver ?/kS ved ppm and the by rats ise Tttlm 1.'. Incidence of LAS, LA, A+ + /+ + + t and A-*- +/+ + + in male Wider rata in relation to concentration of VC adminiitcred by inhalation for 52 weeks. K\|BT 7 PT IT Otr.:r * PIT KT 17 Concentration, ppm 10,000 6,000 2,500 500 250 50 1 0 Animals with tumors tnd correlated changes. * LAS LA A-t- +/+ + + T A++/+ + '*- 29.6 _ 3.3 _ 11.5 7.7 - 3.3 12.0 * 3.3 10.7 3.6 3.3 3.3 3.7 3.3 _ *_ * 1.0 1.7 0.8 October 1981 21 1! UCC 084136 Table 44. Incidence of hepatomas, neoplastic liver nodules. nodular hyperplasia of th liver and diffuao hyperplasia of th IWtr in mala Wiatar rata in relation to concentration of VC administered by inhalation for 32 weeks. Experiment BT 7 BT 17 Contrail BT 7, BT 17 Concentration, ppm 10,000 6,000 2,500 500 250 60 1 0 Animals with tumors and correlated chances. % Hopatomaa Neop.nod. Nod. hyp. Dif.hvp. - * 6.7 7.7 6.7 3.3 6.7 4.0 - 6.7 6.7 6.7 * 3.3 - - 16.7 <w - 10.0 1.0 - 5.0 4.2 1.2 2.3 Table 45. Incidence of NEPHRO-BL in male Wiatar rata in relation to concentration of VC adminictered by inhalation for 52 weeka. Experiment Concentration, ppm Animals with NEPHRO-BL, % BT 7 BT 17 Controls BT 7, BT 17 10.000 6.000 2,500 '5&0 250 50 1 0 3.7 7.7 7.1 3.6 - Table 47. Incidence of Zymbal (land CA In male Witter rati in relation to concentration of VC adminietered by inhalation for 52 weeka. Experiment Concentration, Animal! with ppm Zymbal gland CA. t BT 7 BT 17 Control* BT 7, BT 17 10.000 6.000 2,500 600 250 50 1 0 7.4 7.7 - - - - 2.0 2.3 Table 46. Incidence of NEURO-BL in male Wiatar rata in relation to concentration of VC adminietered by inhalation for 52 weeka. Experiment Concentration, ppm Animals with NEURO-BL, * BT 7 BT 17 Controls BT 7, BT 17 10,000 6,000 2,500 500 250 50 1 0 11.1 3.8 4.0 - " Table 48. Incidence of foreetomach Pa and Ac in male Wittar rati in relation to concentration of VC adminietered by inhalation for 52 weeks. Experiment Concentration, ppm Animalt with forestomach Pa and Ac. rt BT 7 BT 17 Controls BT 7, BT 17 10.000 6.000 2,600 500 250 50 1 0 _ - * - 0.7 are among the most important areas of public health nowadays. These studies have demonstrated that long-term carcinogenicity bioassays: may predict carcinogenic risk for humans; may give indication of the level of risk, in relation to dose; may provide information on 22 possible target organs and, in genera] terms, on the quality of neoplastic response; may represent a tool for obtaining information on the relative risk repre sented by different compounds, provided that they are tested under the same standard conditions (Table 73); have revealed the need to identify Environmental Health Perspective* UCC 084137 Tablt 49. Incidence of toUl MT end BT in Swiaa mice in relotion to concentration of VC ndminietered by inholetion for 30 week*. Experiment Concentration, ppm M Tumore/100 animal* MT BT F Total M F Total BT4 10,000 6,000 2,500 500 250 SO 0 16.6 83.3 60.0 83.3 113.3 98.3 26.7 86.6 56.7 100.0 100.0 100.0 40.0 76.7 58.3 80.0 100.0 90.0 36.7 80.0 58.3 93.3 113.3 103.3 36.7 90.0 63.3 116.7 80.0 96.3 6.7 50.0 28.3 20.0 26.7 23.3 6.2 24.3 14.7 13.7 15.7 14.7 Table 50. Incidence of LAS and LA in Swiaa mice in relation to concentration of VC adminiatered by inhalation for 30 weeka. Experiment Concentration, ppm U LAS F Animate with tumora. % Total M LA F Total BT4 10.000 5$ 500 250 50 0 3.8 30.0 17.8 3.8 16.7 10.7 6.7 36.7 21.7 6.7 16.7 11.7 20.7 33.3 27.1 6.9 10.0 8.5 20.0 26.7 23.3 3.3 13.3 8.3 30.0 30.0 30.0 20.0 16.7 18.3 3.3 - 1.7 - 3.3 1.7 * * " ** " " Table 51. Incidence of ELAS and ELA in Swiaa mice in relation to concentration of VC adminiatered by inhalation for 30 weeka. Experiment Concentration, ppm M ELAS F Animal* with turnon. % Total M ELA F Total BT 4 10,000 6,000 2,500 500 250 50 0 3.3 1.8 7.7 6.7 7.1 - 3.3 1.7 6.7 3.3 5.0 13.8 13.3 13.5 3.3 1.7 6.7 16.7 11.7 3.3 6.7 5.0 6.7 3.3 6.0 6.7 3.3 5.0 3.3 1.7 3.3 13.3 8.3 - 1.4 0.7 1.2 * 0.7 Table S2. Incidence oflung tumor* (Ad and Ad T ) In Swiaa mice in relation to concentration of VC adminiatered by inhalation for 30 weeka. Experiment Concentration, ppm Animal* with lung turnon (Ad and Ad T ). * M F Total BT 4 10,000 6,000 2,500 500 250 60 0 76.9 76.7 62.1 80.0 80.0 10.0 10.0 86.7 80.0 73.3 86.7 56.7 10.0 10.0 82.1 78.3 67.8 83.3 68.3 10.0 10.0 October 1981 23 UCC 084138 Table 53. Incidence of nummary CA in female Swisa mice in relation to concentration of VC administered by inhalation for 30 week*. Experiment Animals with Concentration, ppm mammary CA, % BT 4 - 10,000 6,000 2,600 500250 60 0 43.3 26.7 26.7 23.3 40.0 40.0 1.4 animal systems more equivalent to humans in neoplastic response, which in turn depends on partly-known factors, such as basic "spontaneous" tumorigram and enzymatic profiles. Prospects At present the most important goal of research on environmental and occupational carcinogenesis is, in our own view, the extrapolation of results Table 54. Incidence of foreetomach Pa and Ca in Sw|m mice in relation to concentration of VC adminietered by inhalation for 30 week*. Experiment Concentration, ppm Animals with forestomach Pa and Ac.* _ M F Total BT 4 4* . 10,000 6.000 2,500 500 250 50 0 3.3 1.8 3.3 - 1.7 3.3 1.7 -- - 3.3 1.7 3.3 * 1.7 - Table 55. Incidence of total MT and BT in Sprague-Dawley rati in relation to concentration of VC administered by inceition for 52 (or $9) weeks. Experiment Concentration, rngOtg M Tumors. 100 animals MT BT F Total M F Total BT 11 BT 27 Controls BT 11 BT 27 50.00 16.65 3.33 1.0 0.3 0.03 0 0 35.0 42-5 38.7 20.0 50.0 35.0 22.5 37.5 30.0 - 35.0 17.5 5.0 15.0 10.0 2.5 47.5 25.0 13.3 36.0 24.7 12.0 58.7 35.3 12.0 14.7 13.3 20.0 36.0 28.0 8.0 28.0 18.0 14.7 48.0 31.3 12.5 15.0 13.7 10.0 35.0 22.5 8.0 24.0 16.0 9.3 48.0 28.7 Table 56. Incidence of LAS, LA, A+ */* + * f and A+ +/+ + + in Sprague-Dawley rat* in relation to concentration of VC administered by ingestion for 52 (or 59) weeks. Experiment BT 11 BT 27 Controls BT 11, BT 27 Concentration, mg/kg 50.00 16.65 3.33 1.0 0.3 0.08 0 Animals with tumors snd correlated changes, % LAS LA A* + + T A+ +/ + - -f M F Total M F Total M F Total M F Total 20.0 22.5 21.2 2.5 5.0 3.7 7.5 5.0 12.5 7.5 10.0 8.7 10.0 15.0 12.5 * - - 5.0 5.0 5.0 7.5 15.0 11.2 _ * *. - 2.5 7.5 5.0 15.0 22.5 18.7 1.3 2.7 2.0 * - - - - 1.3 6.7 4.0 *_ 1.4 0.7 - 1.4 0.7 * 1.3 0.7 1.3 1.3 1.3 ------- 0.9 0.4 - 0.9 0.4 24 Environmental Health Perspectives UCC 084139 mans in tfs on ^search . renesii ; isuJts i n for JO | r*blf 57 Incident* of ELAS and ELA in Sprague-Dawlty rata in relation to concentration of VC adminietered by Infection for 52 (or 59) week*. BT 11 BT 27 Cor. !:BT 1 ] BT 27 Concentration, mg/kg 50.00 16.65 3.33 1.0 0.3 0.03 0 M - * - ELAS F 5.0 - 5.0 1.3 -- - Animate with tumori, It Total 2.5 - 2.5 0.7 - U 2.5 * _ - ELA F 2.5 * 2.5 _ - Total 2.5 1.2 * Tahir > Incidence of hepatomaa, neoplaatic liver nodule*, nodular hyperplaaia of the liver, and diffuse hyperplasia of the liver in Sprague-Dawlcy rats In relation to concentration of VC administered by inceetion for 52 (or 59) week*. F.vfw - - vA BT i: BT j: t (/,*r .- . \ ~ :i BT 27 Concentration, mgOcg 50.00 16.65 3.33 *F.O 0.3 0.03 0 Animal* with tumor* and correlated change*. % Hepatomas Neop.nod. Nod.hyp. Dif.hyp. M F Total M F Total M F Total M F Total --- 5.0 2.5 17.5 17.5 17.5' 15.0 15.0 15.0 - - - - - - 17.5 30.0 23.7 25.0 32.5 28.7 - - - 2.5 - 1.2 10.0 20.0 15.0 13.0 42.5 28.7 1.3 - 0.7 1.3 2.7 2.0 6.7 13.3 10.0 6.7 14.7 10.7 1.3 - 0.7 - 1.3 0.7 9.3 6.7 8.0 _ 10.7 5.3 - - - - - * 4.0 6.7 5.3 - 10.7 5.3 " - 0.9 0.4 5.2 6.1 5.6 7.0 8.7 7.8 T.ri'1. .'i1*. Incidence of NEPHRO-BL in Sprague-Dawley rat* m n i.itiun to concentration of VC administered by ingestion for 32 (or 39) weeks. E\i"T:ments BT 11 BT 27 Con: ml# BT 11. BT 27 Animal* with NEPHRO-BL. 9 Concentration, mg'kg M F Total 50.00 16.65 3.33 1.0 0.3 0.03 0 2.5 2.5 2.5 6.0 2.5 3.7 ___ __ -*- Table 60. Incidence of NEVRO-BL in Sprsfue-Dawley rat* in relation to concentration of VC administered by incestion for 52 (or 59) week*. Animal* with NEURO-BL. 9 Experiments Concentration, mg/kg M F Total BT 11 BT 27 Control* BT 11, BT 27 60.00 16.65 3.33 1.0 0.3 0.03 0 _ -_* --__ - __ - -w -__ " from animal to human, both in qualitative and in on occupationally exposed population groups have quantitative terms. been made and are being carried out in different \ C carcinogenicity may again provide an impor parts of the world, particularly in Western Europe tant tool towards solving this problem. and in the U.S.A., with reference to genera] We now know a great deal about the effects of pathology and neoplasias. 1 \ C' in experimental animal systems, both in quali If these epidemiological investigations provide tative and quantitative terms. precise figures on the whole group considered, 4 On the other hand, epidemiological investigations including figures on the level and length of expo- i October 1981 25 l ucc 084140 Table (1. Incidence of Zymbal (land CA in Sprague-Dawley ratt in relation to concentration of VC adminiatered by ingestion for 52 (or 59) weeks. Animals with Zymbal gland CA, * _________________ Experiment* BT 11 BT 27 Controls BT 11, BT 27 Concentration, mg/kg U 50.00 16.65 3.33 1.0 0.3 0.03 0 2.5 2.5 - 2.7 - F Total 1.2 2.5 2.5 * 4.0 3.3 --- 1.7 0.9 Table <3. Incidence of mammary MT in female Sprat* Dawley rets in relation to concentration of VC admininLe by ingestion for 52 (or 59) weeks. Experiment BT 11 BT 27 Controls BT 11 BT 27 Concentration mg/kg 50.00 16.65 3.33 1.0 0.3 0.03 0 0 Animals eitfc mammary MT. \ 10.0 15.0 5.0 16.0 5.5 18.7 10.0 9.3 Table <2. Incidence of forestomach Pa and Ac in SpragueDawley rats in relation to concentration of VC administered by ingestion for 52 (or 59) weeks. Experiment* Animals with fore- stomach Pa and Ac, % 1* Concentntion, mg/kg M F Total BT 11 BT 27 Controls BT 11. BT 27 50.00 16.65 3.33 1.0 0.3 0.03 0 5.0 2.5 - 2.5 1.2 -_ 1.3 2.7 2.0 2.7 1.3 * 1.8 0.7 1.7 0.9 sure (so as to define homogeneous exposed groups), and collect all possible available data on pathology we shall have an opportunity, unique at present, to compare animal and human data, both in qualitative and quantitative terms, and to help find a possible key for extrapolating from animals to humans. The Cost With the presentation made in Paris last Novem ber (2) and with today's report, ten years of wort on our VC experimental project seem to be nearly concluded. After having presented the results, wt also wish to present the data of the cost of the project, which cannot be expressed only in financial terms. The cost of the BT project of long-term carcino genicity bioassays on vinyl chloride includes the cost of (1) the planning and setting-up of experi mental apparatus, including inhalation facilities, of Tabic 64. Incidence of LAS and Zymbal gland CA in Sprague-Dawley rat* in relation to achedule of treatment with VC administered by inhalation. Experiment BT 1 BT 3 BT 10 BT 1 BT 3 BT 10 Animals with tumors, * LAS____________________Zymbal gl.ca VC concentration, ppm Schedule* u F Total M F Total 10,000 10,000 10,000 6,000 6,000 6,000 I 10.0 13.3 11.7 33.3 20.0 26.7 II - - - 17.8 13.3 15.5 III 1.7 - 0.8 13.5 1.7 7.6 IV 1.7 _ 0.8 8.5 6.7 7.6 V * 1.7 0.8 3.3 10.2 6.7 I 10.3 33.3 22.0 10.3 13.3 11.9 11 3.3 1.7 20.0 10.0 15.0 rvIII - - 10.0 5.0 7.5 3.4 1.7 2.5 8.5 - 4.2 v 1.7 0.8 10.0 5.0 7.5 `Schedules: (I) 4 hr/day, 6 days/wk, 52 weeks; (II) 4 hr/day, 5 dayt/wk. 17 weeks; (111)4 hr/day, 5 days/wk, 5 weeks; (IV) 1 hrday. 4 days/wk, 25 weeks; (V) 4 hr/day, 1 day/wk; 25 weeks. 26 Environmental Health Perspectives UCC 084141 'ran* fttailnititiK 'umali with unaty MT, % 10.0 15.0 5.0 16.0 5.5 18.7 10.0 9.3 =ed groups, i pathology present, ti i qualitative d a possible 'unans. ast Noveir,ars of wort ft' nearly is, T!st of the in financii rm carcino ldudes the of experiacilities, of ent with VC lea Total 26.7 15.5 7.6 7.6 6.7 11.9 15.0 7.5 42 7.5 .')1 hr div.i :ti* u..- |n,idrne* of LAS in relation to (pacta (male Sprmgue-Dawley Rat*, Wistor rmU. Swta mle* and eolden haniittra), treated with VC administered by inhalation. | jj.--.rWK7; K7T. FT; BT& Concentration, ppm 10,000 6,000 2,500 600 250 50 0 Sprague-Dawley rats 10.0 10.3 20.0 3.4 - Animals with LAS, St Wistar rats Swiss mice 29.6 3.8 11.5 6.7 12.0 20.7 10.0 20.0 3.7 30.0 - 3.3 "" Golden hamsters - 3.3 6.7 - " TtMr fe Im ><i. m r of Zymbal (land CA in relation to strain male >pra4U.Ha*lev and Wiitar rats) treated with VC administered by inhalation. 11 Animals with Zvmbal gland CA, < "tirentration, Spragueppm Dswley rats Wistar rats i:: nr: K'.ooo 6.000 2.500 500 250 50 0 33.3 10.3 3.3 10.0 7.4 7.7 a type uncommon in 1971, and the working out of a protocol for long-term bioassays; (2) the study of nearly 7000 animals up to the point of their natural death, equivalent to more than 3,000,000 rodent days; (3) ten years of work; (4) the routine exami nation of some 200,000 histological slides; (5) a financial commitment equivalent to more than $2,000,000 U.S. at present prices (the average cost of a rat throughout the world in this type of experiment is $300 U.S.); (6) the availability of the same team of scientists throughout the entire 10 years of the project, a prerequisite which may be difficult or even impossible to ensure in many countries at the present time; (7) the highly moti vated commitment of those scientists to a type of work which is long-lasting, onerous and often tedious; (8) the effort involved in maintaining the TsMr 67. Im irti nrc of LAS in relation to age (newborn and adult) Sprague-Dawley rats treated with VC administered by inhalation 4 hr/day, 5 days/week, 52 weeks. K\:- HT 1" r.T 14 Concentration, ppm 10.000 6.000 Animals with LAS. % Newborn rats 11 week old rats M F Toul M F Total 25.0 45.0 34.1 1.7 - 0.8 27.8 60.0 40.5 Table 68. Tumors presently correlated to VC exposure, by experiments on rodents. ATumors Tumors Lympho- .7U.i of of mas and Heps- ' f-r brain lung leukemias tomss Angio sarcoma* and an gioma* Nephro* of other blasto- sites mss Sebaceoua cuta neous carci noma* Other cuta Foresto neous mach pa epith- Mam pillomas elisl mary car ind acan tumors cinoma* thomas Mela noma* ++ <) <*> <-> + + (-) + ( + ) < + ) + (+) October 1HS1 27 UCC 084142 \ Tablt M. Total cancer-bearing animal* significantly in aicaw by Fiahar exact probability teat (p 0.05). Dose level at which total cancer Sex bearing animals in excess Male Female 30,000 10,000 6,000 2,500 500 250 200 60 ppm 50 mg/kg 30,000 10,000 6,000 2,500 500 200 ISO 60 ppm 60 mg/kg Tabic 70. Tumor* significantly in cxccu by Fisher exact probability test ip * 0.05). * Dose* at which tumors Tumor type Sex in excess Zymbal gland carcinoma Liver angiosarcoma Nephroblastoma Neuroblastoma Mammary gland adenocarcinoma Forestomach papilloma M 30,000; 10,000 ppm F 30,000; 10,000 ppm M 30,000; 2500; 200 ppm 50 mg/kg Y 30,000; 6000; 2500; 500 200; 150; 50 ppm 50; 16.65 mg/kg M 2500; 200; 150; 100 ppm F 500; 250 ppm F 10,000 ppm F 150; 50; 25; 10; 5 ppm M 30,000 ppm F 30,000 ppm Table 71. Onset of tumor* considered VC-correlated at the lowest doses. Dose Tumor* 25 ppm 10 ppm 1 mg/ltg 0.3 mg/kg Over 120 animal*, 5 fiver angiosarcoma*, 4 Zymbal gland carcinomas and 1 nephroblastoma Over 120 animals, 1 fiver angiosarcoma, 2 extrahepatk angiosarcomas, and 2 Zymbal gland carcinomas Over 150 animals, 3 fiver angiosarcomas, 1 extrahepatic angiosarcoma. 1 hepatoma, and 5 Zymbal gland carcinomas Over 150 animals, 1 fiver angiosarcoma and 1 hepatoma 28 Table 72. History of vinyl chloride carcinogenicity ha, Date 1961 1970 1970 July 1971 August 1972 April 1973 1973 December 1973 February 1974 February 1974 1974 1974 1974-75 1976 VC was found to produce liver enlargernc and microscopic hepatic degenerative change* (6) Zymbal gland carcinoma* were reported a rat* exposed to 30,000 ppm of VC, by inhalation IS) An increase in atypias in respiratory cells r* observed among worker* heavily expmcdk vein A vast project of long-term carcinogenicity bioassays on VC was started in Bentivogjb. near Bologna, Italy (BT project) Zymbal gland carcinomas, nephroblastoma and liver angiosarcomas were observed a rats exposed to VC by inhalation (Mahon. BT project) The first data oftheBT project wererelend to the scientific community: the oncogenic effect was observed up to 250 ppm U) Splenomegalic liver disease was found poly<vinyl chloride) production workers (t) For the first time a case of liver angiaesraos in s polytvinyl chloride) production worker was correlated to VC exposure (9) On the basis of the BT project data indkttiai a carcinogenic effect at 250 ppm. OSHA proposed a TLV of 50 ppm The BT project data showed that VC is a muitipotential carcinogen, producing a variety of tumor*, in different animal specie The BT project data indicated a caranofcm effect at 50 ppm U0); OSHA proposed an stricter rules Early epidemiological observations (parallel ing the experimental information) indicated an increase in tumor* other than liver sarcoma* (of brain, lung, fiver, heroolympboreticular tiasues) among worker# of VC-PVC industries ill) BT project data showed that VC had car cinogenic effects in rots also when given by ingestion (if) In rets of the BT project exposed to VC by inhrJstion, angiosarcomas were observed down to the level of 25 ppm, and Zymbsl glcnd carcinomas down to the level of 10 ppu (if) consistency of the methodology, which has as its reverse side the limits placed on the exercise of imagination--the most positive element in scientific life; (9) the effort involved in establishing and preserving objectivity and balance in the evaluation and interpretation of data; (10) and finally, the strength required to withstand the sense of loneli ness arising from the lack of co-operation of many of those bodies which should properly be concerned with the progress of science in this field, not excluding part of the scientific community who** Environmental Health Perspective* UCC 084143 Studies 'r nlarfnIR- r nerativ* e reported m ! 'VC, by | I *tory cilktx. Hy exposed u t ^dnofinidtv n Bcmivcftit n) broblattomv baerved in on (Msltoni, wereltnwi i oncogenic opin U) - found amonf workers (t) 'ngiourranii -ion worker () ate indicating i. OSHA `t VC it a a peri** .ogenic 'Poeed new ne (parallel.) indicated liver sngioemolympho- afVGPVC , bad arn given by I to VC by bserved Zyrahal I of 10 ppn ; ' as as iu ' irdse of : ` dentific ing and aluation Uy, the >f lonelimanyaf ncerned H not .ose ectives . :2 Comparative effect* of three related compounds--vinyl chloride (VC), vinylidcne chloride (VDC) and ethylene dichloride (EDC) on the eame animal eyetcma. Com p.-jrd Angiosar Tumors Tumors comas of of the of the bver brain hing Hepa tomas Angio Tumors of sarcomas the kidney and an giomas Nephro Adeno of other blasto carci sites mas nomas Seba ceous CUtAncoui card* noma* Fore- Other stomach cuta papillo neous Mam mas and epithelial mary car acan tumors cinomas thomas Rat *:-ragueI i lev) + + +++ VC M'j'jf* Swiss) ++ (+) + + <*) + ( + ) Kat m-rogue* I >awlev) VIM Mouse Swiss) (+> + Rat vrague! Mwiev) El" Mouse Swiss) f* indiffi nee sometimes degenerates into frank hos tility. Thi i.ijh costs probably represent the reason u h\. in the field of experimental and environmental cardir-jt-nesis, words overlap facts, opinions over lap and meetings and commissions reports sulmii i cv good laboratory work. REFERENCES 1 M..:- r.i. C., Carcinogenicity of vinyl chloride: current reExperimental evidence. (6th International Sympo- Mx-. 'T. the Biological Characterization of Human Tumours, l '!- i-.hagen 1975). In: Advance* in Tumour Prevention, 1>, -.< .non and Characterization, Excerpts Medics, Amaterd-. 1978. VoL S, pp. 216-237. 2 M.:l ni. C.. Lefemine, G., Cffiberti, A., Cotti, G., and t .:"v:ti D. Vinyl chloride carcinogenicity bioassays (BT pr vi't) u an experimental model for risk identification and a-*r-.-ment in environmental and occupational cardnogene- In: EpidCmiologie animal* et epidemiologic humaine: !- c*f du chlorure de vinyl* monomere. Publication* K--vr.tielles. Pari*, I960, pp. 15-112. 3 M..:->ni. C., Lefemine, G., Ciliberti, A., CotU. G., end ( ^rrrtti, D. Vinyl chloride carcinogenicity bioeaeayt (BT pr >ct) a* an experimental model for ri*k identification and n..-t'-*ment in environmental and occupational cartinogene- Ospedali Vita. Field Research, Kept. 10,7:1-208(1980). c.,4 V,,ltoni, Lefemine. G., Chieco P., end Carretti, D. La tmeerogeneti ambients)* e professional*: nuove prospetUve October 1981 alia luce della cancerogenesi da doruro di vinile. Ospedsli Vita 1 (5-6): 4-66 (1974). 5. Torkelaon, T. R., Oyen, F., and Rowe, V, K. The toxicity of vinyl chloride a* determined by repeated exposure of laboratory animal*. Am. Ind. Hyg. Assoc. J., 22:354 (1961). 6. Viola, P. L., Bigotti, A., and Caputo, A. Oncogenic reeponse of rat skin, lungs and bones to vinyl chloride. Cancer Rea. 31: 516-519 0971). 7. Msltoni, C. Occupational carcinogenesis. (2nd International Symposium on Cancer Detection and Prevention, Bologna 1974) In: Advances in Tumour Prevention, Dectection and CharacterizaUon, Esrc>rpta Medics, Amsterdam, Vol. 2, 1977, p. 26. 8. Marsteller, H. J., Lelbnch, W. K.; Miiller, R., Juhe, S., Lange, C. E., Rohner, H. G., and Veltman, G. Chronic toxic liver damage in workers of PVC producing plants. Deut. Med. Wochschr, 98: 2311-2314 (1973). 9. Creech, J. L., end Johnson, M. N. Angiosarcoma of liver in the manufacture of polyvinyl chloride. J. Occup. Med. 16: 150-151 (1974). 10. Msltoni, C.,, and Lefemine, G. Carcinogenicity bioassays of vinyl chloride: current results. In: Toxidty of Vinyl ChloridePolyvinyl Chloride. New York Academy of Sciences, New York, 1975, pp. 195-218. 11. Wagoner, J. K. Statement before the Subcommittee on the Environment of the U.S. Senate Commerce Comitt**, (1974). 12. Msltoni C., Ciliberti, A., Gianni, L., and Chieco, P. Insorgenza di angiosarcomi in ratti in seguito a somministrazione per via oral* di doruro di vinile. Oepedali Vita 2 (1): 65-66 (1975). 13. Msltoni C. Vinyl chloride carcinogenicity: an experimental model for carcinogenesis studies. In: Origins of Human Cancer, Cold Spring Harbor Laboratory, 1977, pp. 119-146. 29 UCC 084144 Environmental Health Perspectives Vol. 41, pp. 31-52,1981 Neoplastic and Nonneoplastic Effects of Vinyl Chloride in Mouse Lung by Yasunosuke Suzuki* Neoplastic effects of vinyl chloride were studied in lunp of 27 mice exposed to vinyl chloride monomer at 2500 and 6000 ppm for 5 and 6 months (large doses and longterm exposure). Pulmonary tumors were observed in 26 of 27 experimental animals. Light microscopy showed the tumors to be multiple and arranged in either tubulo-papillary or adenomatous formations. Although occasional mitotic divisions and invaginations into the bronchiolar lumen were observed, no metastases were found. By electron microscopy, short microvilli, tight junctions between two adjacent cells, appearance of osmiophilic lamellar bodies, large mitochondria of irregular shape, well developed Golgi complexes, continuous or discontinuous basement membranes, occasional appearance of "sequestration" and of crystalloids and lack of both cilia and mucous secretory granules were observed as characteristic features of the neoplastic cells. Some of the cells wereqtborly differentiated and were equipped with poorly developed organoids, without formation of osmiophilic lamellar bodies. The pulmonary tumors corresponded to "alveologenic" tumors. It is suggested that the neoplastic cells were transformed from type II alveolar epithelium via its hyperplastic form. Nonneoplastic effects of the chemical were also studied in the 27 mice. Major light microscopic alterations observed were proliferation and hypertrophy of the terminal bronchiolar cells, consisting of ciliated and Clara cells, hypersecretion of the epithelial mucin in the goblet cells of both the bronchial and the proximal bronchiolar epithelium, hyperplasia of alveolar epithelium, mobilization of alveolar macrophages and occasional presence of peribronchial or bronchiolar chronic inflammation. Electron microscopically, Clara cells of the terminal bronchiolar epithelium showed proliferation of the rough and smooth surfaced endoplasmic reticulum and appearance of large and abnormally shaped mitochondria. Similar alterations were found in the ciliated cells. Submicroscopic changes of pulmonary alveoli were represented by focal thickening of the basement membrane, multiple foci of hyperplastic type II cell (the precondition of the alveologenic tumor), active discharge of osmiophilic lamellar bodies from the type II cell and phagocytosis of the bodies by macrophages, appearance of cholesterol crystalloids in the macrophages, degeneration of alveolar septal cells and occasional appearance of a large nucleus with swelling of the capillary endothelium. The neoplastic effect of vinyl chloride of smaller doses (100, 10, 1 and 0 [control] ppm) and shorter exposure (four weeks) was studied in lungs of 120 mice. Our preliminary observation indicated that sacrificed animals at 40 weeks after the exposure showed productions of the alveologenic tumor In5of9(100 ppm),2of9<10 ppm), 1 of 9(1 ppm) and Oof 10 (control Oppm). A dose-response relation was considered in the incidence of the alveologenic tumor production of vinyl chloride. It is concluded that mouse lung is an extremely sensitive indicator of the oncogenicity of vinyl chloride. Introduction Hepatic hemangiosarcoma has been accepted as a serious health hazard associated with vinyl chloride 'Environmental Sciences Laboratory, Department of ComMedicine and Department of Pathology, Mount Sinai Sch oi of Medicine of the City University of New York, One Gu.-.av* Levy Place, New York, N.Y. 10029. October 1981 exposure among workers in vinyl chloride polymer ization plants (1-7). A risk of lung cancer has also been reported among the workers on the basis of epidemiological studies (8,9), Experimental studies in rats, mice, and hamsters have shown that, in addition to liver, various organs such as lung, brain, breast and skin, includ ing sebaceous glands, were involved in induction of primary neoplasia by vinyl chloride. Although a 31 UCC 084145 number of studies have demonstrated that pulmo nary tumors can be induced by vinyl chloride in mice, the significance of such occurrence and the nature of the tumors have not yet been appropri ately explored (10-17). The occurrence of the nonneoplastic pulmonary abnormalities among vinyl chloride polymerization workers has been reported on the basis of chest x-ray (18), pulmonary function (19) and smear cytology (!) of the worker's sputum. No histopathological evaluation of the abnormalities has been reported. It is believed that a relationship between lung cancer and vinyl chloride exposure exists from epidemiological studies (6,8,9,80). A high incidence of pulmonary tumors in mice exposed to vinyl chloride has been reported by several investigators (10-15). However, the nonneoplastic pulmonary effects of the chemical have not been completely explored. We have, therefore, undertaken detailed light and electron microscopy of the mouse lung, to characterize the neoplastic and nonneoplastic pul monary effects of vinyl chloride. Materials and'Methods - Twenty-seven CDI Charles River white strain male mice, 4 to 5 weeks old at first exposure, were used. All of 27 mice used for this study were alive until they were sacrificed at three separate stages. The mice that died in the course of the experiment were excluded from the study. Group I consisted of six animals exposed to vinyl chloride at 2500 (three mice) and 6000 (three mice) ppm/hr, 5 hr/day, 5 days/week, for 5 months. They were then kept for 6 days without exposure before sacrifice. Group II included 13 mice exposed at 2500 (seven mice) and 6000 (six mice) ppm for 6 months and were kept for an additional 2 days for recovering before sacrifice. Figure 1. Two pulmonary tumors induced by vinyl cMaridt are seen in the peripheral pan of a mouse lung (2500 ppm * group HI). Hematoxylin and eosin; 64 x. Group III included eight animals (seven at 2500 ppm and one at 6000 ppm) which were exposed to vinyl chloride monomer for 6 months followed by a 37-day recovery period. The inhalation exposure; were accomplished at the Industrial Bio-Test Labo ratory, Northbrook, Illinois. In addition to the experimental animals, 16 mice (four for group I. four for group II, three for group III, and five which were 12 months old) were used as controls. To study the pulmonary effects of the chemical at smaller doses with shorter exposure, 120 mice of the same strain, sex and age were prepared. These animals were divided into four groups (30 mice in Tabic 1. Pulmonary tumor production in CDl male mice with lower dose* of VC and shorter exposure (4 weeks).* VC dose, ppm 1st sacrifice (immed Between 1st and iately after dosing) 2nd sacrifice 2nd sacrifice (12 weeks) Between 2nd and 3rd sacrifice 3rd sacrifice (40 weeks) 100 (IV - 80) 10 yv - so) UV1 - 30) 0 UV . 80) 0/10b 0/4' 0/6b 0/1' 5Db 0/10* 0/1' 0/& 0/1' 2'9b 0/10* 0/10b 0/1' lDb 0/10* 0/1' 0/9*1 0 lflh 'Reported as pulmonary tumor-bearing mice/tots) number of mice. . ^Sacrificed. `Found dead. 32 Environmental Health Perspectives r.it ( -I'il tin|H-r an ][.n U-l "ini four L -coj wvir. tiorr *nt. F )</; pan <.V6 i-osi; >odk bv <j tech -mal Octc UCC 084146 nary tumors and nonneoplastic pulmonary tissues and were fixed in 1% phosphate-buffered osmic acid at pH 7.2-7.4 for 2 hr or in 2% paraformaldehyde fixative followed by the osmic acid. After alcohol dehydration, the blocks were embedded in epoxy resin. Ultrathin sections were obtained with an LKB microtome. The sections were stained with uranyl acetate and lead. A Siemens 101 electron micro scope was used for ultrastructural observations. Observations chloride Ppm in 2500 : ed to J -*bo1 the Jp I, five ols. Jat e of iese e in i { ! l i Fisi k` 2 Neoplastic cells stained with PAS. An arrow ir.di.' fine PAS-positive material digested by diastase. The nr-' labeled M shows an abnormal mitosis (2500 ppm in pr..-', lili. 560*. each gr-mp) and were exposed to the chemical for 4 week- ' hr.day, and 5 days/week) at 100 ppm, 10 ppm. 1 ppm and 0 ppm (control). The low dose expe-uiv* were performed at the Toxicology ResH-arvh Laboratory, Health and Environmental Sci ence*. Dow Chemical U.S.A. As shown on Table 1, these animals were sacrificed at three different peri<hN: immediately after, 12 weeks after and 40 week? ;.fter exposure to the chemical. Six (four 100 ppm. one 10 ppm, and one control) were found dead between the first and second periods, and three (one 1 <0 ppm, one 10 ppm and one 1 ppm) were found dead between the second and third periods. Lunps were examined under a dissecting micro scope alter the organs were removed from sacrificed animal*, to determine whether macroscopic ab normalities including tumor production were pres ent. For light microscopy, the organs were fixed in lO'T neutral buffered formalin and embedded in paraffin after dehydration in alcohol. Sections (5-6 jim) were made and stained with hematoxylineosin, Masson's trichrome, Weigert's silver, per iodic acid-Schiff's (PAS) with and without digestion by diastase, elastin and Van Gieson's picrofuchsin technique. For electron microscopy small pieces, smaller than 1 mm8, were taken from both pulmo October 1981 Neoplastic Effects of Vinyl Chloride at Heavy Doses and Long-Term Exposures Gross Anatomical Findings. Pulmonary tu mors were observed in all experimental mice except one from the 6000 ppm series of group 11 (26 of 27). None were found in 16 controls. These tumors were round, whitish in color, multiple in number and variable in sue from 1 to 5 mm in diameter. No metastases to regional lymph nodes or other organs were observed. Neither parenchymal fibrosis nor fibrotic adhesions of the pleura were detected. Light Microscopy. As shown in Figure 1, the tumors were usually seen in the peripheral part of Figure 3. Hyperplastic pulmonary cells are seen beneath the visceral pleura of a mouse lung (2500 ppm in group III). Hematoxylin and eosin; 430 x. 33 I UCC 084147 L Figure 4. Low-power electron micrograph of a well-differentiated pulmonary tumor. Arrows indicate junctional structures between neoplastic cells. B. Basement membrane (2500 ppm in group III), 0s04: 7900 x. lung parenchyma, although occasionally tumors were found in more proximal parts of the lung. No direct connections of the tumors with bronchi or bronchi oles were observed. The neoplastic cells were ar ranged in various ways, such as tubulopapillary and adenomatous forms. Pleomorphism and atypical structures were not striking. However, sometimes abnormal mitoses were observed, as shown in Fig ure 2 (arrow labeled M). The nuclei were round in shape and small, and chromatin was generally finely distributed. Nucleoli were generally poor in devel opment. Two different types, eosinophilic and ba sophilic, were distinguished in the neoplastic cells. Some of the cells stained with PAS, and the sub stance so stained was digested by diastase, sug gesting that it was glycogen. The neoplastic tissue was not encapsulated by connective tissue. Often, air spaces separated neoplastic tissue from normal tissue. Although malignant invasion, such as de struction of preexisting tissue, was not observed in 34 the animal lungs, invagination of the neoplastic tissue into bronchiolar air spaces was detected in instances of extremely large tumors. Collagen and reticular fibers showed little development in the neoplastic tissues. In addition to neoplastic chang es, as shown in Figure 3, focal and multiple hyper plastic changes of the alveolar lining cells were noted in lungs exposed to vinyl chloride. In Figure 3, the hyperplastic cells are seen just beneath the visceral pleura. Since the lining cells beneath the thin connective tissue of the visceral pleura are known to be alveolar epithelium, the hyperplastic cells are assumed to be alveolar epithelial cells. Hyperplastic cells are also found in the deeper pan of lung parenchyma. Occasionally, neoplasia and hyperplasia coexisted in the same lobe of the lung, and the distinction between neoplastic and hyper plastic cells with confidence was not always clear, as some cellular similarities were found between the two. Identification of the cell types of both Environmental Health Perspectives neoplastic was not fe Electron neoplastic trastructu.' included tr. tochondria osmiophilic (arrows in and a bas> .-erved. Fi; area of the tubular lu than those ultrastruct tlria, Golgi i*s, were arrangeme common, a well-develo lum (Fig. f `ytoplasmi -tructures October IS UCC 084148 Figvre 5. Differentiated neoplasm teen in the animal lung shown in Fig. 3. Formation ofthe tubular lumen and microvilli is poor. 0*0,; 6500 x. aplastic cted in ren and in the changhyper- were Figure ith the th the ra are plastic cells, r part a and lung, iyperclear, -.ween both - tivet > ; neopla.-tic and hyperplastic cells with confidence wa.' i.' feasible at the level of light microscopy. El< ctron Microscopy. Figure 4 is derived from neophistic tissue of the tubulo-papillary form. Ultra-ouitural characteristics of the neoplastic cell imhi'lc] microvilli, large, round, or rod*shaped mi-' tih'>h'lria, well-developed Golgi complexes, and o.-mi 'i iiilic lamellar bodies. Junctional structures (arvt'ws in Fig. 4) between adjacent neoplastic cells and a basement membrane (B) were usually obsen cil. Figure 5 was derived from an adenomatous area. ``xhe tumor. Neoplastic cells had poorly formed tubular lumens and microvilli and were smaller than those shown in Figure 4. However, other ultra-tructural characteristics, such as mitochon dria. Golgi complexes, and osmiophilic lamellar bod ies. '..ere almost identical in the two. Irregular arrarcements of mitochondria] cristae were fairly common, and mitochondria were often wrapped by well-developed, smooth-surfaced endoplasmic reticu lum 1 Fig. 6). Some of the neoplastic cells contained cytoplasmic compartments formed by membrane structures (Fig. 7). The occurrence of such com October 1981 partments has been reported by Svoboda (21), who made electron microscopic observations on the neo plastic cells in mouse pulmonary tumors induced spontaneously or by urethane. Occasionally, crys talloid structures were observed in the cytoplasm of the neoplastic cells (Fig. 8). The above described neoplastic cells w*ere quite similar in ultrastructure to type II alveolar epithelium. Capillaries in the neoplastic tissue consisted of single layers of nonfenestrated endothelium as seen in the normal alveolar capillary. In addition to well-differentiated neoplastic cells, poorly differentiated ones were also recognized (Fig. 9). As seen in Figure 9, the cells were cuboidal or cylindrical in shape and lacked formation of osmiophilic lamellar bodies. Mitochon dria were small in size, although the cells were relatively rich in rough-surfaced endoplasmic retic ulum. These cells seemed to correspond to the basophilic ones observed by light microscopy. Ex cept for the lack of a large amount of glycogen, these cells resembled immature alveolar epitheli um, as observed in fetal lung in late gestation. Neither cilia nor mucinous secretory granules were 35 UCC 084149 Figure 6. Part of the cell cytoplasm of a neoplastic cell. The aiTow indicates irregular mitochrondrial cristae (2500 ppm in Group III). 0s04; 29, 400 x. Figure 7. Intracytoplasmic compartment* formed by mem brane structures (2500 ppm in group III). Os04; 20. 000 x. Figure 8. Crystalloid structure seen in the cytoplasm of a neoplastic cell (2500 ppm in group III). Os04; 30,000 x. Environmental Health Perspectives Octobe Ucc 084150 7 reup9II). aSoii; neopU*tic eeUs- No "niiophilic lmIkr bodies are observed (6000 ppm in %T' -fi' ` v3> '/Oa e i. * .fl. gA'c-'' ' ; ' A -n -v r,i/^ .6---iV;4. ,v.^vv . . fir* C- ^ '-r V. .{ V - ^ `e V > - - f. . ri * r.y \ ;'/ . / , - .' 'I-.. .''/' I ' . #<U T* - T.V - <& .* vA Vo'- - 9 x yT7;TI5fcv ' X ,, tv-V-'-U-- > ' V'v^' - ^\.s- f * ** `- 4* ' ` ' 3- .. ' .. f .c- * v ' ,* V F.0LRE 10. Hyperplastic type II cell, are illustrated. Group 1; 6000 ppm; 0.0, 5300 x. October 1981 37 Ucc 084151 Figure 11. Light microscopy of a bronchiolo-alveolar area. Arrows indicate the site of transition between the respira- ton.- bronchiole and the alveolus. Control mouse; Masson's trichrome staining; 420 x. Figure 12. Proliferated and hypertrophic bronchioles. Desquamated bronchiolar epithelial areas are illustrated. Masson's trichrome staining; Group 1; 2500 ppm, 420 >. observed in the neoplastic cells. Based on these findings, it was strongly suggested that the neo plastic cells were derived from the alveolar epithe lium, particularly from type II cells. A hyperplastic pulmonary alveolus is illustrated in Figure 10. Electron microscopically, aspects of the hyperplastic cells were evidently those of type II alveolar cells, although they showed some differences in ultra structure from the normal type II cell. Mitochon dria were large in size and irregular in shape, and, occasionally, retention of huge osmiophilic lamellar bodies was noted in the cell cytoplasm. Cristae mitochrondriales were arranged irregularly, and well-developed endoplasmic reticulum was frequently 38 seen in the cytoplasm. Early stages of the mem brane formation responsible for "cytoplasmic com partments" were observed in the hyperplastic cell. In many respects, the hyperplastic type II cell is assumed to be the precursor of the neoplastic cell. An intermediate form between type I and II cells was frequently observed in the hyperplastic pul monary alveoli. The arrow in Figure 10 indicates a part of the cell cytoplasm which may represent a transitional form between type I and II cells. Though the secretory granules were observed in the neo plastic cells, based on these findings, it was strongly suggested that the neoplastic cells were derived from the alveolar. Environmental Health Perspectives UCC 084152 s. Dmi. Mac- Fk.i Kt 1-!. Hrpersecmion of epithelial mucin in bronchial epi'.hvi jm. Arrows indicate mucinous substance stained with I AS. Group III; 6000 ppm, 420 x. Figure 14. Hyperplasia of alveolar epithelium is shown. Hematoxylin-eosin; Group III: 2500 ppm; 670 x. ienv com cell ell is cellcells pul.es a >nt a OUgh neonglv ived 1 Nonru nplastic Effects of Vinyl Chloride at Heavy Doses with Long-Term Exposure Light Microscopy. In the bronchi and bronchi oles. a> a common finding in the treated animals, proliferation and hypertrophy of the bronchiolar epithelium were noted. As shown in Figure 11, the terminal and respiratory bronchioles of the control mice were relatively simple in structure and the transitional point (arrows) of the respiratory bron chiole into the alveolus was easily distinguished. To differentiate the two areas, we found that Masson's trichrwne was a useful stain, since the cytoplasm of the bronchiolar cells was stained an intense brown red. The bronchioles of all the animals treated with vinyl chloride monomer showed proliferation, and October 1981 cellular hypertrophy, through the degree varied among the animals (Fig. 12). The proliferated cells were irregular in arrangement (Fig. 12). Frequent ly, hypersecretion of epithelial mucin in goblet cells of the bronchi as well as the proximal bronchioles was observed (Fig. 13, arrows). It was noteworthy that those alterations were still found in the ani mals of group III, which had a recovery time of 37 days after vinyl chloride exposure. Chronic inflam matory changes represented by marked lympho cyte infiltration into the perivascular and peribron chiolar connective tissue were seen, particularly in group III. The most significant finding in pulmonary alveoli was a high incidence of alveologenic tumors in the treated mice, as stated before. In addition to the neoplasm, multiple foci of hyperplastic alveolar epi- 39 UCC 084153 r\ V .* -\* . #_ V. a i % ^ 1. *'' -.*/ *.*.!, ^ ^ ' *.' 1 \ v ' go A.-V-1 .> .4%, . : . ?-# * ** . +* . T* * _- %t. # 1 #k A V, * * * ' /V*- * * '* ^ *"s W-%l.a 'N Figure 15. Large clear macrophages (foam cells) as well as smallbasophilicmacrophages areseeninthealveolarairspaces.' Hematoxylin-eosin: Group III: 2500 ppm; 420 x. , Figure 16. Striking accumulation of a large number of for. cells. Hematoxylin-eosin: Group 111: 6000 ppm: 420x. thelium (Fig. 14), which were strongly suggestive of being preneoplastic for alveologenic tumors (22), were frequently observed. Mobilization of alveolar macrophages in the alveolar space was fairly com monly seen in the three groups of animals (Fig. 15). In several cases, foam cells were markedly accumu lated in alveolar space (Fig. 16). Two animals in group III showed bronchopneumonia-like changes. As shown in Figure 17, coexistence of the prolifer ated bronchioles with alveologenic tumors (arrow) was frequently observed. Electron Microscopy. The epithelium of the ter minal bronchiole consists of the Clara cell (nonciliated) and ciliated cells; it lacks mucous-producing cells iftthe mice. Both cell types are illustrated in Figure 40 18, obtained from a control mouse. Clara cells lack typical microvilli and their apical portion present dome-like shape (Fig. 18). The smooth-surfaced endoplasmic reticulum and Golgi complex were wel! developed. Mitochondria were generally round in shape and their cristae were few in number (Fig 18). Two distinct granules, a beadlike structure (electron-dense; the long axis was 1.6-0.2 p.m) and s round phagolysosomal granule (electron-dense or opaque; 0.6 x 0.6 pm in size) were observed in the cells. It is noteworthy that the ultrastructure ofthe cell is not identical among animal species and, fur ther different fixation methods result in different structural appearances of the endoplasmic reticu lum in the cell. Environmental Health Perspective* The cli iU* cri.-ta* tin- ce "re tural c niu e a A lo i- illus fivque rli'iop] V.iif. U: mvgu n.rmbi "b.-tn * ktolx UCC 084154 *< X * # J. ( r * A nber of foam 420 x. cells lack iresent a .-surfaced were well round in ber (Fig. structure xm) and a dense or ed in the ure of the and, furdifferent ic reticu* tives K; t.t IT Han of lung tissue showing coexistence of the ahi-.v c.: .i tumor (arrow) with the proliferated bronchiole. .Mi-- - richrome staining: Group I: 6000 ppm; 170 x. Tht- t i .plasm of the ciliated cell was relatively dt ar anil it contained rod-shaped mitochondria with crixtac i Fm. 18). Cilia and microvilli were seen in the evil -.a face (Fig. 18). The two distinct granules were al-M occasionally seen in the cell. Ultrastructural chances seen in those cell types of the treated mice ai\ described below. A low-power view of the proliferated bronchiole is illustrated in Figure 19. Hypertrophic Clara cells frequently included dark cells rich in rough-surfaced endoplasmic reticulum and free ribosomes. The cell was uMially large and its shape was occasionally irrepilar. Deep interdigitation of the lateral cell membranes of two adjacent cells was occasionally obsened. Golgi complexes were well developed, October 1981 and the two distinct granules described above were increased in number in the cytoplasm. The dark round granules are shown in Figure 19. Although smooth-surfaced endoplasmic reticulum of the nor mal Clara cell was generally vesicular (with a single osmic acid fixation as used in this study, though this cell organoid is cisternal with double fixation by glutaraldehyde and osmic acid), the hypertrophic cells contained various forms of the organoid and the transformation of the rough surfaced endoplas mic reticulum into smooth-surfaced endoplasmic re ticulum was easily observed (Fig. 20). Mitochondria of abnormal shapes and large size occasionally ap peared. Cristae were rather clearly shown in such abnormal mitichondria (Fig. 21). Ciliated cells were also involved in the prolifer ated alteration. The shape of the cells was occasion ally irregular. Golgi complexes were sometimes well developed and phagolysosomal granules as well as round dense granules frequently appeared in the cytoplasm (Fig. 22). Large round mitochondria in which cristae were fewer in number were seen. In some ciliated cells, the rough and smooth surfaced endoplasmic reticulum were markedly developed (Fig. 22). Although light microscopic observations failed to detect details of damages in the pulmonary alveo lus, various ultrastructural alterations of the alveo lar cells were revealed by electron microscopy. Mobilized alveolar macrophages were rich in phagolysosomal granules, as shown in Figure 23. Other cell organelles were also well developed. Basophilic macrophages contained a large number of free ribosomes as well as the rough-surfaced endoplasmic reticulum, while clear macrophages were represented by intracytoplasmic osmiophilic lamellar bodies (Fig. 23) which seemed to be phagocytosed from the alveolar space. Occasionally, cho lesterol crystalloids were found in the macrophages (Fig. 24, arrows)! As shown in Figure 10, hyperplastic alveolar epithelium consisted of type II cells, precursors of alveolar tumor (15). The evolutional process of the neoplastic transformation has been reported (15). Deformation of the cell shape, appearance of giant mitochondria with abnormal cristae, retention of large osmiophilic lamellar bodies, early introcytoplasmic "sequestration," and occasional huge lipid granules were observed. Microvilli of the cell sur face were frequently decreased in number. These alterations were observed in almost all mice ex posed to vinyl chloride, regardless of difference in dose and duration of recovery time. Swelling-of the cytoplasm and appearance of ly sosomal granules were occasionally observed in type I cells. Transformation of the type I cells into the 41 UCC 084155 1 u- m L-'-fe'' m ztr m iT.y ? S' . / . -7 Wuyi.V G -* Figure 18. Fart of the terminal bronchiole. Clara cells and ciliated cells are illustrated. Control mouse; 0s04; 6700 x. type II cells was suggested, since intermediate cell types between the two were found on the alveolar lining. Focal thickening of the basement membrane was commonly seen (Fig. 25). Sometimes, the thickened basement membrane showed a fibrillar appearance ("f" in Fig. 26) and contained cell debris (arrows in Fig. 26) which seemed to be derived from alveolar septal cells. In addition to swelling of the cytoplasm, lyso somal granules and a large nucleus (Fig. 27), seg mented or nonsegmented, were sometimes observed in the alveolar endothelium. Alveolar septal cells frequently showed hyper trophy (h in Fig. 28) and degeneration (arrows in Fig. 28). In some cases, focal reticulosis was ob served in the alveolar septum. From these light and electron microscopic stud ies, mouse lungs exposed to vinyl chloride at 2500 42 and 6000 ppm for 5 and 6 months clearly show: nonneoplastic pulmonary changes in both bronchilar and alveolar cells. Since these findings werencdetected in control mice, they are considered nlated to vinyl chloride. Neoplastic Effects of Vinyl Chloride at Smaller Doses with a Shorter Exposure Detailed studies on pulmonary effects of viny' chloride at smaller doses (1,10 and 100 ppm) withi shorter exposure (4 weeks, 5 hr/day, 5 days/ week are still in a process of analyses in 90 mice. Howe' er, as shown in Table 1, our preliminary study thainvolved gross anatomical and histological observa tions revealed that alveologenic tumors were in duced in 5of 9 (100 ppm), 2 of 9 (10 ppm) and lot(1 ppm), while the tumor was not seen in 10 control- Environmental Health Perspective III I >..M .illll MT-illiT rr.i-mka a;. ! liiiij. A do- <1 .1 'lull Disci. it. ::..i i 'ib'aint* UCC 084156  - * :! ;* A / - f. : * v :t .. j ^ I \'* -' _ 4-'-- ... f-y - ' I- ii *^.v O"- /.*-: r-V -:-i <>'/ .. .* - r i -i-'t V'* -' i i . .i - < * fci.iwuiv isc* t x iv.u' .u 4&v- & , i i Figure 19. Proliferated bronchiolar epithelium. Group I: 6000 ppm; 3300 x. y showed bronchio' were not dered re- ride at posure of vinyl m) with a vs/ week) Howevtudy that observawere in* ind 1 of 9 controls | i [ j j pective* ! m ppm1 4i weeks after vinyl chloride exposure. Sow aw! i .mber of the induced tumors were generally smalli r ;; ...n those of the tumors produced by the cht-mii;.; larger doses (2500 ppm and 6,000 ppm) and Imj.l'i r exposure (5 and 6 months). A <Imm response relation was suggested in pro duct im; alveologenic tumor. Discussion E\; n i l mental studies (10-17) on the oncogenicity uf \ iin! chloride have revealed that the monomer can iiul'.jL-e various neoplasms including hepatic hcntan,:.''sarcoma (rat, mice, hamsters), Zymbal gland carcinoma in the external auditory meatus (rat.- breast cancer (mice), nephroblastoma (rats), "lung adenoma" (mice), skin trichoepithelioma (ham sters', lymphoma (hamsters) and forestomach pap illoma ! hamsters). Evidence of the pulmonary on cogenicity of vinyl chloride in animals has been obtained. Viola et al. (16, 17) have reported that October 1981 rats exposed to vinyl chloride exhibited lung cancer (32%). Histological features of the cancers were stated to be those of adenocarcinoma, with the exception of a single epidermoid tumor. Maltoni and Lefemine (13,14), however, reviewed the histo logical slides of Viola et al. and stated that the lung cancers reported by the latter were not primary tumors of the lungs, but metastatic cancers from Zymbal glands. Maltoni and Lefemine (13,14) also have reported on the pulmonary oncogenicity of vinyl chloride on the basis of their own data. Though they could not find bronchogenic carcinoma in rats, rare pulmonary hemangiosarcomas and fibrosarcomas were induced in these animals. Unlike the case in rats, pulmonary' tumors ("adenomas") were found in mice (89 of 471). Maltoni and Lefemine (13,14) noted that some of the adenomas underwent malig nant transformation. Keplinger and associates (11) have found "alveologenic adenomas" in the lungs of mice exposed to vinyl chloride (44 of 49). Lee and associates (12) have stated that "bronchiolar ade 43 UCC 084157 Figure 20. Put of the cytoplasm of a Clara cell. Various profiles of the endoplasmic reticulum are seen. Group 1:2500 ppm; 21,000 x. Figure 21. Irregular shaped mitochondria with crisue in tht cytoplasm of a Clara cell. Group 1:6000 ppm; 0s04; 12.600 noma" developed in mice 2 months after exposure to vinyl chloride at 50-1000 ppm. Holmberg and associates (10) found "alveologenic adenoma" in 13 of 24 mice exposed to vinyl chloride at 50 ppm for 24-52 weeks. Our present study has also confirmed that pulmonary tumors are induced by vinyl chlo ride of both the large doses (2,500 and 6,000 ppm) with long exposure (5 and 6 months) and the smaller doses (1, 10 and 100 ppm) with a short exposure (4 weeks). Based on all the data available, it can be con cluded that mouse lung is an extremely sensitive organ for demonstrating the oncogenicity of vinyl chloride. Gross anatomical and histological aspects of the tumors in our investigation corresponded to the "alveologenic tumor or cancer" of Steward et al. (22-22,). The alveologenic tumor has been induced by various carcinogens (22-28), such as polycyclic hydrocarbons, urethane, nitrogen mustard, methylcholanthrene, and nitrofiir derivatives and is known 44 to occur spontaneously with aging (6,29,30). The cancer induced has been distinguished from tin: occurring spontaneously by multiple primary foci, occasional formation of huge tumors, and occur rence without any relation to aging. It is also know, that in certain strains, such as A and DD, sponta neous tumors are quite common after 10 to 1months ofage. Spontaneous pulmonary tumors could be excluded in our experimental animals; in addi tion to the above-mentioned points, neoplastic change in the lungs were absent in the controls. Electron microscopically, alveolar epithelium, par ticularly the type II cell, was assumed to be 0* precursor of vinyl chloride-induced tumor in tto mouse lung. This assumption was derived froultrastructural similarities between the normal type II cell and the neoplastic cell. Similar suggestionhave been made by other investigators (21, 28,11 after studying pulmonary tumors induced by agenother than vinyl chloride. Environmental Health Perspective It wa f'irmatic iR-oplast the leve ititerme< alveolar the linir type II internet type II < process, patholog 'ia of tl Kmbryo >ame ori i.eoplast ated, w< lure alv these pe at ion ob * >ctober UCC 084158 1 SO). Tht f :rom that nary fod. nd occurso knowr >, sponta10 to 12 ' ore could | ; in addi- f cchange < mm, par- | o be the ;>r in the ed froir mal type rgestionf 1,28,31 ; >y agent1 pectfcw li wa- noteworthy that the processes of transformation of the normal alveolar epithelium into the ru-oplastiv cell could be followed morphologically on the level >f ultrastructure; the appearance of an intemieih,. e form between type I and II cells in the alveolar lining, the disappearance of type II cell in the lining clue to replacement by the hyperplastic type II cells, which were transformed from the intermediate form, and the neoplastic change of the type 11 tells were assumed to be a sequence of the process. The intermediate form appears in certain pathological conditions, prior to cuboidal metapla sia of the attenuated alveolar epithelium (15, 32). Embryv-i ipcally, both type I and II cells are of the same origin, the entodermal epithelum. Some of the neopla-tK cells, distinguished as poorly differenti ated. wriv similar in ultrastructure to the imma ture aheolar epithelium of fetal lung (IS). From these )'.-."'pectives, the process of neoplastic alter ation oi.-erved in the epithelium may be interpre- October 1981 ted as a retrograde process of the normal differen tiations of the alveolar epithelium. Kaufman et al. (33) have reported that Clara cells of the mouse bronchioles developed into neoplasms which could occur in a malignant form, after transplacental ex posure to ethylnitrosurea. However, such a Clara cell tumor was not produced in our material. Waxweiler and associates reported an increased number of deaths due to lung cancer among vinyl chloride workers (9). They observed 12 cases com pared to the 7.7 cases expected. Eight of the twelve were examined histologically and were classified as undifferentiated large-cell carcinoma (five cases) and adenocarcinoma (three cases). Since these human lung cancers are of bronchogenic origin, it may be that target pulmonary cells in vinyl chloride carci nogenesis are different in human and mouse lung. Neoplastic invasion and metastases were not found in our material. However, it is known that some times both induced and spontaneous alveologenic 45 UCC 084159 Tigure 23. Alveolar macrophage including phagolysosomes and osmiophilic lamellar bodies. Group 1:2500 ppm; 0s04; 5800 x. tumors (22, Si-37) of mice show such changes and that the malignant transformation occurs with some delay after initiation of the tumor. In addition, transplantation of this tumor has been accomplished (23). Steward and associates (22-2i) therefore dubbed it an "alveologenic tumor" or "alveologenic cancer." Maltoni and Lafemine (lS,li) have found that some vinyl chloride-induced pulmonary tumors undergo transformation, although we did not observe this in our materials. Alveologenic tumors may be considered unique in some ways, since it is possible to observe the pro cess of malignant transformation sequentially from the precursor to the malignant cell via hyperplastic and benign neoplastic states. Hepatic hemangiosarcoma is recognized as a char acteristic malignant tumor related to vinyl chloride exposure. The tumor can be induced in a variety of 46 experimental animals (mice, rats, and hamsters1 (13,li), and histological features of the tumor an almost identical in humans and animals. In con trast, the intrapulmonary target cells of vinyl chlo ride oncogenesis may be different in humans and mice. Beyond these differences, moreover, the in duction of alveologenic tumors in mice by vinyl chloride may be predictive or a risk of human bronchogenic cancer from the chemical. Consistent with this is the fact that various carcinogens, such as polycyclic aromatic hydrocarbons, nitrogen mus tard and chromate compounds, are known to induce alveologenic tumors in mice, on one hand, and, on the other, to be associated with excess bronchogenic carcinoma among workers exposed to the carcino gens (38). It is noteworthy that a similar relation has been suggested for vinyl chloride. Nonneoplastic pulmonary effects of vinyl chloride Environmental Health Perspectives October UCC 084160 1 1 *1 wi FicvjtE 24. Part of a macrophage. Two cholesterol crystalloid* are ahown. Group III: 2600 ppm; 0*04; 27,000 x. msters) nor are In conyl chloms and the inv vinyl human sistent s, such i mus* induce nd, on ogenic Lrdnoelation loride es Figure 25. Thickened baaement membrane of an alveolar capillary. Group 1:6000 ppm; 0*0; 15,000 x. October 1981 UCC 084161 47 ....................... ;>:.*-:"# r\ * .* t '!---- i A 4.-' 4P -jL- - . , ' : &*&*& 'S' T? - SV".^^' '*> r?r- ~'T' ' ~' T- -jK*w V * Figure 26. CeD debris of degenerated alveolar septa] cells (arrows) and fibrillar appearance of* basement membrane (with an arrow) are illustrated. Group 1: 6000 ppm; OsO; 10,300 x. have been suggested by observations among work ers in vinyl chloride polymerization plants. This suggestion was based on data obtained by chest x-ray examinations, pulmonary function tests, and sputum cytology studies among workers. Lilis and her associates US) have found radiologic pulmonary changes, such as linear, reticular, and nodular opac ities, in the lower and mid lung fields in a propor tion of cases. They found that the prevalence of pulmonary changes increased with longer duration of exposure and that there was a significant associa tion with peripheral circulatory abnormalities. How ever, pathological evaluation of these changes was not available. Miller et al. U9) have examined pul monary function of 348 workers in a vinyl chloride polymerization plant. The major finding was dimi nution of air flow in 200 workers (57.7%). Again, no physicopathological relations were established. Maltoni and Lefemine (U) reported cytological studies of sputum in vinyl chloride and poly(vinyl 48 chloride) workers. They found a significant increase in cellular changes of the bronchial epithelium; squa mous metaplasia and squamous dysplasia were com mon among workers heavily exposed to vinyl chlo ride monomer. Recently, McNamara and McLaughlin (39) have confirmed that a single 1-hr exposure to vinyl chlo ride in doses of 500 ppm or more induced pneumonitis in ICR mice and that aggravation of latent pulmo nary changes, particularly bronchopneumonia, oc curred in Fischer 344 rats. Our present UO) study has shown that CDl Charles River male mice exposed to vinyl chloride at a heavy dose (2500 and 6000 ppm), over relatively long term (5 and 6 months), obviously showed bronchiolo-alveolar changes. These alterations were recognized in almost all of the treated animals regardless of difference in doses (2500 and 6000 ppm), duration of exposure (5 and 6 months) and recovery time (2, 6 and 37 days). Environmental Health Perspective* Oct UCC 084162 Figure 27. Large nucleut in the alveolar capillary endothelium. Group 11:2500 ppm; OsO(; 7900 x. ncrease n; squa re comyJ chlo- "*) have *d chlomonitis pulmoia, oc* 'haries at a itively lowed -were limals 6000 ') and je The types of pulmonary cells which were involved in the structural alterations varied. It was interest ing that the ultrastructural changes seen in Clara cells and to some extent in the ciliated cells were similar tu those of hepatic cells of animals exposed to vinyl chloride; cellular hypertrophy and prolifer ation of the endoplasmic reticulum were common responses, seen in both the bronchiolar epithelium and the hepatic cells. The endoplasmic reticulum of the hepatic cells has been suggested as the site where vinyl chloride is metabolized, to be trans formed into a chemically reactive metabolite which is the ultimate carcinogen (36, 41-45). Although it has not heen shown that lung has the capacity to metabolize the chemical to produce the carcinogen; if it were so, the bronchiolar cells, particularly Clara ct-lls, may provide this mechanism: the cells are normally equipped with well-developed smoothsurfaced endoplasmic reticula and the organelles have shown a proliferative response after mice are exposed to vinyl chloride. The fact (46) that vinyl chloride has a tendency to October 1981 be soluble in lipid substances suggests that lipidrich pulmonary cells, such as type II cells (rich in osmiophilic lamellar bodies) and alveolar septal cells (containing lipid granules) may bind to vinyl chlo ride. If this assumption is correct, at least some of ultrastructural alterations seen in those cells might result from this mechanism. Both type II cells and Clara cells have been known as surfactant factorproducing cells (4 7). Hyperproduction of the surfac tant factor was suggested, since hyperplasia of those cells was commonly seen in our material. Osmiophilic lamellar bodies and cholesterol crystal loids, which were seen in alveolar macrophages, may represent lipid substances bound to vinyl chlo ride. They may be removed from lung as part of the clearance mechanism for vinyl chloride. It is well accepted that mesenchymal elements such as bone, connective tissue, and blood vessels are involved in responses to vinyl chloride in various organs (36, 48-50), Above all, malignant transformation of the blood capillary endothelium, induction of hemangio endothelioma in liver, and the subcutaneous con- 49 UCC 084163 Figure 28. Degenerative alterations of the alveolar septal cells (arrows) and a hypertrophic septal cell (h with an arrow). Group I; 6000 ppm; 0s04; 6300 x. nective tissue, lung, and adipose tissue have been well documented (10, 13, U, 36). It is reasonable to assume that the alveolar capil lary endothelium and the septal cell suffered toxic effects by vinyl chloride, since these cells are part of the mesenchymal elements in lung, sites of up take and excretion of the chemical and its metabo lites (51, 52). A dose-response relationship has been suggested in the production of alveolongenic tumors by vinyl chloride. The same relationship has been seen in occurrence of alveolitis (mouse) and bronchopneu monia (rats) with the chemical (9). A delayed appearance of these inflammatory changes after periods of recovery, following exposure to the chem ical, has been postulated. A threshold dose for the induction of the nonneoplastic pulmonary lesions which are reported here has not been established. 50 This work was *upported by Research Grant OH-OQ681 (hut the National Institute for Occupational Safety and Health, U S Department of Health, Education and Welfare. REFERENCES 1. Block, J. B. Angiosarcoma of the liver following vimchloride exposure. J. Amer. Med. Ass. 229: 53-54 0974' 2. Creech, J. L., Jr., and Johnson, M. N, Angiosarcoma c' liver in the manufacture of polyvinyl chloride. J. Occup Med. 16:150-151 (1974). 3. Falk, H.,Creech,J. L., Heath, C. W., Jr., Johnson,M.N and Key M. M. Hepatic disease among workers at a vmy. chloride polymerization plant. J. Am. Med. Assoc. O' 59-63 (1974). 4. Lange, C. E., Jiihe, S., and Veltman. G. Ober Anftreten von Angiosarkomen der Leber von zwei Artwtar der PVC-herstellender Industrie. Deut. Med. Wochensdt 31: 1598-1599 (1974). Environmental Health Perspective UCC 084164 661 from 1th. V.S g tinvl 11974). :om of Occup M. N.. a vinvl c. m -*r dtf Teitas nschr. . i_ p i. md Harry D. S. Angiosarcoma of the liver in a Ttr.vl chloride worker. Lancet i: 1316-1319 (1974). 6 Sichol-'r.. W. J.. Hammond, E. C., Seidman, H., and I J. Mortality experience of a cohort of vinyl tWondc workers. Ann. N. Y. Acad. Sci. 246: 225-230 T Thoma- L. B.. Popper, H,, Berk, P. D.. Selikoff, I. J., and Falk H Vinyl chloride-induced liver disease. N. Engl. J. Jlrd 2W 17-22(1975). Tabcm-ha'.' L. R.t and Galley, W. R. Mortality study of worker- it. the manufacture of vinyl chloride and its polvmer 1 Occup. Med. 16: 509-518 (1974). Wa*w*,!*r. R. J-. Stringer, W,, Jones, J.. Wagoner, J. K., Falk. H . and Carter, C. Neoplastic risk among workers t" vinyl chloride. Ann. N.Y. Acad. Sd. 271:39-48 (l!*7*ii. 1" Hulmlr.v B., Tronevi, T., and WineD, M. The pathology of vir,\! ihlonde exposed mice. Acta Vet. Stand. 17: 1X761. 11 Krplmyi r. M. L., Goode, J. W,, Gordon, D. E., and CaJamlra. J. C. Interim results of exposure of rats, ham-'.i-r- and mice to vinyl chloride. Ann. N.Y. Acad. Sd. 21M 22" (1975). 12 L**e. c . Bhandari, J. C., House, W. B., Woods, J. B., and liivr.. R. L. Inhalation toxidty of vinyl chloride (VC) or vir... Inline chloride (VDC) in rats and mice. Phamacolo(n>: le, 24'i .1976). l.< Maltor.:. (1. and Lefemine. G. Carcinogenicity bioassays of vinyl civ.rule: current results. Ann. N. Y. Acad. Sd. 246: JfG-Jl* l`<75). 14 Maltor.: ( and Lefemine. G. Cardnogenidty bioassays of vinvl <).:.-ide. I. Research plan and early results. Environ. Re- 7 1-7.405(1974). l.'i Suzuki ) Pulmonary tumors induced in mice by vinyl chlon4. r .nomer. Environ. Res. 16: 285-301 (1978). K, Viola. I' L. Carcinogenic effects of vinyl chloride. Ab stract- I ' h International Cancer Conference, Houston, Texa.- 1!7u. 17 Viola. V L., Bigotti, A., and Caputo, A. Oncogenic re.-i*,!-, ,f rat skin, lungs and bones to vinyl chloride. Cam,- Res. 31: 516-522 (1971). 1*. Lili.-. K.. Anderson, H., Nicholson, W. J., Daum, S., Fischi',-::.. A. S.. and Selikoff, I. J. Prevalence of disease among . ,i.yl chloride and polyvinyl chloride workers. Ann. N.Y. A-.-ad. Sci. 246: 22-44 (1975). 19 Miller. A.. Teirstein, A. S.. Chuang. M., Selikoff, I. J., and War.-r.i A. R. Changes in pulmonary function in workers l"wi to vinyl chloride and polyvinyl chloride. Ann. N.Y. Aead. Sci. 246: 42-52 (1975). 2n. Buffer A., Wood, S., Eifler, C., Suarex, L., and Kilian, D. J. Mortality experience of workers in a vinyl chloride monor-.i r production plant. J. Occup. Med. 21: 195-202 G97J". 21. Svobf'da. D. J. Ultraatructure of pulmonary adenoma in mice. Cancer Res. 22:1197-1201 (1962). - Stew. ;. H. L., Dunn, T. B,, and Snell, K. C. Pathology of tum"r.- and non-neoplaatic proliferative lesions of the lungs of mice In: Morphology of Experimental Respiratory CarciMcenesis (P.N. Nettesheim, M. G. Hanna, and J. W. Death,-rage, Eds., Atomic Energy Commission Sympo sium >-ries. No. 21, Oak Ridge, Tenn., 1970, pp. 161-168. 21. Stew art. H. L. Pulmonary tumors in mice. In: Physiopatholog> of Cancer, F. Homburger and W. Fishman, Eds., HoeU r and Harper, New York, 2nd ed., 1959, pp. 18-37. 24. Stewart. H. L., Grady, H. G., and Andervont, H. B. Development of sarcoma at site of serial transplantation of pulm nary tumors in inbred mice. J. Natl. Cancer Inst. 7: 207-225 (1974). October 1981 25. Heston, W. E. Induction of pulmonary tumors in strain A mice with methylbisO-chloroethyl) amide hydrochloride. J. Natl. Cancer Inst. 10:125-130 (1949). 26. Heston, W.E. Carcinogenic action ofthe mustards. Cancer Res. 10: 224 (1950). 27. Larson, C. D. Pulmonary tumor induction with alkylated urethrsnea. J. Natl. Cancer Inst. 9:35-37 (1949). 28. Matsuzald, 0. Histogenesis and growing patterns of lung tumors induced by potassium l-methyl*l,4-dihydro-7-(2(5-nitroftuyl)vinyl}-4-oxO'l,8'naphthyridine-3-carboxylate in ICR mice. Gann 66:259-267 (1975). 29. Gardner, M. B., Henderson, B. E., Rongey, R. W,, Estes, J. D., and Huebner, R. J. Spontaneous tumors of aging wild house mice. Incidence, pathology and C-type virus expressions. J. Natl. Cancer Inst. 60: 719-734 (1973). 80. Rabstein, L. S., Peters, R. L., and Spahn, G. J. Spontane ous tumors and pathologic lesions in SNR2J mice. J. Natl. Cancer Inst. 50: 751-768 (1973). 31. Brooks, R. E. Ultraatructure of mouse pulmonary adeno mas. In: Morphology of Experimental Respiratory Carcino genesis, (P. N. Nettesheim, M. G. Henna, and J. W. Deatherage, Eds. Atomic Energy Commission Symposium Series, No. 21, Oak Ridge, Tenn., 1970, pp. 185202. 32. Madrazo, A., Suzuki, Y,, and Churg, J. Radiation pneumonitis; Ultraatruetural changes in the pulmo nary alveoli following high doeet of radiation. Arch. Pathol. 96: 262-268 (1973). 33. Kauffman, S. L,, Alexander, L,, and Sass, L. Histologic and ultrastructural features of the Clara cell adenoma of the mouse lung. Lab. Invest. 40: 708-716 (1979). 34. Amaral-Mendes, J. J. Histopathology of primary lung tumors in the mouse. J. Pathol. 97: 415-427 (1969). 35. Matsuyama, M,, Suzuki, H., and Nakamura, T. Carcino genesis in dd/1 mice injected during suckling period with urethane, nitrogen mustard N-oxide and nitrosourethane. Brit. J. Cancer 23:167-171 (1969). 36. Schaffner, F. Effect of long term vinyl chloride exposure in mouse liver structure. In: Primary Liver Tumours. H. Remmer, Ed., MTP Press Limited, Falcon House, Lancas ter, England. 1978. pp. 189-199. 37. Wells, H. G., Slye, M., and Holmes, H. F. The occurrence and pathology of spontaneous carcinoma of the lung in , mice. Cancer Res. 1: 259-261 (1941). 38. Higginson, J. The role of the pathologist in environmental medicine and public health. A review. Am. J. Pathol. 86: 460-484 (1977). 39. McNamara, B. P. Personal communication. 40. Suzuki, Y. Nonneoplastic effects of vinyl chloride in mouse lung. Environ. Res. 21: 235253 (1980). 41. Antweiler, H. Studies on the metabolism of vinyl chloride. Environ. Health Perspect. 17:217-219 (1976). 42. Bartsch, H., MalaveBle, C., Barbin, A., Bread. H., Toma- tis, L., and Montesano, R. Mutagenicity and metabolism of vinyl chloride and chloride and related compounds. Envi ron. Health Perspect. 17; 195198 (1976). 43. Bolt, H. M., Kappus, H., Butchter, A., and Bolt, W. Disposition of 1,2-C-vinyl chloride in the rat. Arch. Toxicol. 35:155188 (1976). 44. Bolt, H. M,, Laib, R. J.. Kappus, H,, and Buchter, A. Pharmacokinetics of vinyl chloride in the rat. Toxicology 7: 179-188 (1977). 45. Remmer, H. Metabolism of carcinogens: its significance for the initiation of liver tumors. In: Primary Liver Tumours, H. Remmer, Ed., MTP Press, Falcon House, Lancaster, England, 1978.. 46. Wolff, M. S. Evidence for existence in human tissues of monomers for plastics and rubber manufacture. Environ. Health Perspect. 17:185187 (1976). 51 UCC 084165 r 5 L 47. Smith, P., Heath, D., and Moosavi, H. The Clara cell. Thorax 29:147-163 (1974). 48. Cook, W. A., Giever, P. M,, Dinman, B. D., and Magnuson, H. J. Occupational aero-osteolysis II: An industrial hygiene study. Arch. Environ. Health 22: 74-82 (1971). 49. Popper, H., and Thomas, L. B. Alterations on liver and spleen among workers exposed to vinyl chloride. Ann. N.V. Acad. Sci. 246:172-194 (1975). 50. Veltman, G., Lange, C. E,, JOhe, S,, Stein, G., and Bachner, U. Clinical manifestation and course of vim' chloride disease. Toxicity of vinyl chloride-polvvinyl chlo ride. Ann. N.Y. Acad. Sd. 246: 6-2] (1975). 51. Watanabe, P. G., McGowan, G. R., Madrid. E. 0., in! Gehring, P. J. Fate of fMC] vinyl chloride followim inhalation exposure in rata. Toxicol. AppL Pharmacol r 49-59 (1976). 52. Watanabe, P. G., and Gehring, P. J. Dose-dependent bis of vinyl chloride and its possible relstion to oncogenicity k rats. Environ. Health Ferspect. 17:145-152 (1976). E o b B Int & OCCL shov crea pent risk year: to gi ptric than conti Di\ Jn-titi `Ha -Dri pi', ion; 52 Environmental Health Perspective Oclot UCC 084166 aw of vim- Environmental Health Perspectivtt Vol. U, pp. 53-S7,1981 pendent {*u oogenicitvr 1976). Effects of Aging on the Induction of Angiosarcoma by David H. Groth,* William B. Coated Borge M. lilland* and Richard W. Hornung* Adult, Sprmyue-Diwley albino rata of four differant ifti (6,18,32 and S2 weeks) were exposed to 940 ppm vinyl chloride by inhalation for 24 weeks, 5 days/week, 7 hr/day. In each ait group, there were 110 to 128 males and the same number of females. The similarly housed control group, which was not exposed to vinyl chloride, consisted of the same number of males and females in each age group. All animals that died spontaneously, or were sacrificed moribund, or were killed at scheduled times (3, 6 and 9 months after initial exposure) were autopsied. All organs were examined grossly, and several tissues from each animal were examined microscopically. The older the rats were when they were first exposed, the greater the incidence of angiosarcomas. The*incidences of angiosarcomas in the four age groups (from youngest to oldest) in the exposed males in the nonscheduled sacrifice groups were; 0/37 (0%); 0/44 (0%); 3/45 <6.7$); and 13/55 (24$). Similarly, for the females, these incidences were: 2/38 (5.3$); 7/47 (15$); 23 49 (47$); and 11/54 (20$). Most of the angiosarcomas were highly anaplastic, primary tumors in the livers that metastasized to the lungs. Only one angiosarcoma was seen in all the control rats; that occurred in subcutaneous tissue. This study demonstrated that older, adult animals and females are more susceptible to the angiosarcoma>inducing effects of vinyl chloride than young adult animals and males, respectively. Introduction Several epidemiological studies performed on occupational groups exposed to carcinogens have shown greater increased risks of cancer with in creasing exposure durations. In addition, latent periods (time between initial exposure and increased risk of cancer) in these groups are commonly 10-30 years. These findings have been commonly attributed to greater total doses in those exposed for longer periods of time. However, there is one factor other than the total dose which could be responsible for contributing to the increased risk. That factor is "Divifior, of Biomedical and Behavioral Science, National Institute f.*r Occupational Safety and Health. Laboratories of America, Vienna, Virginia 22180. -Divisi' r, of Technical Services, National Institute for Occu pational Safety and Health. aging. It is equally reasonable to postulate that older adults are more susceptible to the carcino genic effect of some chemicals than young adults. That is, for the same dose of carcinogen, the incidence of cancer might be higher and the latent period shorter in older adults than in younger adults. It has been suggested that only older people should work in carcinogenic environments, since the commonly observed latent periods for cancer induction would exceed their life expectancies. If, however, the latent periods were shorter in older individuals, that approach would be counterproduc tive. The purpose of this study was to determine whether or not older adult rats were more or less susceptible to the angiosarcoma-inducing effects of vinyl chloride than young adult rats. This experi ment was not designed to test the susceptibility of sexually immature animals or to determine the lifetime effect of relatively short-term exposures. toi October 1981 53 UCC 084167 Materials and Methods A total of 473 male and 478 female SpragueDawley rats were exposed to 948 ppm of vinyl chloride monomer in a single 14 x 13 x 10 ft stainless steel walk-in chamber with a diffusionscreen false ceiling. Exposures were for 7 hr/day, & days/week for a mean duration of 24.5 weeks. An equal number of control male and female rats, kept in a similar exposure chamber, were exposed to conditioned outside air only. Air flow into the chambers was maintained at 300 ft3/min. Air tempera tures were kept at 75 3#F. The concentration of vinyl chloride in the chambers was initially moni tored by gas chromatography and later with an ultraviolet photoionization analyzer, 7 times/day on each day of exposure. The animals were individually housed in sus pended stainless steel wire-mesh cages equipped with automatic watering taps. Water was provided ad libitum, but food (Wayne Lab Blox) was re moved during exposures. Four differently aged sets of rats of both sexes were used in both the exposed and control group; Their ages at initiation of exposure were 6,17-|j 32-33 and 51-53 weeks. The numbers in each grot; and their disposition appear in Tables 1 and 2. Because of the large number of animals, it nnot practical to start exposures on all rats imni-f neously. Consequently, the controls and expo* rats were divided into five squads, with proportiot. ate representation of each age group and sex t each squad. Rats in each squad were assigned ,, the chambers over a 2-week period. Assignments all rats to the chambers were completed throughor a 10-week period. The original plan was to expose the rats for l months, but because of an epidemic of pneumonia among the exposed animals during the 28th wed the exposures were terminated 29 weeks afte initiating exposures. As the results will show, tte exposure period was adequate to demonstrate it differences in effects between groups. The experiment consisted of two subsets. Atmals scheduled for sacrifice at 3, 6 and 9 month constituted one subset, and animals that died e Group 2 2 4 4 6 6 8 8 Totals fable 1. Number and disposition of rate exposed to vinyl chloride. Age at first Mean body exposure, weights at first weeks exposure, g Sex Initial number of rats Number of deaths and moribund sacrificed Number at final sacrificed Number sacrificed at 3, 6 and 9 months 6 228 M 110 36 6 66 6 167 F 110 16 23 70 17-18 541 M 119 39 13 67 17-18 304 F 120 33 16 70 32-33 693 M 116 43 4 69 32-33 350 F 120 45 6 69 51-53 739 M 128 60 0 67 51-53 375 F 128 52 6 70 M 473 178 23 269 F 478 . 146 51 279 Total number of ntf sutop&ied 106 109 119 119 116 120 127 128 470 476 Group 1 1 3 3 5 5 7 7 Totals Table 2. Number and disposition of control rats. Age at first Mean body exposure, weights at first weeks exposure, g Sex Initial number of rats Number of deaths and moribund sacrificed Number at final sacrificed 6 230 M 110 6 173 F 110 17-18 550 M 119 17-18 304 F 120 32-33 701 M 115 32-33 353 F 120 51-53 772 M 128 51-53 385 F 127 M 472 F 477 9 6 11 9 12 10 23 27 55 52 6 23 13 16 4 6 0 6 23 51 Number sacrificed at 3, 6 and 9 months 69 71 70 70 70 69 70 69 279 279 Total number of rati utopsied 84 100 94 96 86 85 93 102 357 382 vt-re sac sacrifice these tv referred latter as the rats i rt-mainin autopsier br^an an number i the final. in each o: At the each aniir analyses, p-.unma gl ami y-glu At the: at.'l secti a<! renal, t or uterus lungs, tr; lymph no any abnoi neutral 1 I'uraplast lu. and e pat hologii Result No clir em t-s in n mtsi-ureir controlgr interim sa The me both sexes pituitary control gr< tumors. A '.roup 2 2 4 4 6 6 b t* 54 Environmental Health Perspective October 1* UCC 084168 V B B .sa a to group 6. The incidence in group 8, however, is lower than in group 6 and closer to that in group 4. The first angiosarcoma, however, was seen in group 8, the oldest group. In comparing the males and females, it can be seen in Table 3 that the first angiosarcoma ap peared earlier in the females in each group and that the incidence was higher in females for each age group, with the exception of group 8, the oldest age category. Since the mean survival times and expo sure durations for males and females in groups 4 and 6 were similar, the differences in incidence can be attributed to sex. The incidences of angiosarcomas in the interim sacrifice, nonscheduled sacrifice and combined groups appear in Table 4. The females sacrificed at 6 and 9 months had a much lower incidence ofangiosarcomas than those in the nonscheduled sacrifice groups, whereas, the difference in incidence between sim ilar groups of males was not as great. The incidences of angiosarcomas in the different age groups were compared using Fisher's exact test. Because of multiple comparisons, the a-level for each individuaf comparison needed to be <0.01 for the incidences to be significantly different with an overall a 0.05. In the nonscheduled sacrifice groups, the incidence of angiosarcomas in group 8 males was significantly different from those inci dences in group 4 and group 2 males; the incidence ofangiosarcomas in group 6 females was significantly different from those in group 4, group 2 and group 8 females. The same comparisons between the same groups in the combined nonscheduled and interim sacrifice groups were also found to be significant. The effect of age on angiosarcoma incidence in males was examined using the method of weighted least squares regression. A quadratic equation was shown to be a good model for predicting angiosarcoma incidence as a function of age in weeks. Tbe percent of variability in incidence rates (R2J explained by this model was: R2 99.96% for nonscheduled sacrifice groups and R2 99.85% for combined nonscheduled and interim sacrifice groups (Fig. j, ttbi Both of these models were statistically signifim- (p " 0.02 and p * 0.001, respectively). --- The fact that most of the angiosarcomas in th females occurred in the animals that died spontans In" ously suggested that their deaths might be directh * related to the angiosarcomas. A comparison i mean survival times, however, revealed that aai- s mals with angiosarcomas survived as long frequently longer, than other animals in their i*. ? spective groups (Table 5). At 4-week intervals, tht j. accumulative incidence of angiosarcomas was tabu- 4 lated (Table 6) for exposed females. Although the incidence of angiosarcomas at all intervals in group >! 2 and 6 is about the same, in group 8 the inddenct; decreases with time, and in group 4 it increase n with time. v Although a few brain tumors, mammary adeno carcinomas and zymbal gland tumors occurred h w exposed animals, their incidences did not appear to * be significantly different from those of the controls. in Figure 1. Angiosarcoma incidence: males (combined deaths. \ interim sacrifices and final sacrifice). Curve fitted by regres sion methods showing a significant quadratic fit. R1 * 99.85*. Tabic 4. Incidence of angiosarcomas in exposed rate, nonscheduled (NS), interim sacrifice (IS) and combined croupe. Group Sex NS Combined IS NS + IS 2 M 0/37 1/46 (2.2*) 1/83 (1.2*) 2F 2/38 (5.3*) 0/50 2/88 (2.3*) 4 M 0/44 2/47 (4.3*) 2/91 (2.2*) 4F 7/47 (15*) 0/50 7/97 (7.2*) 6 M 3/45 (6.7*) 4/49 (8.2*) 7/94 (7.4*) 6 F 23/49 (47*) 4/49 (8.2*) 27/98 (28*) 8 M 13/55 (24*) 5/47 (11*) 18/102 (18%) 8 F 11/54 (20*) 3/50 (6*) 14/104 (13*) 56 Table 5. Mean aurrival of exposed rats in nonscheduM | sacrifice groups. Group 2 * 6 8 Mean survival, weeks Males Females Rats with Rats with All rats ftngiotarcomi* All rats angiosarcomit 30.6 _ 37.5 36.5 31.6 __ 33.8 38.9 30.5 35.3 30.0 32.0 28.9 31.2 30.2 27.3 Environmental Health Perspective* UCC 084170 i). jam 'las in the spontanee directly arison of that anilong and _-Aeir re* ~vals, the vas tabu* ough the ingroups incidence increases y adeno:urred in appear to controls. ()' 5iC d deaths, >y regres 96.85%. cheduled with imrconw 56.8 58.9 52.0 rt.z ves TtUt t. Accumulative angiosarcoma incidence in exposed females, nonscheduled sacrifice (roup. Interval, Group weeks 2 Angiosarcoma incidence Group 4 Group 6 Group 8 16-19 20-23 24-27* 23-31 32-35 36-39 40-43 0/0 0/1 0/6 1/13 (7.7%) 1/14 (7.1%) 1/15 (6.7%) 2/38 (5.3%) 0/1 0/2 0/5 3/7 (43%) 0/14 823 (35%) 1/22 (4.5%) 12/31 (39%) 2/28 (7.1%) 14/37 (38%) 3/29 (10%) 18/41 (44%) 7/47 (16%) 23/49 (47%) 2/5 (40%) 3/9 (33%) 6/22 (27%) 8/34 (24%) 10/40 (25%) 11/46 (24%) 11/54 (20%) `Exposures terminated. Discussion The results clearly indicate that the incidence of angiosarcomas is higher and these tumors occur earlier in older rats of both sexes. In addition, the incidence of angiosarcomas is generally higher and these tumors occur earlier in female rats than in male rats. Therefore, it can be concluded that older rats are more susceptible to the angiosarcomainducing effect of vinyl chloride than are young adult rats and that female rats are more susceptible than males. The authors have been unable to find comparable studies in the scientific literature. However, Maltoni U) reported in a summary article of his research with vinyl chloride that exposure duration was an important factor in determining angiosarcoma inci dence. In that article, he reported that rats ex posed to 10,000 ppm vinyl chloride, 4 hr/day, 5 days week for 17 weeks did not develop fiver angiosarcomas within a 155-week period, whereas, 13'60 (227c) of rats exposed to 6,000 ppm vinyl chloride 4 hr/day, 5 days/week for 52 weeks (and held for a 155-week period) developed liver angiosarcomas. In the authors' opinion, the differ ence in total dose between the two groups was not sufficient to account for the large difference in the angiosarcoma incidences, and that the major factor, therefore, was probably the difference in ages while they were being exposed. There is suggestive evidence in the literature that older adult humans might be more susceptible than young adults to the carcinogenic effects of Thorotra.-t. Curry et al. (2) stated in their article that "although the latent period between thorium injection and liver malignancy has varied from 3 years to 35 years, all of these 123 cases occurred in patients between 49 and 55 years of age." There is suggestive evidence that older beryllium workers are more susceptible to the carcinogenic effects of beryllium. The data of Mancuso's study (3) of beryllium extraction workers show an extremely high risk for lung cancer in workers between the ages of 38 and 65 who were exposed for relatively short periods of time. Studies specifically designed to test this theory in humans, as well as in animals, with other compounds are needed. If these findings can be reproduced in animals with a wide variety of classes of compounds, then it would be justifiable to modify chronic bioassay experiments by utilizing older animals at the be ginning of the studies and shortening the durations of the experiments by 6-12 months. In many cases, this should result in decreasing costs by 20-30% and, thereby, permit a greater number of chemicals to be tested. The observation in this study that the accumula tive incidence of angiosarcomas in the 6-week-old group of rats did not increase with time after discontinuation of the exposures suggests that the carcinogen is metabolized and inhibited or excreted before most of the animals became susceptible. Whether or not these animals would have exhibited a higher incidence of angiosarcoma at some later time is not known. However, as mentioned above, Maltoni (J) was unable to induce liver angiosarcomas in young adult rats exposed to 10,000 ppm vinyl chloride 4 hr/day, 5 days/week for 17 weeks and held for a lifetime. The total dose in his experiment was 10,000 ppm x 340 hr (3,400,000 ppm-hr). The total dose in our experiment was 948 ppm x 858 hr (813,384 ppm-hr). Therefore, it is unlikely that the youngest groups in our experiment would have developed a higher incidence of angiosarcomas if they were held for a lifetime. The results of this study also suggest that older people should not be preferentially placed in carci nogenic working environments. REFERENCES 1. Maltoni, C- Recent findings on the carcinogenicity of chlori nated olefins. Environ. Health Perspect. 21:1-5 (1977). 2. Curry, J. L., Johnson, W. G., Feinberg. D. H., and Updegrove, J. H. Thorium induced hepatic hemangioendo thelioma. Am. J. Roentgenol. Radium Therapy Nucl. Med. 125: 671-677 (1975). 3. Mancuso, T. F. Relation of duration of employment and prior respiratory illness to respiratory cancer among beryllium workers. Environ. Res. 3: 251-275 (1970). October 1981 57 UCC 084171 Discussion In this animal model, ingested ethanol is a cocarcinogen in relation to VC induction of tumors in the liver. The incidence of angiosarcoma in VC-ethanol dosed rats (50%) was more than double that resulting from .VC exposure alone (23%). VC-ethanol also induced a greater number of hepatocellular carcinomas (60%) than occurred in VC-treated animals (44%). The first deaths from angiosarcoma and carcinoma of the liver occurred earlier in VC-ethanol dosed animals indicating a shortened latent period. The Sprague-Dawley rats used by Maltoni and Lefemine in 1974 U) were more resistant to the effects of VC on the liver than the animals used in this VC-ethanol study. Following a year-long expo sure to 500 ppm VC 4 hr/day, 5 days/week and observation from first VC exposure for 135 weeks, only 7 of 59 rats (12%) were reported to have angiosarcoma in the Uver (4). Angiosarcomas de veloped in other sites such as in subcutaneous tissue, the abdominal cavity? neck, lung and uterus. Hepatocellular carcinomas were not reported. Zymbal gland carcinomas were seen in 8% of Maltoni's VC exposed animals; none were seen in this study. Ethanol has been reported to potentiate the toxicity of other halogenated hydrocarbons. In whole animals, a variety of alcohols increased the hepatotoxicity of carbon tetrachloride (CCU) when ingested 16 to 18 hr prior to inhalation of CCI4 (7). Following acute exposures, CCU toxicity was en hanced by ethanol as judged by the elevation of serum glutamic-oxaloacetic transaminase levels. In similar studies, trichloroethylene (TCE) or 1,1,1trichloroethane hepatotoxicity was potentiated by ethanol, but only at high concentrations of inhaled TCE or 1,1,1-trichloroethane (3). Ethanol potentiation of VC carcinogenesis in the liver is probably due to an effect on VC metabolism. Inhibition of VC uptake (5) and metabolism (<?) by ethanol suggests there is a shared step in the oxidation of the two toxic agents. The most lit candidates for competition are acetaldehyde ** chloroacetaldehyde. The normal substrate, scr* dehyde, would be oxidized preferentially resuL in an increased half-life of chloroacetaldehyde. Toxic manifestations of exposures were which were not related to the neoplastic respott, Many animals died because of neoplasms or semary changes caused by tumors; however, dec.directly attributable to toxicity was not seen. Ti toxicity of ethanol will be discussed in inotk publication. I with to thank Frank Grande, Morris Blackstone andJv Kurahals for their technical aaaiatance and Dianne Douot k secretarial support. REFERENCES 1. Creech, J. L., Jr., and Johnson, M. N. Angiosarcoma ofInc in the manufacture of polyvinyl chloride. J. Occup. Red ISO (1974). 2. Delorme, F., and Mark, L. Angiosarcomas of the lire: workers having had prolonged contact with vinyl chlon* morphological description of the lesions. Union Med. Cc 104:1836 (1975). 3. Viola, P. L., Bigotti, A., and Caputo, A. Oncogenic resper.of rat skin, lungs and bones to vinyl chloride. Cancer Rtt l 516 (1971). 4. Maltoni, C., and Lefemine. G. Carcinogenicity biosssay.: vinyl chloride. 1. Research plans and early results. Emi-/. Res. 7: 387 (1974). 5. Hefner, R. E., Jr., Watanabe, P. G., snd Gehring. f . Preliminary studies of the fote of inhaled vinyl chlcr.> monomer (VCM) in rata. Ann. N.Y. Acad. Sd 246 !i (1975). 6. Hultmark, D., Sundh, K., Johansson, L.. and Arrhenius.1 Ethanol inhibition of vinyl chloride metabolism in isolsttd? hepatocytes. Chem.-Biol. Interact. 25:1 (1979). 7. Cornish, H., and Adefoin, J. Potentiation of carbon tr.t chloride toxicity by aliphatic alcohols. Arch. Environ. Hcav 14: 447 (1967). 8. Cornish, H., and Adefoin, J. Ethanol potentiation of halor nated aliphatic solvent toxicity. Am. Ind. Hyg. Assoc. J T 57 (1966). Cane Multi Amo by Rot Josepl Georg< Introducl 1 r, the las < 'r'.- by int identify card ca exposu u-i-d in t Therefore, o t|i',-edtOSU *1 ' Consum I'-.Ming, Ri jv * '< - ArmyC - aid A. W eased. 62 Environmental Health Penpectiw flctiiher 1981 UCC 084172 "to*. dke!. *hyde *te, iceti v resuhk;hyde. ere fount responit . r second er, denseen. Th n another rod Jwtf -0OUOBig . na offivtr p. Med. M he liver k W chloride Med. Cul ioa&syi of . Environ. dog. P. J. ] chloride 246: 135 henius. E. voiced m bon tetnjn. Health of hakg* x-J.Z: Active* Environmental Health Ptrepeetivet Voi. ii, pp. u-n, mi Cancer Induction Following Single and Multiple Exposures to a Constant Amount of Vinyl Chloride Monomer by Robert M. Hehir,* Bernard P. McNamara,1** Joseph McLaughlin, Jr.,* Donald A. Willigan,* George Bierbower* and Jerry F. Hardisty* Vinyl chloride IhSnomer (VCM), already identified aa a human animal carcinogen, waa -elected aa a model afent to explore an area of concern for single and intermittent low level r\po<ure. In traditional cancer bioasaay. animali are repeatedly expoeed over their lifeepan to a dure of suspected chemical. In the current itudiea rati and mice were expoeed in an inhalation chamber to single one-hour doses of VCM ran(in( from SO to 90,000 ppm. A eecond group waa given 10 one-hour expoaurea to 500 ppm or 100 one-hour expoeuree to SO ppm of the aame chemical. All animali were then obaerved for the remainder of their Uvea, generally 18-24 montha. Moribund animate were euthanized, and aurvivora were sacrificed on schedule and their tiaauea examined for pathological changea. Specifically, the oncogenic atudy demonstrated dose related effects for single one-hour exposure of VCM at high levels, l.e., 9,000 and 50,000 ppm. These concentrations increased the incidence of pulmonary adenomas and carcinomas in mice. Repeated exposure of A/J mice to the aame chemical at 500 ppm x 10 one-hour expoaurea alao increased the incidence of pulmonary adenomas and carcinomas which are considered highly significant (p * 0.001) when compared to match controls. At the lower dose of 50 ppm x 100 une-hour exposure, no significant increase in tumors was obaerved. Rats exposed to identical concentrations of VCM failed to elicit a tumorigenic response. Introduction In the last decade there have been concerted efforts by industry and the Federal government to identify ca: cinogenic substances in the workplace. However, carcinogens are not limited to occupa tional ex]<> ures. Many of these same chemicals are also used in the formulation of household products. Therefore, consumers in all walks of life may be exposed to suspect chemicals in their homes without Cor.-umer Product Safety Commission, Westwood Tow ers Buildir+\ Room 738, 5401 West Blvd., Washington, D.C. AW,. 'VS. Army Chemical Systems Laboratories, Edgewood, Md. 21010. -Donald A. Willigan, Inc., Bound Brook, NJ, 06805. "Dece-rd. October 1981 their knowledge. This type of consumer exposure is usually brief and at very low levels. The suspect chemical may be modified in the process of manu facturing the consumer product, i.e., as in the case of polymerization of vinyl chloride (VC) to poly(vinyl chloride) (PVC), or trace quantities of the unreacted monomer may be present in the product which may be leached out under normal conditions of use. There are other situations wherein a chemi cal like VC is used because it is chemically inert, for example as a propellant, and as an unreacted gaseous chemical it could become a potential health problem. While regulatory bodies try to establish safe exposure levels and industry attempts to control exposures in the production facilities, no such control measures would be of practical value in the 63 ucc 084173 home environment. Another complication associat ed with making value judgements about potential risks of consumer exposure is that traditional cancer bioassays involve daily exposures to the test chemical over the animal's lifetime. There were no comparable studies on short-term exposure to a carcinogen like VC followed by a lifetime monitor ing for toxicological symptoms with complete histopathological examination at death. Therefore, our approach was to explore what happens to laboratory animals following brief or intermittent exposure to a known carcinogen like VC. Vinyl chloride appeared to be the ideal chemical to use in these experiments because of its widespread use in industrial and consumer products. Furthermore, the relationship for inducing unique pathological lesions, i.e., angiosarcoma of the liver for high exposure levels in animal and man was already established by Viola et al. (J) Maltoni (2) and Creech et al. (3). Quite apart from the need to establish a bench mark for acute short-term intermittent exposures to a carcinogen, such as vinyl chloride, was the question of "threshold effects" or "safety factor" for low level exposures. In setting up our experiments we were mindful of the many factors that could have an impact on the study design. Some of the more important factors are that (1) the substance may not reach a susceptible cell; (2) the substance may make noncarcinogenic biochemical combina tion with the cell; (3) the "initiated" lesion may not receive adequate "promotion"; (4) host factors may be unfavorable to carcinogenesis; (5) biochemical repair of the DNA lesion may occur; (6) morpholog ical regression of tumorigenic proliferation may occur; (7) carcinogenic cells may be destroyed by the body's immune system. These items need to be addressed in any conventional cancer bioassay but are even more critical in searching for noncarcinogenic exposure levels. Experimental Conditions Two strains of rats, Fischer 344 (Charles River Laboratory, Wilmington, Mass.) and SpragueDawley/Wistar (Chemical Systems Lab, Edgewood, Md.), and two strains of mice, A/J (Jackson Lab, Bar Harbor, Maine) and ICR (Charles River Labo ratory) were treated in single or multiple intermit tent inhalation exposures to VC. The chambers were Rochester type, stainless steel, 1000 liter, constructed to provide laminar air flow and insure uniform exposures to VC to test animals. Chamber concentrations were established by proportioning the amounts of VC being dispersed with the air flow through the chamber. Airflow 4 through the chamber was created by a bloe motor located in the flow pipe on the exhaust adetf the chamber. A negative pressure was maintain*in the chamber at all times when operational the exhaust gas completely filtered (M6A1 gt particulate filter) before discharge to the envir. ment. The concentration of gas in the inhalatit chamber was monitored by using a Hewlrc Packard 5830A gas chromatograph with a dm flame ionization detector. Exposure Procedures for VC Lifetime Cancer Studies Male and female rats and Fischer 344 and 1C! mice were totally exposed for 1 hr to 50, 500, SO); and 50,000 ppm VC. Fischer rats and Al} mio equally divided by sex received ten 1 hr exposure to 500 ppm VC (1 hr/day, 5 days/wk for 2 weeks) 100 1-hr exposures to 50 ppm (1 hr/dav, 5 daysvt for 20 weeks). Male and female parents (SpragwDawley/Wistar) rats (obtained from Veterinary Met ical Division, Edgewood Arsenal, Md.) from tk reproduction study were also maintained and ob served for 24 months post exposure to 50 to 50( ppm VC 1 hr per day, 5 days per week for 10 week; (49 exposures). Following exposure, all animals were air washed until the chamber concentration was less than 1 ppm VC. Animals of the same sex were segregated in stainless steel cages with a maximum number oi 5 rats in each compartment and placed in the animal holding area. Mice were similarly treated, but smaller cages were used and the number of mice per com partment was limited to two. The animals wen observed twice daily for general health, sores, mass es, alertness, activity or mortality. All animals were weighed weekly for the first 8 weeks pos exposure and monthly thereafter. The exposure schedules for the studies described above are short in Tables 1-3. No blood chemistries or hematology studies were performed. Pathology Cross and Light Microscopy. A complete gross and microscropic examination was performed on most control and exposed animals which died or were sacrificed. Autolysis precluded such examina tion in a few cases. All rodents were to be serially sacrificed at 8,16 and 24 months post exposure. However, the lift span of the mice forced some changes in the later times of sacrifice and termination of mouse experi ments. For single exposure the planned 16 and W month sacrifice were replaced by 18 month sacrifices Environmental Health Perspectives Spc ICK Rtf Hoi. Sf*f File A.J Fisc A/J i *(C *S; kE Octi UCC 084174 vbio*., haustsid* ' maintain rational a* (M6AJ & *he envin, v inhalati a Hewlr 'ttb a dL Retime *4 and ICi K 500,50. i mic. exposwv ' weeks) cr ' 5 days (Spragu* inaryUtt 1 frtmi ttr *d and ot50 to 5( |Jnwekiir wash se than 1 egregatec number o: heanimi J at smaller per comlals wen es, mass1 animat ieks por. exposun .re shown matolop ?te gross med on died or xamina- at 8, 16 the life he later ' TenI J 24 rcrifices. ectiro f 344 rv. jrR mouse fu ll-.( Tabic 1. Sinflc exposure schedule of animals to VC. Exposure date Sex Dose, ppm AM M 50 8/4/75 500 3/11/75 5000 3/18/75 50000 3/25/75 F 50 500 5000 50000 M 50 3/4/75 GOO 3/11/75 6000 3/18/75 50000 3/25/75 F 50 500 5000 50000 M Neg/Cont. F Neg/Cont. M Neg/Cont. F Neg/Cont. PM 3/4/75 3/11/75 3/18/75 3/25/75 3/4/76 3/11/75 3/18/75 3/25/75 Exposure Age st time of group size exposure, weeks 90 15 90 16 86 17 90 18 90 15 100 16 95 17 88 18 90 15 90 16 90 17 90 18 90 15 90 16 90 17 90 18 92 15-18 79 15-18 82 15-18 88 15-18 Table 2. Exposure schedule for animals exposed repeatedly to VC. } i-cht-r rst A J mouse Fischer nt A J mouse Sex M F M F MF M F Exposure periods, Dose, ppm days 50 GOO 50 500 GO 500 60 500 Neg. Control Neg. Control Neg. Control Neg. Control 100 10 100 10 100 10 100 10 100(c)* 10(c) 100(c) 10(c) 100(c) 10(c) 100(c) 10(c) Exposure dates From To 8/27/75 7/7/75 8/27/75 7/7/75 7/7/75 8/27/75 7/7/75 8/27/75 -- -- ____ -- _ -- 1/26/76 7/28/75 1/26/76 7/18/75 7/18/75 1/26/76 7/18/75 1/26/76 Exposure group size Age, weeks Start End Start End 90 86 21 41 90 90 14 16 90 87 21 41 90 90 14 16 90 87 15 35 90 90 8 10 90 88 15 35 90 90 8 10 50 50 21 41 60 50 14 16 50 47 21 41 50 50 14 16 40 39 15 35 50 50 8 10 50 60 15 35 50 50 8 10 Vi denote.- control for corresponding dose sbove. Table 8. VC multigeneration study, F, parents.* Group Compound Doseb Number of males Number of femsles I Air Control 25 II VC Low dose 25 (50 ppm) III VC High dose 25 (500 ppm) 25 25 25 *Sprague-Di\cley/Wjstar rata. `Exposure to 50 or 500 PPM of VC 1 hr/day, 6 days/week for 10 weeks (49 exposures) before mating. October 1981 $5 UCC 084175 This observation period was the minimum suggested by the National Cancer Institute U) for cancer bioassays in small animals. For multiple dose studies in mice the final sacrifice was at 20 months rather than 24 months. The change was made in consider* ation of the risk of animal loss through death and possible cannibalism. Tissues examined were lung, trachea, heart, liver, stomach, small intestines, spleen, kidney, bladder, bone marrow (sternum), adrenals, pancreas, duodenum, brain, eye, zymbal gland, ear, nose, muscle and bone (femur). Electron Microscopic Studies. Groups of five male and five female Fisher (344) rats from each of the single 1-hr exposure studies (50, 500, 5000 and 50,000 ppm) with equal numbers of their corres ponding control groups were sacrificed at 8, 16, 24 months. Groups of five male and five female Fischer (344) rats from the multiple 1-hr exposure studies at 50 and 500 ppm VC along with equal numbers of control animals were sacrificed at 16 and 24 months. *& Results Toxicity During Exposure Rats and mice exposed for 1 hr to concentrations of VC ranging from 50 to 50,000 ppm or for repeat ed exposures, i.e., 50 ppm or 500 ppm, produced no remarkable signs of toxicity with the exception of - mice at the 50,000 ppm level. At 50,000 ppm VC 50% of the male mice exhibited hyperventilation at 45 minutes together with twitching and possible ataxia. Female mice became hyperactive after 40 min exposure, and respiratory difficulty and ataxia was observed in approximately 25% of the female mice after 55 min. Upon removal from the test atmosphere, all animals recovered to normal appearance within 24 hr. After exposure there were no consistent or dose-related differences between control and exposed (single or multiple) mice or rats in death rate, toxic signs or change in body weight. Gross Pathology There was a suggestion of higher frequency { masses in the lungs and livers of mice exposed ott or repeatedly to VC at the higher dose levels u 500, 5000 or 50,000 ppm. Histological Examination of ICR Mice: Single Exposure Changes ascribable to vinyl chloride were appar ent primarily in the lungs with the induction c pulmonary adenomas and pneumonitis. Pneumonia was evident in all animal groups which were a posed to VC at 500 ppm and above. The development of bronchio-alveolar adenoma increased with exposure to higher dose levels i VC. Tables 4 and 5 summarize the significant hisulogical changes observed in ICR mice at 8 and 1> months following single exposure to graded dose of VC. Mice were more susceptible than rats to pneo monitis following exposure to VC. The effect hoi ever was not incremental with dose level Th incidence of pneumonitis, adenoma and cardnom in ICR mice following single exposure is presentee in Table 6. No correlation was observed betwte: the incidence of pneumonitis and adenoma or pneumonitis and carcinoma. However, males seemed more prone to the induction of pneumonitis, partic ularly at 50,000 ppm, i.e., 34% M vs. 13% F. A: 5000 ppm and below, male and females were aboc equally sensitive. There was an increase in bronchio-alveolar ade nomas with exposure to higher doses of VC and the condition manifests itself more frequently in male; i.e., at 50,000 ppm: 51% M vs. 18% F. This trend continued at the 5000 ppm: 22% M vs. 13% F. Maleand females were equally susceptible at dose level 500 ppm and below. The upper respiratory tnc (nasal turbinates) and trachea revealed no unusual changes specifically attributable to VC. Histolog t 8. 16 * Multiple soopp* \Y were s fwiuction o 1,-nomas iproxima' TtMeS.Ovc Tiv-ik- rr-pc L:\rr TUmt Hrpi'.if tlll'IiiW- Hi-fi', if c H if f Ar.fii-ctaf Sinu-wda He|ur.if c Hr)u'.IC C Hi-rr^np' Hir.^np` Lure 'turn pi-jTnon Kroiichio- hri'r.chio Number VC e\|-~u p.r.fi.. fprr b icijr.'.roli Tabic 4. Histological examination of ICR mice at 8 and 18 month* following a (ingle (1-hr) exposure to vinyl chloride monomer Vinyl chloride concentration, ppm Histologic*] changet attributable to vinyl chloride Induction of pulmonary adenoma* Progreaaion to carcinoma 50,000* 5,000* 600* 50 0 (control) 45/137 (33.3%) 24/143 (16.8%) 18/139 (12.9%) 14/139 (10.1%) 12/120 (10.0%) 3/137 (2.2%) 1/143 (0.7%) 1/139 (0.7%) 0/139 (0%) 0/120 (0%) Pneumonitia wat evident in all animal groups which were exposed to VCM at doses of 500 ppm or more. 66 Environmental Health Perspective $.*** Vi "T'-ial i Octobei UCC 084176 iquency of poeedonct evels, ie., H ere apparduction of leumoniti: , were exadenomu levels of anthisto- 8 and 18 ded doses to pneuTect how* ;vel. Tie ardnoms /resented s seemed s, partic% F. At re about lar ade* 'and the n males, iis trend F. Males )se level ry tract unusual onoroer. ecthes Histological Examination of A/J Mice at 8,16 and 20 Months Following Multiple Exposure SO0 ppm, 10 dayt, 1 hr. Changes ascribable to VC were apparent in the lung only, primarily the induction ofpulmonary adenomas. Bronchio-alveolar adenomas were induced in the test group with approximately equal frequency in males and females, i.e., 73.7C; M vs. 75.6% F, respectively. The in crease in incidence as shown in Table 7 for the test group over that of the controls was substantial, by a factor of 2.2, i.e., controls, 34.4%; 500 ppm; 74.7. Progression to malignancy (carcinoma) in the test group vs. controls was also highly significant: con trols, 3/90 or 3.3%; 500 ppm, 22/166 or 13.3%. In animals scheduled for evaluation (survivors) pul monary adenomas were observed as early as 8 months post exposure in 60% of males and females; at 20 months, 75% of animals were affected. The incidence of pneumonitis, adenoma and car cinoma in A/J mice following multiple exposure to VC is presented in Table 8. Pneumonitis was ob served more frequently in the control animal than Table S. Overall summary: incidence of nonneoplaatic chance* and hiatologically proven ncoplaami within the liver and lunff of ICR Swiai mice exposed to vinyl chloride in eintle inhalation expoauraa. Tissue response 0 M (62)* F (77)* Incidence of response for various vinyl chloride concns 60,000 ppm 5,000 ppm 500 ppm M (74)* F (82)* U (76)* F (82)* U (72)* F (75)* SO ppm M (81)* F (80)* Liver (number evaluated) SO 75 63 78 68 76 67 72 64 68 Hepatic cel) necrosis 10 3 5 S 7 4 6 2 3 Hepatic cell vacuolation (lipidosis 1 2 11 4 2 12 3 5 1 4 Hepatic cel! hypertrophy 1 28 8 4 18 1 Hepatic cel! hyperplasia 44 Anpectasis 14 Sinusoidal reticulosis 5 Hepatic cell adenoma 2 1 1 2 Hepatic cel! carcinoma 2 41619 2 Hemangioma 1 Hemangiosarcoma 1 Lung (number evaluated) 60 70 61 76 65 78 66 73 71 68 Pneumonitis 1 6 21 10 13 17 19 15 4 7 Bronchio-aheolar adenoma 4 8 31 14 14 10 8 10 8 6 Bronchio-alveolar carcinoma 121 1 `Number* in parentheses denote animals per group. Total includes animals from scheduled sacrificed (8 and month periods) and spontaneous deaths. Table 6. Single inhalation exposure of ICR mice to vinyl chloride monomer. cVoCnctnx, mppumre Group Lung tissue: incidence of response/number evaluated* Pneumonitis Adenoma Carcinoma 0 (control) 50.000 5.000 500 50 Hale Female Combined (M+F) Male Female Combined (M + F) Male Female Combined (M + F) Male Female Combined (M + F) Male Female Combined (M + F) 1/50 (2%) 6/70 (9%) 7/120 (6%) 21/61 (34%) 10/76 (13%) 81/137 (23%) 13/65 (25%) 17/78 (22%) 30/143 (21%) 19/66 (29%) 15/73 (21%) 34/139 (24%) 4/71 (6%) 7/68 (10%) 11/139 (8%) 4/50 (8%) 8/70 (11%) 12/120 (10%) 31/61 (51%) 14/76 (18%) 45/137 (33%) 14/65 (22%) 10/78 (13%) 24/143 (17%) 8/66 (12%) 10H3 (14%) 18/139 (13%) 8/71 (11%) 6/68 (9%) 14/139 (10%) 0/50 (0%) 0/70 (0%) 0/120 (0%) 1/61 (2%) 2/76 (3%) 3/137 (2%) 1/65 (2%) 0/78 (0%) 1/143 (1%) 0/66 (0%) 1/73 (1%) 1/139 (1%) 0/71 (0%) 0/68 (0%) 0/139 (0%) *Total includes animals from scheduled sacrifice (8, 16, 20 months period) and spontaneous deaths. October 1981 67 UCC 084177 in either test group. No correlation was observed between the incidence of pneumonitis and adenoma or for pneumonitis and carcinoma. These results are similar to those observed in the single exposure study. SO ppm, 100 days, 1 hr. Again changes attribut able to VC were apparent in the lung only, primari ly pulmonary adenomas. However, the incidence in the induction of adenomas and progression to carci noma are considered only marginal and not statisti cally significant. Comparatively, the potential for development of pulmonary adenomas as shown in Table 7 was great er in A/J mice following multiple exposures at 500 ppm than at 50 ppm, i.e., incidence at 500 ppm, 74.7%; at 50 ppm, 44.1%, despite an equivalent total dose of5000 ppm VC. Also, pulmonary adenomas were induced earliest (8 months) following multiple exposures at 500 ppm. It is also of interest that the Table 7. Histological examination of A/J mice at 8,16 and 20 month* following multiple fl-hr) exposure* to vinyl chloride monomer. Number of exposures and concentration ofVCM Histological changes attributable to vinyl chloride monomer Induction of Progression pulmonary adenomas to carcinoma 0 (controls) 10 x 500 ppm* 0 (controls) 100 x 50 ppmb 31/90 (34.4%) 124/166 (74.7%) 29/84 (34.5%) 65/158 (44.1%) 3/90 (3.3%) 22/166 (13.3%) 2/84 (2.4%) 7/158 (4.4%) Highly significant difference in the number of pulmonary adenomas (p-0.001) observed at the 500 ppm x 10 hr exposure level versua control by Z test. bNo significant difference for pulmonary adenomas (p < 0.14) and carcinomas (p ~ 0.19) observed at the lower multiple expoaure level. control groups ofA/J mice for both multiple inh^ studies showed a baseline incidence for pniw^. adenomas which was nearly identical, Le., it j< ppm, 34.4%; at 50 ppm, 34.5%. Table 9 provides an overall summary of the a dence of histologically proven neoplasms obstr.in both strains of mice, i.e., ICR and A/J, follow single and multiple exposures to VC. The neopi tic and nonneoplastic changes observed in the b* and/or lungs of A/J mice'following multiple a? sures to VC at 50 and 500 ppm are shown in Tit* 10 and 11. Although other neoplasms and nonaplastic changes occurred variously in all remair^ organs and tissues, the response appeared ase sporadically or was shared by all test groups inch: ing controls. Relationship by incidence and sever to test exposure was not evident. Furthem^ morphologic deviations were not unlike those n mally observed in aging A/J mice maintained unor standard laboratory conditions. Reprod One h Pawley ^ with equ gpecifitT obtained Edpewcx a hen ini were ex; acre car general l**t exp A coir examina* control t Table 6- Si Electron Microscopic Results In general, these studies indicate that expos.' to vinyl chloride increased organelle turnover as *: as loss of volume control (bleb formation) and t creased lysosomal activity in the liver ofrats. The. alterations progressively decreased as recovery & exposure increased. Hepatocellular carcinoma was seen in one naFischer rat which had received 10 exposures of5 ppm. Lymphosarcoma was noted in one fenaFischer rat which had received a single exposure i 500 ppm. Since these were individual cases ii: since no cancers were seen at 50,000 ppm, i* lymphosarcoma and the hepatocellular aramz. are not likely related to vinyl chloride exposure. Inhab expo Single ' Multipli ICR Tsbl* 10. Tabic 8. Multiple inhalation exposure of A/J mice to vinyl chloride monomer. VC Expoaure Frequency concn, ppm Group Lung tissue: incidence of response/number evaluated* Pneumonitis Adenoma Caranom* 10 x 1 10 x l 100 x 1 100 x 1 0 Male 0/43 (0%) Female 2/47 (4%) Combined (M + F) 290 (2%) GOO Male 0/76 (0%) Female 090 (0%) Combined (M + F) 0/166 (0%) 0 Male 599 (13%) Female 3/45 (7%) Combined (M + F) 894 (10%) 50 Male 4/77 (6%) Female 691 (6%) Combined (M + F) 9/158 (6%) 15/43 (35%) 16/47 (34%) 3190 (34%) 66/76 (74%) 6890 (76%) 124/166 (75%) 11/39 (28%) 18/45 (40%) 2994 (35%) 27/77 (35%) 3891 (47%) 66/158 (41%) 0/43 (0%) 3/47 (6*) 390 (39 ) 12/76 (169) 10.90 (119) 22/166 (13%) 2/39 (59) 0/45 (09) 294 (29) 3/77 (49) 491 (59) 7/158 (49) Total includes animals from scheduled sacrifice (8,16, 20 months period) and spontaneous deaths. 68 Environmental Health Pertpc^i'** Tlwue ft: Lung tnu: Rdcma Conge? Fucxl h Pr+unv Bronch Ov*ou bronch Bronch Rrticul Numb- Suntan*, Octobei UCC 084178 Jtipleinhj^J forpuin^ ^ *. K > ry ofthec T? ?bserA/J, folk,,. The neor ` ^inthei.. nuJtiple^ own in Tt. nd now, -U remain, reared Toupsinc;. and sever 'urthenne those & ainedunc- Reproduction Carcinogenesis Study (<nr hundred and fifty colony rats (Sprague;pimirV IVistan were divided into three groups ' * eiiual number? of males and females. These ---.nr-pathopen-free, random bred animals were from the Animal Resources Branch at f Arsenal. The rats were 12 weeks old vr. initial!v exposed to VC. One hundred rats f^po>ed a? described and the remaining 50 carried as unexposed controls. The parental fvr-ra:in? of S-D IV rats were maintained 24 months exprtsure f'-r carcinogenic evaluation. ' A mmplete prs? and microscopic pathological twmmatinn of all tissues was performed on each r r.:n>l and exposed animal. Particular emphasis was placed on examination of brain, lung, and liver tissues and zymbal gland in the rodent ear. The livers of randomly selected rats were prepared and examined by electron microscopic techniques. Neoplastic and nonneoplastic lesions were observed in approximately equal frequency in control and F0 parent generation of Sprague-Dawley/Wistar rats exposed to 50 ppm or 500 ppm of VC, 1 hr per day, five days per week for 10 weeks (49 exposures). The only lesions that occurred in higher frequen cy in the exposed animals than in control rats were eosinophilic cellular alterations presented as foci/ or areas. The appearance of these foci was related to the dosage of VC. The nature of these lesions are of interest but as yet are controversial, so that no inference can be drawn. T*Mr * Summin uf incidence of hictoloficmlly proven neoplasms obterved within tiuuei of mice at varioui intervale following inkle or multiple exposures to vinyl chloride monomer. tt expose.* "Vrast. id r rai-s-Tht. ovetyaftf i one nu. ; jresofon - <e ferns:\posures cases tr<: j ppm, th:arcinoiw posure. IrMlatiur figure Exposure concentration, ppm Number of neoplasms observed (scheduled sacrifice) 8 months 16 18 20 months months months Totals ,r 11 hr M.!::plr ll hr. 50,000 5,000 500 50 0 (control) 500 x 10 0 (control) 50 x 100 0 (control) 5 3 1 0 0 12 0 4 1 24 18 29 16 14 22 70 2 38 16 63 5 27 29 21 30 16 14 104 40 83 33 *k'K strain u-il in single (1 hr) exposure studies; and A/J mice used in the multiple (1 hr) exposure studies. Total number of neoplasms observed 110 78 82 62 72 170 45 137 41 Table 10. Overall summary; incidence of nonneoplastic change* and histologically proven neoplasms within the lungs of A/J mice exposed to vinyl chloride in multiple inhalation exposure*. ?d* oma Turtle response 09) *) n> 169) 119) 39) 1) L^r.f inumber evalusted) Edema Congestion Focal hemorrhage Pneumonitis Bronchio*alveolar hyperplasia Osseous metaplasia Bronchio-alveolar adenoma V t) Bronchio-ah eolar carcinoma Reticulum cell sarcoma ) c) Incidence of response Control (0 ppm), 100 x l Vinyl chloride, GO ppm, 100 x 1 M (39)* F (47)* M (81)* F (83)* 39 45 77 81 2 411 22 584 6 33 1 11 18 27 38 2 34 J 13 18 30 43 Number? ir. parentheses denote animals per group. Total includes animals from scheduled sacrifice (8, 16, 20 month periods) and spontaneous deaths. eclivei October 1981 69 ucc 084179 ft. Discussion The fact that the severity of carcinogenic effects of VC had been described by various investigators like Maltoni (2,5) and Lee et al. (6) to coincide with dose and length of exposure implies that the total dosage (concentration x exposure time) may be an important factor in the carcinogenicity ofVC. There fore, the inhaled dose was approximated by the Haber (7) concept. In its simplest form this concept states that the dosage, Ct is the product of C (concentration in milligrams/cubic meters) and t (time in minutes). The total concentration can also be expressed in parts per million (ppm) and the time can be expressed in hours, producing Ct i ppm-hr. Factors for breathing rate and detenu tion can be added. However, this simplifi^ f. approximation of total inhaled dose is relative:-, usefbl, as is, for comparative purposes. In his experiments Maltoni (5, 10) exposed % and mice as shown in Table 12 to a series ofdoses c VC ranging from 50 to 10,000 ppm for 4 hr/day, * days per week for 52 weeks. The results indicate i questionable carcinogenic effect at 50 ppm or tot* dosage of 52,000 ppm-hr after 135 weeks. In anotier experiment (BT3), Sprague-Dawley rats, tra ed in a similar fashion to BTl but for 17 weeks onh show after 86 weeks a negative carcinogenic n- TaMe 11. Overall summary: incidence of nonneoplaetic changes and histologically proven neoplasm* within the liver aid h* of A/J mice exposed to vinyl chloride in multiple inhalation exposure*. Tissue/response Incidence of response Control (0 ppm), 10 x 1 Vinyl chloride, 500 ppm, 10 x 1 H (461* F (48)* M(78) F (92)* Liver (number evaluated)' * Hepatic cell necrosis Lymphoid cell infiltrate Hepatic cell lipidosis Neutrophil infiltrate Bile duct hyperplasia Granulomatous foci Sinusoidal reticulosis Hepatocyst Amyloidosis Angiectasis Hepatic cell adenoma Cholangiocarcinoma 45 48 78 89 4 6 6 13 11 22 21 1 1 1 1 1 1 _1 _1 U 6 13 16 Lung (number evaluated) 43 47 76 90 Edema 1 Pneumonitis 2 Bronchio-alveolar hyperplasia 2 1 2 Bronchio-alveolar adenoma 15 16 56 68 Bronchio-alveolar carcinoma J 12 10 17 22 68 81 Number* in parentheses denote animals per group. Total includes animals from scheduled sacrifice (8, 16, 20 month periods) d spontaneous deaths. spon?e able re genic expen dose# descri' at wt. sugge; obtain' Sprag seem# upon i was k intent VC at week with: In tumo: to 30 mont ppm- In tats: days expo ppmwere and rabb Kt mice com] dosa mor; ham L< leve day.dost Test BTl BTS BT6 BT7 BT4 70 Table 12. Maltoni vinyl chloride studies.* Spedes Results (csrdnogenesis), ppm-hr RATS RATS RATS RATS MICE Questionable at 52,000 Negative at 17,000 Questionable at 85,000 Positive at 170,000; 850,000; 2,000,000; 3,000,000 Positive at 24,600,000 Negative at 52,000 and 260,000 Questionable at 520,000 Positive st 2.600,000; 6,200,000; 10,400,000 Positive st 30,000; 150,000; 300,000; 600,000; 1,500,000; 3.600,000 _ Environmental Health Perspective* Auth K>U Ctpu Kepi L Com Com .------- ,, Oct UCC 084180 1(1 detoxift mpUfie<j f 5 relative!; xposedi*. s of doses t: **hr/day,; s indicate i pm or toti '* In anoti rats, trea;. veeksonh 'ogenic i* erandliu^ m. (92)* 99 13 1 0 1 2 3 ) eriodf)ind mens* at a total dose of 17,000 ppm-hr, a question able response at 85,000 ppm and a positive carcino- fenic response at 170,000 ppm-hr and above. In experiment BT7, Wistar rats treated with VC at doses ranging from 50 to 10,000 ppm, for 4 hr daily, 5 days'week for 52 weeks in the same manner as described above show positive carcinogenic affects at total dosage of 2,600,000 ppm-hr. The author suggests from comparison of the experimental data obtained with two different strains of rats (BT1/BT3), Sprague-Dawley and (BT7) Wistar, that the strain wems to be a factor in neoplastic response. Based upon neoplastic lesions observed, the Wistar strain was less responsive than Sprague-Dawley. Exper iment BT4 with Swiss mice, involving exposure to VC at 50 to 10,000 ppm, 4 hr per day, 5 days per week for 30 weeks produced carcinogenic effects with a total dosage Ct of 30,000 to 3,600,000 ppm-hr. In the studies of Viola, Bigotti and Caputo (1), tumors were seen in rats which had been exposed to 30.000 ppm VC, 4 hr/day, 5 days/week, for 12 months. TV total dose (Ct) ot VC was 28,800,000 ppm-hr. In the studies of Caputo, Viola and Bigotti (S)t rats and rabbits were exposed to VC for 4 hr/day, 5 days week for 12 months at six dose levels. The exposure to 50 ppm VC or total dose of 48,000 ppm-hr pr< >duced no tumors. Carcinogenic effects were observed at total dosage of 320,000 ppm-hr and above for rats and at 7,800,000 ppm-hr for rabbits. Keplingi-r et al. (9) exposed rats, hamsters and mice to VC. Only the data on mice were sufficiently complete for examination of total dose effect. Total dosage of 16,000 ppm-hr and above produced tu mors in mice. The final report on the rats and hamsters i- still unavailable for evaluation. Lee et al. (6) exposed mice and rats to three levels of VC: 50, 250 and 1000 ppm, 5 hr/day, 5 days'week, for up to 12 months. All tests with a total dose of -l.vOOO ppm-hr and below were essentially negative for mice. Positive carcinogenic effects were noted, however, in mice above 78,000 ppm-hr. The results of our study indicate that a positive carcinogenic effect in rats may not appear until the total dose (Ct) of VC exceeds 50,000 ppm-hr. The single exposure study with ICR mice was negative at 50 and 500 ppm-hr, borderline at 5000 ppm-hr but did produce neoplastic lesions in the lung at 50,000 ppm-hr. The A/J mice exposed to multiple doses of VC, ie., 50 ppm x 100 days x 1 hr or 500 ppm x 10 days x 1 hr for a total cumulative dose of VC of 5000 ppm-hr show a significant tumorigenic response, but only at the higher dose level. In our studies Fischer rats exposed to a total dosage of 50,500,5000, and 50,000 ppm VC for 1 hr showed no chemically induced tumor response. Nei ther did the Sprague-Dawley/Wistar rats that were exposed to 500 ppm VC 1 hr/ day, 5 days/week for 10 weeks (total dosage 24,500 ppm-hr). Table 13 summarizes various investigators' test results, including our own, on vinyl chloride. The tests with ICR mice, single exposure to VC, show an increased frequency of adenomas at total dosage of 5000 ppm-hr and above. For A/J mice, repeated exposures to 50 and 500 ppm VC for a total dosage of 5000 ppm-hr shows a similar dose response pat tern for adenomas. In general, in terms of total dosage Ct, carcinogenic effects are seen in the two mice strains at Ct levels of 5000 to 50,000 ppm-hr. Thus total dosage for carcinogenicity in mice is in general agreement with Lee et al. (6) (78,000 ppm-hr) and Maltoni (5) (between 30,000 and 150,000 ppm-hr) and other investigators. There is no doubt that risk is related to length of exposure and hence total dose. In our discussion much attention has been focused on the risk of cancer associated with total dosage of VC- Howev er, the multiple exposure experiment at 50 and 500 ppm dose levels with A/J mice for an equivalent total exposure to 5000 ppm-hr appears inconsistent with the thesis of total dosage. Indeed, it appears Authors Viola. Bipiif.i and Caputo U) Caputo, Vii.ia and Bigotti (8) Krplinger e; al. (9) Lee Mi Consumer Product Safety Commissi":. (1979) Tabic 13. Other vinyl chloride itudies. Species Reaulta (carcinogenesis), ppm-hr Rata Rata Rabbita Mice (rata and hamsters) Mice ICR mice A/J mice Fischer rata Positive 28,800,000 Negative at 48,000 Positive st 320.000; 1,280,000; 3,200,000; 6,400,000; 12,800,000 Positive at 7,200,000 Positive at 56,000 All tests essentially negative below 78,000 and positive above 78,000 50 and 500, negative 5000, borderline positive 50,000 positive 50, 500, 5000 and 50,000, negative 24,500, eosinophilic loti, no cancers October 1981 71 UCC 084181 from our own data that concentration may be the dominant factor for acute or low level intermittent exposures. This result may be explained on the basis of a number of factors, i.e., metabolism, de toxication, DNA repair or a time for tumor devel opment for low level exposure beyond the animals' lifespan. As is evident from Table 13, the two strains of rats, Fischer (344) and S-DAV, were more resistant to the adverse effects of single and multiple inter mittent exposures of VC. Our studies are in agreement as to the dose-time relationship for carcinogenesis related to the VC exposure. All of the continuous exposure studies considered collectively indicate that there is a life time total dose (CO for VC. However, from our own studies with single or intermittent low level expo sures to VC we believe that concentration may be the most dominant factor in whether or not carci nogenic effects are observed. For single dose stud ies with VC in ICR mice, neoplastic lesions were produced at 5000 ppm. For multiple intermittent exposures studies with A/J mice the critical concen tration for VC was 500 ppm, total dosage 5000 ppm-hr. Approximate carcinogenic Ct levels of VC based on data for mice and rats are Ct 5,000-50,000 ppm-hr, carcinogenic tendencies; 500,000 Ct > 50,000 ppm-hr, definite carcinogenicity; Ct > 500,000 ppm-hr, high incidence of carcinogenicity. Considerations of Carcinogenicity of VC: Conclusions Cancer seems dependent on total dose of vinyl chloride, especially in life-time exposure studies, but for short-term exposure the concentration may be the most critical factor. One dose is sufficient if dose is high enough. Tfc carcinogenic total dose was 5000 ppm-hr for a* and 50,000 ppm-hr for rats. There were apparent noncardnogenic doses t the study. Mice were more sensitive indicators than rats k carcinogenic effects of vinyl chloride. REFERENCES . 1. Viol*, P. L., Biogottl, A., and Caputo. A. Otwopa response to rat skin, lungs and bones to vinyl chlondt Cancer Res. 31: 616-522 (1971). 2. Maltoni, C. Communication sent to OSHA. Proceeding the Proposed Permanent Standards for Occupational En sure to Vinyl Chloride, Occupational Safety and He& Administration, U.S. Department of Labor, Washing!* D.C., 1974. 3. Creech, J. L., Jr., and Johnson, U. N. Angiosarcoma t liver in the manufacture of polyvinyl chloride. J. Qw; Med. 16:150-151 (1974). 4. National Cancer lnatitute. Guidelines for carcinogen bot any in small rodents. NCI Carcinogenesis Techniod Jtepr Series No. 1, NC1-CC-TR-1, U.S. DHEW. February ltt 5. Maltoni, C. The value ofpredictive experimental fawaiay: occupational and environmental carcinogenesis. An eat pie: vinyl chloride. Ambio. 4:18-23 (1975). 6. Lee, C. C., Bhandari, J. C., Winston, J. M.. House, W B Dixon, R. L., and Woods, J. S. Carcinogenicity of nr chloride and vinylidene chloride. J. Toxicol. Environ. Heat: 4:15-30 (1978). 7. Haber, F. Die Chemie im Kriege; Zur Geschiecht* if Gaskampes- In: Funf Vortrage sus den Jahren 192K Julius Springer, Berlin; cited in Prentiss, Chemicals in Ir McGraw-Hill, New York, 1937. 8. Caputo, A., Viola, P. L., and Bigotti, A- Oncogenicity i vinyl chloride at low concentrations in rats and rabbits J Int. Res. Commun. 21:1582 (1974). 9. Keplinger, M. L.t Goode, J. W,, Gordon, E. .. ik Calendra, J. C. Interim results of exposure of rau, ta sters and mice to vinyl chloride. Ann. N. Y. Acad. So. W, 219-224 (1975). 10. Maltoni, C., and Lefemine, G. Carcinogenicity assay i vinyl chloride. Ann. N.Y. Acad. Sd. 246:195-218 (1975'. Pn Po by i Moc D.V Intro Appr chloride m 1979. Lon prc >ion po particle than thi vinyl ch fty of ii 'tabilizt several product ofPVC and con M'iinjz. nsuliijt fWtilt curtain? automot UCC 084182 *Lh\ i'i. Health U'.rju W.i. Otio 72 Environmental Health Perspective October "gh.Tfc ' for a*. Environmental Health Perspectives Vol. il, pp. 73-61,1981 doses r n ratsftr Oneottu J ehlondt rading, or alEjtjt id Hah.ashingto-, arconutf J. Oeo? -rn biatr d Rtpor 'ary 1976 oassiyir in tXMib e. W. B of vmr. i- Heifc J. . J3 in Wtr. niritv ol obit*. J, r.., ind j, him- S3.246 ssiy cf 1975). Pneumoconiosis in Animals Exposed to Poly(vinyl Chloride) Dust by David H. Groth,* Dennis W. Lynch,* William J. Moorman,* Lloyd E. Stettler,* Trent R. Lewis,* William D. Wagner* and Choudari Kommineni* Rats, guinea piKf and monkeys were exposed by inhalation (6 hrdsy, 5 daye/week) for up to 22 months to a 13 mg/m1 concentration of PVC duet. Autopeiet on raU and guinea pig* were performed after 12 months of exposure and on monkey* after 22 month* of exposure. Lung funi-tion test* were performed on monkey* after 9,14 and 22 month* of exposure. Aggregate* of alu'olar macrophage* containing PVC particles were found in the lungs of all animal*. These at'cregates were more numerous in the monkey lungs. No fibrosis or significant cellular infiltrate* were present in or near these cellular aggregates. No significant effects on pulmonary function could be demonstrated in the monkeys exposed to PVC. Under the conditions of this f\periment, inhaled PVC produced a benign pneumoconiosis. Introduction Approximately seven billion pounds of poly(vinyl chl'iride) (PVC) were produced in the United States m 15*79. There are two major types of PVC produc tion processes, suspension polymerization and emul sion polymerization. The latter process produces {articles which are respirable and much smaller than those in the former process. These polymers of vinyl chloride are usually compounded with a vari ety of ingredients (e.g., plasticizers, light and heat stabilizers, pigments and fillers) and processed in several different ways to produce thousands of end products in common use in our society. About 40% of PVC is used to make sewage pipes, water pipes and conduits. It is also used to make construction siding, window sashes, electrical wire and cable insulation, packaging films (for meat, etc.), vinyl fluortile. wall coverings, phonograph records, shower curtains, bottles, fabrics for clothes, furniture, automotive parts and many other products. Chest x-ray abnormalities,, respiratory dysfunction and pulmonary granulomas have been reported in workers exposed to PVC dust during PVC manu facturing and fabrication (1-6). Consequently, experimental studies were initiated in 1975 to study the effects of inhaled PVC dust in animals. Materials and Methods Test Material Ten pounds of PVC (trade name Geon 121) were obtained from Goodrich Chemical Company and used in this experiment. The manufacturer's speci fications stated a particle size range of 0.5-1.5 pm. Electron microscopic examinations in this labora tory confirmed that at least 90% of the particles were less than 1.5 pm in diameter. The PVC was stored in its covered, fiberboard shipping container throughout the duration of the study. Division of Biomedical ind Behavioral Science, Department Health ar.'l Human Services, National Institute for Occupa- ti"To! Safety sr.d Health, Robert A. Tsft Laboratories, Cinrinw.i. Ohio 43236. Dust Generation and Measurements PVC powder was packed daily or every other day into a Wright dust feeder at a pressure of 3000 vcs October 1981 73 UCC 084183 Ib/in.2. The generated dust was fed into the main stream of the inhalation exposure chamber intake air supply and through a static eliminator before entering the 160 ft3 chamber. Airflow through the chamber was maintained at 40 ft3/min with a nega tive chamber pressure of 0.2 in. water. Animals were exposed toPVC dust 6 hr/day, 5 days/week for up to 22Vi months. Four chamber dust samples were collected each day by drawing chamber environment air, at a rate of 10 liters/min.for 20 min, through DM 5 pm pore size Metricel filters with a vacuum pump. In addi tion, simultaneous samples consisting of particles with an aerodynamic diameter * 7 pm (respirable fraction) were collected with a 10-plate, horizontal elutriator. All samples were weighed immediately after each sampling period and the chamber dust concentrations calculated. Adjustments in the dust generating system after each sampling period were made when necessary to maintain a concentration approximating 10 mg of respirable dust/m3 of air. Daily and grand means (derived from averaging the daily means) for the*tt>tal and respirable dust frac tions were calculated. Midway through the experiment, two 6-hr cham ber air samples were collected on charcoal tubes while PVC dust was being generated. Those two samples and the bulk PVC were analyzed for vinyl chloride by gas chromatography. Samples of dust that were allowed to settle on Formvar-coated copper grids placed in the chamber during the PVC dust generation were examined by transmission electron microscopy. Animals Animals used in this study were male, cesareanderived, Sprague-Dawley rats (Laboratory Supply Company, Inc., Indianapolis, Indiana); male, Hartley guinea pigs (Sweetwater Farms, Hillsboro, Ohio); and imported, adult, male Cynomolgus monkeys (Primate Imports Corp., Long Island, New York). The treatment and control groups each contained 80 rats, 40 guinea pigs and 10 monkeys. Because of difficulties in obtaining imported monkeys from the supplier, the control group of monkeys was re ceived several months before the exposed group of monkeys. They were not randomly assigned, be cause the control group was also used for the con trol group in another ongoing experiment. Conse quently, at time of flrst exposure, the mean weight of the control monkeys was 4219 and that of the exposed group 3361 g. In the ensuing 22V* months, the controls gained 652 g in weight, whereas, the exposed group gained 2116 g. The rats and guinea pigs were quarantined for 74 two weeks and the monkeys were quarantined fo one month prior to the initiation of the inhai^ exposures. Stainless and galvanized steel open ** mesh cages were used as exposure caging to p& vide adequate distribution ofthe dust aerosols riifc the exposure chambers. All of the animals in th study were individually marked by toe-dipping, tattoo. All three spedes were individually house during the 6-hr exposures, whereas the rats ig guinea pigs were housed two to four animals pe cage at all other times. Control animals were house in similar cages in separate animal quarters ia exposed to filtered air 24 hr/day. The exposed at mals were also housed in the animal quartets a cept during the 6-hr inhalation exposure. Kil< guinea pigs, and monkeys were fed standard lafcratory pellet diets (Rodent Laboratory Chow, Guife Pig Chow, and Monkey Chow-Jumbo from Raistor Purina, St. Louis, Missouri). Monkeys were give fresh fruit (oranges, bananas or apples) taint week. Tap water was available ad libitum excep during the exposure period. Food was available t die rodents at all times except during exposun The monkeys were fed once daily at the cessation i the exposure period. Pathology Within one day after the last exposure day, i the surviving rats and guinea pigs were autopsiec Their lungs were inflated with 10% buffered form, lin and sections of liver, spleen, heart, kidw; pancreas, adrenals, thyroid, testis and urinary bid der from each animal were fixed in 10% buffer?: Table 1. Reeulte of pulmonary function tests in monbn after 14 months exposure to PVC dust.* Pulmonary function test Groups Control Expo* RL, cm H,0/1,/see CL, ml/cm H,0 TCL, ml VC, ml IC.ml RV, ml RV/TCL, * FeV 0.5/FVC, % PF, ml/sec FEF SOW, ml/sec FEF, 25%, ml/sec FEF 10%, ml/sec CV, ml AN,/100tnl Vise V, ml 12.1 4.0 13.81P 22.9 10 17.5:7 85" 39 360:7 384 a 36 339:7 185 * 19 210 i'r 40 10 36:7 11.8 2 9.9:1 87.7 5.3 86.5: 943 91 960 : 1920 s 91 905 64S 173 655 262 114 269 :* 21 9 21 : 1.05 0.3 0.67 28.7 * 19 19.9 :1' *Dsts are presented as means s one standard deviation t each of the parameters. Environmental Health Perspecthe llM'KE bfoni formal each 1< tissue? micros all sur of the brunch rtomai ce>sed with ti lobe of lung timi.-sioi I*ulm Befo *>ctobe UCC 084184 "antined fce inhabtit-1 open w* ring to pp, OSolsWiti; '''JaJs in tt -dipping c- ally house nun uiimals pt'ere house; larters ; * posed an uartm ti ure. Rit. ndardlabciow, Glare* ym Rakto: ,were giver i) twicej um excey ivailable t exposun essationc; re day, al autopsied red formst, kidney 1 .iary blad c buffered in monktyi rti- - v *< * ^ * *-. > V -.V-v ,r - v . /. r UV - 'i V* - ^w- **t\ **&- . -/ yrv. * * . 1 *' ... r' i.\ v,.,*. - ` * - .J . . ** * * 'v-r' * . .. .. ", J /*' * *. . .'J ^vv. ` * ** - . * * ^a ' t /* * * n "N_ ^ >. . / 1: ri 1. M;. r-iphage aggregates in lung of monkey exposed to PVC dust for 22 months. Aggregates are primarily in respiratory bp>nrhiolt> r.` 1 alveolar ducts. (Original magnification 40 x). ____ ExpOMC i 0 13.8 s J- } * 17.5 = V j * 360 = " ( 1 339 = ~ * 210 = if 36 = 11 9.9 = : 3 66.5 = f 960 = 11 905 = 11 '3 655 = S 4 269= 1521 =11 , 0.67 = 01 - '0.9 = M vmtioo (v spectivei formalin. Ht-matoxylin and eosin stained sections of each lobe of each lung and of each of the above t:ue? weiv jirepared for and examined by light microscopy. Within 48 hr of the last exposure day, all surviving monkeys were autopsied and sections <>f the same aforementioned tissues plus tracheo bronchial ami mesenteric lymph nodes, prostate, stomach, dii- lenum and skin were fixed and proo-v-ed in th- same manner as those for the rodents i',h the exceptions that two sections from each l"!* of the lungs were examined, and some of the lung tissue \\ as processed for examination by trans.T.i.-sion electron microscopy. Pulmonary Function Before onset of exposures and after 9,14 and 22Vi October 19S1 months of exposure to PVC dust, the following pulmonary function tests were performed on fast ed, anesthetized (pentobarbital anesthetic) exposed and control monkeys: total lung capacity (TLC), vital capacity (VC), inspiratory capacity (IC), re sidual volume (RV), forced expiratory volume in 0.5 sec (FeV 6), peak expiratory flow (PF), maxi mum expiratory flow volume (FEF) at 50%, 25% and 10% of vital capacity, resistance (RL), compli ance (CL), closing volume (CV), N2 washout (ANg/100 ml) and volume of isoflow (VisoV). These tests were performed with a variable pressure, whole-body plethysmograph. Means and standard deviations for all parameters in each group were calculated at each interval and comparisons made between groups using parametric and nonparametric statistical analyses. ucc 084185 75 0 F Figure 2. Macrophage aggregates in lung of monkey exposed to PVC dust for 22 months. (Magnification 385 *). Results The mean total dust concentration in the cham bers for the rodents was 13.0 mg/m3 (SD * 2.34) and for the monkeys 12.9 mg/m3 (SD * 4.69). The mean respirable dust concentration was 10.4 mg/m3 for both the rodents and the monkeys. The mon keys were exposed on 464 days for a total of 2818 hr, while the rodents were exposed on 245 days for a total of 1426 hr. The vinyl chloride concentrations in the cham bers at the two sampling periods were 0.01 and 0.02 ppm. A small nonqualified amount of vinyl chlo ride was detected in the bulk PVC. Electron micrographs of the settled chamber dust showed individual particles ranging from 0.13 to 1.68 p.m in diameter and agglomerates measuring up to 12.8 pm in diameter. Although the agglomer ates measuring greater than 7 p.m in diameter 76 accounted for only 2.3% (5/222) of all the partidr counted, they were estimated to account for non than 20% of the mass. Pulmonary Function A summary of the extensive pulmonary fiinctk: evaluations indicated some signs of loss of lur* recoil pressure, probably a result of the animalaging process. In most cases, differences were note: during the second and third testing periods (expsure months 9 and 14) and were indicative of sorsmall airway obstruction. At this time, however these differences were not statistically signifies;(see Table 1). At the last evaluation (month compared with baseline (preexposure) data, then were no significant differences for any parameter tested. Because of the differences in animal sizes be Environmental Health Perspective Ficnt the par tweei the 14 be me mean the er in Ta exist* not a this s Path Ter topsi< gross orgar. Light ofexp iKig. Octol UCC 084186 V \ f v i :f Tra: -mission electron micrograph of a macrophage from the lung of a monkey exposed to PVC dust for 22 months. Note :r.r rumi-nu- r >jnd and oval, electron dense particles comprising most of the cytoplasmic space. These are the inhaled PVC U-.klt-' articleir morv mctior f lun; limalnotec .'expo` some vever ifican: :h 22 there .meter !u,-i-n the coir.rol and exposed groups for all except r.t- M-month interval, meaningful comparisons could i. made only ut that time period. At that time, the m. an weight "f the controls was 4470 g and that of tht* exposed animals was 4190 g. The results appear in Table 1. No statistically significant differences exi.-ted. Im: airment of respiratory function does n><: appear t be indicated under the conditions of :hi> study fr..m exposure to respirable PVC dust. Pathology Ten expo.-ed and ten control monkeys were autf'psied 22-. months after initiating exposures. No cross abnormalities were seen in the lungs or other l.,|Tan'i ^at could be related to the exposures. Light microscopic examination of the lung sections fexposed animals revealed macrophage aggregates (rig. 1 and 2) in the alveolar walls, alveoli, alveolar October 1981 ducts, respiratory bronchioles and around veins. The majority of the aggregates were 100-200 p.m in diameter and some were as large as 475 p.m in diameter. Their concentration varied from three to seven per microscopic field at 100 x magnification. The tightly packed, large, spherical macrophages contained colorless cytoplasm which appeared light blue under phase contrast microscopy. Only a rare aggregate contained any other type of infiltrating cells, which usually consisted of a few polymorpho nuclear leukocytes. No other lesions that could be related to experimental treatment were present, and no metaplasia, interstitial fibrosis, nodular fibrosis or pneumonitis were present. The tracheobronchial lymph nodes contained aggregates of the same type of macrophages described above in the lungs. Trans mission electron microscopic examination of the macrophage aggregates revealed numerous round particles that do not normally occur in macrophages 77 UCC 084187 Figure 4. Scanning electron micrograph of a S-iun section of lung of monkey exposed to PVC dust for 22 months. This photo ihon the numerous PVC particles which obscure the cellular outlines of the macrophages in which they are residing. and were of the same size and shape as PVC particles (Fig. 3). Analysis of these particles with the microprobe revealed high concentrations of chlo rine (Fig. 4 and 5), thus, farther establishing their identity as PVC particles. A few aggregates of birefnngent particles appeared in the lungs and high concentrations in the lymph node of both the exposed and control monkeys. These particles were identified as mica, kaolin and quartz by the use of microprobe, electron and x-ray diffraction meth ods. The bulk PVC did not contain these minerals. No macrophage aggregates were present in the control monkey lungs. No treatment related lesions were seen in sections of the other organs examined. The 57 exposed and 64 control rats were autop- 78 Bied 12 months after initiating exposures. Micro scopic examination of the lungs of the exposed animals revealed 0-3 macrophage aggregate&'microscopic field at 100 x magnification (Fig. 6). These aggregates were smaller and much less frequent than those seen in the monkey lungs. Chronic pneumonitis, typical for rats, was present wilt equal severity and frequency in the control anc exposed rats. No treatment related lesions wen seen in sections of the other organs examined. The 36 exposed and 39 control guinea pigs wen autopsied 12 months after initiating exposures. Light microscopic examinations of the lungs of expose! guinea pigs revealed fewer collections of giant mac rophages with dear foamy cytoplasm than those Environmental Health Perspectives UCC 084188 T I1 i.* <* * > photo thot *es. Microe expose: ites micro6). The* s frequent j. Chronir isent with ontroi and 'ions were mined, pigs were ires. Light jf exposed it marlud those rspectives F. *r 5. Chi- r.nt %-ny map of the tame area and magnification depicted in Fig. 4. The white dots indicate the presence of the rli-ment chlnn:.?. Note that the dots are clustered in the same area as the PVC particles, thus confirming the identification of the I'VC panic!?' in the exposed monkeys or rats. Interstitial hmphocytic pneumonia was a constant finding in r.','t of the exposed and control animals, and the i- ierity and incidence were not related to treat ment. Few nixcrophage aggregates similar to those M-vn in the lungs were present in the tracheobron chial lymph i.mles of the exposed guinea pigs. No trvatment-i\ luted lesions were seen in sections of the other organs examined. Discussion The monkeys in this study developed a benign, simple pneumoconiosis resulting from the inhala- October 19>1 tion of PVC dust at a mean concentration of 13 mg/m3 for 464 days (2818 hr). The cellular response visible at 22 months of exposure consisted of PVCladen macrophages aggregated into clusters in the lungs. On the other hand, the lungs of the rats and guinea pigs contained very few macrophage aggre gates and in a much lower concentration than in the monkey lungs. This difference in degree of cellular response could possibly be explained on the basis of fewer PVC particles being deposited in the lungs of these rodents. Rodents at rest in the chambers during the day breathe exclusively through their noses. Monkeys under the same conditions do not. The rodents in this experiment had extensive bronchitis and 79 UCC 084189 Figure 6. Macrophage aggregates in the lung of a rat exposed to PV'C dust for 12 months. Note vacuolated appearance of a. (Magnification 385 x). pneumonitis, whereas the monkeys did not. Both nose breathing and bronchitis are factors which reduce the percentage deposition of inhaled parti cles in the alveolar regions of the lungs. Two studies have been published on the pathologi cal effects of inhaled PVC in rats (7, 8). In one study (7) rats and guinea pigs were placed in a PVC bagging facility. Two guinea pigs and an unstated number of rats were autopsied 2, 4 and 7 months after their continuous residence in the facility. Al though the animals developed pulmonary diseases, the small number of animals studied and the lack of adequate controls makes it impossible to assess the significance of the exposure to PVC. In the other study (8) rats exposed to high concentrations (97 gm/m3) of PVC dust in a static air chamber for 1 hr/day for up to 12 months developed bronchiecta sis, emphysema, purulent pneumonia, lung abscesses 80 and squamous metaplasia in bronchial epitheliur. Although the control rats were free of these dis eases, there were only 10 controls examined, k view of the propensity for rodents (controls) u contract acute and chronic pulmonary diseases, the experimental conditions under which control ani mals are kept is extremely important, and should be stated in the protocol. No mention of this made in that experiment. Two cases reports showing granulomas in lungof two PVC workers have been reported tf. 3Except for the more closely packed macrophage; r the lesions shown by Aranaud et al. (5), the mor phology of the lesion is similar to that seen in our exposed monkey lungs. Part of the compactness o. the cells in their lesion could be explained on thr basis of artifactual compression caused during the taking of the lung biopsy. No excess collagen Environmental Health Perspectives trpare granul tney d pulmor tares > ere ' phagethey s appear vuiual found he re! differi tient ' keys v expos i* hr the in lung v time. Sze *|>ecir year ; a gra met lungs Th. ti.'su* tothi a va: PVC initia are i PVC It W, infor font, effec if on e PVC con! Alth flat* impt in a difft dete after Wht havt Oct, UCC 084190 J f - : ' * V ice of cells. >ithelium. hese dislined. In ltoIs) to ases, the itrol aniid should this was in lungs d (J, 5). ihages in the moren in our ctness of d on the ring the ' was ^pciives apparent in the light microscopic pictures of the eranuloma? they showed in their article, although thev did refer to their case as a "case of discrete pulmonary fibrosis." Their electron microscopic pic tures of the PVC particles in in vitro cell systems were very similar to what we saw in the macro phages in the monkey lungs. The PVC particles they showed in a macrophage from the lung biopsy appear to be clustered in lysosomes and the indi vidual particles are not as dense as the ones we found in the monkey lungs. That difference might be related to the different exposure durations and differing intervals since last exposure. Their pa tient was exposed to PVC for 23 years (our mon keys were exposed for 22Vz months) and had no PVC exposure for 6 years (our tissue was sampled within 4P hr of last exposure). It is possible that some of the ingredients in the PVC particles in the human lung were altered and leached out over a period of time. Szende et al. (3) reported that the lung biopsy specimen from a worker who shoveled PVC for one year show ed moderate diffuse fibrosis and contained a granuf ma with concentrically arranged connec tive tissue fibers. We did not see this in the monkey lungs. The apparent difference in response of the lung tissue from two workers exposed to PVC compared to the monkeys exposed to PVC might be related to a variety of factors, including differences in the PVC du-:s. Since various types of emulsifiers and initiator- are used in making PVC, and since these are not completely removed from the powdered PVC. they might explain the differences observed. It would be prudent in the future to obtain more information on PVC manufacturing processes and content of PVC dusts when studying their health effects. Mastrangelo et al. (6) published health findings on employees who were currently working in a PVC production factory. Twenty cases of pneumo coniosis w ere found in a population of 1216 workers. Although the data were not given, the authors stated that slight restrictive respiratory function impairments were associated with chest x-ray changes in a sr all percentage of cases. In our study, no differences in pulmonary function tests could be detected between exposed and control monkeys after 14 months of exposure to 13 mg PVC/m3. Whether any pulmonary function deficits would have occurred upon further exposure cannot be ascertained from this study. The lack of any significant pulmonary function abnormality in these monkeys, however, does not mean that animals or humans exposed to other types of PVC dust or mixtures of PVC dust with vinyl chloride (or a multitude of other ingredients that might be used in fabricating PVC products) might not exhibit pulmonary func tion changes. For the first time, we have been able to show that a PVC dust generated under controlled exper imental conditions is respirable and is deposited in cell aggregates in the lungs of monkeys, that PVC particles within macrophages are fairly unique in appearance, and that their identity can be confirmed with microprobe analyses. No pulmonary function deficits were found after 14 months of exposure to PVC concentrations of 13 mg/m3, thus, confirming the pathological diagnosis of a benign pneumoconio sis. The authors wish to acknowledge the assistance of the follow ing people in this project: George Madden, Brandon Barton. John Clark, David Brewer. Margrit Stoll, Myra Springs. Hazel Patterson, Lea Kalejs, Ardith Grote, John Holtz. Charles Gorski. Richard Niemeier, Richard Homung and Patricia Combs. REFERENCES 1. Tribukh, S. L., et al. Work conditions and industrial hygiene measures in the manufacture and utilization of vinyl chloride plastics. Gig. Sanitar. 10: 36-44 (1949). 2. Vertkin, Yu. 1., and Mamontov, Yu. R. On the state of the bronchopulmonary system in workers engaged in the manufacture of articles made of polyvinylchloride. Gig. Truda 14: 29-32 (1970). 3. Szende, B., Lapis, K., Nemes, A., and Pinter. A. Pneumo coniosis caused by the inhalation of polyvinylchloride dust. Med. Lav. 61: 433-136 (1970). 4. Lilia, R., Anderson, H., Nicholson, W. J., Daum. S.. Fischbein, A. S., and Selikoff, I. J. Prevalence of disease among vinyl chloride and polyvinyl chloride workers. Ann. N.Y. Acad. Sci. 246: 22-41 (1975). 5. Aranaud. A., Pommier de Santi, P., Garbe. L., Payan. H.. and Charpin, J. Polyvinyl chloride pneumoconiosis. Thorax 33: 19-25 (1978). 6. Mastrangelo, G., Manno, M., Marcer, G., et a). Polyvinyl chloride pneumoconiosis: epidemiological study of exposed workers. J. Occup, Med. 21: 540-542 (1979). 7. Frongia, N., Spinazzola, A., and Burcarelli, A. Experi mental lung damage from prolonged inhalation of PVC dust in a work environment. Med. Lav. 65: 321-342 (1974). 8. Popow, J. Influence of polyvinyl chloride (PVC) dust on the respiratory system in the rat. Roczniki Akad. Med. im. J. Marchlewskiego w Bialymstoku 24: 5-48 (1969). October 1981 81 UCC 084191 Environmental Health Perspective*** Vol. il, pp. 83-Si, 1981 Preliminary Observations of the Effect of Inhalation of PVC in Man and Experimental Animals by J. C. Wagner* and N. F. Johnson* Atti ntinn has been focussed, both in man and experimental animals, on the effect* of inhal.t' ori of the gas monomer, vinyl chloride. Recently, note i* being taken of the possible tffi'it' nf the inhalation of the polymer in man. The particle* in question are those produced rommi rejally as paste polymer or dispersion polymer or having an average diameter of 0.15 u.m, and iu i Hunting for more than 10*% of the production in Britain. There are now strict regulations for th mntrol of the monomer gas, but the particles are regarded as nuisance dust and their eiru"i..ri is not covered by specific legislation. Our .tudies on rats, where both inhalation and implantation methods of exposure have been u*<-d. .rid examination of tissue from human cases exposed to paste polymers, indicate that these small panicles can only be regarded as evidence of exposure, and on present evidence there is no induMion of causation of significant pulmonary disease. Techniques have been developed by hull: heft particles can be demonstrated in ordinary histological preparations and by transmis sion ilrftron microscopy. I-, finer panie!t?s of PVC known in the United - a.- di.'fH-r.'i n polymer, are usually less than ' urr. in dianieu-r. During the last five years we conducted a number of preliminary investiga- . - u.-inp this material, and have also observed .'mall par.;, ies in the lungs of men exposed to .yja* of PVc . and have recovered these parti:.* from the lui^# and livers of human cases using oration techniques. A second series of experi- has been -'.anted but no results are available. The rccopniiien of PVC in tissue has been greatly fs-.lnated by a staining method developed by Wh--n (l). Normally processed histological sections .-tained wi: h a Sudanophilic dye, which stains particle.' a bright red. As the tissue has been ; - x'e.'.'cd and lipid removed, only the PVC and - me other re!; - ed plastics will stain. The particles o*r. also be cognized under the transmission '.'V.ron micru'i-ope, and the morphological appeara.r.*es supported by the confirmation of the pres ence of chloride when examined by x-ray microanalysis. *Mi-ri,cil Reseirch Council. Pneumoconiosis Unit. Llandough ** Penar.r., Wales, U.K. October 1981 Animal Experiments Experiment 1 The experimental animals were caesarean-derived, barrier-maintained rats of the I.C.I. Alderley Park Wistar strain. Six*week old rats were randomized, with equal numbers of each sex, and inoculated intrapleurally by using a previously described tech nique (2). Forty-eight animals received 20 mg of PVC dispersion polymer into the right pleural cavi ty. The control animals were inoculated in a similar manner (Table 1). The rats were allowed to live out their lives and all are now dead. Between 12 and 18 months after inoculation, nine of the animals receiving the PVC died. Of these, five had tumors of the liver and one had a tumor originating from the site of inoculation. None of the other animals injected with PVC, nor any of the control animals, had a tumor of this type. These tumors were shown to pathologists in Britain and the United States. It was generally agreed that they were poorly differentiated sarcomas, and in three of the animals, the possibility of Kupffer cell origin was considered. As no other animals devel- 83 UCC 084192 Table 1. Intrapleural inoculation (rats 6 weeks old). No. ms Treatment 48 rats 24 control rats 24 control rats 24 control rats 20 mg PVC in saline 20 mg U1CC crocidolite in saline 20 mg Min-U-Sil (quartz) in saline saline oped these tumors, two further experiments have been started. In the first, dispersion polymer from three British manufacturers was used, and in the second, freshly produced dispersion polymer from two sources has been inoculated, as well as similar material from which all evidence of detergent or vinyl chloride monomer has been removed. These investigations are still in progress, but in the first of these studies, the animals have passed the 18 month period without any occurrence of the tu mors. Inhalation Studies 4 > A group of 48 rats, 24 of each sex, of the same stock as used in the previous experiments were exposed in an inhalation chamber to PVC dust, the apparatus and methods being the same as previously described (3). The animals were exposed to disper sion polymer, at a concentration of 12 mg/m3 for 7 hr/day, 5 days/week, for 5 months. There were also 48 nonexposed controls. The cumulative dose of the exposed rats was 8552 mg/m3 (Table 2). Six rats from each group were killed at the end of the exposure, and a further six a year after the start of the exposure. The remaining animals were allowed Tabic 2. Inhalation study. No. of rats Exposure 48 rets 6 weeks old 48 control rata 22 weeks, 12 mg'm3; cumulative dose 8552 mg/m3 -hr None to survive until they died of natural causes. The PVC particles were present in the mac: phages within the alveoli arising directly from ^ respiratory bronchioles immediately after the ti posure. The distribution of these accumulatr. was widespread but less than a third of the priirAunits were involved. Occasional dust particles ut-. observed in sections from the bronchopulnionjr lymph glands, the Kupffer cells in the liver and * the spleen. At the end of a year, the dust wa? -f present in the spleen and around some foci of mT rophages there was evidence of a slight prolifer, tion of reticulin fibers. This early dust reticuhna:^ did not show evidence of progression in any of tiother animals, some of which survived for me* than two years after the initial exposure. Experience with Human Tissue We have had the opportunity of examininf; limited amount of human tissue. This included th> cases of accepted angiosarcoma of the liver, a it* with severe hepatic fibrosis who underwent a sr.sequent porto-caval shunt and material from peo;, who had been employed in a PVC factory. The, people had either had pulmonary biopsies or hi: died of diseases unconnected with their occupation In all but one case we found small amounts of PVC in the lung tissue. In two of three angiosarcomaparticles of PVC were found after the maceratior.: the liver tissue. At this stage of the investigation, these particle can only be regarded as evidence of exposure: dispersion polymer. REFERENCES 1. Wilson, N. A method for staining polyvinyl chlond,: sections using Sudan IV. Stain Technol o-i: 101-102 (19^ 2. Wagner, J. C., and Berry, G. Mesotheliomas in rats follow.' inoculation with asbestos. Brit. J. Cancer 23: 567-581 (1K- 3. Wagner, J. C., Berry, G., Skidmore, J. W., and Timbrel ' The effects of the inhalation of asbestos in rats. Bn: Cancer 29: 252-269 (1974). Re Wc Me by ( Intro Ini' examii medic, p!artic jiilvlv: This IVder. and b; region The tan V( ha.-is o markc m mict of dost ppm (, ntirma'. of exp quent <ond at;, of a sr *' the among oi the I.-.-'.r.U- 84 Environmental Health Perspec*i,tf (>ctobe UCC 084193 tacroom the -he exlatiom riman s were tonary -nd in as still f macliferalation of the more * ng a hree nan subople lese had ms. VC les to if n$ *. J. Environmental Health Perspectives Vol. il, pp. 85-88,1981 Results of Sputum Cytology among Workers Exposed to Vinyl Chloride Monomer and to Poly(vinyl Chloride) by Cesare Maltoni* and Paola Lodi* The results of systematic cytological sputum examinations of 3.380 Italian VC-PVC industry workers and of 2,287 workers in other industries at different potential risk and chosen as control iroups are reported. The results indicate an increase in cellular abnormalities and dysplasias in the epithelium of the respiratory tract aiporg VC-PVC workers. These data are in line with experimental results showing that VC produces lung tumors in mice and with early epidemiological evidence among exposed workers. Introduction In 1975. it was decided to include the cytological mminatif'VL of sputum in the protocol of systematic medical surveillance of the workers in all the Italian plastic fact Ties exposed to vinyl chloride (VC) and poly<vinyl chloride) (PVC). This program was co-sponsored by the Italian Federation of Unions of Chemical Workers (FULC) and by thv Public Health Service of the Italian regions wL-re the factories were located. The deci-ion to investigate ecologically all Ital ian VC-PVC industry' workers was taken on the basis of the following facts: (1) the observation of a marked increase in the incidence of lung adenomas in mice exposed by inhalatory route, to a spectrum of doses of VC ranging from 10,000 down to 250 ppm u-Jk (2) the unusual finding of cellular ab normalities in a high portion of the lung adenomas of exposed mice (I-J); (3) the observation of fre quent severe abnormalities (squamous dysplasia and atypical adenomatous hyperplasia) in the sputa of a small group of heavily exposed workers (3); the report of some increase in lung carcinomas among workers from two VC-PVC factories U); <5) the finding that the majority of lung carcinomas Institute of Oncology and Tumor Center, Bologna, July. October 19S1 observed among exposed workers were not of a common histotype i.e., giant cell carcinomas (5). Planning and Methods The investigation was carried out on workers from 13 Italian VC-PVC factories located in the northern, central and southern parts of Italy, namely, in Villadossola (1), Portomarghera (3), Bollate (1), Ferrara (1), Ravenna (1), Rosignano (1), Terni (1), Brindisi (1), Ferrandina (1), Porto Torres (1) and Cagliari (1). A total of 3380 workers was examined. These workers have been and/or are exposed to the monomer and part of them also to PVC dust. For comparison 2287 workers in other industries at different potential risk were examined: namely, workers manufacturing PVC products, workers in chemical industries not dealing with plastics, metal workers, miners and workers in the chromium industry. For each sputum examination four cytological slides were prepared. The smears were stained by the Papanicolaou technique. The slides were screened and evaluated indepen dently by the pathologists of the hospitals in the area where the factories were located, then by a trained cytologist in our institute. All abnormal smears were reviewed by the senior pathologist of 85 UCC 084194 Table 1. Type, aequence and clarification of local chance* in the feneei* of the various hictotypes of pulmonary carciiM^ Stage Cytologic Norma] respiratory epithelium 4^4Nonciliated cuboid epithelium ' Initial nonspecific stage Adenomatous hyperplasia 4 Squamous metaplasia 4 ^ <-- Basal cell hyperplasia 4 Intermediate specific state Atypical adenomatous proliferation Tumor stage Predinical tumor Clinical tumor I In situ 1 adenocarcinoma r* I Invasive [adenocarcinoma --} Squamous dysplasia * In situ quunous carcinoma 4, Invasive squamous carcinoma <-- Basaloid cell --> dysplasia In situ ansplsstic carcinoma 4 Invssive ^ anaplastic .fc carcinoma H. n-dii. ii-iii --1 (ID-Ill. III. III-IV IVindV Table 2. Classification, characterization, distribution by classes and code of sputum cytology findings. Cell character Class Type* Degree Quantity Code Not performed I Normal epithelium (LRE, URE, OCA) Histocytes MI Normal epithelium (LRE, URE, OCA) Histocytes II Squamous metaplasia LRE Hypersecretive mucous cells II-(III) Squamous metaplasia LRE Adenomatous hyperplasia LRE II-III Mild atypical adenomatous hyperplasia LRE Mild squamous dysplasia LRE Mild dysplasia URE. OCA (ID-Ill Mild atypical adenomatous hyperplasia LRE Mild squamous dysplasia LRE Mild dysplasia URE, OCA III Well defined atypical adenomatous hyperplasis LRE Well defined squamous dysplasia LRE Well defined dysplasia URE, OCA III-IV Grave atypical adenomatous hyperplasia LRE Grave squamous dysplasia LRE Grave dysplasia URE, OCA IV Adenocarcinoma Suspected Squamous carcinoma Undifferentiated carcinoma V Adenocarcinoma Squamous carcinoma Undifferentiated carcinoma Not evaluable +++ *LRE - lower respiratory epithelium; URE upper respiratory epithelium; OCA oral cavity. 1. 2. 3 1, 2 1, 2, 3 3 1, 2, 3 1, 2. 3 1 1 1 2. 3 2, 3 2, 3 99 01 02 03 04 (3 06 or Ob 09 10 11 86 Environmental Health Persped'1 Tab --- On'- rvt PV( (art. Wor vtn teal Met Mm. Wor chn ink ~*C `V Till Groi Kor VCmdu PV( fsct W0r v*r xal Met Min Wor chn. rndt K kt Groi Wot PV[ Wot Met Mm. W'or Oct UCC 084195 T , f ,,riou* types of cytological changes in sputa: companion of multi among VC-PVC worker* and worker* taw l liwaetwe 0f the reference group*. Cytological changes Non- tvaluable ca-es un ef ficient Eval- Cases Without epithelial changes Hyper- secretive mucous Squamous cells and metasquamous plasia metaplasia LRE LRE+/+ + + + + of mate- liable ea.-e- rial) cues No. % No. % No. % Squamous Atypical metaplasia Adenoma- adenoma- with horn tous hyper- tous hyper- Squamous pearls plasia plasia dysplasia LRE LRE LRE LRE No. % No. % No. * No. % Dysplasia URE, OCA No. ft a VC-St-- 2558 799 31.2 1153 45.1 374 14.6 70 2.7 794 31.0 38 1.5 219 8.6 44 1.7 * 4* a-,.-.,f 4*, . rr.ffti* 4^ 101!* 79 130 -i11-' 4 4 fi* 1M1 28 343 99 28.9 253 73.8 889 165 18.6 604 66.9 210 73 34.8 109 51.9 354 47 13.3 254 71.7 152 9 5.9 89 58.5 36 10.5 83 9.3 30 14.3 41 11.6 69 45.4 1 0.3 74 21.6 3 0.3 227 25.5 4 1.2 8 0.9 1 0.5 5 2.4 - - 1 0.3 59 16.7 6 1.4 1 0.6 7 4.6 6 3.9 4 1.2 10 1.1 6 2.8 4 1.1 28 18.4 1 0.3 *- -_ 1 0.3 -- * *.. ir.r. VC-l'V'( and chromium industries and not exposed to a known risk. N n;>.ed to a t.i 'jwn risk. '" 4 Di.iribuiinn. by ciassei of cytological changes in sputa: companion of mutts among VC-PVC worker* and worker* of the reference group*. Not N> cases Eval- I, I-II Classes ii ii-diD II-I1I (ID-Ill 111 I1I-IV IV V cam - material) cases No. No. ft No. ft No. ft No. ft No. ft No. ft No. ft No. ft * r of 33>" 822 2558 799 31.2 705 27.5 780 30.4 211. 8.6 21 0.8 35 1.3 7 0.2 :'W : *' TATii- 422 `A . w, ()f l'*!*-* ' ir chem- -a ..'.dj-tne.s* k-* ..rker> 2''-i St - 4"2 a -\rr- of 1'" *" -rum 79 130 54 48 28 343 99 28.9 135 39.3 102 29.7 4 1.2 1 0.3 1 0.3 1 0.3 889 165 18.6 399 44.8 313 35.2 6 0.7 6 0.7 _ 210 73 34.8 102 48.6 28 13.3 6 2.8 - - 1 0.5 354 47 13.3 220 62.1 82 23.1 2 0.6 1 0.3 1 0.3 1 0.3 152 9 5.9 63 41.5 51 33.6 18 11.8 2 1.3 5 3.3 4 2.6 Vr.tr than \\ J'VC and chromium industries and not exposed to e known risk. 'N ' t. a known risk. Tsble 3. Ib-tri button of classes Il-dll) and over among VC-PVC workers and the workers in reference group*. ^ rai-r> of \T-I'\ C industry t *l manufacturer.- ^ 'ter' of van- > chemical industries h-u! aorkers k.vn- * rkcr> in chr r.ium industry Classes Il-(III). ft 30.4 29.7 35.2 13.3 23.1 33.6 Classes ll-III, (ID-III, ft 9.4 1.5 1.4 2.8 0.9 13.1 Classes III, III-JV, ft 1.5 0.6 - 0.5 0.6 5.9 October 1981 87 UCC 084196 the same institute. A joint critical reevaluation was carried out for those cases where there was not full agreement. The same criteria of classification of the lesions and their distribution by classes were adopted by all pathologists. Such criteria are based on our knowledge of the local cytological changes and of their sequence in the genesis of the various histotypes of pulmonary carcinomas (Table 1). The list of the most relevant changes correlated with environmental and occupational exposure, their distribution by classes following qualitative and quantitative parameters, and the code, are given in Table 2. This list takes into account not only cells from the pulmonary tree, but also cells from the upper respiratory tract and oral cavity. Results The number of valuable cases, the distribution of the cytological changes and the distribution of the results expressed *by classes in the group of work ers in the VC-PVC industries and in the control groups, are given in Tables 3 and 4. The incidence of dysplastic changes is particularly high in the plastics industry workers when, compared to the other control groups, with the exception of chro mium workers, which can be considered a positive control. The situation is well illustrated by the distribution of classes II-(III) and above (Table 5). It may be stated that, in relation to the incidence of respiratory cell abnormalities, the workers in the VC-PVC industries can be placed halfway between chromium workers and other groups. A finding which deserves attention is the occur rence of atypical cells in the oral cavity and upper respiratory tract in 44 workers (17%) among VC-PVC workers (Table 3). The results were highly homogeneous in diffc. ent factories, suggesting that variations in clima t which may affect the incidence of common pnt, mopathies, is not a determining factor. ^. The difference in the distribution of the patholof ical findings was not dependent on tobacco smoi ing. Conclusions The results presented are consistent with exper imental data and early epidemiological evidence K the potential oncogenic effects of VC exposure k the lungs. Furthermore, our data suggest a possible onctgenic risk for the upper respiratory tract whic should now be explored by proper epidemiologies; investigation. Much remains to be done to clarify the par played by the monomer and by polymer dust z determining the observed cytological changes. Oe data are now being re-examined, on the basis oftht complete exposure history of single workers, u better establish the role played by PVC particles REFERENCES 1. Maltoni C.. and Lefemine G. Carcinoger.'city bioassjyi i vinyl chloride. I. Research plan and early results. Ernw. Res. 7: 387-405 (1974). 2. Maltoni. C., and Lefemine, G. Carcinogenicity bioassiy, i vinyl chloride: current results. In: Toxicity of Vinyl CNonoPolwinyl Chloride, New York Academv of Sciences, N York, 1975, pp. 195-218. 3. Maltoni, C., Lefemine, G., Chieco, P., and Carretti, D Li cancerogenesi ambientale e professional: nuove prosprtuv alia luce della cancerogenesi da cloruro di vimle. 0pedali Vita, 1 (5-6): 4-66 (1974). 4. Wagoner, J. K. Statement before the Subcommittee on U* Environment of the U.S. Senate Commerce Commitut 1974. 5. Thomas, L. B. Personal communication. Environmental Health Perspective UCC 084197  Is*. J j>* 'UfTi inion pr, he path.,;, bacco yir. with e\|. evident xposurt -sible or, act h. emiolop. the pter du.<: ingej, ft. asis oft: jrker.v : panicle lOtfw. 'I Chin, nc*f. V. nti. t> L iiwpn:. milt tlet or. onuni:> vft Environmental Health Penpectivti Vol. 11, pp. 89-91, 1981 Observations of the Site-Specific Carcinogenicity of Vinyl Chloride to Humans by Peter F. Infante* A rf'.evi of epidemiologic itudie* of worker* expoted to vinyl chloride (VC) wa conducted. Sorru of these studies comprised small cohorts and thus were insensitive in the evaluation of ran inoeenic response for sites that do not demonstrate a high relative risk. Other larger stud it- used methodology end design that precluded an interpretation of the results. Such linutMii.ins were acknowledged by some authors. I'M of restrictive disease rubrics alio lead to the submerging of sites that would have demi,n-i rated significant excesses. For example, some investigators analyzed data for liver ram t r deaths w ith the board category of digestive system cancer deaths, while others combined data f,,r t'NS cancer deeths with the broad cateogry of "other and unspecified cancer," and most itudu- analyzed information for lymphatic and hematopoietic system cancer deaths with all data i i.mhined. Only four of eight studies reviewed could demonstrate a significant excess of liver ram t r among VC-exposed workers--a site confirmed in humans by 1974. In contrast, five of tight -tudits appear to demonstrate a significant excess of CNS cancer mortality. Workers evpii-i ri to VC also demonstrate a significant excess of mortality for lung cancer, while the data fur lymphatic and hematopoietic system cancer are suggestive. Interpretation of cancer of the laitt r -> -terns may have been clarified if investigators had not analyzed their data by broad diM-a-i classifications. ! lwi. shortly after vinyl chloride (VC) was -l-ced intc. commerce, VC toxicity was re- : "-'I ^ e\|)on:v.tntal animals (J). Over the next * 'i< cutlet-. su: ly throughout the world indicated t-mijl.ivrnfi,! in the VC industry was associated * ' wide rar.ye of toxicity in humans. This has inch:,led nonmalignant pathologic ef- ur symptom,', involving (but not limited to) t-'nes. liver, central nervous system (CNS), -v*. and blood (.?). I-`.w,-en IftTti and 1974, experimental bioassay " a-:rated VC-induced cancer in multiple or*'* deluding the liver, brain, lungs and lymphatic m i.f. i). This carcinogenic response has been T "f Carcir.,,L`vr. Identification and Classification. Health V, f'i' ^r"k'T"' Occupational Safety and Health Adminis_* 'is I it ;:"t*nx of Labor, Washington, D.C. 20210. vxj.ri-'-. 1 ,r, this paper do not necessarily represent - >. :iw Ortujij-., nal Safety and Health Administration. October 1981 observed in several species, given a wide range of doses, by various routes of administration. Between 1973 and 1977, several epidemiologic studies were undertaken to assess the site-specific cancer risk among workers exposed to VC. For this presentation, findings of these studies will be limited to an assessment of cancer of four organs or organ systems in humans. These same sites are known to be associated with nonmalignant VCrelated disease or symptoms in humans and cancer in experimental animals. Liver Cancer in Humans Table 1 shows a summation of data from the epidemiologic studies as related to liver cancer. Some authors did not present site-specific analyses for liver cancer deaths. Therefore, the most specific information available is presented. Waxweiler et al. (5) conducted a cohort study of workers who had been exposed to VC in the U.S. 89 UCC 084198 ! X- Table 1. Epidemiologic study raaulU of VC-expoied worker* w related to biliary and liver or diieetiv* system canctr^ Investigation Waxweiler et al. (5) Total cohort Latency > 15 jt Byren et al. (6) . Total cohort Latency > 10 yr Fox and Collier (7) Total cohort Plant #2 > 15 yr Seven other plants Monion et al. (8) Total deaths Tsbcnhaw and Gaffey (9) Total cohort Highest exposure. > 5 yr employment Buffler et si. (JO)* Ott et al. (11)* EEH US) Total cohort Latency > 20 yT Site Biliary and liver Liver and pancreas Liver Biliary and liver Digestive organs Digestive organs Observed 7 7 4 4 4 3 1 8 19 11 Deaths Expected 0.6 0.4 0.97 0.68 1.64 0.13 1.51 0.7 21.7 7.5 SMK 1155* 1606* 413* 589* 244 2308* 66 11.0*> 94 151 29 40.8 9 13.6 71 70 *p < 0.01. < 0.05. `Proportional mortality study risk ratio. dNo liver cancer identified among 8 cancer deaths. *No liver cancer identified among 20 cancer deaths. for at least five years and who had achieved a period of ten or more years since initial exposure (latency). On the basis of seven liver and biliary cancer deaths that fit the cohort definition, the study demonstrated an 11-fold to 16-fold excessive risk of death from cancer of this site among VC-exposed workers. These findings represent an underestimate of the risk because seven additional individuals who died from liver/biliary cancer at the plants being studied were not included in the analyses. Of these latter seven cases, four individu als diagnosed with liver angiosarcoma were still alive at the study cut-off date, while two individuals who died from biliary cancer had incomplete infor mation on length of exposure to VC. A seventh individual did not fit the study cohort definition as he was exposed for only three years. He died from liver angiosarcoma 17 years after his initial expo sure to VC. Byren et al. (6) conducted a cohort study of all Swedish workers ever employed in positions where exposure to VC could have occurred. The investi gators combined deaths from cancer of the liver and pancreas because they believed that there was 90 some overlap in reporting. There were foe.' liver/pancreatic cancer deaths observed, compared to 0.77 expected (p < 0.02). An additional dean from liver angiosarcoma was identified as havinf occurred after the study cut-off date and thus m not included in the study. Fox and Collier (7) studied U.K. workers ex posed to VC. In eight factories studied, the} observed a total of four liver cancer deaths * compared to 1.64 expected. Three of these death.occurred in factory 2, where only 0.13 would have been expected (p < 0.01). The authors stated that r. was difficult to identify angiosarcoma of the liver from death certificates (the usual method of identification), since some of these deaths wen classified as primary, some as secondary liver cancer, and others were not certified as canfer deaths at all. The results from the Fox and Collier studprobably represent an underestimate of the ob served risk of death from cancer for the followinf reasons: (1) 75% of the study cohort was emplo.' for less than ten years; (2) only 8% of the cohor. was employed for more than 20 years; and (3) ever Environmental Health Perspective jho: Tht tt hi tali: plar *.uc eiph rr T roh wdi dau dra cat* Tat froi the yea can oft Y Mlfc rnt Of not the arc An we wa. bet pn. um cir eni dia res ris tha thi de' ex; foil uai the su. of u be ea. Oc UCC 084199 V ',f those who completed 20 years of service, the iuthors stated that "because their service has only rKently been completed, the follow-up period is too ihort to evaluate the carcinogenic effect of VCM." Th* statement obviously applies to the liver as well * to other sites. Monson et al. (8) conducted a proportional mor ality studv of 161 deceased workers from two plants where VC was used. These plants were also studied by Waxweiler et al. (5). They observed upht deaths from liver and biliary tract cancer versus 0.7 expected; the risk ratio was 11.0. Tabershaw and Gaffey reported the results of a f,,hort study of workers exposed to VC in 33 U.S. industrial facilities. The authors did not analyze the data separately for liver and biliary cancer. Thus, deaths for these causes are accounted for in the catepory of digestive organ cancer. As noted in Table 1. for the total cohort there were 19 deaths fn-m digestive organ cancer and 21.7 expected. For the highest exposure cohort, with more than five >ears of exposure, there were 11 digestive organ cancer death- observed versus 7,5 expected. None of the obsert ations are statistically significant. However, the risk of liver cancer in this cohort is -ubmerged by including data for this cause of death ir. the analysis with digestive organ cancer deaths, of the 19 digestive cancer deaths, the authors noted that seven were from liver cancer. Two of these liver cancer deaths were listed as angiosarcoma according to the diagnosis on the death certificate. An addition;.1 four deaths from liver angiosarcoma wereidentified in this cohort by the time the study was published in 1974. Two of these deaths had been categorized by death certificate diagnosis as primary liver cancer, and two had been certified under cause; of death other than cancer, i.e., cirrhosis of the liver and hepatoma. This study again demonstrates one of the inher ent limitati ms of epidemiologic studies (incorrect diagnosis in relatively rare causes of death) that result in an underestimate of the relative cancer risk. An additional factor, indicated by the authors, that may huve led to an underestimate of the risk in this study was that the group with no vital status determination, 15% of the population, began their exposure ten years before the group for whom followup was completed. As a result, some individ uals with linger latency periods were omitted from the study. In addition, 57% of the cohort actually studied hud less than 15 years of latency. Because of the healthy worker effect, the authors appropri ately stated that SMRs higher than expected may be worthy of attention even if they are not statisti cally significant. Buffer et al. (10) and Ott et al. (11) did not October 1981 observe any liver cancer deaths among eight and twenty deaths, respectively, in their studies. An unpublished study conducted by Equitable Environmental Health (12) reported the mortality of a cohort of workers from 37 U.S. industrial facilities. This study included data for the facilities studied by Tabershaw and Gaffey (9). Data were not analyzed separately for liver cancer. However, the category of death from cancer of the digestive organs, which includes liver cancer deaths, indi cates a deficit of mortality. As shown in Table 1, even for those individuals who had achieved 20 or more years of latency, the SMR was only 70. It is somewhat unusual to observe such a deficit of mortality among workers who had achieved such a long latency period. Brain Cancer in Humans Brain cancer also has been associated with expo sure to VC. A summary of the results of mortality studies is shown in Table 2. Although the number of cases upon which observations were based are small, Waxweiler et al. (5) and Byren et ai. (ff) demonstrated significant excesses of brain cancer. The relative risks were five and six, respectively. Waxweiler et al. (5) also noted an unusual distribu tion in the cell type of brain cancer. Of 10 brain cancer deaths identified among the VC-exposed workers, nine (90%) had a histologic diagnosis of glioblastoma multiforme. The tenth case had no confirmation of cell type. The authors contrasted this high proportion with that of the Yale autopsy series in which 33% of primary intracranial neo plasms were glioblastoma multiforme. Fox and Collier (7) observed two brain cancer deaths as compared to 3.7 expected for the entire cohort. For those cohort members categorized as having high exposure, one brain cancer death was observed versus 0.4 expected. Monson et al. (8) demonstrated a fourfold risk of brain cancer. Tabershaw and Gaffey (9) categorized brain can cer with "other and unspecified causes of cancer death;" therefore, it is not possible to determine the actual brain cancer risk identified in this study. Since the Tabershaw and Gaffey study (9) was a subset of the EEH study (12), the latter study was used to estimate the expected number of brain cancer deaths in the former study under the as sumption that the age distributions were similar. The proportion of expected brain cancer deaths from "other and unspecified cancer deaths" in the EEH study (12) was then applied to the expected from this same category in the Tabershaw and 91 UCC 084200 Table 2. Epidemiologic itudy result! of V'C-exposed workers as related to central nervous system. Investigation Site Observed Deaths Expected SMR Waxweiler et al. (S) Total cohort Latency > 15 yr Byren et al. (fi) -Total cohort Fox and Collier (7) Total cohort Highest exposure Monson et si. (3) Total deaths Tsbershsw and Gaffey (S) Total cohort Highest exposure, > 5 yr employment All exposure levels Buffler et al. (JO)d Ott et al. (W Total cohort Total cohort *s EEH U2) Total cohort Brain and CKS Brain Brain Brain Other and unspecified Brain All sites other than digestive and respiratorv Brain Brain and CNS 3 0.9 329 3 0.6 498* 2 0.3 612* 2 3.7 55 1 0.4 278 5 1.2 4.? 1? 11.8 155 7 3.5 204 6 2.4' 250* 6 6.8 88 2 0.7* 286 12 5.9 203* *p < 0.05. Proportional mortality study risk ratio. 'Estimated. dNo brain cancer identified among 8 cancer deaths. Ir'r Mar To- u- Hvrr To: Fo * To: Hie To: Tiber To; Hit hJtl. To: Lor Sh. let e: Tot. EEH Tot. H.f Mrt Low ~ Gaffey study (9). As a result, 2.4 brain cancer deaths were estimated to have been expected and compared to six observed in the study. This difference is significant. Buffler et al. (10) did not identify any deaths from brain cancer in their small cohort. Ott et al. (11) did not analyze their data separately for brain cancer, but rather included brain cancer deaths with cancer deaths from "all sites other than digestive and respiratory." Therefore, using an analytical tech nique similar to that described above, the propor tion of expected brain cancer deaths among "all sites other than digestive and respiratory" from the EH study (12) was applied to the expected in the study by Ott et al. (11). As shown in Table 2, there was a resultant estimated 0.7 brain cancer deaths expected as compared to two observed. The excess risk is estimated to be about threefold. The EEH study (12) also demonstrates a significant excess brain cancer among workers occupationally ex posed to VC. In summary, the data for brain cancer appear to be more consistent between studies than the data for liver cancer, although the magnitude of the excessive risk is not as great for brain cancer. 92 Lung Cancer in Humans As shown in Table 3, Waxweiler et al. observed 11 lung cancer deaths as compared to5* expected (p < 0.005) for cohort members who ha; achieved 15 or more years of latency. The authoralso noted what appeared to be an unusual distribu tion in the histologic types of lung cancer. Of eift: histologically confirmed lung cancer cases, fivt were classified as large cell undifferentiated.: three were categorized as adenocarcinoma. The* cell types are different from those usually assocated with a cigarette smoking etiology, i.e., snal cell undifferentiated and epidermoid carcinomas With the exception of the study by Fox an: Collier (7), the remaining studies show excess riflof lung cancer ranging from 7 to 200%. However the reservation expressed by Fox and Collier (7). amentioned earlier, about the short period offollow; limits the interpretation of their study. This cor. cem is supported by the observ ation that the SM-'for total mortality was only 75, 75% of what wo;.-' be expected on the basis of comparison to tfe standard population. Environmental Health Perspecli' t.m- irvtf--- *"* Eoj g,JWl Tiber HipEE " Uli ___ Mnt. rL As BufR< do<*. and ^ goriz; u with Octob UCC 084201 li** 53 276 4J*` 135 204 230* 66 2*6 203* T*bl 3. Epidemiologic study results of VC-exposed workrn ii related to r--piratory eyetem cancer deaths. .o-^v.ion * *\a. tvhort u----- > 13 JT i -- c: si <(> T oft 7 '.A. K'hnrt H e*po*urf Site Respiratory Lung Lung Observed 12 11 3 46 2 Deaths Expected 7.7 5.7 1.8 51.2 3.7 SMR 156 194* 168 90 54 * - al (#i 7 dtiih* Lung 13 7.9 1.6b 4-, :.* and Gafft-y (91 7 * chon H exposure, j yr employment Respiratory' 25 23.9 112 12 8.5 144 r .** f. al. 7 r-'hort ; rx[)<urf dj-ation '* - npisMirt lijrauon Lung 5 1.7 289* 4 1.05 381* 0 0.45 -- al iJJp * m*i cohort Respintory #* 7 5.8 121 t-H 7 ohort H ,-r-: (-\jiosori- rXpwurv t. * r\|i-Urt' Respiratory \ o `lo i - ;*r.jonal m- --.ality study risk ratio. 45 44.3 107 7 5.1 141 19 17.0 116 19 22.2 92 et al. ared to 5.* !'S who h* he authoral distribi. r. 0/ eipfc: cases, fi\t .iated. an; ma. The* ally assoc i.e., smil cinomas. Fox arc xcess riskHowever, llier (7). a.offollowuF This cor.t the SMF. chat woulc on to tht Ipecti'c* TMr 4. Epidemiologic study results of VC-xposed workers as related to lymphatic and hematopoietic system cancer deaths. ! r--ifation Site* Observed Deaths Expected SMR **t#rilrret al. Iiti-ncv > 15 vr ! v ir.d Collier i r. X -.-.r. <M " r-hau i GafiVv (9) H i't-j-t exposure. > 5 years rn|>iovmen'. iEHiJJ) Uvncy > 2" yrsrs (200-205) (200-205) (200-207) (200-205) (200-203, 205) (200-203.205) 4 3 9 5 6 4 11 4 2.50 1.70 9.01 3.4 6.06 1.84 10.36 3.10 159 176 100 1.5* 106 222 112 136 `Ir-rrrjtiorjj t Unification of Diseases, 7th Revision. 'ir.-.rmatiora! Classification of Diseases, 8th Revision. Tfuimrtional mortality study risk ntio. As shown in Table 3, data from the EEH (12) and huffier et al. (10) studies suggested a qualitative d--e-response relationship between VC exposure d lung cancer risk. However, retrospective cate? -nzation of high, medium and low exposure, as used in '.he EEH study (12), must be viewed *v.h caution because of the subjective nature of October 19S1 judgment. The study by Buffler et al. (JO) is particularly noteworthy; within a small cohort of only 464 workers, a fourfold risk of lung cancer was observed. When the investigators examined the effect of smoking, under the extreme assumption that those with unknown smoking habits were smokers, the data still demonstrated a significant 93 UCC 084202 excess of lung cancer (5 observed versus 1.98 expected.) Cancer of the Lymphatic and Hematopoietic System in Humans Table 4 summarizes data on cancer of the lym phatic and hematopoietic systems among workers exposed to VC. The relative risks for various studies ranged from 1.0 to 2.2, and none of the results demonstrated a significant excess. Although somewhat suggestive, the data need to be ftirther analyzed by latency period and exposure levels combined. Analysis of data separately for lym phatic cancers and leukemia might also lead to meaningful observations. Summary In summary, epidemiologic evidence demonstrates that the carcinogenic effects of VC in humans extend beyond the liver. The brain and lung should also be considered target organs. Some studies indicate that the lymphatic and hematopoietic sys tems are also involved. These observations in humans are supported by studies demonstrating the induction of cancer of these same sites in experimental animals. REFERENCES 1. Patty, F. A., Yant, W. P., and Waite. C. P. Acute response of guinea pigs to vapors of some new commercial organic compounds. Publ. Health Repta. 45: 1963-1971 (im 2. Selikoff, I. J, and Hammond. E. C. Eds. Toxieitv tftr chloride-polyvinyl chloride. Ann. N.Y. Acad. Sci '246 ~ (1975). ^ 3. Viola, P. L.. Biogotti, A., and Caputo, A. Onife responses of rat akin, lungs, and bones to vuirl diiotw Cancer Res. 31: 516-519 (1971). '^ 4. Maltoni, C., Lefemine, G., Ciliberti. A., Cotti, c. Carretti, D. Carcinogenicity bioassay* of vinvl diae monomer: A model of risk assessment on epm--, bases. Environ. Health Perspect. 41: 3-29 (1961). 5. Waxweiler, R. J., Stringer, W,, Wagoner, J. K,. Joee.; Falk, H., and Carter, C. Neoplastic risk among mv exposed to vinyl chloride. Ann N.Y. Acad. Sd. 271 a* (1976). 6. Byren, D., Engholm, G.. Englund. A., and Westerkta.) Mortality and cancer morbidity in a group of Swedish VC1 and PVC production workers. Environ. Health Pmtr17: 167-170 (1976). 7. Fox, A. J., and Collier, P. F. Mortality experitm* workers exposed to vinyl chloride monomer in the ture of polyvinyl chloride in Greet Britain. Bnt. J. k Med. 34: 1-10 (1977). 8. Monaon, R. R., Peters, J. M.. and Johnson. M. N. Pnpt tional mortality among vinyl-chloride workers. Lam-.t 397-398 (1974). 9. Tsbershaw, I. R., and Gaffey, W. R. Mortality studt i workera in the manufacture of vinyl chloride sad o polymers. J. Occup. Med. 16: 509-518 (1974). 10. BufOer, P. A., Wood. S., Eifter, C., Suarez. L.. andfch: D. J. Mortality experience of workers in a vinyl chlew monomer production plant. J. Occup Med. 21: 19> (1979). 11. Ott, M. G., Langner. R. R. and Holder. B. B. Vinylditaa exposure in a controlled industrial environment. A Ieq term mortality experience in 594 emplovees. Arch. Emm Health 30: 333-339 (1975). 12. Equitable Environmental Health. Epidemiological stud; i vinyl chloride workers. Prepared for Manufacturing Che iats Association, 1978. 94 Environmental Health Perspw*^8 UCC 084203 - "'X, / <rfv. // /. / Environmental Htalth Pertpedivts Vol. il, pp. 95-99, 1981 A. Onttf, vinyl efckr,, Cotii. G v ^.vl chi*,. JiT*"*K.. JOflt; ' nont woii,'. w. 271 wtertobr.: iu ediahV'. IUi Ptrtfr- Petwnct tht Snt- J. Ir,: X- Prop- ' Luxe. 'y itudy. 'de and K. and Kiln; iji chJorr, 21: 193-3. 0blontfi Dr il studi c ng Cher German Investigations on Morbidity and Mortality of Workers Exposed to Vinyl Chloride by H. Weber,* W. Reinl,* and E. Greiser* To itudiei on mortality and morbidity of worker* expoaed to vinyl chloride monomer (VCM) which have been carried out on behalf of the Miniatry of Labour, Health and Social Affair* on Northrhine-Weatphalia are reported. Vinyl Chloride Mortality Study The aims of this study were to determine stan* dardized mortality ratios (SMR) for male workers e\;Ksed to VCM, using the mortality rates of the West German male population as reference, to study the SMRs of a cohort of workers of the chemical industry comparable concerning age dis tribution and observation period but not exposed to VCM and to determine the SMR of a cohort of a.-rkers in PVC-processing plants. The study was designed as a historic cohort study, covering the period from the beginning of the VCM- and PVC-production in all of the German plants till the end of 1974. Table 1 shows the main characteristics of the three cohorts investigated. Only Germans and Austrians were included in data analysis because of insufficient mortality data on various foreign na tionals employed in German factories. To deter mine the mortality rates of Austrians, West Ger man rates were used. To calculate expectations of total mortality, the mortality rates of the adequate years have been used. To calculate expectations of specific causes of death for all years before 1968, the rates of 1968 have been used; for the following years the rates of the corresponding years. Follow ing the procedure applied by Tabershaw (l). Ftaatlicher Gewerbearzt. Duaaeldorf. W. Germany. `Diibete- Pesearch Institute at the University of Duaaeldorf, Division of Medical Statistic* and Epidemiology, Duaaeldorf, W. Germany. October 1981 weighting of observed cases of specific causes of death according to unknown causes of death has been done with weighting factors calculated sepa rately for three observation periods (up to 1959, 1960-1969,1970-1974) as well as for six age groups. In all of the cohorts, follow-up rates have been near or above 90%. The percentage of causes of death that could not be investigated due to loss or deletion of death certificates varied from 7.3% to 13.1%. To calculate age-standardized mortality ratios of specific causes of death, weighting has been done according to the procedure used by Tabershaw and Gaffey (1) to compensate for unknown or unidentified causes of death. Table 2 displays total mortality as well as some of the relevant specific causes of death. It can be observed that the otherwise observed "healthy worker effect" cannot be demonstrated in the German cohorts exposed to VCM or employed in PVC-processing plants. In the VCM cohort there are significant eleva tions of SMR of malignancies of the lymphatic and hematopoietic tissues (ICM 200-209), and of malig nancies of the GI tract (ICD 150-159). The latter is due to the paramount elevation of SMR of tumors of the liver (ICD 155). It must be noted that there is a modest elevation of SMR of tumors of the liver also in the cohort not exposed to VCM nor employed in PVC-processing plants. No obvious explanation for this observation can be offered. In addition elevated SMRs for ischemic heart disease (ICD 410-414) can be found in all of the three cohorts. Due to methodological 95 UCC 084204 shortcomings of the study no assessment of cardio vascular risk factors has been made. Therefore these results are of minor interest. When subdividing the VCM-exposed cohort ac cording to time of exposure there is a clear-cut increase of the SMR of liver tumors with time (Table 3). This seems to be highly suggestive of a time-response pattern. As it has been impossible, determine concentrations of VCM retrospects due to technological and methodological problemno dose-response pattern can be established. Ho. ever time of exposure seems to be the best avi. able guess for dose. Subclassification according to observation perio: Table 1. Characteristics of study cohorts. Group 1. VCM/PVC production Group II. reference group Population (Germans + Austrians) Man yean Follow-up completed till 12/31/74, % deceased Observed Expected Unknown causes of death No. % Total mortality (SMR) Foreigners (excluding Austrians) Deceased `' 7.021 73.734 93.2 414 435 30 7.3 95 862 6 4.910 76.029 89.8 417 533 47 11.3 78 711 6 Groyp 111, PVC processing 4.007 52.896 92.1 360 380 47 13.1 95 1.454 10 Table 2. Standardized mortality ratios. 1CD 8 Cause of death Total mortality 140-209 All malignant tumors 140-199 Malignant tumors of organs 200-209 Malignancies of lymphatic and hematopoetic tissues 150-159 Malignant tumora of G1 tract and peritoneum 155 Malignant tumors of the liver 191 Malignant turnon of the brain 410-414 Ischemic heart disease 410 Acute myocardial 800-949 Accidents VCMTVC production Obs. SMR 414 95 94 112 79 103 15 214b 45 149* 12 1523b 2 162 91 127* 66 114 61 137* Beyond 95% confidence interval (2). Beyond 99% confidence interval (2). Reference group_____ Obs. SMR 417 78 83 83 77 83 6 77 27 71 4 401* 2 184 115 131* 83 120 44 99 PVC processing Obs. SMR 360 95 62 85 60 89 2 34 15 56 3 434 5 535* 96 158' 69 143' 32 110 Table 3. Standardized mortality ratios by duration of exposure. 1CD 8 Cause of death _______________Duration of exposure, months < 12 13-16 61-120 Obs. SMR Obs. SMR Obs. SMR > 121 Obs. SMR Total mortality 140-199 200-209 150-159 155 191 Malignant turnon of organa Malignancies of lymphatic and hematopoetic tissues Malignant turnon of GI tract and peritoneum Malignant turnon of the liver Malignant turnon of the brain S3 6 1 3 0 0 93 138 102 93 87 130 96 74 20 88 22 116 31 115 92 4 186 5 287 5 249 101 12 135 13 173 17 158 - 2 874* 3 1525" 7 233` " 0 * 1 350 1 276 96 Environmental Health Perspective UCC 084205 - iblt: spectiv*; 1 problem, 'bed. Ho* best avt ion perio. Table 4. Standardised mortality ratio* by period of observation. ICD 6 Cause of death let-159 1-V) '.91 Malignant turnon Malignancies of lymphatic and hematopoetic tiitue* Malignant turnon of GI tract and peritoneum Malignant turnon of the liver Malignant turnon of the brain `btiond 95G confidence interval. 'Beyond 99G confidence interval. To 1959 Obi. SMR 12 160 1 147 8 270* 1 1282 1 557 Observation period 1960-69 1970-74 Obi. SMR Ob*. SMR Total Obi. SMR 29 84 194 103 414 95 9 275b 5 168 15 214b 13 94 24. 177b 45 149* 3 834* 8 2264b 12. 1523b 0 l 223 2 162 SMR ~~ 9o " 63 6$ & 36 434 533* 136" H3* 110 MR 96 113 J49 136 7** .78 Table 5. Standardlied mortality ratio# by age. I'T'8 Cau.-e of death Age group 24 23-84 35-44 45-54 55-64 >65 Total Obe. SMR Ob*. SMR Ob*. SMR Ob*. SMR Ob*. SMR Ob*. SMR Ob*. SMR T'.taJ rtalitv 10 68 45 111 65 104 90 101 105 80 90 103 414 95 140-199 Malignant turnon of orgaift' 0 - 4 141 13 188* 19 141 22 76 21 100 79 103 Malignancies of lymphatic and hematopoetic tiaaue* 0 - 2 194 4 303 4 264 3 162 2 197 15 214b r*-i59 Malignant turnon of Gl trar. =nd peritoneum 0 - 3 397 10 365" 10 145 10 89 12 140 45 149b IV. Malignant turnon of thelr-er 0- 0 - 6 6865b 0 3 934b 3 1664b 12 1523b 19! Malignant tumors of the brain 0"0 0" 1 254 1 362 0 2 162 'Beyond 9-V; confidence interval. :Beyond 99'; confidence interval. Table 6. Group- for aubdiviiion of laboratory examination*. Onjp reification A 1 3 CM PVC production A 11 PVC processing - B I \ CM PVC production and PVC processing, w . rk capacity losa < 20ft H II VCM PVC production and PVC proeewing, u ork capacity lou * 20% Cl Germans and Austrian! C II Foreigners (Exd. Austrians) !>-] 1'iants with high morbidity I'll Fiants with low morbidity Table 8. Bromsulfalein retention.* German* and Austrians Foreigners Retention normal Retention abnormal Total 17 30 33 21 50 51 A to c* *Chi square) - 6.25 Total 47 55 101 Table 7. Bromsulfalein retention.* VCM/PVC PVC Production Processing Retention r.> rmal Retention abnormal Total 26 21 44 10 70 31 8.09 (p < lft). October 1981 Total 47 54 101 Table 9. Bromsulfalein retention.* Work capa- Work capacity loea city lou < 20ft > 20ft Retention normal Retention abnormal Total 41 6 32 22 73 28 *Chi square) - 9.81 (p < 1%). Total 47 54 101 97 UCC 084206 (Table 4) reveals a rather inconsistent pattern: malignancies of the lymphatic tissues (ICD 200-209) are significantly elevated in the sixties only, whereas SMRs for tumors of the liver increase till the end of the study period. This might be referred to differ ent latency periods for both kinds of malignancies, but other causes might likewise have contributed to these results. However, it has to be reported that the number of angiosarcomas confirmed histologi cally in the Federal Republic of Germany in pa tients previously exposed to VCM has actually come to 17 in contrast to mere 4 at the endpoint of the mortality study (12/31/1974). The distribution of SMRs by age (Table 5) demonstrates an obvious susceptibility of males aged 35-44 for malignancies in general as well as for malignancies of the liver. The data base for the German morbidity study consists of all of the reports of suspected cases of occupational disease due to VCM or PVC produc tion or PVC processing. The reference population for these reports has to be defined as the total ^ s. NORMAL UDMe& PATHOL. > 120 MG/DL normal 1.0 PATHOL > 1.0 WORK CAPACITY LOSS WORK CAPACITY LOSS <20% 2 20 % . Figure 2. Vinyl chloride morbidity study: oral glucose uler- j ance teat, 120 min after loading (normal 12<< mg dl). %. VCM-/PVC PRODUCTION AND PVC PROCESSING WORK CAPACITY LOSS K9S VCM-/PVC PRODUCTION AND PVC PROCESSING WORK CAPACITY LOSS 220% Figure 1. Vinyl chloride morbidity itudy: total bilirubin (nor mal 1.0). 98 AND PVC ffiOCESSING WORK CAPACITY LOSS < 20 % AND PVC PR0CESINC WORK CAPACITY LOSS 220 % Figure 3. Vinyl chloride morbidity ttudy: reticulocytes in*' mal 15%). Environmental Health Perspectives UCC 084207 w & d> txS * tooticnoN oassiw :itv lOSS ' toler nrkins copulation in 1974 in the above mentioned iSFle, 6,500 workers in VCM or PVC production and 42,800 workers m PVC processing .. -jven bv the German Association of Plastic producing Industries). Till the end of 1974, 269 rtiwrts of suspected cases of occupational disease had been received. As there has been no consistent w: of examinations performed on each of the cases, numbers of observations for various variables ana* Ivzed van- according to examination method per formed. Insofar as the results of this study are of much lower validity than those of the mortality rtudy. one should regard them as hints for farther investigations. Four attempts to subclassify observation on the _v,u cases have been undertaken (Table 6). Only those results showing significant differences when applying Mt-sts or chi-square tests are so classified. Amazingly none of the more sensitive lab examina tions of liver functions showed a marked difference in all of the subclassifications besides bromsulfalein Mention. In this instance there is a significant difference when subdividing^ VCM/PVC produc tion versus processing (Table 7), as well as by nationality (Table 8) and most pronounced when subdividing by extent of work capacity loss (Table 9). This latter result, however, must be expected when an effect of exposure on liver function is anticipated. An impairment of the excretory liver function is suggested by elevated total bilirubin values in the subgroup with work capacity loss greater than 20% (Fig. 1). There seems to be an impaired glucose tolerance in this group, although observed in a small subsample only (Fig. 2), as well as a lower number of reticulocytes (Fig. 3). The thromocyte count in both groups was the same. These results, however, lead to no sensible inter pretation, as all results attempts failed to standard ize the methods applied for thrombocyte counts by various laboratories. REFERENCES 1. Ttberahaw. I. R.t and Giffey, W. R. Mortality atudy of worker* in the manufacture of vinyl chloride and its poly mer*. J. Occup. Med. 16: 509-518 (1974). 2. Bailar, J. C. Significance factor* for the ratio of a Poiaaon variable to its expectation. Biometrics 20: 639-643 (1964). 'ON % 55 ves October 1981 v. ucc 084208 99 Ennronmental Htalth Ptrsptctu ti Vol. 11, pp. 101-m. 1981 Epidemiologic Study of Vinyl Chloride Workers: Mortality through December 31,1972 by W. Clark Cooper* A population of 10,173 man, employed in 37 planti, vu identified ai havinc worked for at least one year in jobs involving probable exposure to vinyl chloride monomer (VCM) prior to January 1,1973. Of the 9677 men whose vital status was determined, 707 were known to have died. For 699, death certificates were obtained. The standardised mortality ratio (SMR) for all causes was 89, that for all malignancies was 104. The only type of malignancy found in significant excess was in the category of malignant neoplasms of the brain and other parts of the nervous system; 12 deaths occurred where 5.9 were expected, for an adjusted SMR of 203. There were slight but inconclusive upward trends in all malignancies, and for malignancies of the respiratory tract, digestive tract, and central nervous system associated with reported levels of maximum exposure to VCM. When groups in whom less than 20 years had elapsed from the first exposure were compared with those with 20 or more elapsed years, and 25 or more elapsed years, no significantly different SMR's were detected for major primary sites of malignancy. Plans for an updated study of mortality, to include deaths in the period 1973-1979 are briefly discussed. The epidemiologic studies of vinyl chloride work ers summarized in this report were carried out during the period June 15,1973 through December, 1976 by Tabershaw-Cooper Associates, Inc., and Equitable Environment^ Health, Inc., for the Manufacturing Chemists Association (MCA) (now the Chemical Manufacturers Association). An initial report, dealing with 8,384 workers from 34 plants, was prepared May 3, 1974 (J). A summarized version (2) was published in 1974. The study population was subsequently increased and follow-up was improved. After an interim report in 1976 (J), a Anal report based on 10,173 workers was prepared in January, 1978 U). In all of these studies the observation period ended December 31, 1972. Participating Plants ' In mid-1973, the MCA identified 43 plants in the United States, belonging to 19 companies, which either produced vinyl chloride monomer (VCM) or used it in the production of poly(vinyl chloride) *21)0 Shattuck Ave., Suite 401, Berkeley, California 94704. October 1981 (PVC). Of these, 34 were included in the initial study; four were excluded because they had been in operation less than 5 years, one had stopped production in 1966, and in others information on job histories or exposures was deficient. Three plants were subsequently added to the original 34, so the 1978 report included 37 plants. Of these, 11 pro duced only VCM, 18 produced only PVC, three produced both,, and five plants produced homo polymers and copolymers, with or without VCM and PVC. The geographical distribution of those in the study, as shown in Table 1, indicates a dispropor tionate number of workers from the South, particu- Tablt 1. Geographical distribution of 10,173 vinyl chloride worker* in 1978 report Region U.S. male* (1970). * Workers in study, % Northeast North Central South Wen 23.8 27.9 30.9 17.4 25.9 18.4 64.8 0.9 101 UCC 084209 i larly from the Eut South Central and West South Central States. The South, with 30.9% of the total U.S. male population in 1970, supplied 64.8% of the study population. Of the plants participating, the one which had first begun operations with VCM had done so in 1935, the most recent was in 1968. Four plants had begun in 1942 or earlier, 13 in 1952 or earlier, and 27 in 1962 or earlier. The Study Population The objective was to include all male employees whose work had involved exposure to vinyl chloride for at least one year prior to December 31, 1972. The designation ofjobs which involved exposure to VCM was made by staff members at individual plants or by a corporate industrial hygienist. In approximately two thirds of the study population, TCA staff copied personnel records on individuals who were identified as having been in exposed jobs. In the remaining portion of the population, detailed information on exposed individuals was provided by plant personnel. The methods used in doing this are described in the complete reports cited earlier. Study Period The period of time in which the work-force of a plant was included in the study depended upon the date it began making or using VCM and also upon the earliest date when personnel records were complete for all employees, if that was later than the foregoing. This was done to eliminate periods when there was differential record retention of workers terminated, deceased, or retired. The end of the study period was December 31,1972. Estimates of Exposure In each plant, every job and location with VCM exposure was graded in terms of probable expo sure. Originally, a job history form was designed in the expectation that the exposures could be quantified in parts per million. This proved impossible in practice. However, for each plant, jobs and loca tions involving the highest exposures could be classified as "high", and other jobs classified as "medium" or "low" relative to the "high". It is recognized that this subjective classification is of questionable validity in categorizing the past and present exposure of a given worker. From the number of months spent in jobs with classifications of 3 (high), 2 (medium) and 1 flow), a number of exposure categories were developed for use in later 102 Table 2. Bum for development of VCM exposun -- t,u Criterion I'm ; Duration of exposed employment Interval from beginninf of exposure to end of observation Estimated maximum level to which an individual waa expoaed for at least 12 month*, classified aa high, medium, or low. Integrated or cumulative exposure, crediting 1 for each month at low, 2 for each month at medium and 3 for each month at high exposure to VCM Exposure index (El) - Cumulative acore/iverage number of months Monti* Monti* High Medic Lev 1 2 3 ; i i analyses. As shown in Table 2, individual exposu% in various papers were classified in a number i ways, including the maximum level at which k individual had been exposed for at least 12 month* an integrated or cumulative exposure, ud c exposure index based on the cumulative ton divided by the number of months. Follow-Up i As is customary in historical prospective studies. ' all who had left employment were traced whr. ' possible. Methods included form letters sent b; mail and use of retail credit follow-up. For the first report, there was insufficient time to utilize Socii. Security Administration records, but for sub* quent reports such follow-up was used. In the first, or 1974 report, 85% of the stud;, population was located; for the final or 1978 repor. : the percentage had been increased to 95%. [ The mortality calculations were based only * those who were successfully traced, which is equh- , alent to assuming that mortality among those M found was the same as among those who wen found. This usually, but not always, results in son* overestimation of mortality. Calculation of Standardized iI Mortality Ratios Each worker in the study, i.e., everyone who# vital status was ultimately known, was considered to have been under observation from the date ot which he attained a year of exposed employment or from the date when his plant's records were com plete, whichever came later. Observation period- ended December 31, 1972, or on the date of dealt whichever occurred first. 1 Observed deaths were classified by cause accord ing to the 7th (1955) revision of the Internatior* Environmental Health Perspective j Cli dr w nu tio *\ ot> dis ob' cal rat vi Ct mf SE If 1. at st. th ot fic P SL SI d* P fc u. e. 3. re t) T; >* s S X s s T l* 0 UCC 084210 9 1 atetorih Unit Homin' Month, Hijti Mcditm Low 1 2 t xposurt? umber of which ar. month# - and ar. e aeon- ^Vher. , by the fir?: '.e Socii subse- .e study report. only on ' equivose not o were -o some whose idered ate on tent or e com* eriod# death. Classification of Diseases. The expected number of deaths by cause were calculated by using age and suse-specific mortality rates for United States gules with the same birth years and age distribu tion for the years 1950, 1955, 1959, 1965, 1967 and 1P70. Deaths for which death certificates could not be obtained were assumed to have the same cause distribution as the death certificates that were obtained. Appropriate increases were made in calculated SMR's. The statistical significance of the deviation of each S.MR in the study population from an expected value of 100 was tested by a method derived from Chin Leong Chiang (5). The formula for determin ing the standard error of the SMR was 100 X SMR SE No. expected deaths Ifan observed SMR differed ffrom 100 by more than l.Hti standard errors, it was regarded as significant a: the 55 level; if it differed by more than 2.57 -tandard errors, it was regarded as significant at the Iff level. SMR's based on fewer than five observed deaths were usually not tested for signi ficance. Results Table 3 summarizes the numbers of individuals, Success of follow-up, person-years and deaths in successive phases of the study. The number of deaths per 1000 man-years of observation, which in general reflects the age distribution of the work force, suggests that the proportion of older individ uals increased in the study population as it was expanded and follow-up improved. Even so, the deaths per 1000 man-years indicates that a relatively young population was being observed; the I'.S. male population 20 and above has about 11 TiUe 1 Xumlxr* of individuals, success of follow-up, pnsonrm. and deaths analysed in successive phases of the study. Report 1, Report 2. Report 3, 1974 1976 1978* * Nti of men No. found * found No deaths No. certificate# Total min-jT tVs:h# 1000 man-yr 8,384 7,128 85% 352 328 77,846 4.52 9,109 8.714 96% 525 511 94.221 5.67 10.173 9,677 95% 707 669 120.203 5.88 October 1981 deaths per 1000 man-years. Some published occu pational epidemiologic studies will show 20 or more. Duration of Exposure to VCM In the first report, only 15.2% of those studied had begun exposure prior to 1950 (22 years before end of the observation period). In the third report, 33.4% had had 20 or more years for observation since exposure began. This resulted from finding more early employees by improved follow-up, and the inclusion of an older group from one plant in the augmented population. Standardized Mortality Ratios Standardized mortality ratios (SMR's) for selected causes of death are shown in Table 4, based on the 352 deaths analyzed in Report 1 and the 707 deaths analyzed in Report 3. Results in the first report led Tabershaw and Gaffey (2) to conclude that vinyl chloride may be associated with cancer of a number of sites, notably digestive cancer, respiratory can cer, cancer of other and unspecified sites (primarily those of the central nervous system) and lympho mas. This was based not on statistically significant excesses in each category7, but upon apparent trends when different levels and durations of exposure were compared. With the enlarged study group, the SMR for malignancies in the entire population dropped slight ly, as did the SMR's for malignancies of the buccal cavity and pharynx, digestive tract and respiratory tract. However, tumors of the brain and central nervous system, when examined separately, still appeared to be in excess. A number of analyses were done in the third report in an attempt to sharpen the focus on work exposures. There appeared to be a slight but definite trend in the SMR's for all malignancies, malignancies of the digestive tract, the respiratory tract, and for other and unspecified sites with increasing levels of estimated maximum exposure (Table 5). However, the numbers of expected deaths were relatively few in some categories and the groups differed widely in age distribution as manifested by deaths per 1000 person-years. To reduce dilution of the study population by men whose exposures had begun only recently, a sepa rate analysis was carried out on those whose expo sures to VCM had begun 20 years or more prior to 1972, and on those whose exposures had begun 25 years or more prior to 1972 (Table 6). Another analysis was made of a population of men who had worked in plants producing only PVC 103 UCC 084211 (where VCM exposures were presumably high), whose exposures had begun 20 years or more be fore the end of the study period and who had been reported as having medium or high VCM exposures for a year or more (Table 7). This group experi enced 210 deaths where 249.7 had been expected. The pattern of mortality from malignancies wu not appreciably different from that of the total study group. ' In summary, increasing the study population ind Table 4. Observed and cxpactad death* (O/E) and atandardixed mortality ratio* for oelected cauaca (SMR'a adjuated for death certificates). Cause (ICD Mo, 7th Rev) 1974 Report O/E SMR 1978 Report O/E SMR All cause* All malignancies (140-205) Buccal and pharynx (140-148) Digestive (150-159C Respiratory (160-164) Other and unspecified (190-199) Brain and CNS (193) Leukemia and aleukemia (204) Lymphomai (200-203, 205) Major cardiovaac. renal (330-334. 400-468, 592-594) Cirrhosis liver (581) *1 No. of workers Person-yr 352/467 79/77 5/2.84 19/21.7 45/44.3 17/11.75 32.77 6/6.06 155.207 3/15.6 7.128 77.846 75* 110 189 94 112 155 -- 85 106 80* 21 707/795 139/141 5/5.19 29/40.8 25/23.9 28/20.2 12/5.9 9/6.65 11/10.38 347/385 14/26.5 9.677 120,203 89* 104 102 76 107 147 203b 143 112 95 56* Significant at 1% level. ^Significant at 5% level. Table 5. Observed and expected death* (O/E) and atandardixed mortality ratio* for aelected carnet at related to maximum level of reported expoaure to vinyl chloride monomer (SMR'a adjusted for missing death certificates). Cause (ICD Mo, 7th Rev) Reported maximum exposure VCM Low Medium High O/E SMR O/E SMR O/E SMR All malignancies (140-205) Digestive (150-159) Respiratory (160-164) Other and unspecified (190-199) No. of workers Person-vr Deaths/1000 person-yr 65/71 14/20.9 19/22.2 112.9- 4,925 56,741 6.16 98 56/53.6 72 . 10/15.6 92 19/17.1 119 132.5 3.021 39,927 6.6 109 67 116 180 18'16.5 5/4.4 7/5.1 4/2.7 1,731 21,535 3.9 112 117 141 150 Table 6. Analysis of deaths based on time from beginning of exposure to end of study period (SMR'a adjuated for mining death certificates). Cause of death (ICD No. 7th revision) AH causes All malignancies (140-205) Digestive (150-159) Respiratory (160-164) Other and unspecified (190-199) Leukemia (204) Cardiovascular-renal < 20 yr No. SMR 158 77* 31 95 8 96 8 80 6 108 3 155 68 84 > 20 yr No. SMR 549 93 108 107 21 70 37 116 22 162 6 137 279 97 > 25 vr No. SMR 393 96 73 104 16 74 22 100 13 146 4 137 211 105 Significant at 1% level. 104 Environmental Health Perspective* UCC 084212 / r,proving follow-up did not strengthen the sugn-.rd iwociations between VCM exposure and saJipiancief other than those caused by hepatic r.ciwarcoma. as will be pointed out later, and a umsied association with tumors of the brain and (vmraJ nervous system. T*M* * Death' in plant* producing only PVC. based on aim who** firit exposures began before 1952, and who kd audium or high VCM exposures (SMR's corrected for miicing death certificate*). i.*. of death ;So, 7th revision) A.. CtJr** A. rjlipiancie- '140-205) :ive (l.V~159) (:-;.iratorv t rriT and un-ircified (190-199) --r -i- of liver -561) `.\Ti4tim at l'i level. 0/E 210/249.7 46/46.04 9/13.63 17/14.75 10/ 6.33 6/7.95 SMR 84* 106 70 122 167 80 Angiosarcomas Nine angiosarcomas are known to have occurred in the U.S. during the study period, i.e., prior to 12/31/72. As shown in Table 8, eight of these were found in the study, but only three were coded as angiosarcoma on the death certificate. However, four others were coded as tumors of the digestive tract. Unfortunately, two were coded 230x so as to fail out of the category for malignant tumors of the GI tract, and one was coded as cirrhosis of the liver. As shown in Table 8, the angiosarcoma which was not found was in a man who had died in 1961. We have not determined how he failed to be in the study population. The years of exposure for the eight cases ranged from 4 to 23 years, while elapsed time from beginning of exposure to death ranged from 16 to 24 years. Tumors of the Central Nervous System The 12 tumors of the brain had been diagnosed on death certificates as follows: glioblastoma multiforme, 4 (1 confirmed by autopsy); astrocytoma, 2 (2 au- Tabic 8. Angiosarcoma death* and data on VCM exposure*. Id So * First expoaed Year of death Time from first exposure to death, yr Total yr exposure Eat. max. exposure Age at death (S.A-02 414 05 07 -10 -n -12 16 -OK 1955 1949 1944 1944 1946 1951 1949 1950 -- 1971 1968 1964 1968 1970 1968 1969 1969 1961 16 19 20 24 24 17 20 19 14 High 18 High 20 High 14 Med 23 Low 17 Med 20 High 4 High Not in study group 38 43 52 45 70 60 50 41 'Njmher un-I> in registry periodically prepared by J. Stafford, Imperial Chemical Induetriee Ltd., Plastics Division. fw no. 1 2 3 4 5 6 i b 10 11 12 Table 9. Summary of brain tumor deaths (1CD No. 205) and data on VCM exposures. First exposed Yr of death Time from 1st exposure to death, yT Total yr exposure Max. exposure 1958 1972 1967 1972 1957 1968 1941 1958 1950 1970 1956 1971 1947 1971 1945 1963 1949 1971 1947 1971 1935 1956 1935 1967 14 5 11 17 20 15 24 18 22 24 21 32 5 Low 5 Low 7 Med 0 Med 8 High 3 Med 23 Low 18 High 21 Low 23 High 18 Low 22 Low thluber 19S1 Age at death 67 43 54 61 43 54 57 44 58 49 59 57 105 UCC 084213 V -el- topsies); ependymoma of the 4th ventricle (autop sy); "malignant brain tumor" or "carcinoma of the brain," 5 (with no autospies). This group is cur rently being made the subject of more rigorous review. The information obtainable from our re cords, summarized in Table 9, is insufficient to prove or disprove a cause-and-effect relationship between occupational exposure and these tumors. Conclusions A study of 707 deaths in a population of 9677 men who had worked for one year or more in jobs involving exposure to vinyl chloride and whose vital status had been determined as of December 31, 1972, did not show a significant excess of deaths due to malignancies. There did appear, however, to be a significant excess of tumors of the brain and central nervous system, based on 12 such deaths. There also continued to be slight but inconclusive trends toward higher SMft's for deaths from digestive tract and respiratory tract tumors associated with maximum levels ofpast exposure. No striking changes in malignancy patterns were apparent when analy ses were directed toward individuals in whom 20 to 25 years had elapsed since first exposure. The results suggest that, except for a proven associa tion with hepatic angiosarcoma and a strongly sug gestive association with central nervous system tumors, vinyl chloride probably is not associated with significant excess cancers of other sites. It should be emphasized that the epidemiologic study summarized in this report was planned, the populations defined, and analysis under way before cases of hepatic angiosarcoma had been diagnosed in workers exposed to vinyl chloride (0). An ujxfc, is scheduled with inclusion of additional deathH the cohort during the years 1973 through 1979. study can be unproved by a separate analysis t data from the plants which began operations befo 1960, and by separating, insofar as possible, up sures to vinyl chloride monomer, polyvinyl ehkride, and various copolymers. It is also hoped tk criteria for defining exposure and for rating lev* of exposure can be improved to permit better int ces of integrated exposure. This study was begun June 15,1973 under a contract betvte the Manufacturing Chemists Association, 1825 Connecticut A: enue, N.W., Washington, D.C. (now the Chemical Ihnu&ctc era Association) and Taberahaw/Cooper Associates, Inc. It tv continued under later contracts with TCA and with EquuU Environmental Health, Inc. REFERENCES 1. Taberahaw/Cooper Associates, Inc. Epidemiological ttsdvtf vinyl chloride workers, final report. Submitted to the Mini* turing Chemists Assodation, May 3,1974. 2. Taberahaw, I.R., and Galley, W. R. Mortality noth i workers in the manufacture of vinyl chloride and iu por. mera. J. Occup. Med. 16:509-518 (1974). 3. Equitable Environmental Health, Inc. Supplemental1}' tpdemiological study of vinyl chloride workers. Report pnpared for the Manufacturing Chemists Association, Septem ber 1976. 4. Equitable Environmental Health, Inc. Epidemiological stud, of vinyl chloride workers, final report. Prepared for tb Manufacturing Chemista Association, January 1978. 5. Chiang, C. L. Standard error of the age-adjusted death nu Vital Statistics Special Reports 47: 275-285 <1961). 6. Creech, J. L., and Johnson, M. N. Angiosarcoma of liver ir the manufacture of polyvinyl chloride. J. Occup. Med. 16: la(1974). 106 Environmental Health Pertpectives UCC 084214 w. ^ I death.. :h197s. Tr. analyst tions'bef'- sible, tip /vinyl *fc hoped ti. -ting le\t better ir,: -esct b*i,, Miecticut A , Alanuitc.. Inc. It i. -th Equjit. Environmental Health Perspective* Vol. il, pp. 107*113,1M1 Epidemiology of Hepatic Angiosarcoma in the United States: 1964-1974 by Henry Falk,** John Herbert,* Steven Crowley,* Kamal G. Ishak,* Louis B. Thomas,** Hans Popper * and Glyn G. Caldwell* cal itud; the Mar,^ rty stud) end iu p TH-ntan' f; Report p- caJftj: red for l1- "ft. death ra:> .). a of liver l- ed. 16.IV k.ivei k nationwide survey of hepatic angioiarcoma (HAS) in the United State* during the yean 1961 through 1974 identified 168 caae*. Of theae. 43 ca*e* (2591) were aasociated with known etiolocic fm tort, such at vinyl chloride monomer exposure durinc preparation of poly(vinyl chloride), ute of Thorotrast in angiography, exposure to inorganic arsenic, and treatment with androgenic* anabolic steroids; 126^Caxes (7S9t) are of uncertain etiology. HAS most often affects males (ratio of approximately 3:1), peaks in the sixth and seventh decades of life (somewhat earlier than other sarcomas of the liver) and appean to occur more often in the industrialized Northeast and M rNest (although reporting artifact may be a factor). There is an extraordinary relative risk for p< Iy(vinyl chloride) polymerization workers; there may also be other chemical-industrial a-.ociations that require further investigation. Prospective epidemiologic studies of HAS should be considered as a means of identifying other causative factors (e.g., chemical* or drugs) related to HAS. Introduction Thi# repor. is an overview of the nationwide hepatic angiosarcoma (HAS) case-finding study for '.hi- years 19*-i-1974 conducted by the Centers for lb-vase Control (CDC). At the start of this study, three causative factors had been ide ,lifted for HAS: vinyl chloride mono mer (VCM) u. 2), Thorotrast (3), and inorganic ar-enic (4). The recently discovered association between VCM and HAS has served as a stimulus for this investigation, and multiple epidemiologic studies of polyvinyl chloride (PVC) polymerization "Chronic Di-r^e? Division, Center for Environmental Health, wr.>rs for Di--.-.se Control, Public Health Service, U.S. Dept. Health and H -man Services, Atlanta, Georgia 30333. `Author to v jm reprint requests should be addressed. tDvpartmer of Hepatic Pathology, Armed Forces Institute 'f Pathology. Washington. D.C. 20012. ""Laborato-.. of Pathology, National Cancer Institute, Natf nal Instituti - of Health, Bethesda, Maryland 20014. fft'.ration L,. oratory for Liver Disease, Mount Sinai School <' Medicine of the City University of New York, New York workers exposed to VCM have since demonstrated very high relative risks for the development of HAS (5, 6). Thorotrast is a colloidal suspension of thorium dioxide, a radioactive alpha-emitter with markedly prolonged radiologic and biologic halflives, which was used for carotid angiography and liver-spleen scans in the period 1930-1955. The thorium dioxide is sequestered by the reticuloendo thelial system, primarily in the Kupffer cells of the liver; radiation injury to adjacent cells is the presumed carcinogenic mechanism. Epidemiologic studies of Thorotrast recipients have shown very high relative risks for the development of HAS as well as hepatocellular tumors (7,8). The association between arsenic and HAS is based on data from several small autopsy series in German vintners in the 1940s and 1950s U, 9), which demonstrated an increased incidence of liver disease, including HAS. These workers were exposed to inorganic arsenical pesticides during application of the pesticide and also by drinking beverages prepared from the skins of the sprayed grapes. Subsequently, HAS cases were reported following long-term ingestion of Fowler's solution (potassium arsenite) (10,11) and October 19S1 107 UCC 084215 i arsenic-contaminated well water (12), Individual cases suggesting associations between HAS and hemochromatosis (13) and copper exposure (U) have also been reported. Earlier reports from this study reviewed cases associated with single causative factors (15-18), including androgenic-anabolic steroids which we feel are implicated as a fourth cause of HAS (19). In this paper, we present an overview of the case finding effort, placing the known causative factors and cases of idiopathic origin in perspective. Methods Information relating to cases of HAS occurring in the United States during the years 1964 through 1974 was solicited by CDC in a variety of ways: (1) announcements were placed in seven medical journals; (2) a mailing was sent to all pathologists in the country; (3) separate mailings were sent to all state epidemiologists, major tumor referral centers, and statewide tumor registries; (4) a death certificate review fo,r International Classification of Diseases (ICD), Eighth Revision, Code 197.8 (liver tumors, unspecified primary or secondary) for the period 1966-1973 was conducted with the assistance of the National Center for Health Statistics (NCHS) and the 50 state health departments (Code 155.0, primary liver tumors, was not reviewed because it would nave been impractical to obtain the much larger number of certificates in this category and because it was felt that the majority of cases of HAS listed as such on the death certificate would have been coded as 197.8); (5) arrangements were made with the Armed Forces Institute of Pathol ogy (AFIP) to include cases in their files (1943-1975) in the review; (6) a number of cases were identified from industrial surveys of PVC polymerization workers and others potentially exposed to VCM; and (7) permission was requested to include the previously published cases of HAS occurring in 1964-1974. The evaluation procedure for each identified case was as follows: Initially, permission was requested to review the appropriate pathologic specimens (all submitted non-AFIP case material was reviewed at the National Cancer Institute's Laboratory of Pa thology by H. P. and L. B. T.). Following confirmation of the diagnosis, the local physician was notified, and, with his permission, the nearest of kin was identified and contacted. Consent was obtained to review medical records, and a questionnaire was administered by telephone to obtain detailed occu pational, residential, and chemical exposure histo ries. In selected instances, friends, employers, previous physicians or others were also interviewed. 108 In all, approximately 350 submitted cases wen reviewed by the pathology review group, son outside our requested time period of 1964-1974. Pathologic specimens were obtained for review t approximately 95% of cases, many of which considered by our pathology panel not to be HAS - Since survival after diagnosis is very brief at' many cases were only diagnosed at autopsy, > have included all 168 confirmed cases with deaz ' during 1964-1974 in the study group. ~. The above effort is essentially a case review ! Subsequently, the 22,432 death certificates obtains from the review of Code 197.8 were used to can;, out a case-control study of occupation as recorded , on the death certificate in the following manner ' Death certificates were sought for all 168 confirmed i HAS cases; 166 were available. Controls wen sought from among the 22,432 death certificates it ICD Eighth Revision Code 197.8 (liver tumor, unspecified primary or secondary) that had bee: t obtained in the HAS case-finding effort (see above. certificates of confirmed HAS cases were excluded j from the control selection process. Although death.- in Code 197.8 might not represent the ideal control , group, the rationale was that these deaths resulted from a broad variety of tumors of multiple site- ; metastatic to the liver or represented cases which were diagnostically uncertain; it was therefore . unlikely that any single diagnostic category would predominate or that the occupational listings would be heavily biased by any single group of cases. ' Up to four controls (as many as were available were matched to each case > 30 years of age on the basis of the following criteria: age (6 years), sex. ; race, county of residence, and year of death (:3 1 years). One hundred thirty-five cases were success- ' fully matched (79 of these had 4 matched controls. ; the overall ratio of controls to cases was approxi- I mately 3:1). Individuals who could not be matched were primarily young females and residents of sparsely populated counties. A combined occupation and industry coding scheme was developed to accommodate all listings recorded ; on the certificates and to group listings on the bast of potential hazardous exposures. The data were ; analyzed by Rothman's method for matched groups with multiple controls per case (20). irfe: tin. T cer an<: me mo' the sue cor of: 19*' cer epi sea l eon nor Tab __ Ur *s T* A i F | T* F|T ( i _ . ; Results Our study identified 168 deaths from confirmed ! HAS during the years 1964 through 1974. Forth!? i rare tumor, the best sources of case identification were the pathologists, with the largest number o. cases identified through the single mailing to at pathologists and the second largest number of caf* ; Environmental Health Perspective* Fl, Oc UCC 084216 some VH974. view in h were e HAS. ief and sy. we death eview. otained 0 camcorded '*nner. firmed - were ates in :umor, 1 been bove); 4 'uded *Jeaths ontrol suited - sites which 'efore s. lable) m the . sex, (3 ' cesstrols; iroxi:ched ts of ,eme >rded basis were -oup6 identified through pathology referral centers (par ticularly the AFIP). Table 1 summarizes the results of the death certificate review portion of the case-finding effort and points up some of the inadequacies of using this method in epidemiologic studies of uncommon tu mors. Only 42% of the cases initially identified on the death certificate as HAS were confirmed as such on pathologic review; 50% of the cases were confirmed not to be HAS. Furthermore, only 23% of all the total cases in our study during the years 1966-1973 would have been identified by the death certificate search alone. It can be seen that an epidemiologic study based only on a death certificate search ofCode 197.8 would have been quite inadequate. Figure 1 compares age, race and sex data for the confirmed HAS cases in our study with 131 cases of non-angio hepatic sarcoma identified in the death Table 1. HAS cues, CDC aurvey: death certificate review-- code 197.8 (8th reviaion ICD), 1966-1973 Length of review 7.5 year.`! 1966-1971, 1973, 1/2 of 1972) Total number of death certificates reviewed 22,432 Sarcomas of the liver, death certificate diagnoses: Angiosarcoma (HAS) 74 (36.1%) Leioimosareoma 24 (11.7%) Fibrosarcoma 14 ( 6.8%) Sarcoma (type unspecified) 64 (31.2%) Sarcoma (other types) 29 (14.1%) Total Final pa:vologic diagnoses of 74 cases identifier! on death certificate as HAS Confirmed HAS Confirmed not HAS -Nopathology available 203 31 (42%) 37 (50%) 6 ( 8%) certificate survey (these latter cases were not confirmed by pathologic review). HAS has a strik ing male preponderance of approximately 3:1; this is not true for other hepatic sarcomas. HAS also appears to occur more often in younger age groups. The higher proportion of males than females with HAS first appears in the 40- to 49-year-old group (Fig. 2) and is associated with a younger peak age for males than females, although the mean age for female HAS cases (50.1 years) is lower than that for males (57.9 years). These findings are not solely related to the VCM-induced cases among polymer ization workers. The male preponderance is also present in the Thorotrast, arsenic, and androgenicanabolic steroid associated cases, as well as in the idiopathic cases (Table 2). Cases with known etiolo gy, however, have a younger age distribution than idiopathic cases (Table 3), with a mean age of 51.0 years compared to 57.6 years for the idiopathic cases. Table 4 presents the 168 cases of HAS by year of death and etiologic status. The VCM-, Thorotrast* and androgenic-anabolic steroid-associated cases were more common during the latter part ofthe study Tabic 2. HAS caaea, CDC aurvey, 1964-1974: aex ratioa, etiologic categoriea. Male Female Ratio Vinyl chloride Thorotrast Araenic Androgenic-anabolic ateroids Subtotal Idiopathic 12 15 4 _3 34 93 0 (12 : 0) 5 ( 3 : 1) 2 ( 2 : 1) _1_ ( 3 : 1) 8 ( 4.3: 1) 33 ( 2.8: 1) med - this ation er of all Figure l. Hepatic angiosarcoma (HAS) cases compared with non-angio hepatic sarcoma cases, by age group: U.S., 1964-1974. October 1981 Figure 2. Hepatic angioaarcoma caaes, by age group and aex: U.S., 1964-1974 109 UCC 084217 4 Tabic 3. HAS caacc, CDC survey, 1964-1974: iff distribution for cases of known cause and for idiopathic cases. cases (including five adults with a history of prolonged use of Fowler's solution and one child with Known etiology Idiopathic environmental exposure) occurred primarily during Age, yr No. * No. * the earlier years of the study and may represent the tail end of a larger problem in previous yean. 0-9 10-19 20-29 80-39 40-49 60-59 60-69 70-79 80 Total 1 ( 2) 0 ( -) 0 ( -) 4 (10) 8 (19) 22 (52) 4 (10) 3 ( 7) 0 ( -) 42 2 ( 2) 4 ( 3) 1 ( 1) 8 ( 6) 19 (15) 24 (19) 39 (31) 21 (17) 8 ( 6) 126 The number of idiopathic cases was low during the first few years of the study (perhaps related to poor recall by pathologists, and to the fact that the death certificate search started with 1966). Case nun* bers, however, remained steady for most of the study period except for a spurt in 1974. The latter occurred right after the original report and the attendant publicity of the first cases of VCMinduced HAS (January 1974) and may be related to improved diagnostic evaluation. Review of the idiopathic cases occurring in 1974 demonstrated * period. For the VCM- and androgenic-anabolic large number of elderly cases with no evidence of steroid-associated cases, this is due to the rela clustering in a particular exposure setting. tively recent introduction of these causative agents. The HAS mortality rate for the entire United For the Thorotrast-induced cases, however, this States during the study period was 0.75 cases per pattern was an unexpected finding. Based on the 10T population per year. Crude mortality rates by originally calculated latent period of approximately region, based on county of residence at time of 20 years (21), the general impression was that such diagnosis (Table 5), suggest a somewhat higher cases would be diminishing by 1975. However, the incidence in the Northeast and in the industrial number of cases appeared to still be increasing as of portions of the Midwest. There was also an increase 1974, apparently due to an increase in cases having in the mountain region, although this is based on a relatively low-dose angiographic procedures and very small number of cases. The rates were low in prolonged latent periods (16). The arsenic-associated fanning states and in the South; however, since Table 4. HAS cases, CDC survey, 1964-1974: distribution by emulative factor* and year of death. 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 Total Idiopathic Vinyl chloride Arsenic Thorotraet Androgenic-anabolic steroids Total 4 1 1 - - 6 10 9 13 12 13 11 12 13 11 18 126 -- 321 1- 3 1 12 * 1 2 1- - - - 1- -- 1 22324 1 5 20 -- 1- - - 1- 1 14 10 10 17 18 17 15 16 17 17 25 168 Region 1. New England 2. Mid-Alantic 3. E.N. Centra] 4. W.N. Central 5. S. Atlantic 6. E.S. Central 7. W.S. Central 8. Mountain 9. Pacific Total 110 Table 5. HAS cases, CDC survey. 1964-1974: distribution by region. States Pop. 1970 No. of cases (HAS/l07/yr.) ME, NH. VT, MA, RI. CT NY, NJ. PA OH, IN. 1L, MI, WI MN. LA, MO. ND, SD, NB, KS DE, MD, DC, VA. WV. NC, SC, GA, FL KY, TN, AL. MS AR, LA, OK. TX MT, ID. WY, CO. NM, AZ, UT, NV WA, OR, CA. AK, HI 11,847,186 37,152.813 40,252,678 16,324,389 30,671,337 12,804,552 19,322,458 8.283:585 26.525.744 203,184,742 12 (0.92) 38 (0.93) 35 (0.79) 10 (0.56) 23 (0.68) 7 (0.50) 12 (0.56) 10 (1.10) 21 (0.72) 168 (0.75) No. of idiopathic am (idiopathic HAS/10'^r.) 9 (0.69) 28 (0.69) 30 (0.68) 9 (0.50) 15 (0.44) 1 (0.07) 10 (0.47) 7 (0.77) 17 (0.58) 126 (0.56) Environmental Health Perspective* ucc 084218 of y child rimarily du.\\ * may reprt>- previous ytt low during c, related to ]?,tthatthedr.6). Case nur j! most of u, 974. The lav.*eport and i> uses of VCX y be related', leview of Up ojnonstratHi i no evidence <: etting. entire Unite 9-75 cases pe ality rates t, ce at time i what higV.ehe industry, so an inert*.** is based on * s were low u wever, sine* ... are diagnosed only after referral to -j hospital and tumor centers, it is possible that `rural rates could be artifactual. ' x. summarize this portion of the study, it is parent that HAS has a strong male prepondert.T that it appears to occur more often in younger groups than other sarcomas of the liver, and -y there may be geographic differences which are fisted simply to the distribution of VCM associ- cases (the largest number of which were in k-r.tucfcy and West Virginia). As part of the `* -up effort we looked at occupation in the Vi-r. certificate case-control study. Table 6 shows x the case-control ratios were elevated only for last two occupational categories. The first of - i07) shows a highly significant difference for -..-.iral workers that is entirely related to expo*.n to VCM: all 10 cases were PVC polymerization > *M-rs. The last category (#8) combined a large -.-her of laboring groups with potential exposure a variety of chemicals; included are laborers, rwhmists. maintenance workers and others. The a---riation of this heterogeneous grouping of occuratwns with HAS is not statistically significant, nor reviewing the individual Occupational data from interview- with family members were we able t. identify a specific chemical, plant, or process as a .-votive factor. Nevertheless, taken together with :.v earlier findings, this association suggests that - me chemical exposure or industrial factors may > related to a portion of the idiopathic cases. Such *' a-sociation would not be unreasonable; machin.-v. e.g.. art potentially exposed to trichloroethylm,- ian experimental hepatocarcinogen that is struc-rally related, to vinyl chloride), inorganic arsenic and nitrosanrnes (which have been identified in r.v.ing fluid- and are a known cause of HAS in animals) UJ. JJ). pathic ea/tf HAS IOvjt.i (0.69) (0.69) (0.66 > (0.50i J.44) 0.07) 0.47; 0.77) 0.58) ).56) fives Discussion A particularly intriguing feature of HAS is that there are new four probable causes of this tumor, and yet about 75% of the cases are of uncertain etiology. Given that the HAS cases associated with the four quite distinct etiologic factors (VCM, Thorotrast. arsenic, and androgenic-anabolic ste roids) share a common morphologic progression to HAS which is indistinguishable from that of idio pathic cases (2i), it is likely that additional causal factors arc- (or will be) associated with HAS. In this study, the male preponderance, the younger age distribution, the possible geographic relationship with industrial portions of the country, and the suggestion from the death certificate case-control October 1981 study that groups with chemical exposure may be at higher risk, raise the possibility that some of the idiopathic cases may be related to presently unidentified environmental or occupational expo sures. This study and that of Baxter et al. (25) confirm the limited diagnostic reliability of death certificate diagnosis of HAS and the need to assess a variety of Table 6. Occupation a> recorded on death certificate, caeecontrol study, CDC HAS survey, 1664-1974. Occupation Cases (N -135) Control W -421) Professional, technical, engineers Managers, administrators Sales, wholesale/retail trade Clerical Communications Finance, insurance, real eatate Buaineaa, store owners, proprietors Service worker* Housewife, homemaker Military, government Unlisted, retired, disabled 16 fi 3 9 1 2 6 8 18 2 _5 40 23 29 13 5 4 11 36 58 3 J2 Agricultural (farming, stock, feed, fisherman) Mining Transport Carpenters, craftsmen Manufacturing (unspecified, untitled, other) Lumber, logging, wood products Metal, steel Food, beverages, tobacco, packing Textiles Paper, printing Rubber/plastics Automobile 74 (56*) 4 (3*) 1 (1*) 4 (3*) 2 (1*) 2 0 0 2 3 1 1 0 234 (56*) 23 (5*) 8 (2*) 21 (5*) 9 (2*) 13 3 5 6 9 5 2 3 9 (7*) 46 (11*) Chemical 10 (7*) 1 (O*) P - 4.29 x lO-7^ Machinist-metal cutter 7 14 Machine operators 0 8 Forgers, molders, caster* 1 3 Painter* 14 Sanitation, water works, power 3 2 Maintenance, custodians 5 9 Laborers 8 20 Construction 12 Heavy equipment operators 2 6 Repair services 16 Mechanics 26 31 (23*) 79 (19*) p - 0.11* Statistical analysis for case-control study with multiple matches (20). Ill UCC 084219 I sources of data in order to identify cases for studies of rare tumors such as HAS. The Thorotrast data are instructive because the initial estimate of the latency period has lengthened with time; recent cases have been in individuals who had relatively low-dose procedures but pro longed latent periods (J6). This accentuates the need to continue evaluation of VCM exposed groups for the possible appearance of a similar pattern. The time frame covered by our study is perhaps too early to detect a sizable number of cases with relatively low VCM exposure either in occupational or environmental settings. In addition, Thorotrastinduced HAS was noted approximately 10 years before Thorotrast-induced hepatocellular tumors were recognized; given the identical morphologic appearance after VCM exposure, involving mixed hyperplasia of sinusoidal cells and hepatocytes, and the occurrence of hepatocellular tumors in experi mental animals exposed to VCM (26), we need to continue to follow-up VCM-exposed cohorts for the possible appearance of hepatocellular tumors. Cases of HAS associated with various factors have previously been reported (U, 27, 28); individ ual cases associated with hemochromatosis, prior radiotherapy, chloroprene exposure and chemother apy with urethane were also noted in this study, but we have not discussed them in detail here. It would appear valuable to continue epidemiologic studies of this rare tumor. This might enable early detection of additional etiologic factors for this disease, such as the various structural analogs of vinyl chloride (e.g., vinyl bromide and vinylidene chloride) which have had industrial use. However, because of the difficulty and time involved in establishing adequate surveillance for rare tumors such as HAS or mesothelioma, it would be best to establish a single framework for studying a number of rare tumors or marker Alnesses at once. One would then be able, e.g., to survey pathologists or other groups at a single time to obtain information on a variety of such conditions. HAS is a rare tumor with at least four probable causes and undoubtedly others that have not yet been identified. Ascertainment of the range of causative agents for HAS, as well as for more common tumors, presents a challenge to epidemiol ogists. We acknowledge the support of Dark W. Heath, Jr., Matthew Zack, Joyce Cannon, Robert Albin, Alice Little and Carolyn Forrester of the Centers for Disease Control; Paul Leaverton of the National Center for Health Statistics; Irving J. Selikoff of the Mount Sinai School of Medicine; Norman C. Telles of the Bureau of Radiologic Health; and Donald M, Austin of the California Tumor Registry. We particularly appreciate the 112 support of the many physicians, pathologists, and tun.^ ~ trars who provided information and participated in the Rue REFERENCES :i al 1. Creech, J. L., Jr., and Johnson, M. N Angiosarcoma; liver in the manufacture of polyvinyl chloride. J. Otr- 1 Med. 16:160-151 (1974). 2. Falk, H., Creech, J. L., Jr., Heath, C. W,, Jr., Johnior..* i N,, and Key, M. M. Hepatic disease among workers vinyl choloride polymerization plant. J. Am. Med. Asm 230: 5943 (1974). 3. MacMahon, H. E., Murphy, A. S., and Bates. X ] Endothelial-cell sarcoma of liver following Thorotrast m* tions. Am. J. Pathol. 23: S85-561 (1947). 4. Roth F. Arsen Lebertumoren (Hemangioendothelkun, 2 Krebsforsch. 61: 468-603.1957. 5. Waxweiler, R. J., Stringer, W., Wagoner. J. K., Jones.) Falk, H., and Carter, C. Neoplastic risk among work,- 1 exposed to vinyl chloride. Ann. N.Y. Acad. Sd. 271: i (1976). ' 6. Spirtaa, R,, and Kaminski, R. Angiosarcoma of the liver t vinyl chloride/polyvinyl chloride workers--1977 updattc' the NIOSH register. J. Occup. Med. 10: 427-429 (1ST* 7. Da Silva Horta, J., Da Motta, L. C., and Tavares, X K Thorium dioxide effects in man--epidemiological, dim and pathological studies (experience in Portugal). Envinc Res. 8:131-159 (1974). 8. Faber, M. Twenty-eight years of continuous follow-up r : patients injected with thorotrast for cerebral angiopapt;. J Environ. Rea. 18: 37-43 (1979). j 9. Roth, F. Delayed sequelae of chronic arsenism in rintnt* I on the Moselle. Deut. Med. Wochenschr. 82:211-217 (1%; 10. Lander, J. J., Stanley, R. J., Sumner. H. W., Boswell. I j C., and Asch, R. D. Angiosarcoma of the liver issoor.it ` with Fowler's solution (potassium arsence), Gastroenttn, - ogy 68:1582-1586 (1975). 11. Regelson, W., Kim, U., Ospina, J., and Holland, J. F , Hemangioendothelia) sarcoma of liver from chronic arsw* intoxication by Fowler's solution. Cancer 21:514-522 UK; 12. Rennke, H., Prat, G. A., Eteheverry, K. B., Katz. K. V and Donoso, S. Hemangioendothelioma maligno del higadoj j arsenicismo cronico. Rev. Med. Chile 99. 664-698 (197U t 13. Sussman, E. B-, Nydick, I., and Gray. G, F, Hemanp- 1 endothelial sarcoma of the liver and hemochromatosis. Ant > Pathol. 97: 39-42 (1974). 14. Pimentel, J. C,, and Menezet, A. P. Liver disease in vmyri sprayers. Gastroenterology 72: 275-283 (1977). 15. Berk, P. D., Martin, J. F., Young. R- S.. Creech. 1 t Selikoff, I. J., Falk, H,, Watanabe, P.. Popper, H.. ** i Thomas, L. Vinyl-chloride-associated liver disease. Ar.r. i Intern. Med. 84: 717-731 (1976). , 16. Falk, H., Telles, N. C., Ishak, K. G-, Thomas, L. B. rt j Popper, H. Epidemiology of Thorotrast-induced hcpr-s angiosarcoma in the United States. Environ. Res. 18: &~ (1979). 17. Falk, H., Herbert, J. T., Edmonds, L., Heath, C. W..Jr_ Thomas, L. B., and Popper H- Review of 4 cases < childhood hepatic angiosarcoma-elevated environmental r j settle exposure in one case. Cancer 47: 3c2-391 (1961). 18. Falk, H., Caldwell, G. G.. lahak. K. G,, Thomas, L. B. ar: 1 Popper H, Arsenic-related hepatic angiosarcoma. An. 1 Ind. Med. (in press). 19. Falk, H., Thomas, L. B,, Popper, H. Ishak. K. G. Hejaji' ( angiosarcoma associated with androgenic-anabolic steroid.- Lancet 2: 1120-1123 (1979). i Environmental Health Perspectives UCC 084220  irn/u. study. igroeariomi of ide. J. Occup a , Johnson. J| workers at i Med. Assoc Bates, M 1 orotrast inj. dotheliom). Z. *K., Jones. J,, nong workerSd. 271:4tM` of the liver ir. 977 update of 129 (1978). t jrts. M. H 'gical, clinics! .'ll). Environ. follow-up of angiography n in vintners -- (1957.. ell. D. associated astroenterol- lland. J. F. ronic arsenic 4-522 ( 196n. Xatz, R. l\. ' del higado v 98(1971). . Hemanpiatosis. Arch sein unvard Creech. J.. er, H.. and seaae. Ann. . L. B.. and ced hepatic et- 18. 65-73 C. W..Jr.. 4 cases of nmental ar19811. s, L. B. and -na. An. J. G. Hepatic ic ateroids the* j, Rothman. K. J. Computer analysis for case-control studies with individual matching. Int. J. Biomed. Comput. 5: 241-247 il974). *1. Baserga. R., Yokoo, H., and Henegar, G. C. Thorotrast- induced cancer in man. Cancer 13:1021-1031 (1960). 21. 1ARC Monographs on the Evaluation of the Carcinogenic Risk of Chemicals to Humans. Vol. 20: Some Halogenated Hydrocarbons. Trichloroethylene. 1ARC, Lyon, 1979, pp. 515-72. 33 Rappe. C., and Zingmark, P, A. Formation of S'- nitrosamaines in cutting fluids. In: Environmental As pects of X-Nitroso Compounds. E. A. Walker, et al., Eds.. 1ARC Scientific Publication 19, Lyon, 1978. 24 Popper. H., Thomas, L. B,, Telles, N. C,, Falk, H., and Selikoff. I. J. Development of hepatic angiosarcoma in man induced by vinyl chloride, Thorotrast, and arsenic-- comparison with cases of unknown etiology. Am. J. Pathol. 92: 349-376 (1978). 25. Baxter, P. J., Anthony, P. R., MacSween, R. N. M., and Scheuer, P. J. Angiosarcoma of the liver Annual occurrence and aetiology in Great Britain. Brit. J. Ind. Med. 37:213-221 (1980). 26. Maltoni, C. Predictive value of carcinogenesis bioaasavs. Ann. N.Y. Acad. Sci. 271: 431-47 (1976). 27. Locker, G. Y., Doroshow, J. H., Zwelling, L. A., and ' Chabner, B. A. The clinical features of hepatic angiosarcoma: A report of four cases and a review of the English literature. Medicine 58: 48-64 (1979). 28. Daneshmend, T. K., Scott. G. L,, and Bradfield, J. W. B. Angiosarcoma of liver aaaociated with Phenelzine. Brit. Med. J. 10: 1679 (1979). i October 1981 113 UCC 084221 Environmental Health Penpeetives Vol. il, pp. US-116,1981 The British Hepatic Angiosarcoma Register by Peter J. Baxter* A rtfiiter of Britiih ctwi of primary hepatic atifiotarcoma (HAS) u eetahliihcd in 1974 to monitor the occurrence of caaee from 1963 onward*. Detail* of case* dying in 1963-77 hare been obtained. Thirty-five cue* were agreed a* HAS by a panel of liver pathologists, and occupational and medical information was obtained in the majority of these. Two case* were attributable to VCM exposure, and eight other* had received intra-arterial Thorotrast. In 1978-79, two more case* were confirmed in VCM polymerization worker*. Introduction In 1974, the Health and Safety Executive em barked upon a mortality study of all workers in Great Britain who had been exposed to vinyl chloride in the manufacture of vinyl chloride (VCM) or polyvinyl chloride) (PVC), and a register of British rases of primary hepatic angiosarcoma (HAS). The molality study embraced over 7000 people, and an analysis of deaths up to the end of 1974 has been ].< iblished (1). The main finding was four certified cases of liver cancer, two of which were histologically confirmed HAS. An update of this analysi- has been postponed while, with the collab oration of the factories concerned, exposure data are being refined to take into account job changes and exposure to PVC dust. A mortality study of PVC fabricators was considered, but remains in the planning stage. The register is also the basis for a case-control study of occupation for those cases occurring from 1974 onwards (2). To ri-termine the annual occurrence of HAS and to monitor its incidence, cases dying in 1963-73 were reviewed as well as those occurring after this period. Information on cases for the 15 years 1963-77 has now been obtained and will be outlined here. Further details may be found elsewhere (2, i). *He'-,h and Safety Executive, 25 Chapel Street, London, N'Vl oi it. England. Present address: Chronic Diseases Divi sion. S ocial Studies Branch, Center for Disease Control, Atlanta. Ga. 30333. October 1981 Methods Cases were identified by a search of death certificates in seven appropriate categories of the International Classification of Diseases for a diag nosis of HAS (or one of its synonyms). Hospital pathologists and cancer registries were requested to report cases, as were the medical departments of factories manufacturing VCM or PVC. Some cases were identified from publications. When available, histological material was sought for all the reported cases and submitted to a panel of three liver pathologists (Drs. P. P. Anthony, R. N. M. MacSween and P. J. Scheuer), who reviewed the slides independently and without knowledge of the prior diagnoses. For control purposes, histological material from other liver cancers was included. For those cases agreed by the panel as HAS, the full medical records were sought and further informa tion, for example, occupational histories and alcohol consumption, was obtained when possible by inter view with the next of kin. Results and Discussion Eighty-eight cases u'ere reported from all sources. The panel agreed the diagnosis in 32 cases and three more were agreed from among the controls. In half of the confirmed cases the diagnosis had been recorded on the death certificate, but the remainder would have been missed if reliance had been placed upon death certificates as the sole method of ascertainment. At least some clinical and 115 UCC 084222 i necropsy details were obtained in all but two pa tients. Occupational histories were obtained in 91%, the occupation recorded on the death certificate being accepted for the remainder. The annual numbers of both reported cases and those agreed by the panel increased after 1975, so that in 1977, 12 cases were reported, 10 of which were agreed by the panel. Between 1968 and 1977 an average eight cases per annum were reported and three per annum were agreed by the panel, the population of Britain during this period being about 50 million. The observed increase in incidence was almost entirely due to 10 cases of known etiology; eight were patients who had received intra-arterial Thorotrast (a colloidal suspension of thorium diox ide), and two others had been VCM polymerization workers. Plotting on a map the last places of residence of all 35 agreed cases revealed a cluster of six Thorotrast cases in or around Edinburgh, where the use of Thorotrast in neurological diagno sis had been greater than at any other British center. One hundred and nine patients who had received intra-arterial Thorotrast in Edinburgh during 1933-48 have been followed up in detail (5): about three quarters of these patients have died, 13 (17%) from liver tumors. Histological material for review by the panel was available in nine of these. In those cases dying in earlier years, the tumors were predominantly cholangiocarcinomas, but later cases were all HAS, confirming that the recent emergence of Thorotrast-induced HAS in Britain is a real increase in incidence and not an artifact due to under-reporting of cases occurring in the past. Twenty-eight of the 35 cases were males; one female infant died aged 8 months. For idiopathic cases, the male'.female ratio was 4:1. Adult cases were assigned to one of the Registrar General's five social classes according to the occupation on the death certificates^ The social class distribution was unremarkable, except that the only cases in social classes one and two were four men, all of whom were designated as electrical engineers. In fact, six out of the 28 males had worked in the electrical industry at Borne time, a figure in excess of any other industry. Three other men had been em ployed in workplaces where PVC was fabricated, but the occupational histories were inadequate to confirm that these men had worked with PVC. One other male case had lived for six years before his death within a half mile of a plant manufacturing PVC. Occupational exposure to arsenic did not appear to be a factor in any of these cases. Arsenical drugs were commonly prescribed in Brit ain in the past and, in a few areas, even until the 116 early 1960's, However, one case only was suspects to have clinical evidence of chronic arsenical intox- cation, but nail and hair analyses for arsenic **.> negative and the medical records were inadeqtu:. for verifying the use of arsenical drugs. Now a' these cases was recorded to have taken androgen steroids (6), but one woman had taken an estrogc: preparation for several years. Alcohol did &. appear to be an important factor in the majority of cases, only four men having a history of heavy consumption. In its age distribution, clinical presentation arc prognosis, HAS resembled primary liver carcinotsi U). Upper abdominal pain and a hepatic miv were the commonest presentation, and extrahepa:* metastases were found in 23% of cases only. Ex cluding the Thorotrast cases, and for men only, th median interval between the onset of symptom, and death was six months for those aged under !sixty years, and only six weeks for those aged sir.;, and over, a difference which was statistically high!;, significant. Hemochromatosis was not evident ir. any of the cases. In 1978-79, two more cases of HAS have bee: confirmed in polymerization workers, and another case has led to speculation that hydrazine derm tives, such as phenelzine, may induce angiosarcoma in man (7). It is too early to predict the full impar of past industrial exposure to VCM in Britain and at least until the picture becomes clearer the monitoring of HAS should continue. & M D( by REFERENCES 1. Fox, A. J. and Collier, P. F. Mortality experience id workers exposed to vinyl chloride monomer in the nwi facture of polyvinyl chloride in Great Britain. Brit. J. W Med. 34: 1-10 (1977). 2. Baxter, P. J. Epidemiological studies of PVC manufactur ers and fabricators, and primary angiosarcoma of the liver Proc. Roy. Soc. Med. 69: 297-299 (19761. 3. Baxter, P. J., Anthony, P. P., MacSween, R. N. M- sr.i Scheuer, P. J. Angiosarcoma of the liver in Great Britair 1963-73. Brit. Med. J. 2: 919-921 (1977). 4. Baxter, P. J., Anthony, P. P,, MacSween, R. N MScheuer, P. J. Angiosarcoma of the liver: incidence tfi etiology in Great Britain. Brit. J. Ind. Med. 37: 213-22: (1980). 5. Baxter, P. J., Anthony, P. P,, MacSween. R. N. M- am) Scheuer, P. J. Angiosarcoma of the liver: a marker tumor for the late effects of Thorotrast in Great Britain. Brit J Cancer 41: 446-453 (1980). 6. Falk. H., Thomas. L, B., Popper, H. and Ishak. K- < Hepatic angiosarcoma associated with androgenic anabolit steroids. Lancet ii:1120-1123 (1979). 7. Daneshmend, T. K., Scott, G. L., and Bradfield. J w " Angiosarcoma of liver associated with Phenelzine. Bn'- Med. J. 1: 1679 (1979). j ; : | : ; Environmental Health Perspectives Inti In have tial occu lions med. varii o'.he mar *L U-pa and C Louis Octa UCC 084223 as suspecttc inical intoxi *rsenic wen J inadequate gs- None of i androgenic an estrogtr. iol did no: majority of 7 of heavy ntation and " carcinoma Patic mas* ?xtrahepatk s only. Exen only, the ' symptom.aged under . aged sixty cally highly evident in have beer, md another ine deriva- rcoma impact Britain and learer the xperience of in the manuBrit. J. Ind manufactur of the liver, t, N. M. and reat Britain. N. M. and iridenee and 37: 1113-21 .. N. M. and .rker lumour Lain. Brit. J. shah. K G enic anabolic eld. J W. B .lzine. Brit. rspective* Environmental Health Perspectives Vol. il, pp. 117-m, 1981 Effectiveness of Federally Required Medical Laboratory Screening in the Detection of Chemical Liver Injury by Carlo H.Tamburro*and Richard Greenberg* The increasing concern of industrialized societies over the potential health hazard of synthetic chemicals in the occupational environment has led to goverment requirements for medical laboratory- screening of workers. The speciAc tests for such screening programs are most often -elected on the basis of medical experience which utilized them in symptomatic or hospitalized populations. Required screening tests for hepatic injury including cancer in vinyl chloride workers has been systematically and prospectively studied'in an industrial population working w ith synthetic rubber and plastics. Approximately 1300 employees were studied over a five-year period. A cohort of %9 mate employees, for the purposes of analysis, were divided into a "standard" and "nonstandard" population based upon the absence or presence of eignificant medical disease (including liver disease). A subcohort of 120 individuals was further identified based on svailabiliity of liver biopsy. Evaluation of federally required studies included alkaline phosphatase (AP), -y-glutamyl transpeptidase (GGTP), alanine aminotranserase (ALT, SGPT), aspartic aminotransferase (AST, SGOT) and bilirubin (BR). Also studied were indocyanine gTten clearance (ICG) and radioisotopic liver spleen scans (L-S scans). The GGTP provided the highest pusitive predicted value as a screening test for identifying "nonstandard" individuals (individuals ith sll types of medical disease) followed by ICG, AST, ALT, L-S scan, AP, and BR. In the identification of asymptomatic liver disease the GGTP had the least specificity due to a high false positive rate, while the AP provided the highest specificity. The ICG clearance however, provided the best combination of positive predictive value and sum of specificity and sensitivity. The AP provided additional increase in specificity as a followup study. There was no evidence that any of the other federally required tests added any additional benefit and did add significant increase in the false positive rate. These studies support the need for evaluating screening tests as to their sensitivity, specificity and positive predictive value, in asymptomatic individuals, before they are made established requirements. Introduction Industrialized societies throughout the world Have become increasingly concerned over the poten tial health hazard of synthetic chemicals in the occupational environment. Governmental regula tions have increased the number and types of medical laboratory screening required for a large variety of halogenated hydrocarbons as well as ether potential environmental hazards. The pri mary objective of these screening programs is to Liver Re-earch Center, Division of Digestive Diseases, Ivpinmen! of Medicine, and Department of Community Health a-.d Cancer Center, University of Louisville School of Medicine, lAiuville, Kentucky 40201. October 1981 reduce disability, morbidity and mortality in work ers, especially as related to serious low-grade health hazards. In general, screening programs are instituted because of the presence in the work environment of a suspected or proven environmen tal toxin or carcinogen, which has the potential of producing low-grade iiyury over long periods of exposure. Most screening studies are directed toward the detection of abnormalities in certain body systems. The specific tests are frequently selected on the basis of medical experience which utilized them in symptomatic or hospitalized populations. Prior expe riences utilizing nonspecific multiphasic health sur veillance screening and maintenance have not proven to be cost effective except under certain limited 117 UCC 084224 A conditions (1). The cost effectiveness of such tests, however, in the determination of medical screening requirements, has played a limited role due to the potential seriousness of these occupational agents. Little attention has been paid as to whether the effectiveness of federally required screening pro vides the best or, more importantly, a necessary benefit when applied to asymptomatic and other wise healthy worker populations. The discovery in 1974 of hepatic toxicity and cancer formation in vinyl chloride workers provided the opportunity to systematically and prospectively study the effectiveness of federally required and federally recommended medical screening proce dures for the detection of chemical Uver injury, including cancer development (). Table 1 lists the federally required medical screening procedures since 1974 for environments utilizing vinyl chloride or polyvinyl chloride. Table 2 lists the federally recommended studies for these same environments. This paper will present a preliminary assessment of the effectiveness of these federally required studies in the accurate detection and identification of chem ically induced liver injury due to halogenated hydro carbons, especially vinyl chloride. Materials and Methods The industrial population studied consisted of approximately 1200-1400 employees of a chemical plant whose two major products were synthetic rubber and plastics. The industrial plant had been in operation for over 35 years and had a predomi nance of male employees (96%), approximately 80-87% of the work force being white, 11-12% black, less than 1% of other racial origins. Turnover of the plant was approximately 10 to 15% per year with 65-70% of the work force having worked five years or more at the plant. Employee ages ranged from 1&65, with a mean of 52 years. A cohort consisting of 969 male employees who worked continually from June 1, 1976 to May 31, 1977 was, for purposes of this analysis, divided into a "standard" and a "nonstandard" population. These designations were given on the basis of a review of Table 1. Federally required itudiee for vinyl chloride worker*. History and physical < 10 yean as vinyl chloride worker--(annual) > 10 yean as vinyl chloride worker--(semiannual) Biochemical studies SCOT(AST) SGPT(ALT) GGTP AP TB 118 Table 2. Federally recommended (not required) studm. Hepatic studies LDH isoenzyme Total protein Protein electrophoresis HMe Radioisotopic scan Kidney dysfunction (urine examination) Albumin RBC Exfoliative abnormal cells Pulmonary system FVC FEV, Chest x-ray (PA and lateral) all present standard medical data on each emplov ee, including the federally required studies. Other screening studies of the medical surveillance pn, grams were not utilized in the classification of overall medical status because, at that time, thee clinical usefulness was unknown or controversy All studies were performed on an annual basithose individuals with ten years or more of employ ment were examined and screened semiannually Compliance with medical screening studies durin; the five-year study period showed a continuokparticipation in the history and physical examiu tions by over 75% of the work force, laboratory tests and chest x-rays by 86%, and Iiver-splot: scans by 85%. Seventeen percent failed to under? at least one history and physical examination 9% did not have any of the radiological studies and only 4% failed to have laboratory' studioduring this period. Approximately 40-50% of the* individuals who did not undergo an examination claimed to have been examined by their private physician. A subcohort of 120 individuals was further identified based on the availability of a liver biopsy performed for medical reasons, both related and not related u their work. The term "standard" is used for those individual1 who, based upon the best medical opinion, demonstrated no evidence of any significant media disease, occupational or nonoccupational in origin The "nonstandard" population included all othernot included in the standard population. The subcohort population was divided into those individuals with and without histological evidenn of liver injury and further subdivided into tho* with and without histological features characters tic of chemical injury. All employees had individual work histories These consisted of a standardized job ciassificatior for all jobs within the plant since its opening an*11 Environmental Health Persp*rii'K ran peccals wer exp oft: this ran emj cal abs mal: chei dou two knohist- Re A wer< pap< fede dea and Ficvi id I* pr in' hy ea H th Octi UCC 084225 4i, i employ, es. Other ance procation of ne, their oversial. al basis: ' employinn ually. s during ntinuou.i xaminaoo-iton een ^BRirlergo lination, studies, studies of these lination private lentified formed lated to vjduals demonnedical origin. others ) those idence those cteris- tones. cation and a n nnk ordering of exposure for 22 different sus pected or potentially hazardous heptatoxic chemi cals used within the work place (3-5). The agents were rank ordered on the basis of the intensity of exposure for each of the job classifications for each of the years that the plant was in operation. From this detailed work history, a cumulative exposure nn month ration (CERM) was determined for each employee for each of the 22 chemicals. All histologi cal material was classified as to the presence or absence of liver disease, and to whether the abnor malities were consistent with chemical or nonchemical injury. This classification was conducted double blindly by three experienced physicians, two pathologists, and a hepatologist (6), without knowledge of any medical data, exposure or work history. Results Although 50 or more biochemical screening tests were performed during this study period, this paper will limit itself to,the evaluation of the federally required studies, the indocyanine green clearance (ICG) study at the 0.5 mg/kg dose (7, 8) and radioisotopic liver and spleen scan (9). The 100 GGTP IC6 SOOT SGPT LIVER SPLEEN 0.S AST ALT SIZE TESTS Ficm 1. Positive predictive values of screening tests in idemif.:ation of medical disease in an asymptomatic working population (AT 969). All those screening tests with positive predkrive values of greater than 70 are shown except for indirt.t bilirubin (due to high number of congenital indirect hyperbilirubinemia) and triglyceride determination. Above each bar in the graph are shown the sum values for sensit.vity and specificity of each test. They generally follow the sa-ne ranking. October 1981 Figure 2. Frequency with which clinical biochemical tests cor rectly reflex the presence of hepatic damage in chemical workers suspected of having liver disease: (SGPT) alanine aminotransferase (ALT) (GGT) y-glutamy) transpeptidase, (SCOT) aspartic aminotransferase (AST), (Aik. Phos.) alka line phosphatase, (ICD) isodtric dehydrogenase (ICG) Indo cyanine Green clearances at 0.S and 6.0 mg/kg dose. federally required biochemical studies include alka line phosphatase (AP), "y-glutamyl transpeptidase (GGPT), alanine aminotransferase (ALT/SGPT), bilirubin (ALT/SGPT), and the aspartic amino transferase (AST/SGOT). The positive predictive values of these screening tests in identifying medical disease (including liver disease) in this asymptomatic working population are shown in Figure 1. The GGTP provided the highest positive predictive value as a screening test for "nonstandard" individuals. It also provided the highest sensitivity and specificity sum shown in brackets. The predictive value of the other tests, in decreasing positivity were ICG, AST, ALT, liver and spleen scan, AP, and bilirubin. Further evaluations were conducted on the subcohort population in whom we had both histolog ical and biochemical data concerning hepatocellular damage. If one looks at only those individuals who received liver biopsies for suspected liver disease then one would find the percent of positive tests as illustrated in Figure 2. The ALT (SGPT), GGTP, AP and AST (SGOT) demonstrate a very high degree of sensitivity in identifying individuals with hepatic disease. As shown on the right, ICG clearances at the 0.5 mg/kg level provide a similar degree of sensitivity to SGOT and AP. The higher dose ICG clearance (5 mg/kg) appears to provide the most sensitivity for latent hepatic disease. These findings are consistent with the general medical experience with hospitalized patients. Sensitivity alone however is not an adequate indicator of a test's screening value, especially when used in asymptomatic individuals. More appro priate evaluation of these tests' value as screening instruments are shown by their sensitivity, specificity 119 UCC 084226 Cl' CHEMICAL LIVE* WiJUMT ID* LIVE* DlSEASt ,$D-STAN0A*D-HOH 60 o AVElACt WC ECJU|J l aiimgs | Figure 3. Sensitivity and specificity of various biochemical screening tests and their sensitivity and specificity sum values (S & S) based on 78 with biopsy documentation of their hepatic status and all of the biochemical screening studies listed. All screening tests with S & S sums less than 110 (e.g. bilirubin and isocitric dehydrogenase, are not illustrated. CLI GROUP Ratings Figure 4. Correlation between the histologic finding; on b\- i biopsy and each individual's average total vinyl chlcm exposure based on their average CERll (Cumulative En sure Rank Months) ratings. Rankings: 1 lowest powii, ' exposure; 2 - minimal exposure, low levels; 3 - moder. exposure; 4 * worked in areas subject to occasional Lr ; excursions, or frequently high and/or had intimate coma- 1 and sum values shown in Figure 3 in the biopsied subpopulation. Here again, ^-glutamyl transpeptidase and ICG clearance (0.5 mg dose) show the greatest sensitivity for identifying individuals with liver disease. However, GGPT had the least specificity, reflecting its high incidence of false positives. Specificity increased with the use of AST, ALT, and ICG clearance. The alkaline phosphatase pro vided the highest specificity, suggesting that mild or low grade chronic hepatic injury due to environ mental agents may be activating hepatic AP syn thesis in the absence of biliary tract obstruction or cholestasis. The ICG clearances, even at the low dose (0.5 mgiig), clearly remains the test with the best combined sensitive and specific screening study for detection of individuals with subclinical hepatic disease. This subcohort biopsied group was further exam ined on the basis of the histological interpretation of their liver biopsies and their work exposure to vinyl chloride. All biopsied individuals were subdivided into three groups: 19 with histological evidence consistent with chemical liver injury; 30 with histo logical evidence of liver disease, nonchemical liver injury; and 29 with normal liver biopsies. Each of the histological subgroups were further subdivided based on their vinyl chloride exposure, on a scale of 1 to 4 (Fig. 4). The chemical liver injury group contained the highest percentage of individuals with the highest average rating (CERM) for vinyl chloride expo sure. In contrast, with those with liver disease, nonchemical, and those with normal livers have a 120 more even distribution of individuals relative u . their degrees of vinyl chloride exposure. In our previous studies we noted that almost a! individuals with histologically specific lesion of vinyl chloride injury or angiosarcoma had a toul average CERM rating of 3.5 or greater. Tht asterisk in Figure 3 indicates the percentage of , individuals in each of the three histological groupwith exposure ratings of 3.5 or greater. Again, the chemical liver injury group have the highest percentage of individuals with the high exposure ratings. This further supports previous work (i,lo t identifying focal hepatocellular hyperplasia as the earliest histological characteristics ofchemical injury in liver disease. A study of the frequency with which these tests are positive among those individuals with liver ; disease, based on their histological findings (chem- > ical versus nonchemical), provides additional data supporting the clinical observation that an increased AP has a greater specificity for chronic liver injury Figure 5 shows the ratio of the proportion of ; positive screening tests in those with histological chemical liver disease divided by the proportion of positive tests in those whose disease is not of chemical origin. All tests, independent of their sensitivity and specificity for liver injury'. wer* . more frequently abnormal in the presence of nonchemical, subclinical liver injury, except for AP. In contrast, AP was far more frequently abnormal in those individuals with chemical liver ; injury', which tended to be more chronic than acute and generally less severe. Environmental Health Perspectives . * ik q:c T) me spec reqi first of ir. tion use< exp syir din abil fror tonfils GG fica and pro "lc: the em &er as\ ret me Oct UCC 084227 't ll 1 I 53 'g*<m liver iyi chloride ative Expo*t possible 1 modem* sionaJ high `.e contact ative to most all sion of a total T. The ofmgroups tin, the st perposure U, 10) as the iiyuiy e tests t liver chem* 1 data eased njury. ion of ogical ion of iot of their were :e of t for ently liver tcute picrRE 5. Frequency with which biochemical tests were abnor mal in those with different typr'of hepatic injury expresses as a ratio: (CL1) chemical liver injury, (LD) liver disease, nonchemical. Discussion This preliminary systematic review of the posi tive predictive values and the sensitivity and specificity of federally and some non-federafiy required tests for chemical workers provides the first scientific and biological basis for the selection of medical screening tests for liver injury in occupa tional environments. Although these commonly used medical tests have been found by clinical experience to be effective as diagnostic tools in the symptomatically ill or hospitalized population, little clinical work has been done to determine their ability to accurately separate biological variations from early latent or underlying disease in asymp tomatic individuals. Tests which provide very high false-positive rates (decreased specificity) such as GGTP, interfere with the screening process identi fication of the high risk worker by the extra time and cost required for repeat testing, the decreased productivity for the employer, the employees' increased anxiety, and by the loss of confidence in the effectiveness of the testing program by both employees and employer. Determination of the sensitivity and specificity of screening studies for asymptomatic individuals is essential if effective recommendations are to be made a federal require ment. This evaluation process also provided the October 1981 best means of developing effective triage protocols for the screening program. For example, in this particular population of industrial workers, we have shown that the assessment of hepatic function is best accomplished by low dose ICG clearance (0.5 mg/kg). The ICG clearance is somewhat a more complicated technique (i.e., injection of substance and repeated blood sampling) but requires only 10 min to perform, and needs only one needle stick. In exchange it provides the best singular screening test for latent hepatic injury. If adequate medical facilities are not easily accessible, then ALT should be substituted. If either ICG clearance and/or ALT studies are found to be abnormal, an AP should be done and a diagnostic work-up instituted to deter mine the etiology (11). The rationale for these recommendations is based on the actual study of chronic subacute chemical injury in an asymptomatic population, not preselected because of signs or symptoms. Therefore the test's ability to correctly differentiate disease from nondisease or one type of injury from another is more accurately determined. Chemical and envi ronmental agents of low toxicity tend to produce repeated or persistent injury which accumulates over time. Tests which measure overall functional capacity quantitatively or semiquantitatively, rather than measuring acute low-grade injury over time are more likely to detect changes. For this reason, clearance or tolerance studies provide the best means for identifying latent hepatic disease, while enzyme studies like ALT, GGPT, and SGOT usu ally reflect acute cellular injury of higher grade or degree and cannot accurately reflex accumulative damage until very late in the disease process. Tests which provide information concerning the progres sion. or nonprogression of injury will be far more helpful to the practicing occupational physician. They provide him/her with a better capability to discern between nonoccupational and occupational disease, and the best available reassurance for the worker of his or her safety while allowing the greatest possibility for continued productivity and employment. Finally, these data provide a sound scientific basis upon which to modify federal requirements. The removal of specific testing requirements which, with field experience, prove not to have any significant positive predictive value, or effective sensitivity and specificity will aid in reducing overall cost and help maintain continued compliance by industry and workers. There may be theoretical reasons to maintain or continue some of the present federally required screening studies, but these reasons should be separately identified and not be confused with the purposes of the more effective test in the 121 VC084228 detection of occupationally related liver injury. The capabilities and limitations of any new tests or old tests for new screening purposes in detection of other potential occupational hazards, should be validated before making them a required screening procedure. This would lay the foundation for sys tematic determination of effectiveness of screening procedure against a proven standard. Unvalidated federal requirements provide the worker and employer with a false sense of security and safety by what is believed to be effective monitoring. More importantly, such a situation can lead to delay in effective correction of cause and disease preven tion. Conclusions Biochemical screening for hepatic injury in asymp tomatic chemical workers can be done most effec tively by the use of liver specific clearance studies. ICG clearance provides the best combination of positive predictive value and sensitivity and specificity for functional hepatic testing at the present time. None of the presfefit federally required studies provide any significant degree of sensitivity with out marked reduction in specificity in asymptomatic individuals. The ALT (SGOT) is the most useful among those Federal tests presently required and the alkaline phosphatase may provide additional specificity as a follow-up study in those individuals with positive ICG or ALT screening studies. There is no evidence that any of the other federal studies add any benefit and strong evidence that they significantly increase the false-positive results in well individuals. All screening studies should undergo evaluation as to their positive predictive value and sensitivity and specificity in asymptomatic individuals before becoming permanent or established requirements. Portions of this work were supported by National Cm*- Institute Contract No-l-CN-55212 and Manufacturing Chr ' ists Association Grant. The authors wish to acknowledge the help and cooperate Hynson, Westcott Dunning and B. F. Goodrich Cheri Company. REFERENCES t 1. Collen, M. F. Cost effectiveness of multiphasic hay ! testing services. In; Multiphasic Health Testing Sen**. M. F. Collen, Ed., Wiley, New York, 1978, Chapter]: I Section F, pp. 487-630. | 2. Creech, J. L, Makk, L., Whelan. J. G., Jr., and Tambu- j C. H. Hepatotoxicity among polyvinyl chloride produm- ' worker* during first year of surveillance program. Gan- I enterology 67:786 (1974). I 3. Greenberg, R. A., Tamburro, C. H., and KupcheUa. f | Prospective medical surveillance program for detection u: j prevention of industrial related cancer. In; Prevention as: | Detection of Cancer; Part 1, Vol. 2; H. Nieburgs, c ; Marcel Dekker, New York, 1978, pp. 1921-28. 4. Tamburro, C. H., Greenberg, R. A., Newby, L. G , ix Turns, D. M. Implementation and assessment of a dww : stration cancer control detection and prevention prognr.: J a cohort of industrial workers. Program Contract #,V. CN-56212 Final Report, Division of Cancer Control ax Rehabilitation, National Cancer Institute. Bethesda. lUr land, 1978. 5. Greenberg, R. A., and Tamburro, C. H Exposure inthn- for epidemiological surveillance of carcinogenic agents ir. v industrial chemical environment. J. Occup. Med., in pn ` 6. Tamburro, C. H., Makk, L., and Popper. H. Early hept* . histological alterations among chemical (vinyl monomr ' workers. Gastroenterology 77: A33 (November 1979). 7. Fortwengler, P,, and Tamburro, C, H. Use of dye demur- j in the detection of hepatocellular injury among vinyl cb- | ride workers. Clin. Res. 23: 264A (1975). j 8. Tamburro, C. H., Creech, J. L, Davis. A,, and Greenbrrp R. A. Indocyanine green clearance as a prospective indio tor of hepatocellular chemical toxicity. Gastroenterologv 7; { 989 (1978). ( 9. Whelan, J. G.t Jr,, Greenberg, R-, and Tamburro. C. H ; Radioisotopic scans and gray scale ultrasonograph' c detection of liver damage. Gastroenterology 79:1129 (lie- 10. Popper, H. and Thomas, L. B. Alterations of liver : spleen smong workers exposed to vinyl chloride. Ann. N) Acad. Sei. 246:172 (1976). j 11. Tamburro, C- H. Chemical hepatitis, pathogenesis, dt`. , tion and management. Med. Clin. K. Amer. 63: 545 (19*1' P at by P< envi uph< ers, vari< lion unde sterr. term (viny polyt film; ated as a ride. becof mear medi, relatt of th< evalu have of the Ma ride mono ence Fases West 122 Environmental Health Perspective* Octob UCC 084229 T 1 Cincv Thtit ^Pratiw, / *b Chtmici Environmental Health Perepectivee Voi, n, pp. m-m, mi bzzic hil',,, g Senitr. Chipter IT d Tambum,, e productTM TO. Gu;r> Aelli. E. C _ teion tM vention inc burgs. Ed L. G., im! 0t a demor. 1 progTZnt ir. -i* #Xui- rijntrol and "e*da. 3din- sure indioagents in u I., in pm* arlv hepatic pnomcr rarer . Chlir Greenberp. live indicaerologjTo tto. C. H -graphv it. 12Pi19pP' f liver and Ann. N.V tit. deter345 i!9Ti N Poly(vinyl Chloride) Processes and Products by R. N. Wheeler, Jr.* Polyieinyl chloride) retina art produced by four baaic proceaaet: tutpention, emulaion, bulk and aolutfon polymeriaation. PVC tutpeniion retina are uaually relatively duit*free and granular with varying degrees of particle poroaity. PVC emultlon mint art small particle powdera containing very little free monomer. Bulk PVC retina are similar to tutpention PVC retint, though the particles tend to be more porous. Solution PVC resins are smaller in particle tiae than tutpention PVC with high porosity particles containing essentially no free monomer. The variety of PVC resin products does not lend Itself to broad generalizations concerning health hazards. In studying occupational hazards the particular PVC process and the product must be considered and identified in the study. i: Polyfviny] chloride) is a ubiquitous part of our environment today, in that it appears in clothing, upholstery, flooring, wire insulation, food contain ers. phonograph records and an almost infinite variety of other items. Despite this wide applica tion and the size of the industry there is little public understan ding of the term. A part of this confusion stems from the human inclination to abbreviate terms--thus, we say PVC when discussing polyivinyl chloride) resins, poly(vinyl chloride) latexes, polv(vinyl chloride) compounds, poly(vinyl chloride) him and so forth. This confusion has been accentu ated by governmental regulators, who define PVC is a polymer containing any amount of vinyl chlo ride. On taking these two factors into account it has become almost impossible to distinguish what is meant when the term PVC is used in the various media. In order to study possible PVC industryrelated health problems one must know something of the various processes and products to properly evaluate >tudy results. Many study results can have sign: Seance only if the source and composition of the PVC is stated. Manufacture of synthetic resins from vinyl chlo ride and other monomers involves reacting these monomers in agitated pressure vessels in the pres ence ofcatalysts and converting these liquids and/or gases to solid resins. A considerable amount of heat *Union Carbide Corporation, P. O. Box 8361, South Chxrlezton, " Virginia 25303. is generated by the reaction. This is removed by cooling the vessel. As the monomer is converted to polymer during the reaction, the rate of reaction slows down; thus, after some optimum reaction time, the unconverted remaining monomer is re moved from the reacting mass by heat and vacuum and the resin (PVC) is recovered as a dried white powder or as a liquid latex or solution. This polymerization reaction may take place in pure monomer, in a solution, in a water-monomer emul sion or in a water suspension of monomer. The nature of the polymerization process determines the nature of the subsequent recovery process, and the nature of the resin particles produced. Current ly there are four basic vinyl chloride polymerization techniques which give use to the following four processes: (1) suspension polymerization, (2) emul sion polymerization, (3) bulk polymerization, and (4) solution polymerization. Suspension polymerization is the major process used for the manufacture of PVC resins and is used for about 82-85% of U.S. production (Fig. 1). It involves the charging of one or two parts water and one part vinyl chloride monomer or comonomer mixture to an agitated reactor along with initiator and suspending agents such as poly(vinyl alcohol). The mass is reacted at 50-65'C until about 85-90% of the contained monomer is converted to resin. The resin-water mixture is heated, sometimes under vacuum, until the unconverted monomer is substantially removed. The resin is then removed October 1981 123 UCC 084230 from the water and dried in rotary, flash or fluid bed dryers by exposure to heated air. The dried resin is transferred to storage silos, whence it is shipped to fabricating plants in bulk containers or in paper bags. If only vinyl chloride monomer is reacted, the product is PVC homopolymer. If a monomer such as vinyl acetate is mixed with the vinyl chloride then a PVC copolymer is produced. The advantages of the suspension resin process are.its high productivity per unit reactor volume, its flexibility with regard to polymer composition and resin particle characteristics and the granular nature of its product. The relatively large resin particles (50 to ISO pm) cause problems in removing unconverted vinyl chloride monomer. The mono mer tends to diffuse slowly from the center of the resin particle to the surface, where it is removed by the monomer recovery operation; thus removal often is incomplete. In the past, residual vinyl chloride monomer concentrations in suspension PVC resins ranged as high as 2000 ppm by weight until improved methods were developed in response to recognized need for lower residual levels. The process produces a wide variety of products, each of which presents different monomer release characteristics as well as differing suitability for particular fabricating operations. As a general rule, small particle size resins have lower residual mo nomer than large particle size; porous particle resins have lower residual monomer than nonporous particle resins; and resins containing little or no comonomer have lower residual monomer than resins with significant amounts of comonomer. The l relatively large suspension resin particle, whik retaining monomer from the manufacturing pn, , cess, results in a product that has excellent han- ; dling properties such as bulk flow. Recta: : improvements in monomer stripping technology : have resulted in most PVC suspension homopolvn#- resins containing about 10 ppm residual vinyl chloride monomer at the time of shipment while the residual vinyl chloride monomer in most copolv. ; mers ranges from 25 to 200 ppm at the time of i shipment. { The stress on residual monomer content at the . time of shipment in the preceding paragraph if : purposeful. Vinyl chloride monomer is not soluble > in the PVC nor is it absorbed or adsorbed in the : resin particle. It is entrapped, and, given an opportunity, it escapes to the ambient air. Heating tends to accelerate this escape. PVC resin in i 1 bulk-container loses its residual monomer at a nu of 25 to 50% per month. PVC resin in a paper bag loses its residual vinyl chloride monomer at an ' approximate rate of 75% per week. Once the j residual monomer is gone, there is no source f [ monomer from the PVC resin, i.e., the resin dot? i not decompose to yield significant amounts of monomer. If heated, the resin gives off hvdrogtn chloride and turns black. Thus a year-old PVC resin contains almost no residual monomer; on heating until it blackens it will always give off hydrogen chloride. PVC resin fabricating operations drive off the free residual monomer in the first heating step: thus the probability of a toxic response from vinyl chloride monomer contained in the vinyl film or mol> A syst bqu poly so f< soli< mg pen this shut exp< ride with that Cre< foul) was: nate E lv u and of th sion but spec tern the fun: syst Ir part surf syst MATER Figure 1. Suspension polymerization process. 124 Environmental Health Perspective* Octi UCC 084231 T moldings produced is remote. AD pVC processes have a problem with reactor pvjtem fouling to some degree. The conversion of a bquid monomer to a high molecular weight solid polymer while contacting reactor walls, baffles and to forth results in the deposition of some of that tolid polymer on surfaces. This deposition or foul ing interferes with the reactor operation so that periodically it has to be removed. In earlier times, this was removed manually by a man working in a shutdown reactor. These reactor cleaners were exposed to very high concentrations of vinyl chlo ride monomer (several thousand ppm). It was within the group of men in this cleaning operation that the excess of angiosarcoma was observed by Creech (1). More recently, techniques to minimize fouling and techniques for cleaning such as solvent washing and hydroblasting have reduced or elimi nated the need for reactor entry and cleaning. Emulsion ixdymerization is the second most wide ly used process for the manufacture of PVC resins and comprises 10-12% of total U-S. production. One of the important things to understand about emul sion polymerization is that it is not a single process but a large family of processes, each producing specialized products that are defined or specified in terms of performance in a particular application. In the interest of brevity, the two major process families will be discussed: the water-soluble initiator system and the oil-soluble initiator system (Fig. 2). In the water-soluble initiator system, one to two parts water, one part monomer, 0.01 to 0.03 parts surfactant and water-soluble initiator (a redox system or a persulfate salt) are charged or fed to an agitated reactor and reacted at 30~60C to form a synthetic latex. The reactor agitation must be sufficiently vigorous to emulsify the monomerwater mixture but not so vigorous that the latex is coagulated. When 80-95% of the monomer is con verted to polymer, the latex may be gently stripped of the unconverted monomer with heat and vacu um, or it may be subjected to a second initiator treatment and reacted to essentially 100% mono mer conversion. The product of this polymerization may be simply filtered and shipped to consumers as a latex for coatings, mastics, and the like, or the polymer may be recovered as a dry resin. Recovery techniques vary. The most commonly used is sim ply spray-drying of the latex, though some resins are recovered by coagulating the latex and dewa tering with subsequent drying of the coagulum (resin). In the oil-soluble initiator system, one part monomer containing an organic peroxide is emulsified in one to two parts water containing 0.01 to 0.03 parts surfactant. The resulting emulsion is reacted at 30-60C to form a synthetic latex. Approximate ly 80-90% of the monomer is converted to polymer. After reaction, the latex is gently heated and vacuum-treated to remove the unconverted mono mer. After stripping, the latex may be shipped as a product though most of it is converted to a dry powder by spray-drying. The basic difference be tween the oil-soluble initiator process and the water-soluble initiator is that the size ofthe emulsified monomer particle determines the resin particle size in the oil-soluble initiator process, while polymer ization technique determines the resin particle size October 1981 PVC LATEX Ficuxc 2. Emulsion polymerization proceaa. 125 UCC 084232 1 in the water initiator process. The resin particles formed during emulsion polymerization range in size from 0.05 to 2 tun. In the course of recovery and drying these may be agglomerated to particles as large as 30 tun. For some uses the agglomerates may be ground to a median particle size of about 2 tun. The small particle size results in rapid loss of residual vinyl chloride so that the resin contains about 1 ppm free monomer as produced. Because of handling problems, nearly all the resin is bagged, letting the small amount of monomer retained escape easily before it arrives at a fabricating plant. Nearly all dried emulsion process PVC resin is utilized by paste or dispersion fabrication tech niques. The resin, pigments and other additives are stirred into plasticizer, yielding a thick viscous liquid plastisol. This plastisol is spread on a cloth or a paper or poured into molds. The coated mold or cloth is heated, causing the resin and plasticizer to fuse into a solid forming the finished plastic article. In this fashion, the small manufacturer or the producer of elaborate shapes or highly styled items can make a product,with a minimum capital invest ment. The emulsion polymerization process, in addition to the reactor fouling problem noted for suspension polymerization, has less flexibility with regard to changes in process conditions. Each change in reaction, stripping or drying has an identifiable effect on product properties and quality. Some of these properties are well known, and quality tests keep them under control. Others are not well known and are recognized when customers com plain. Emulsion process resins cost more to pro. j duce, and plant operators tend to be very consemtivt ( in the approach to process changes. Because of ths I difficulty, emulsion process plants tend to emr. i more vinyl chloride monomer to tne ambient air per pound of resin produced, lfl Elfrbpe particufifh > tnere nave been reports of worker dermatitis from surfactants and possible pneumoconiosis from rear , dust inhalation in the emulsion process plants (2-ji. j Bulk polymerization is the third major process it } terms of volume for the manufacture of PVC resins I but supplies only about 5% of U.S. production (Fig i 3). The process involves the charging of vinyl * chloride monomer and initiator to a first-stag* t polymerizer, where about 10% of the monomer is l converted to polymer. This batch is then transfer- ` red to a second-stage polymerizer where additions! * monomer, and sometimes initiator, are added. IV ' polymerization is continued until about 80-859 of ' the container monomer is converted to polymer. ; The unreacted vinyl chloride is removed by beat : and vacuum and the finished resin product traw- ferred to storage bins for later shipment to fabriat- } ing plants. The absence ofwater in the polymerization : stage eliminates the need for the drying step and j provides some economy in capital and operating ! costs. The advantages of the bulk process are its , simplicity, the uniformity of the resin particle size, the high porosity of the resin panicles and tV j purity of the polymer (no soaps or suspending aids*. ; The disadvantages are: less flexibility in produ ! mix (homopolymers only) than the suspension pro- te* bul livt T 150 of r of) for gli: res. this pro iha c l*n 29 chl< tor po! ths Th vir rec anc po: SUr M-rr Ms fin SVC RESIN Figure S. Bulk polymerization process. 126 Environmental Health Perspective O UCC 084233 -- IV aer*ni\f Of thl- to emi: ttairptr ticulari. itis frop om resir. 'ts U-;,. Pocess ii *C resinion (Fig of rim, rst-stap. nomer i# ransferdditioni ded.Tht t-So^ of x>lymer. by hea: n traits.abricaterization step and perating its ^ the :tg aids), product -ion pro- x# and poorer removal of residual VCM. These idk process resins are generally directly competi- jve with suspension process PVC homopolymers. " -pie relatively large porous resin particles (50 to 130 pm) tend not to retain monomer, thus removal /residual VCM is theoretically easy. The transfer / heat from the reactor wall to the resin particle for stripping is poor thus offsetting the advantages rained by the high particle porosity in removing residual VCM. In the early 1970s, residual VCM in `j-df type of resin was of the order of 1000 ppm when induced, but more recently these resins have less than 50 ppm in residual VCM when produced. Solution polymerization is a process unique to I'ruon Carbide Corporation and accounts for about of the total resin produced (Fig. 4). Vinyl chloride monomer, comonomer, solvent and initia tor are fed to a continuous reactor system. The polymer formed is soluble in the reacting mass so that the reactor product is a viscous resin solution. This solution is distilled to remove the unconverted vinyl chloride monomer, and the resin product is recovered by treating the resin solution with water and drying the product. The resin particle is very porous, is always a copolymer.Ts free of soaps and spending agents, has a median particle size of 75 nm and contains less than 0.2 ppm residual VCM. Manufacturing investment is high, and the product hnds its greatest use as a coating material, i.e., paints and lacquers, that utilize its good dissolving qualities. It is used in relatively small quantities, and is nearly always shipped in bags rather than bulk. In addition to the basic PVC resins described earlier, there is a wide variety of resin powders, pellets, liquids and latexes in commerce that fall under the general designation of PVC. These are chemically or mechanically converted PVC resins such as post-chlorinated resins and compounded resins containing plasticizers, stabilizers and the like. As a general rule, the additional processing has removed essentially all ofthe residual VCM and agglomerated the dusts. Converted PVC resins have no involvement with problems related to vinyl chloride monomer exposure. Conclusions Poly(vinyl chloride) resins are produced by four basic techniques: suspension, emulsion, bulk and solution polymerization. The variety of PVC resin products does not lend itself to broad generalizations concerning hazards to worker health. In evaluating occupational hazards, the PVC process, the PVC product and other materials present must be considered before valid conclusions can be reached. WATER VENT ve* October 1981 WASTE WATER Figure 4. Solvent vinyl refin proceee. 127 UCC 084234 REFERENCES 1. Creech, J. L. and Makk, L. Liver diiaaM among polyvinyl chloride production worker*. Ann. N.Y. Acad. Sci. 246: 80-87 (1975). 2. Sudu, I., Prodan. L., Ilea, Elena, Pauduram, A., and Paacu, Livia. Clinical manifestation* in vinyl chloride poi soning. Ann. N.Y. Acad. Sri. 246: 53-69 (1975). 3. Popow, J. Effect of polyvinyl chloride dust on the --__ ry system of the rat. Roczniki Akad. Med. im J uZ' lewsldego w Bialymstokur (Suppl. 24) 48: 5 (1969). 4. Vertidn, Yu. I., and Mamontov, Yu. R. The state at it bronchi and lungs in workers employed in the manidir * of polyvinyl chloride articles. Gig. Tmds Prof. ZaboL u 29-32 (1970). " (> 128 Environmental Health Perspecthct UCC 084235 4 - HD J. il&69), *Ut* </.. rnanu!^. Prof. Tik.jj 7 Environmental Health Perspectives Vol. 11, pp. 129-136,1981 Worker Exposure to Vinyl Chloride and Poly(vinyl Chloride) by James H. Jones* Th National Institute for Occupational Safety and Health (NIOSH) in early 1974 betan industrial hygiene studies of vinyl chloride exposed workers. Three VC monomer plants, three VI polymerisation plants, and seven PVC fabrication plants werj surveyed. VC polymerization plant workers and workers in one job category in VC monomer plants were exposed to average lew N above 1 ppm. The highest average exposure was 22 ppm. NIOSH health hazard evaluation studies since these initial surveys have primarily shown nondetectable levels of vinyl chloride. A MtiSH control technology study in 1977 showed that exposure levels in VC polymerization plants had been drastically reduced but exposure levels above 1 ppm were still found in several cases. Introduction Industry-Wide Study Tr.v National Institute for Occupational Safety l* i Health (NIOSH) began studies of vinyl chloride Yt early in 1074 following a report of increased . K nee of angiosarcoma of the liver among VC ,\:..-ed workers. A part of this work included v.r^pective cohort mortality and industrial hyr.,r.e studies of the VC polymerization industry, t.' . NIOSH contracted with Bendix Corporation, Ijjnch Support Division, to conduct industrial r..t-.ene studies in the VC monomer production .; i-strv and the polyvinyl chloride (PVC) fabrica- r industry. These industrial hygiene studies *t-re done to document the levels of VC exposure warring in industry at that time. Three VC r. rmmer plants, three VC polymerization plants ar i seven PVC fabrication plants were studied. In addition to the VC industry-wide study, NIOSH, :r.rough their health hazard evaluation (HHE) :r gram has sampled for PVC at 34 other plants, }r.marily VC fabrication operations. Also a study '"document control methods utilized in the plastics jviustry was performed under contract by Enviro t'- ntrol. This study included work at five VC p'lymerization plants (1S6). *Pi\iion of Surveillance, Hazard Evaluations and Field vj.ies. Xatior.i! Institute for Occupational Safety and Health, tr s Columbia Parkway, Cincinnati, Ohio 46226. VC Monomer Plants One of the VC monomer plants sampled used the acetylene-hydrogen chloride process, the older pro cess for making VC, and the other two used the ethylene dichloride pyrolysis process. It was not possible to assess the difference in worker exposure between the two processes because the plant using the acetylene-hydrogen chloride process was oper ating at only 10% capacity during the surveys in December 1974. As can be seen in Figure 1, only the job of loader shows exposure substantially above 1 ppm. VC exposure for this job was being reduced, at the time of the surveys, by the redesign of tank car hookup systems and the use of air-supplied breathing apparatus while the tanks cars were connected or disconnected. VC Polymerization Plants Three VC polymerization plants were sampled. Located at these plants were three suspension resin operations, three dispersion resin operations, one mass resin operation and one solvent resin operation. As can be seen in Figure 2, suspension and dispersion resin operations had the highest exposure levels. Within plants the reactor area operators and helpers had the highest exposures. lives October 1981 129 XJCC 084236 i Figure 1. Means and ranges of VC exposures in VC monomer production plants. I inf ! US V r Concent ra t Lon Figure 2. Means and ranges of VC exposures in VC polymerization plants. ! 130 Environmental Health Perspectives , UCC 084237 * pvc Fabrication Plants In the seven PVC fabrication plants samples were collected in calendering, compounding, extru sion. molding, and plastisol operations. All expo sures were quite low with calender operators having the only exposures above 1 ppm. Figure 3 shows the relationship of VC exposure between the segments of the PVC industry. As would be ex pected, VC polymerization had the highest expo sures and PVC fabrication the lowest. Changes in Exposure Since 1974 We have no information generated by NIOSH and know' of none in the literature on how VC monomer plant exposures have changed since 1974, although it would be expected that the single "high" exposure category, loader, has had exposure reduc tions. Information on how well VC polymerization plants were able to reduce exposures since 1974 was obtained during the control tpehnology study. This information is in the form of company personnel sampling data for VC over a period of time. At the first plant, a mass polymerization plant, the per centage of personnel samples below 1 ppm has gone from 2dt in 1974 to 73% in 1976 (Fig. 4). At the second plant, a suspension and dispersion polymer ization plant, the percentage of personnel samples below 1 ppm has gone from 0% in 1974 to 65% in 1977 (Fig. 5). At the third plant, a mass polymer ization plant, VC exposures are given by job for the period October 1974 to May 1975 and then for January 1977. In Figure 6, it can be seen that exposures dropped substantially, in most cases by a factor of almost 10. VC exposures at the fourth plant, a suspension polymerization plant, are given for both 1975 and 1976. As seen in Figure 7, in most cases a two-fold drop in exposure levels occurred. Although the percentage drop is lower than the third plant, the final exposures are about the same. At the fifth plant, a dispersion polymerization plant (Fig. 8), VC exposures are given by job for the period May 1975 to December 1975 and then for January 1976 to September 1976. Again reductions were sufficient to bring exposure averages to the same approximate level (less than 1 ppm) as the preceding two plants. PVC fabrication plants had exposures predomi nantly below' 1 ppm in early 1975 when the industry wide study was done. In addition to this work,' HHE's have been conducted at 26 PVC fabrication plants beginning May 1974 and ending in April 1978. Detectable levels of VC were found in only 10 plants with only 1 plant of the 15 sampled since April, 1975 having detectable levels. At that plant sampled in March, 1976, the highest level found was 0.38 ppm. PVC dust exposures were also briefly examined October 1981 Figure 3. Mein* tnd range* of VC exposure* in VC related industries. UCC 084238 131 (0 Figure 4. Distribution of VC exposures st s mass polymerization plant. Figure S. Distribution of VC exposures at a suspension and dispersion polymerization plant. Environmental Health Perspecth** UCC 084239 Per Cent 10/74-5/75 1/77 Supervisor S Foreran Control Hoo*i Operator sa Fiel^ `ten Mis ESI Crew *sst Crew taitoclave Moorran Leader Leader Cleaner *- Figure 6. Change in VC exposures at a mass polymerization plant. Maintenance Man (*ctober 1981 Figure 7. Change in VC exposures at a suspension polymerization plant. UCC 084240 10 n S/7S - j;/-$ 1 /7ft . Off, ee h Ir 6 y I Fortran Ottetor OChpttrrpnitnocr Fuctor Operator Dunping Figure 8. Change in VC exposures at a dispersion polymerization plant. h * sc toiler Plaae* r.AtA*r Figure 9. PVC dust exposures at VC polymerization plants. 134 Environmental Health Perspective UCC 084241 \ > i i irspectivrf (hiring the industry-wide study. Total dust concen trations were determined. Because it was felt that pVC would be the primary constituent of the dust, no analysis for PVC was performed. Respirable iimples were not collected because it was felt that the static charge on PVC particles would cause malfunctioning of the normally used sampling equip ment, such as nylon cyclones. A few samples were examined by optical microscopy. In these samples ill particles had diameters less than 7 jim, and 90% ofthe particles had diameters less than 2.5 tun. The samples examined were from dispersion resin oper ations. This result was expected, since dispersion resins generally are in the range of 2-10 tun in diameter. Suspension resins, the major resins in terms of production, are generally much larger, about 100 nm in diameter. The sampling results displayed in Figure 9 show that dispersion resin bagging had by !nr the highest exposure, averaging 8.6 mg/m3. We have no information on whether PVC dust expo sures have been reduced since 1974. It appears, based on the information that we currently have that the PVC fabrication industry ha# achieved good control of VC exposures. The VC ;.Jymeriza;ion industry was making big strides in cuntrolling exposures, but we have no information tu tell if they have continued to lower exposures >mce 1977. We have no information on exposure reductions in the VC monomer production indus try. but it appeared that only one job category was significantly above the standard in 1974. REFERENCES 1 Burrough-. G. E. Health Hazard Evaluation Determination Report No. 77-13-414, Tee Printing, Lancaster, Pennsylva nia. DHF.W, PHS, CDC, NIOSH. 1979. 2 Butler. G. J. Health Hazard Evaluation Determination Report No. 74-149-189, Protecto Wrap Company; Denver, Colored,, DHEW, PHS, CDC, NIOSH. 1975. 3 Butler. G J. Health Hazard Evaluation Determination Report No. 74-151-181, Western Forge Corporation, Colo rado Spr.iigs, Colorado. DHEW, PHS, CDC, NIOSH, 1975. i Butler, G. J,, and Bodner, A, H. Health Hazard Evaluation Determiiation Report No. 74-29-161, Ethyl Visqueen Divi rion of Ethyl Corp,, Terre Haute, Indiana, DHEW, PHS, CDC. NIOSH, 1974. i Chrostek. W. J., and Thobum, T. W. Health Hazard Evaluation Determination Report No. 74-107-279, General Electni Company, Silicone Products Department, Water ford, NV.v York. DHEW, PHS, CDC. NIOSH, 1976. < Enviro Control, Inc. Engineering control technology astessmert for the plastics and resins industry. DHEW, PHS, . CDC. NIOSH, 1978. > Pleach. J. P,, and Rostand, R. A. Health Hazard Evaluation Determination Report No. 74-94-253, Armstrong Cork Com pany. Jackson, Mississippi, DHEW, PHS, CDC, NIOSH, 1975. Gcium. J, 0. Health Hazard Evaluation Determination October 1981 Report No. 75-90-236, Russell Corporation, Alexander City, Alabama, DHEW, PHS, CDC, NIOSH, 1975. 9. Geissert, J. 0., and Herbert, J. Health Hazard Evaluation Determination Report No. 76-28-332, Welch Plastics and Manufacturing Company, Columbus, Ohio. DHEW, PHS, CDC, NIOSH, 1976. 10. Geissert, J. 0., and Herbert, J. Health Hazard Evaluation Determination Report No. 76-29-322, Columbus Products Corporation, Columbus, Ohio. DHEW, PHS, CDC, NIOSH, 1976. 11. Gilles, D. Health Hazard Evaluation Determination Report No. 74-134-193, PHC Industries, Inc., Camden, New Jersey 08103. DHEW, PHS, CDC, NIOSH, 1975, 12. Gilles, D., and Lybarger, J. Health Hazard Evaluation Determination Report No. T7-111-501, Allied Chemical Corporation, Danville, Illinois. DHEW, PHS, CDC, NIOSH, 1978. 13. Gunter, B. J., Butler, G. J., and Lucas, J. B. Health Hazard Evaluation Determination Report No. 74-125-215, Monoghan Company, Denver, Colorado. DHEW, PHS, CDC, NIOSH, 1975. 14. Gunter, B. J., and Hatch, L. Heath Hazard Evaluation Determination Report No. 75-135-328. A A S Tribal Indus tries, Poplar, Montana. DHEW, PHS, CDC, NIOSH, 1976. 15. Gunter, B. J., and Lucas, J. B. Health Hazard Evaluation Determination Report No. 74-61-232, Gates Rubber Com pany, Denver, Colorado. DHEW, PHS, CDC, NIOSH, 1975. 16. Gunter, B. J., and Nelson, B. Health Hazard Evaluation Determination Report No. 77-4-402, A A S Tribal Indus tries, Poplar, Montana. DHEW, PHS. CDC, NIOSH, 1977. 17. Hervin, R. L. Health Hazard Evaluation Determination Report No. 75-81-252, Artex Manufacturing Company, Inc., Overland Park, Kansas. DHEW, PHS, CDC, NIOSH, 1975. 18. Jones, J. H. Worker exposure to vinyl chloride during production end fabrication of vinyl chloride and polyvinyl chloride. DHEW, PHS, CDC, NIOSH, 1980. 19. Kominsky, J. R., and Wiaaeman, C. L. Health Hazard Evaluation Determination Report No. 77-35-423, Ford Motor Company, Vinyl Operations Plant, Mt. Clemens, Michigan. DHEW, PHS, CDC, NIOSH. 1977. 20. Okawa, M. T. Health Hazard Evaluation Determination Report No. 74-71-142, Delco Remy Division, Anaheim, California 92801. DHEW, PHS, CDC, NIOSH, 1974. 21. Okawa, M. T. Health Hazard Evaluation Determination Report No. 74-96-173, Richdel Corporation, Carson City, Nevada. DHEW. PHS, CDC, NIOSH, 1975. 22. Okawa, M. T. Health Hazard Evaluation Determination Report No. 75-20-209, Richdel Corporation. Carson City, Nevada. DHEW, PHS, CDC, NIOSH, 1975. 23. Okawa, M. T. Health Hazard Evaluation Determination Report No. 75-1-194, Storm Products Company, Palo Alto, California. DHEW, PHS, CDC, NIOSH, 1975. 24. Okawa, M. T. Health Hazard Evaluation Determination Report No. 75-120-220, Storm Products Company, Palo Alto, California. DHEW, PHS, CDC. NIOSH, 1975. 25. Price, J. H. Hazard Evaluation and Technical Assistance Report No. TA 74-45, Appalachian Laboratory and Occupa tional Safety and Health, Morgantown, West Virginia. DHEW, PHS. CDC, NIOSH, 1977. 26. Price, j. H. Health Hazard Evaluation Determination Report No. 77-92-541, Packard Electric, Division of General Motors Corporation, Warren, Ohio. DHEW, PHS, CDC, NIOSH, 1978. 27. Roper, C. P., Jr. Health Hazard Evaluation Determination Report No. 74-120-260, Goodyear Tire and Rubber Compa ny, Gadsden, Alabama. DHEW, PHS, CDC, NIOSH. 1976. 28. Roper, C. P., Jr., and Cromer, J. W,, Jr. Health Hazard 135 * UCC 084242 1 Evaluation Determination Report No. 74-118-218. General Tire and Rubber Company, Marion, Indiana. DHEW, PHS, CDC, NIOSH, 1975. 29. Ruhe, R. L. Health Hazard Evaluation Determination Report No. 75-94-219, Proto Production Plastics, Inc., Boulder, Colorado. DHEW, PHS, CDC, NIOSH, 1975. 90. Ruhe, R. L. Health Hazard Evaluation Determination Report No. 78-70-528, Hospal Medical Corporation, Little ton, Colorado. DHEW, PHS, CDC, NIOSH, 1978. 31. Ruhe, R. L., and Andersen, L. Health Hazard Evaluation Determination Report No. 76-17-395, The Hayes & Albion Company, Spencerville, Ohio. DHEW, PHS, CDC, NIOSH, 1977. 32. Salisbury, S. A. Health Hazard Evaluation Determination Report No. 76-66-348, Sheller-Globe Corporation, Hardy Division, Union City, Indiana. DHEW, PHS, CDC, Nioa 1976. ~~ 83. Straub, W. E. Health Hazard Evaluation Deteraanv Report No. 74-86-185. M. H. Gall Company, Pennsylvania. DHEW, PHS, CDC, NIOSH, 1975. 34. Straub, W. E. Health Hazard Evaluation Deteraiu'jx Report No. 74-89-189, New York Telephone & TekpvCompany, 42nd Street and 7th Avenue. New York. v- York. DHEW, PHS, CDC, NIOSH, 1975. 35. Thobum, T. W. Health Hazard Evaluation Deteraiwr Report No. 73-123-298, Campbell Plastics, Inc., Schaucu dy. New York. DHEW, PHS. CDC, NIOSH, 1376. 36. Vandervart, R. Health Hazard Evaluation DeteminKkr Report No. 74-59-217, Goodyear Tire and Rubber CommiSt. Marys, Ohio 45885. DHEW, PHS, CDC, NIOSH, lri ! V E b' < = 136 In sel P\ pa cai wi CO! it sti ini in* ac be n Gi di. th cu M of *>( IT bi Environmental Health Perspective u W UCC 084243 ;HS, CDC, Kite;. `tion Determira'j TMPny. 1SH. 1975. tion Determine, ^one i TeW. Vork, X,, `.ion Detennini>, *'J"c ' Sch*i)*4 OSH, 1976. ionDeiermuu^,. Rubber Comp*; . OC, NIOSH, J9T, Environmental Health Perspectivet Vol. Ml, pp. 137-113, mi Mortality Among PVC-Fabricating Employees by Leonard Chiazze, Jr.,* and Lorraine D. Ference* The reiulto of cross-sectional mortality atudy of 3817 death* occurring among cumnt and former (white) employee* of 17 PVC fabricator* during 1964-1973 are pre*ented. Sex-race-cautespecific proportionate mortality ratio* (PMR't) were computed by u*ing two teparate itandard*: one, the U.S. mortality in 1968; the tecond, U.S. mortality for the individual year* 1964-1973. In addition, a case-control analyiii, based upon 44 breast cancer death* among white female employees, i* presented. PMR's are significantly different from unity for all cancers, and for cancers of the digestive system among both white males and white females. Although observed deaths significahtly exceeded expectations for cancer of the breast, a subsequent case-control analysis reveals no statistically significant relative risks for breast cancer. Ppectives Introduction In March, 1974, Organization Resources Coun-tl'ir.* (ORCi was requested by representatives of i'VC produc ers who are members of ORC's Occuu'.iona! Safety and Health Standards Group, to .arn' out a study of health risks to employees * rking in the PVC fabricating industry. After considering a number of alternative study designs, r. was decided that a cross-sectional mortality :udy would best meet the need for providing ^formation as rapidly as possible. Details regard ing reason- for selecting this type of study, the actual study design and results of the inquiry have N-en reported previously (J). In the original report, proportionate mortality ratios were calculated according to the method of Guralnick u') and by using the sex-cause-age specific distribution of deaths among U.S. whites in 1968 as the basis for determining expectation (5). For the current report, we have analyzed the data using the Mantel-Haenszel procedure both for determination of PMR's and in order to test whether PMR's differ significantly from unity U, 5). In addition, PMR's are presented using two separate standards as the basis for expectation. Division nflliosUtistiesind Epidemiology, Georgetown Uni'*rsity School of Medicine, 3750 Reservoir Road, N. W., 'ashington, D.C. 20007. A follow-up to the cross-sectional mortality in vestigation, utilizing deaths among white women for whom the underlying cause of death was cancer of the breast, was undertaken (6), and results of the case-control analysis will be presented. Materials and Methods Although alternative study designs were consid ered, several factors led to the decision to carry out a cross-sectional mortality study. First, the pri mary study objective was to determine relatively quickly whether any angiosarcoma deaths could be identified among the study group and this was best accomplished by examining causes of death among relatively recent decedents. Second, it would not have been possible to identify clearly and com pletely (if at all) the cohort of workers necessary for a historical cohort mortality study within a reason ably short period of time. As a result, the study was based upon 4336 deaths which occurred during the years 1964-1973 among active or retired employees of 17 companies engaged in PVC fabrication (Table 1). This report will be restricted to the 3847 deaths among w'hites, since the number of deaths for most causes among nonwhites was quite small, making interpretation of cause specific mortality difficult at best. Since the population at risk could not be deter- October 1981 137 UCC 084244 1 Table 1. Dietribution of death* among employee! of 17 PVC fabricator! by race and aex, 1964-1973. Race Total White Nonwhite Unknown Total 4336 3847 198 291 Male 3676 3252 174 251 Sex Female 658 595 24 39 Unknown 2 0 0 2 mined, mortality rates as measures of risk could not be calculated. Rather, results are summarized in terms of proportionate mortality ratios (PMR) calculated according to the method of MantelHaenszel (5). Two separate standards have been employed. The first is the sex-cause-age specific distribution of deaths among U.S. whites in 1968 (1968 Standard). A second standard employs the sex-cause-age specific distribution of deaths among U.S. whites in each ofthe years 1964-1973 (1964-1973 standard). Cause-specific PMR's based upon the 1968 standard are-adjusted for age, race and sex. Cause-specific PMR's based upon the 1964-1973 standard are adjusted for year of death as well as for age, race and sex. The Mantel-Haenszel procedure for assessing the statistical significance of a difference between the observed and expected numbers of deaths for a specific cause requires the construction of a series of 2x2 contingency tables as shown in Table 2. Separate tables are constructed for each level of the factor(s) to be adjusted for. If, for example, we wish to compute a PMR for all decedents for cause X, adjusted for age (five age groups) and year of death (10 years: 1964-1973), i.e., 1964-1973 stan dard, we would have 50 2 x 2 tables: age < 35, year of death 1964; age < 35, year of death 1965; . . . ; age < 65, year of death 1973. Observed deaths and expected deaths are summed over the 50 separate 2x2 tables to produce a PMR for cause X, adjusted for age and year of death. The resulting age-year of death-adjusted PMR compares the number ofdeaths from cause X observed in the study group to the number of deaths from cause X expected in the study group, if the proportion of total deaths Table 2. Conttniction of 2x2 contingency table*. Number of death* in group I, attributed to Specified cause Other cause* Total deaths Study group A, C, N., Standard B, D, Ntl Total Mi, Afj, T, 138 ascribed to cause X was the same, age group bv a* group and year by year, as for the compari*- group. ` The statistical significance of the PMR (a test of the hypothesis that the PMR is 1.0 against th* alternative that the PMR is different from i.O) t evaluated by using the Mantel-Haenszel continui:. corrected chi-square with one degree of freedom, it. (|XA, - 1E(A,) | - V2f Xmh * X Var At where _ Var A, tHt, -1) E(Ai) - Expected value of A, > The case-control analysis is based on 44 deaths among white females in the study with cancer ofit* breast as the underlying cause of death. Control.were drawn from deaths due to diseases of the circulatory system and accidents, and matched b\ age plus or minus five years and company, if possible. Forty of the cases were matched on both criteria and four on the basis of age alone. The ba.'Lfor the case-control analysis, then, is the 44 brear. cancer deaths and 134 matched controls distributed among eight of the 17 companies. Results Proportionate Mortality Ratios Cause specific PMR's adjusted for age are pre sented for white male and white female employe*; in Tables 3 and 4. For Table 3, expected numbers of deaths are based on the cause-sex-age specific dis tribution of deaths among U.S. w hites applied to the study group. For Table 4, PMR's are adjusted for year of death as well as race, sex and age Statistically significant departures from unity (i.e.. PMR - 1) are evaluated by using the MantelHaenszel continuity corrected chi-square with one degree of freedom. Causes of death for which the j calculated chi-square indicated a statistically sig nificant excess or deficit at the a - 0.05 level of significance are indicated in the table. It is impor tant to remember that when carrying out a large number of significance tests, some number will tun out to be significant on the basis of chance alone, t When dealing with a large number of tests foe ; PMR's, it may be more appropriate to consider the J Mantel-Haenszel test as a screening device rather j Environmental Health Perspectives , tf 1! ti 0 T Ci a: Ot I & UCC 084245 T touP,, * cmpii;^. MR fa t*>; 1 against from i.i," :el contir.u ,, "^^dom. u KM T ' 4J deathweroftr.. i- Contn,:. se# of thniched b. mjjanv. if ^d on bo:: T ba.-:- areas' ribinei: are prenployees mbersof cifie disolied to idj usted nd age. ity (i.e.. Mantelith one lich the Jy sigleveJ of impora large ill turn alone, 'ts for r~ the ier ve* - m\ine it a strict probabilistic interpretation. ' -h these caveats, we see that based upon the . .`i-andard. among white males there are statis- ;'significant PMR's for all cancers, digestive ver. respiratory cancer and other and unspecified cancers (Table 3). Among white females, PMR's are significantly different from one for all cancers, di gestive cancers, breast cancer, urinary cancer and other and unspecified cancers. In contrast to white males, the PMR for urinary cancer among white . , _____ i deaths and causa specific proportionate mortality ratio* (PMR) for employees of 17 PVC fabricator* by sex * (white only), 1964-1973 (expectations baaed on U.S. mortality, 1*68). *_ f death -au-es K. cincer cavity and pharynx Jr^wtive organs and peritoneum Stomach I jrpe intestine Rectum Liver Pincreas Oher and unspecified digestive Respiratory system Larynx *- Trachea, bronchus and lung Other Breast Female genital organs Cervix Corpus Ovary Other Male genital organs Prostate Other I'nnarv organ* Bladder Kidney Brain and nervous system Lymphomas Leukemia.- Other and unspecified cancers inter causes lliabetes Diseases of circulatory system Heart disease Rheumatic heart i Hypertensive diaeaae lschemu heart diaeaae Myocardial infarction Cerebr< vascular disease Other circulatory Diseases. f respiratory aystem Cirrhosis -.f fiver Cholelithiasis, cholecystitis and chi langitis Accident-, poisoning* tnd violence Accident* Suicide All other cause* ICDA 8th Revision 000-999 140-209 140-149 150-159 151 153 154 155 157 152. 156, 158, 159 160-163 161 162 160, 163 174 180-184 180 181, 182 183 184 185-187 186 186, 187 188-189 188 189 191-192 200-203, 208, 209 204-207 170-173, 190, 193-199 250 390-458 (390-398), 402, 404, (410-429) 400-404 410-413 410 430438 460-468 460-519 571 674-575 800-999 800-949 950-959 Residual Male Observed death* PMR 3252 670 16 212 41 72 26 6 37 80 206 9 194 3 0 _ __ __ 42 41 1 37 20 17 16 44 19 79 1.0000 1.1905* 0.8382 1.3058* 1.3000 1.3688* 1.3230 1.4306 1.1307 1.3861 1.1647* 1.0695 1.1704* -- -- -- -- -- -- 0.7936 0.8223 -- 1.1153 1.0053 1.2800 1.1499 1.3560 0.8117 1.6132* 43 0.8655 1930 1.0516* 1495 1.0625* 16 0.6373 36 1.0575 1381 1.0599* 898 1.1040* 290 0.9913 40 1.5294* 144 0.6344* 42 0.6675* 7 1.1018 187 0.7007* 134 0.7043* 39 0.7427 1.0410 Female Observed deaths PMR 595 1.0000 181 1.3266* 3 53 1.6134* 8 1.6226 24 1.5785* 8 2.0822 0-- 7 1.1612 6 1.3680 12 1.0119 0-- 12 1.0788 0-- 44 1.3710* 19 0.8232 5 0.6827 6 1.2911 7 0.6714 1-- ---- ---- ---- 11 2.9296* 4-- 7 3.4535* 4-- 9 1.1900 1-- 25 1.9584* 10 0.6540 278 0.9087* 188 0.9009 7 0.7502 3 158 0.8644* 93 0.9888 65 0.9133 8 1.2398 17 0.5804* 3 3 46 1.1364 37 1.3369 2 57 1.1500 *PMR significantly different from one at a 0.05. October 1981 139 UCC 084246 females is high and, although based upon only 11 deaths, is statistically significant. On the other hand, in contrast to the observation in white men, the PMR for respiratory cancer among white women is very close to unity. Similar to the observation in white men, mortality from cirrhosis of the liver is low, but the corresponding number of ohsene deaths is quite small. | Among both white male and female employ** | diseases of the circulatory system account fa, i large percentage of total deaths. In each ea* observed numbers of deaths are close to expect*: i Tabic 4. Observed deaths and cause specific proportionate mortality ratios (PMR) for employees of 17 PYC fabricator! k -- (white only), 1964-1973 (expectations based on U.S. mortality, 1964-1973). ~ tv -- s> p.i*it- Cause of death lCDASth Revision AH causes All cancer Buccal cavity and pharynx Digestive organs and peritoneum Stomach Large intestine Rectum Liver Pancress <* Other and unspecified digestive Respiratory system Larvnx Traches, bronchus and lung Other Breast Female genital organs Cervix Corpus Ovary Other Male genital organs Prostate Other Urinary organs Bladder Kidney Brain and nervous system Lymphomas Leukemias Other and unspecified cancers Other causes Diabetes Diseases of circulatory system Heart disease Rheumatic heart disease Hypertensive disease Ischemic heart disease Myocardial infarction Cerebrovascular disease Other circulatory Diseases of respiratory system Cirrhosis of liver Cholelithiasis, cholecystitis and cholangitis Accidents, poisonings and violence Accidents Suicide All other causes 000-999 140-209 140-149 150-159 151 153 154 155 157 152, 156, 158, 159 160-163 161 162 160, 163 174 180-184 180 181. 182 183 184 185-187 185 186, 187 188-189 188 189 191-192 200-203, 208, 209 204-207 170-173, 190, 193-199 250 390-458 (390-398). 402, 404, (410-429) 393-398 400-404 410-413 410 430-138 450-458 460-519 571 574-575 800-999 800-949 950-959 Residual *PMR significantly different from one at a 0.05. 140 Msle Observed deaths PUR 3252 670 15 212 41 72 26 6 37 30 206 9 194 3 Q ___ -- -- ___ >*- 42 41 1 37 20 17 16 44 19 79 1.0000 1.1567* 0.8340 1.2667* 1.3084 1.3239* 1.3164 0.9801 1.1202 1.3139 1.1155 1.0563 1.1266 ____ ____ ____ ___ _ 0.7687 0,7964 ____ 1.0942 0.9884 1.2517 1-1267 1.3525 0.8019 1.5975* 43 0.8993 1930 1.0538* 1495 1.0600* 16 0.7030 36 1-1541 1381 1.0512* 898 1.1148* 290 1.0011 40 1.5062* 144 0.6883* 42 0.6438* 7 1.1536 187 0.6991* 134 0.7084* 39 0.7034* 229 1.0246 Female Observed deaths PMR 595 1.0000 181 imp 3 53 1.4813* 8 1.6541 24 1.5490* 8 2.1165 0 7 1.1461 6 1.4546 12 0.9100 0_ 12 0.9787 0_ 44 1.3448* 19 0.8161 5 0.6869 6 1.2736 7 0.6597 1_ ___ -- _ ___ _ ___ 11 2.8365* 4-- 7 3.4206* 4-- 9 1.1944 1-- 25 1.9564* 10 0.C743 278 0.9132* 188 0.9035 7 0.8009 3-- 158 0.8522* 93 0.9962 65 0.9184 8 1.2256 17 0.6546 3-- 3-- 46 1.1173 37 1.3266 2-- 57 1.1197 *1'. 1 in da rv li* up nt- tut li* P> if ft G va iiit nr no be at CD tl< If se te pi ca fo cl w H iir e> sc in 5; se 44 se Environmental Health Perspectives j o TjCC 084247 observ en>Pl0Vtfc unt f0r t each ea. ' exPect aton^, T*bt 5- Distribution of 44 breast cancer deaths and 134 matched controls by exposure category. . Rmsre category x figure .4uble exposure i ...ble exposure exposure '-xva-n exposure Breast cancer, cases Number % 27 61.4 6 13.6 00 2 4.5 _9 20.5 44 100 Matched control Number % 97 72.4 17 12.6 4 3.0 6 4.5 JO 7.S 134 100 P.MR iToor" 1-2856* 1-4813* 1-6541 1.5490* 2.1165 1.146] 1.4548 0.8106 0.8787 1,3448* 738 >.6587 ' 8365* -426* .1944 .9564* 7743 9132* 9035 8008 8522* 9962 9184 2256 6546 1173 3266 .J7 live* though statistically significant. Results based upon the 1964-1973 standard are, - genera), consistent with those on the 1968 stan"jjd (Table 4). There are, however, some notable . MTptions. In general, the PMR's based upon the 1-4-1873 standard are lower than those based .>.n the 19<'.S standard. Further, the PMR for rv.'jiiratory cancer among white males is not sigr.incantly different from one when based on the 1-4-1973 standard. Among^ white women, the {`.MR for other (noncanceH respiratory deaths t- significantly below unity based on the 1964-1973 -tanriard. Case-Control Analysis Comparison of cases and controls on a variety of \ahables where information was available, includ ing length of employment, ever married versus never married, and child-bearing history, reveals m> statistically significant differences (p > 0.65) between cases and controls for any of these vari ables. Review of employment histories for cases and controls revealed a wide variety of jobs ranging from office and clerical work to production jobs such as bench inspector, press operator, trimmer, as sembler and sweeper. The wide range of job con tent and location made it impossible to determine precisely whether there was PVC exposure in every case, or the precise length of that exposure. There fore. a subjective ranking system was developed to classify exposures. Work histories were reviewed with plant personnel and PVC exposure potential was categorized into five classes--no exposure, improbable exposure, possible exposure, definite exposure and unknown exposure. This classification scheme enabled some definitive exposure statement in 80% of the cases and 92% of the controls (Table 5). After matching by age and company, 38 matched sets of cases and controls were developed from the 44 cases and 134 controls. There are fewer matched sets than cases because, in six instances, it was October 1981 necessary to combine cases of similar age within the same set in order to have at least one control per matched set. The Mantel-Haenszel procedure was used to derive a summary estimate of relative risk and to test for significant departures from unity 4, 7). In this procedure, each of the 38 sets can be viewed as a 2x2 contingency table. Thus, the tth set can be represented as in Table 6. Relative risk is defined as the ratio of the proba bility of dying from cancer of the breast among women exposed to PVC to the probability for women not exposed. Estimates of these individual proba bilities are not available from a case-control study. However, a measure of estimated relative risk from case-control studies as suggested by Mantel and Haenszel has been calculated as in Eq. (2). To assess whether the departure from unity of an observed relative risk is too great to have occurred by chance alone, a summary chi-square test cor rected for continuity was performed using the Mantel-Haenszel procedure. The calculated chi- square must be 3.84 or larger in order to conclude with 95% assurance that the observed relative risk did not differ from unity by chance alone. R - li iBtCi/Ti) (2) Combining the five exposure categories into two may be accomplished in a variety of ways, resulting in several possible relative risk measures as shown in Table 7. None of the calculated relative risks, including the second shown which treats anything other than no exposure as definitely exposed, are statistically Caaes Controls Total Table 6. Representation of Ah set. PVC exposure Yes No Total A, B, A'i, C, 3f,, D, A 2, r, 141 UCC 084248 I significant; i.e., they may have occurred by chance alone. Similar analyses were carried out on a company-by-company basis. None of the relative risks so calculated is significantly different from unity. Discussion and Summary The cross-sectional mortality study was designed with two objectives. The first was to determine if any angiosarcoma deaths had occurred among em ployees of the PVC fabricators under study. Since no angiosarcoma deaths were found among the employees studied, the first question has an un equivocal answer. A secondary objective was that of examining the distribution of deaths by cause among the employees under study. Implicit in that objective is the question of whether or not that distribution is, in some sense, unusual. There is no unequivocal answer to the latter question. Whether or not an observed distribution of causes of death is unusual clearly relates to the standard or compari son population as we&as the analytic methodology (5). This is illustrated by the observation that there are PMR's which are significantly different from unity on the 1968 standard and not on the 1964-1973 standard. However, it seems much more important to focus on the large area of agreement between the two standards rather than on the few areas of disagreement. On the basis of the PMR analyses, there are statistically significant excesses in total cancer mor tality among both white males and white females when compared to the distribution of deaths for the total United States specific for color and sex and adjusted for age. Excesses in cancer mortality ap pear concentrated in cancers of the digestive sys tem and, in particular, in cancers of the intestine for both men and women. In addition, there is a suggestion that mortality from cancer of the breast and urinary organs among white women emplmtfr is higher than that for the total U.S. There'>' i however, several reasons why definitive interp-tation is difficult. Factors meant to suggest tO ! proportionate mortality analyses must be interpN i ted cautiously have been reviewed previously (9-j | However, while these results must be interpret- ; with caution, they appear to be consistent , previously studied workers and suggest the nO: ! for some continuing investigation (l). j One such follow-up investigation has been prt- I sented here in the form of a case-control stud. * involving the 44 breast cancer deaths. On the bl- i of a case-control analysis, estimates of relative n-i j were derived but none of these relative risk es: ' mates is significantly different from one, althoup * such results must be interpreted with caution. < Absence of a statistically significant relative ri... * does not demonstrate that there is not an exc*. 1 risk of death from breast cancer among won*: l employees with PVC exposure. In fact, when i> ! statistically significant relative risks are found, it i- j pertinent to ask what the chances are of detect^ ; an increase of a given magnitude from the available data. Using the method described by Walter if* we have subjected each of the relative risk eft. mates (Table 7) to a least significant relative n.- analysis under the conditions that we desire 95''- assurance that a risk of such magnitude, if e'tserved, did not occur by chance alone and 8/- } probability of detecting the least significant relatiu risk if it exists. Even in the case where all but no exposure art counted as exposed, the smallest relative risk which , could be detected from these data is nearly 3:1 Nearly 200 cases and 200 controls would have bet:. | necessary to detect a true doubling of the ri.4 under the specified conditions. Given the sample size in this study and the percentage of control- j exposed (a percentage which was unknown at the | <mlv no largf eviM ^te in rt- 1 l s. & Table 7. Relative Hk (RR) and leait significant relative risk (LSRR) estimated for contrast* of various exposure eat*f? , combinations. Contrast Number of cases RR (Relative risk) estimate* LSRR (Least signifiwr.: relative risk) estimate' Definite exposure vs. no exposure Definite + improbable + possible + unknown exposure vs. no exposure Definite + possible exposure vs. no * improbable exposure Definite + possible + unknown exposure vs. no ^ improbable exposure 29 44 35 44 1.81 1.94 0.624 2.73 6.77 2.92 5.02 3.41 `None of the relative risk estimates are statistically significantly different from unity <p > 0.05). ri'he true relative risk would have to be at least this large to have an BO% assurance of detection (i.e., power * 0.80) with a type I error of 0.05 (i.e., a 0.05). 142 Environmental Health Perspective* XJCC 084249 `*pioy*. . There a* ve interprc "ggest thi- be mterprv ously (9-).i interpret; - istent Hit* -1 the nttc been pr*. 'tro] stud, n the basLilative rW. ` risk e.cti. 'i although iution. lativeri.4 an exces)g womer, when no . )und, it ldetecting available `Iter Ui), risk estjitive risk s; 951 i . obhd 801 : relative sure are sk which Tly 3:1. ive been the risk sample controls n at the .jrt of the study), it would be possible to detect -jv very large increases in risk. There seems reasonable assurance, therefore, that such very aft increases in the risk for breast cancer do not among these PVC fabricators, but no such clement can be made for possibly smaller increases z risk. references 1 Chiszze, L.. Jr., Nichols, W. E., and Wong, 0. Mortality among emplovees of PVC fabricator*. J. Occup. Med. 19: 623-628 (1977). * Gurslnick. L. Mortality by Occupation and Cause of Death Among Mm 20-64 Years of Age: United States, 1950 (Vital Statistic;-Special Reports, Vol, 63, No. 3). U.S. Govt. Printing Office, Washington, D.C., 1963. 3 .National Center for Health Statistics. Vital Statistics of the United States, 1968, Volume II, Mortality, Part A. Washington, D.C., U.S. Govt. Printing Office, 1972, pp. 140-205. 4 Mantel. X. and Haenszel, W. Statistical aspects of the anslvsi* of data from retrospective studies of disease. J. Natl. Cancer Inst. 22: 719-748 (1959). 5. Li. F. P.. Fraumeni, J. F., Jr,, Mantel, N., and Miller, R, W. Cancer mortality among Chemists. J. Natl. Cancer Inst. 43:115M164 (1969). 6. Chiazze, L., Jr,, Wong, 0., Nichols, W, E,, and Ference, L. Breast cancer mortality among PVC fabricators, J. Occup. Med. 22:677-679 (1980). 7. Pike, M. D., and Morrow, R. H. Statistical analysis of patient-control studies in epidemiology: ftetor under inves tigation an all-or-none variable. Brit. J. Prev. Soc. Med. 24: 42-44 (1970). 8. Chiazze, L., Jr. Problems of atudy design and interpreta tion of industrial mortality experience. J. Occup. Med. 18: 169-170 (1976). 9. Redmond, C. K., and Bieslin, P. P. Comparison of methods for assessing occupational hazards. J. Occup. Med. 17:313-317 (1975). 10. Monson, R. R., Peters, J. M., .and Johnson, M. N. Proportional mortality among vinyl-chloride workers. Lan cet u: 397-398 (1974). 11. Lloyd, J. W., and Ciocco, A. Long term mortality study of steelworkers: 1. Methodology. J. Occup. Med. 11: 299-310 (1969). 12. Redmond, C, K., Ciocco, A., Lloyd, J. W,, and Rush, H. W. Long term mortality study ofsteelworkers: IV. Mortal ity from malignant neoplasms among coke oven workers. J. Occup. Med. 14: 621-629 (1972). 13. Taberahaw, I. R., and Gaffey, W. R. Mortality study of worker* in the manufacture of vinyl chloride and its polymers. J. Occup. Med. 16:509-518 (1974). 14. Walter, S. D. Determination of significant relative risks and optimal sampling procedures in prospective and retro spective comparative studies of various sizes. Am. J. Epidemiol. 105: 387-397 (1977). legorj nificant mate1' t'*De J ive* October 1981 143 UCC 084250 Environmental Health Pertpectivet Vol. il. pp. US-151,19S1 Mortality and Cancer Rates among Workers in the Swedish PVC Processing Industry by Gustavo Molina*, Bo Holmberg*, Stig Elofsson1, Lars Holmlund,* Rein Moosing,* and Peter Westerholm** Pcrionne! lifts Crem four PVC-processinf industries were collected on production ofemployee! with at least three months of employment at the beginning of 194S and the last day of employment December 31, 1974. Of 2073 persons, 103 could not be followed up, because they had moved abroad. The remaining persons comprise the cohort of 1970 individuals who were analyzed and compared with the national population with respect to mortality from various diseases and cancer morbidity. The death risk from myocardial infarction is elevated in the cohort. This elevation is most clearly apparent in the subcohort which had at least two years of exposure time and where the analysis was directed at circumstances chronologically close to the time of exposure. The myocardial infarction risk related to vinyl chloride exposure is discussed in relation to earlier studies on the vascular effects of vinyl chloride. An indication of an elevated risk of morbidity and mortality from tumors in the digestive organs is also present. However, this is not statistically confirmed. A few future follow-ups of the present study are necessary in order to clarify any possible elevated risk of tumors in the PVC-processing industry. Vinyl chloride has been shown to cause sderodermia. Raynaud's phenomenon, acroosterolysis, liver damage and liver cancer (hemangiosarcoma) C) in workers exposed to vinyl chloride monomer iVCM). This has been shown in studies (2, 3) performed at companies which fabricate polyfvinyl chloride) (PVC). In animal experimental studies it has been reported that inhalation of VCM causes malignant tumors in different organs in rodents In Sweden, in 1974, two cases of liver heman- *Occupy ional Toxicology Unit, Department for Occupational Medicine, labor Medicine Division, Department of Occupational Safety, B<. \ 100, 26 Stockholm, Sweden. Statif!..al Institution, Stockholm University, Box 6701, 113 sj Stockholm, Sweden. ^ fGroup for Applied Statistics, Karlbergsvagen 82. 113 35 Stockholm Sweden. "Bureau of Statistics, Department of Welfare, 106 30 Stock holm, Sweden. giosarcoma were diagnosed in employees at a company engaged in the processing of VCM and PVC (7). Later another two cases occurred at the same factory. Studies on other forms of cancer (8, 9) suggest that VCM-exposed workers in the PVC fabricating industries may possibly run an elevated risk of contracting forms of cancer other than hemangio sarcoma in the liver. Earlier, an excess mortal ity from cardiovascular diseases was also observed (10) in employees in the PVC manufacturing indus try. The present retrospective cohort study was per formed for the purpose of determining the pattern of morbidity and mortality in the PVC processing industry. The PVC processing industry, generally speaking, has had a lower level of exposure to VCM than the fabrication industry. In the Swedish PVC processing industry, at present, about 5000 persons are employed in production. October 1981 145 UCC 084251 i Material and Methods Information for the study was collected from four PVC processing companies. The four companies all used PVC which, after additions of various chemi cals, is heat-treated for fabrication into floor cover ing, lace, pipes, and food packaging. Data Collection The following data were collected from the per sonnel lists at the companies: personal number, name, beginning and end of exposure (year and month) and class of exposure. In order for a person to be included in the original cohort, at least three months of employment was required in the period beginning in 1945 and the ending December 13, 1974. The exposure was classified as follows: class 3 (high), work in the mixing department; class 2 (medium), heat treat ment machines; and class 1 (low), other production departments. ,s The collected data were transferred to punched cards and magnetic tape for statistical processing. The magnetic tape was coordinated with the na tional total population and the so-called death tapes for the 1961-1976 period and checked against the cancer registry by the Central Bureau of Statistics (SCB). The personnel numbers which could not be recovered at this time were checked by the national taxation office. The original cohort included a total of2,073 persons. Of these, 103 persons (5%) dropped out, 70 or whom had moved abroad, 5 were found in the missing persons register of the tax office, and 28 could not be traced. Study Cohorts For the statistical processing, the results of the cohort of 1970 persons were divided into a number of subcohorts (study cohorts): (1) all persons with at least three months of exposure (follow-up time from the beginning of exposure and through 1976); (2) all persons with at least six months of exposure ex cluding those who stopped before 1961 (follow-up time from beginning of exposure but no earlier than 1961 and through 1976); (3) all persons with at least six months of exposure and where the exposure began no earlier than 1961 (follow-up time from beginning of exposure and through 1976); (4) all persons with at least two years exposure (follow-up time from two years after beginning of exposure but no earlier than 1961 and through 1976 but no more than ten years after exposure stopped); (5) all persons with at least two years exposure (follow-up time from ten years after exposure began but no 146 earlier than 1961 and through 1976). The two latter named study cohorts were cho*- in order to study whether any differences existed: the death cause pattern with respect to when deaths occurred after the beginning of exposun The first of the study cohorts was intended to shr light on possible causes of death which occur ni I tively early, e.g., accidents caused by the job. Tr* 1 second was intended to shed light on such dei1.- I causes as occurred after a longer time had pa**I ( Tumors caused by occupational exposure, for ( ample, often have a long latency period, 5-10 yr I longer. t .tun i n cU Hi nr nr Hblf * retrain Irist *i' Results The original cohort was relatively young at tht j beginning of exposure. The age distribution in th* ! different exposure classes is given in Table 1. Or* finds various dissimilarities between the exposure classes. In class 1 (low), 41.7% were younger thar 35 years at the beginning of exposure; in da ? (average), 47.7%; and in class 3 (high), 50.69. Then !( I irilOY, X.tceni Arndt-n' `Ri'k :.*ar. 19f Table 1. Affe distribution in orifinal cohort at betinnint at I exposure I ft in each exposure class Age 1 2 3 1-3 < 19 20-24 25-29 30-34 35-39 40-44 45-49 50-54 55-59 60-64 > 65 No. of persons 1.6 7.5 13.5 19.1 17.0 13.7 11.1 8.0 5.1 2.6 0.7 100ft (1501) 2.0 14.6 15.7 15.4 13.2 12.6 12.6 7.8 3.9 2.0 0.3 100% (357) 8.9 2.1 14.3 9.2 21.4 144 17.0 18.3 10.7 15.9 9.8 13.3 8.9 11.3 5.4 7.fr 1.8 4.7 1.8 2.4 0.0 0.6 100ft i<r.r. (112) (197(1 acre b aith n r. shot ahich rntran ahich times i has lor The increa- Uonal. the su Stud least si the ris a hat r deaths Table 2. Distribution of exposure time in the orifinal nto* Months <5 6-23 24-59 60-119 > 120 ft in each exposure class 1 2 3 1-3 13.1 38.4 25.0 15.3 8.2 100ft (Af - 1510) 0.3 8.4 17.4 45.7 28.3 100% (A# - 357) 0.0 10.1 8.9 313 10.7 22.8 15.2 20.8 65.2 15.1 _ 100ft ioer. (A/ - 112) (M - I" " Environmental Health Perspective? Table 5 tp Cli tip cli tip cli tip. Cli "mwT tktobi UCC 084252 4.vere chose: *s existed L* " hen the i exposure ded to shri occur reli- job. T}e such death uid passed i*i for ex 6-10 or ung at the tion in the We l. One exposure "ngor than in class 2 Theft eginnins t rr1-3 9.2 14.4 ls.3 15.9 13.3 11.3 7.8 4.7 2.4 0.6 10r,* (1970) al cohort. 1-3 10.1 31.3 228 20.; 15.1 100% 970) .,. 1 i: class 3 it; dSAfl-3 Tabic 3. Observed and anticipated number of deaths as of December 31, 1976. No. of deaths Number Observed Expected Ratio O/E 1303 53 55.5 0.95 356 14 21.9 0.64 112 6 10.3 0.70 1171 73 87.8 0.84 Approx. 95% confidence interval s 0.26 = 0.34 = 0.47 i 0.19 TiMe 4. Observed and anticipated number of deaths from (trum causes during the 1969-1976 period in those with at n*t tii months of exposure including those who stopped before 1961.* Ob Ex Ratio served pected O/E V*..rrxm tumor? 140-209 17 14.0 1.21 organ tumors 150-159 8 4.9 1.63 iri,.ivascular diseases VI! 22 24.3 0.91 X- cardial infarction 410.90 15 20.0 1.49 tvidwits, suicide, etc. XVII 13 9.2 1.42 _____ Ki-l calculated from the beginning of exposure but no earlier 'i- 1961. Study cohort 2 (1771 persons). acre also dissimilarities in the length of exposure with respect to exposure class (Table 2). However, r. should be noted that the table includes cases which were -till under exposure at the final date for entrance into the cohort (December 31, 1974), for which reason, a certain bias toward short exposure times is found. Regardless of this, exposure class 3 rut# longer exposure times on the average. The cohort as a whole reveals no noteworthy increase in the total risk compared with the na tional avenge, nor is there any indication of this in the subgroups making up the study cohort. Study cohort 1, which includes everyone with at least six nv nths of exposure and with calculation of the risk from the beginning of exposure, is some what remaikable in that the anticipated number of deaths is significantly higher than that observed up A Figure 1. Cumulative deaths (in percent): (7) observed; () anticipated. Expected value calculated from beginning of exposure. Study cohort 1 (1970 persons). The percentage for a given year was calculated as 100 (number of persons dying through year in question divided by the number of persons beginning exposure up to and including the year in question). to 1964 (Fig. 1). This is commented on further in the discussion. Study cohort 2 (Tables 3 and 4; Fig. 2) includes persons with at least six months of exposure, excluding those who stopped before 1961. The risk calculation is made from the beginning of the exposure, but no earlier than 1961 and up to the end of the follow-up time (1976). The observed number of deaths is somewhat lower than expect ed, much lower in exposure class 2. Classes 2 and 3 are relatively small and are sensitive to random deviations in this type of analysis. In order for random deviations not to influence the results, the classes were combined. This is true of all study cohorts. This distribution with respect to the vari- Tsble 5. Observed and anticipated number of deaths as of December 31, 1976 in thoee with at least six months of exposure beginning no earlier than 1961.* Cohort Number No. of deaths ' Observed Expected Ratio O/E Approx. 95% confidence interval Exp. class 1 Exp. class 2 Exp. class 3 Exp. class 1-3 1139 43 41.2 1.04 = 0.31 247 4 11.7 0.34 0.34 42 1 1.8 1428 48 54.7 0.88 = 0.35 'Risk calculation from beginning of exposure. Study cohort 3 (1428 persons). October 1981 147 UCC 084253 Figure 2. Cumulative deaths (in percent). Expected value calculated through 1961. Study cohort 2 (1771 persons). Percentage for a given year calculated as in Fig. 1. Figure 4. Observed death riak per year at different potnu i time after beginning of exposure expressed in percec C corresponding anticipated risk in those who began expose in 1961 or later. Study cohort 3 (1428 persona). Figure 3. Cumulative deaths (in percent) of those who began exposure in 1960 or later. Study cohort 3 (1423 persons). Percentage for a given year calculated as in Fig. 1. ou5 death causes is shown in Table 4, The observed and anticipated number ofdeaths during the 1961*1968 period is relatively small, only a few cases, and the death cause classification was modified as mentioned earlier in 1969, for which reason 1961*1968 period is not discussed separately. By and large, the picture is the same there as for the 1969-1976 period re ported on. From Table 4, one sees that the ob served number of deaths, especially those from tumors of the digestive tract, myocardial infarction and accidents, is somewhat higher than anticipated. However, the differences are not significant. Study Table 6. Observed and anticipated number of deaths fret certain causes during the 1969-1976 among those with at Wk six months of exposure beginning in 1961 or later.' Ob Ex Run served pected 01 Malignant turnon 140-209 Digestive organ turnon 150-159 Cardiovascular diseases Vll Myocardial mfarction 410.90 Accidents, suicide, etc. XVII 9 9.7 0.K 4 3.3 U' 16 16.2 O.fc 14 11.2 1.25 11 7.3 1.51 'Risk calculated from the beginning of exposure. Study cob.* 3 (1428 persons). cohort 3 (Tables 5 and 6; Figs. 3-5) which pertain.to those who began working in 1961 or later but which otherwise satisfy the same criteria as study cohort 2, displays a similar picture. An analysis of study cohort 3 according to for mula B (Figs. 4 and 5) indicates that the annual risk during the first year of exposure is somewhat lower than the anticipated one, but that after about ten years, an increased risk occurs so that the observed risk becomes higher than the anticipated. Tabic 7. Obccrvcd and anticipated number of death* from certain cause* during the 1969-1976 among those with at lew* year* of exposure.1 Observed Expected Ratio O/E Malignant turnon 140-209 Digestive organ turnon 150-159 Cardiovascular diseases VII Myocardial infarction 410.90 Accidents, suicide, etc. XVII 6 (9) 2 (4) 15 (16) 11 (12) 4 (5) 7.4 (8.9) 2.6 (3.2) 12.7 (15.8) 5.4 (6.6) 4.6 (6.1) 0.86b (1.01) 0.7$b (1.27) 1.18b (1.01) 2.03b <1.82r 0.87b (0.97) Risk calculated from two yean after beginning of exposure and no more than five yean (10 yean) after end of exposure. Stud;cohort 4 (1155 persons), hp < 0.05. 148 Environmental Health Perspective* UCC 084254 fter in? osur* Joint* of Tent of -xposure H from at lead r* Ratio 0^ 0.93 1.20 0.99 cohort tains but study for1 risk ower t ten ned -11* Table 8. Observed and anticipated number of deaths from certain causes during the 1969-1976 in those with at least two years of expo*ure.* Ob Ex Ratio served pected O/E Malignant tumors 140-209 Digestive orgRn tumors 150-159 Cardiovascular diseases VII Myocardial infarction 410.90 Accidents, suicide, etc. XVII 9 6.0 1.51 4 2.2 1.85 12 11.1 1.08 8 4.5 1.77 2 2.5 0.79 'Risk calculated from 10 years after beginning of exposure. Study cohort 6 (680 persons). Figure 5. Cumulative survival probability (in percent) ofthose who began exposure in 1961 or later and have at least six months of exposure. Study cohort 3 (1428 persons). Table 9. Observed and anticipated number of deaths from cancer during 1961-1976 in thoae with at least six months of exposure excluding those who stopped before 1961.* Ob- Ex- Ratio served pected O/E Malignant tumors (total) 51 44.6 1.14 Digestive organ tumors (150-159) 11 8.5 1.29 'Risk calculated from beginning o( exposure but no earlier than 1961 Study cohort 2 (1771 persons). In study cohort 4 (Table 7) which concerns time during ongoing exposure or a relatively short time after the end of exposure, i.e., "short-term per spective." one sees an increased death risk from myocardial infarction. Other causes are somewhat lower here than expected. In study cohort 5 (Table 8), finally, one finds an indication of an increase in the death risk as regards tumors, but also for myocardial infarction. The differences between the observed and anticipated number? are not, however, statistically confirmed at the 57c level. The result with respect to mortality can be sum marized as follows. In the study cohorts, overall, one finds no noticeable increase in mortality. On the other hand, there are indications of a shift in the death cause pattern compared with the national average. This shift is expressed primarily in the fact that the number of myocardial infarctions is noticeably higher during ongoing exposure or within a relatively short period of time after the end of exposure. There are also indications that the death from tumors can be elevated among persons with a long latency period (Tables 7 and 8). In the question of cancer morbidity, there is no certain increase in study cohort 2 (Table 9 and Fig. 6). In the question of tumors of the digestive or gans. in the same study cohort, 11 cases were observed as opposed to an anticipated 8.5. The Figure 6. Cumulative rates of cases of all cancer (in percent). Study cohort 2 (1771 persons). The percentage for a given year was calculated as 100 (number of persons diagnosed through year in question divided by the number of persons beginning exposure through year in question). difference is not statistically verified. One of these eleven tumors was liver cancer (ICD 155.0). Discussion A noteworthy finding which arises in the analysis of the total cohort mortality (Fig. 1) is that the number of deaths at the beginning of the observa tion period (1947-1964) is significantly lower than one would expect in relation to the national aver age. This difference is so great that one cannot directly consider it to be randomly conditioned, nor can it be entirely ascribed to the so-called healthy worker effect. Theoretically, of course, the possibil ity exists that the selected cohort, in the question of mortality and the factors which influence said mor tality, deviates from the general population. A more credible possibility is, however, that the personnel register that w-as available at the company involved at the time of this study was incomplete in the matter of hirings during this early period. A per sonnel register which, in the mid-1960's, was purged Oct her 1981 149 UCC 084255 V1 c of persons who began employment before 1960, factors. Among other risk factors, one can ^ indii could lead to the difference mentioned above. The name hereditary characteristics and high blood pri not r companies involved reported that such a purging sure. In this connection, there is reason to recoils did not occur, so far as they knew. that the causal network of coronary disease is rc If such a purging (thinning out) nevertheless tifactorial and that the disease has'an environing crea- occurred, this would have resulted in the elimina tal relationship in the broad sense. There is jk nor i tion of persons with a long observation time at the reason to recall the aspect that the total risk r- long V time of follow-up. In the present study, the risk creases when several risk factors, known or m'. inclu calculations were limited to beginning no earlier known, are allowed to collaborate (ll, 12), until than 1961. This means a limitation of the analysis to It has not been possible to establish the distrib. folio- pertain to the group of employees who were living tion of such already known risk factors for coroiur. folio- at the beginning of 1961 and where the risk of an disease in the cohorts studied with respect to ir* me*, elimination is positively eliminated. This limitation, national population in general. Therefore, no cor this. 4 however, signifies a weakening of the analysis, tinued analysis of the matter of the causal relatiu: since parts of the cohort with long follow-up times ship between close environment and heart disei- In *m are excluded. Basically, this weakening signifies a morbidity can be made within the limits of tb m poorer possibility of discovering an elevated inci study. dust: dence of cancer if one exists. Exposure classes 2 and 3 constitute subcohorv I PP* The myocardial infarction mortality (ICD 410.90) that are too small, in the present study, to allow t tinal is elevated in the cohort. This elevation occurs most meaningful discussion of the myocardial, infamk: 1 clearly in the category of the total cohort which has risks relative to the various exposure levels in ib> at least tw'o years of employment time and where processing industry. In this connection, one shoal: the analysis was directed at the period of time also consider the circumstance that the expo$u following two years after the beginning of employ classes in this study are based on interviews wb t. i ment and extending to no more than five years after the employees directed at the work environment i: the beginning of employment. Therefore, this in the time in question some 10 to 15 years ap l' volves that fraction of the mortality from myocar Therefore, this involves an environment which hi.- dial infarction which chronologically is relatively subsequently undergone changes. Objective ckv. 3. closely connected to the time of employment. It is fication criteria in the matter of exposure, e.g.. ir impossible on the basis of such observations to the form of environmental measurements, do nr draw conclusions that the elevation was caused by exist. The distribution into exposure classes is, for 4. exposure to vinyl chloride. The observed increase in myocardial infarction mortality is, however, so striking that it, in combination with the known facts about the toxic properties of vinyl chloride, must be given consideration. There are no reasons to assume that varying diagnostics, standards or practices in filling out the death certificates alone could provide an explanation. A natural conclusion this reason, fraught with uncertainty. In animal experiments, it has been found that tb toxicity picture in rodents chronically exposed u VCM involves the blood vessels. Besides hem:.giosarcoma in the liver and the other organs U. the inhalation of VCM is also believed to cau* development of telangiectasis U) in the liver ofmio which can lead to death from hemocoele. Chang* . . is, therefore, that if one disregards the possibility in the sinus cells have been observed in liver bu of a random local phenomenon, the increased fre sies in VCM-exposed w-orkers (.13). Capillary change- quency is to be ascribed either to selection of indi in the skin of the fingers have also been observe viduals susceptible to the risk or an outbreak of risk (14-16), both in VCM-exposed workers with other 1 factors in the close environment of employees. A vascular-involved diseases, such as acroosteolyss , combination ofthese two circumstances is, of course, Raynaud's phenomenon, and sclerodermia, and ir. also possible theoretically. VCM-exposed w-orkers without such diseases. A: In this connection, it should be noted that many over-representation of deaths from cardiovascular risk factors for myocardial infarction are environ diseases has also been observed in a study on the , mentally conditioned in the fact that they constitute PVC-fabricating industries (10). Animal experimer. ; part of the lifestyle of the modem social environ tal and previous medical studies of VCM-expo*: ment in an industrialized country. Cigarette smok populations therefore support the assumption tha" ing, physical inactivity, overweight and high blood the increased risk ofmyocardial infarction observe lipids constitute environmental factors which are in the present study could possibly be ascribed u related to social behavior. It is a well known fact VCM exposure. that the risk of coronary vascular disease in the As regards the mortality and morbidity fro' heart varies, inter alia, with the total load of risk tumors, the results are uncertain. There are certair ^ 150 Environmental Health Perspective* . Oct * UCC 084256 * ` cations of an elevation, but the differences are statistically confirmed. One can think of two Risibilities here: (1) in reality, there is no increase . .j,e risk of tumors; (2) there is indeed an in* Cancer Res., 31: 516-522 (1971). 7. Byren, D., and Holmberg, B. Two possible cases of angiosarcoma of the liver in a group of Swedish vinyl chloride-polyvinyl chloride workers. Ann. N.Y. Acad. Sci., 246: 249-250 (1975). ^ased risk of tumors. The results neither confirm 8. Monson, R. R., Peters, J. M., and Johnsaon. M. N. r refute this. Tumors do not occur until after a . -p latency period. The majority of the persons -duded in the study did not begin their exposure Proportional mortality among vinyl chloride workers. Lan cet ii, 397-398 (1974). 9. Taberahaw, J. R., and Gaffey, W. R. Mortality study of workers in the manufacture of vinyl chloride and its , :il the 60's and 70's and therefore could not be polymers. J. Occup. Med., 16: 509-518 (1974). :*.!iwed for a sufficiently long time. An accurate 10. Byren, D., Engholm, G., Englund, A., and Westerholm, P. !low-up of the present cohort during the coming i-.r-year period should bring greater clarity into Mortality and cancer morbidity in a group of Swedish VCM and PVC production worker*. Environ. Health Perspect. 17: 167-170 (1976). `.SIS. 11. RCP and BCS. Prevention of coronary heart disease. In the present connection, it is of interest that in Report of joint working party of the Royal College of i recently published mortality study (17) on almost I**! deaths in the American PVC-processing ini^try. an overrepresentation in cancer mortality *:ars to exist (all cancer), especially gastrointes* Physicians of London and the British Cardiac Society. J. Roy. Coll. Physicians, 10: 213-275 (1976). 12- Tibblin, G., Wilhelmsen, L., and Werke, L. Risk factors for myocardial infarction and death due to ischemic heart disease and other causes. Am. J. Cardiol. 35: 514-522 :;na! cancer in both sexes. (1975). 13. Popper, H,, and Thomas, L. B. Alteration of liver and spleen among workers exposed to vinyl chloride. Ann. REFERENCES t a N.Y. Acad. Sd., 246:172-193 (1975). 14. Maries, H., Johnsson, M. N., Whetstone, C. L., and Le 1 Holmberg. B,, and Molina. G.: The industrial toxicology of Roy, E. C. Capillary abnormalities in polyvinyl chloride vinyl chloride. A review. Work-Environ. Health 11:138-144 production workers. J. Am. Med. Assoc., 236: 1368-1371 20. <19741. Z Creech. J L., and Johnsson, M. N. Angiosarcoma of the liver in the manufacture of polyvinyl chloride. J. Oecup. (1976). 15. Maries, H., Johnsson, M. N., Whetstone, C. L., and Le Roy, E. D. In vivo capillary abnormalities in vinyl chloride Med., 16. 150-151 (1974). workers. In: Microcirculation, Vol. 2. J. Grayson and W, m :< Lloyd, VV J. Angiosarcoma of the liver in vinyl chloride-' polvvmyl chloride workers. J. Occup. Med.. 17; 333-334 Zingg, Eds.. Plenum Press, New York, 1976. 16. Maries, H., Darke, C. S,, Archibald, R. M., and Le Roy, <19751 ' E. C. In vivo observations of skin capillaries in workers 4 Holmberp B., Kronevi. T., and Winell, M. The pathology exposed to vinyl chloride. An English-American compari of vinyl cUoride exposed mice. Scand., 17: 328-342 (1976). son. Brit. J. Ind. Med., 35:1-7 (1978). 5 Maltoni. i\ The value of predictive experimental bioassay 17. Chiazze, L., Nichols, W. E.. and Wong, O. Mortality in occup:.' .onal and environmental carcinogenesis. An ex among employees of PVC fabricators. J. Occup. Med., 19: ample: vii.yl chloride. Ambio, 4: 18-23 (1975). 623-628 (1977). 6 Viola. P L., Bigotti, A., and Caputo, A. Oncogenic 18. Chiang, C. L. Stochastic Processes in Biostatistics. An response of rat skin, lungs, and bones to vinyl chloride. Introduction. Wiley, New York, 1971. October 1981 151 UCC 084257 Environmental Health Perspectives Vol. U, pp. 153-1S7,1981 Epidemiological Study of Pneumoconiosis in the Italian Poly(vinyl chloride) Industry by G. Mastrangelo,* B. Saia,* G. Marcer* and G. Piazza* Among 1216 worker* employed in a poly(viny) chloride) production factory, 20 caaee of pneumoconiosis were found. None of there worker* had had previou* exposure to organic or inorganic duiti; 731 had been exposed to PVC duct (employed in drying, lacking and blending of polymer) and 485 had been expoced to monomer alone. Cheit x-ray film* were read by two independent phyiiciani utilizing the 1LO/UC Pneumoconiosi* Classification, 1971. X-ray abnormalitie* werg characterized by limited profuiion, irregular type and low gravity; in a email percentage of caae* these were associated with slight restrictive respiratory function impair* menu. All 20 workers with PVC-induced pneumoconiosis had been exposed to high PVC dust pollution for at least five years. Mild nonspecific alterations (profuiion of 0/1 class) were found both in the group exposed to PVC dust and in the group exposed to VCM alone. Such changes (observed in 388 cases, 31.9% of the whole population), are related mainly to age and smoking habiu, and the role of exposure is minor. We examined the working population of plants producing poly(vinyl chloride) (PVC) in Porto Marghera. Italy; 1216 workers had no previous dust exposure. Of these 731 were exposed to PVC dust polymer alone while 485 were exposed to vinyl chloride nmnomer (VCM). In the drying, sacking and blending departments, PVC dust concentra tions were over 10 mg/m3 of total dust in about 60% of the samples, whereas in the polymerization departments no concentration over 10 mg/m3 was f>und. In the samples taken, particles with diame ters of 1 um to 6 pm constituted 4.5 to 30.9% of total dust weight. All the workers had chest x-rays according to IL0 standards and a spirographic examination. Chest x-ray films were read by two independent physicians utilizing the ILO/UC pneumoconiosis classification. For statistical analysis, a consensus reading was used. _ '1`tituto Hi Medians del Lavoro, University degli Studi iViova, Via Facciolati 71, Padua, Italy. fctitutv <li Radiologia (I Cattedra) University degli Studi 5'"dova. Via Giustinian 3, Padua, Italy, October 1981 Table 1 shows that there are no significant differences in age and smoking habits, but the exposure duration is higher in the workers not exposed to dust. Table 1. Group No. of % of Age, yr Exposure, yr subjects smokers (mean = SD) (mean SD) Exposed to PVC dust Not exposed to PVC duat 731 485 73.9 37.7 8.8 68.7 35.7 8.5 6.1 4.0 8.6 = 4.5 Table 2. exposure, yr Age distribution of cases* * 30 yr 31-40 yr 41-60 yr >50yr <5 5-10 > 10 - 2(2.4) 5(8.3) 1(5.9) 2(3.8) 8(9.0) 2(9.5) `Values in parentheses sre percentages of subjects with PVC pneumoconiosis in each class of age and exposure. 153 UCC 084258 I In 20 subjects we found chest x-ray changes of at least class 1 according to the ILO/UC classification. The mean age of this group was 44.9 5.2 years and the mean length of exposure was 11.6 5.4 years. Sixteen subjects (80%) were either smokers or ex-smokers. Table 2 summarizes the distribution of cases in relation to age and length of exposure. In all age groups there is an increase of disease prevalence associated with the increasing length of exposure. In the case of the x-ray changes, 16 subjects had class 1/0 profusion, 2 cases class 1/1,1 case class 2/1, and 1 case class 2/2. Irregular opacities were prevalent: 10 were type s, three were type t, six were type p and one was type r. They were diffused, mainly over median lobe areas. A chest x-ray of a worker exposed to PVC dust (Fig. 1) for 15 years shows a gross reticular pattern: profusion is class 2/2, type t. In the right hemithorax of the same subject (Fig. 2) there is a mottled reticular pattern. Figure 3 is an enhanced view of the right hemithorax showing the mottled reticular pattern more clearly. Another case <5f PVC induced pneumoconiosis can be seen in Figure 4. The worker was exposed to PVC dust for 20 years. A fine, dense retio^ micronodulation is evidenced. Profusion is das;41 type p-s. Figure 5 shows the right hemithom'd the same subject; pin-point opacities can be set' In spite ofage and the considerable exposure. *1 majority of cases were in a low profusion categor. indicating the slow evolution of the disease. Ail la; worked in high air-borne dust level environme^ (mostly drying and sacking) for at least five va* None of the 20 subjects was in a group unexpo to dust and none had experienced previous oeeuja tional exposure to organic or inorganic dusts, t. considered the alterations to be PVC pneumocor*.. sis. In 388 subjects (31.9%) we found slight ehbx-ray alterations consisting of linear or irrepuvanishing opacities or both, classified as class O', the remaining 808 subjects were class 0/0. Table 3 reports the total population distribute excluding 20 subjects with PVC pneumoconio?.Results are presented in a two-way table: eac entry reports the number of observations. Sample are classified according to age and PVC du? exposure: PVC + represents presence, and PVCabsence of PVC; x-ray + indicates the group it: dasrisk vari. T; sign The for ( degi able vari. Figure 1. Chut x-ny of a worker exposed to PVC dust for IS yesrs. Profusion class 212: type t. 154 Environmental Health Perspecti'** PVC x. X-I PVC x-t X"i ucc 084259 1 MP - ftf*- ^Jsion ig *L hemiUorv` * can b * ejcPOSU>. 'ftision cat** ^ disease. AJ. "J envirwa*" five v*. 0UP unexj,^ reyious octi***ic dust*. k : Pneuniw. slight d-, dj aosr clasj o 'S 0 0. ' distribuo eunioconjv. v table: *.ons- Sami,;. 1 pVC du. . and p\'C e group ur* f, ,i re i Ri^-ht hemithorax of the tame subject at in Fig. 1. Figure 3. Enhanced view of the right hemithorax of Fig. 2, showing the mottled reticular pattern. clas# 01 profusion. To assess the influence of both r.-k indicators we performed a two-way analysis of ikriance for proportions. Table 4 shows that both age and exposure were R^nificant factors influencing x-ray abnormalities. Thr square of a multiple partial association coefficient f r qualitati\e data was calculated to measure the degree of association between the dependent vari able (x-ray changes) and each of the two predictor variables (age and exposure). Age and exposure are alternately held constant. Age is a most important factor. When exposure is held constant, 33.2% of the x-ray changes are shown to depend upon age, when age is held constant, 6.5% are shown to depend upon exposure. Table 5 summarizes the distribution of the cases according to smoking habits in workers exposed and not exposed to PVC dust. Table 6 shows that chest abnormalities are significantly influenced by both risk indicators. Table 3. Tabic 4. PVC 4 X*nv * X-j*v - PVCX-riy - X*riy - Age distribution of subjects 30 yr 31-40 yr 41-50 yr > 50 yr 20 78 123 35 133 197 106 17 17 45 55 15 119 158 67 9 Source of variation Age PVC dust exposure Interaction Error Degrees of Sum of Mean freedom squares squares 3 30.9713 10.3238 1 0.7843 0.7843 3 0.9882 0.3294 1188 227.9403 0.1919 *p < 0.01. *p < 0.05. F 53.81* 4.09b 1.72 t<s October 1981 155 UCC 084260 Figure 4. Chest x-ray of > worker exposed to PVC dust for 20 yesrs. Profusion ei 2/1; type p-s. PVC + X-ray + X-ray - PVC- X-ray + X-ray - Table 5. Nonsmokers 40 - 147 2$ 127 Smokers 216 308 107 226 Source of Variation Age PVC dust exposure Interaction Error *p < 0.01. 156 Table 6. Degrees of Sum of freedom squares 1 7.8850 1 1.7847 1 0.1023 1192 251.9125 Mean squares 7.8850 1.7847 0.1023 0.2113 F 37.31* 8.44* 1.0 Figure 5. Right hemithorax of the sune subject is in Fig < Environmental Health Perspectives UCC 084261 Alien exposure is held constant, habitual smoking s responsible for 17.1% of the changes. When molting habits are held constant, exposure to PVC iuM is shown to be responsible for 8.9% of the i4*v abnormalities. Our epidemiological study confirms experimental md pathological data already reported regarding ,j* effects of PVC dust. Lung changes are directly related to PVC dust exposure, whereas VCM exposure alone fails to cause these changes. There fore, we believe that pulmonary changes are not pathogenically similar to other vinyl chloride in duced abnormalities, that is fibrosis of the liver, scleroderma-like skin changes, and peripheral vas cular damage. In our study there was only a 1.6% prevalence of pneumoconiosis in the total population, but in the workers exposed to effective risk of pneumoconio sis (731 subjects) the prevalence rose to 2.7%. Apart from 20 cases of pneumoconiosis, mild nonspecific alterations (profusion of 0/1 class) were found in the group exposed to PVC dust and in the group exposed to VCM alone. Such changes are related mainly to age and smoking habits, and the role of exposure is minor. & October 1981 UCC 084262 157 Excess Lung Cancer Risk in a Synthetic Chemicals Plant by Richard J. Waxweiler,* Allan H. Smithft Henry Falk* and Herman A. Tyroler** .4 standardized mortality ratio of 1.49 for respiratory system cancer (42 observed deaths versus 2v2 expected, p < 0.01) was observed among a cohort of 4806 males employed at a synthetic i hemicals plant since its startup in 1942. Upon review of pathologic material, the excess was found to be limited to adenocarcinoma and large cell undifferentiated lung cancer. Many of the workers had been exposed to vinyl chloride, as well as to chlorinated solvents, poly<vinyl chloride) (PVC) dust, acrylates and acrylonitrile. To evaluate the association between lung cancer and occupational chemical exposures, detailed work histories for each cohort member w ere combined with exposure ratings for each of 19 chemicals for each job for each calendar year Mnce 1942. A serially additive expected dose model was then constructed which compared the doses of the chemicals observed for the lung cancer cases to the doses expected based on subcohorts without lung cancer individually matched to the cases. PVC dust appeared to be the most likely etiologic agent <p 0.037). Time trends of PVC dust exposure indicated a potential latent period of 5-16 years before death. Introduction Our previously published (1) retrospective cohort mortality study of workers exposed to vinyl chlo* r.Jr mononvr (VCM) at a synthetic chemicals plant drmonstratrd an excess risk of death from respira tory system cancer in addition to the already recognized association between VCM exposure and angiosarcoma of the liver {2-10). Preliminary re new of the lung cancer cases indicated they were all adenocarcinomas or large cell undifferentiated tumors--an unusual histologic distribution. Although lung tumors have been induced exper imentally by exposure to VCM (2), the epidemiologic 'Industry-wide Studies Branch, Division of Surveillance, Hazard Evaluation* and Field Studies, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, Cin cinnati, Ohio 45226. 'Depart:'lent of Community Health, Wellington Clinical School of Medior.t , Wellington Hospital, Wellington 2, New Zealand. {Division of Chronic Diseases, Center for Environmental Health. Centers for Disease Control, Atlanta, Georgia 30333. **Depi.r.ment of Epidemiology, School of Public Health, VDiversity of North Carolina, Chapel Hill, North Carolina 27514. data are suggestive but equivocal. Two cohort studies found no excess lung cancer risk U-6). In six other studies, elevated lung cancer risks were found overall or among subcohorts; however, few of these excesses were statistically significant due to moderate excess risks and/or small numbers of cases (7-9,11-18). Because of the uncertainty in the literature regarding the association between VCM exposure and lung cancer and because of the diversity of occupational chemical exposures experienced by the lung cancer cases in our previous study (l), we decided to evaluate our cohort fijrther to determine whether or not lung cancer was associated with VCM or with other chemical exposures. Thus, the following research had three objectives: (1) by using a retrospective cohort design, to determine if our previously published excess lung cancer risk among employees exposed to VCM at this synthetic plastics plant also existed for the total plant popula tion (2) by using a case-comparand study, to de termine whether an excess lung cancer risk of a particular histologic type was in force at the plant and (3) by using a serially additive expected dose model, to test whether one or more particular October 1981 159 UCC 084263 ) chemicals used at the plant were associated with either the excess risk of all or of a specific histologic type of lung cancer. Methods and Results Retrospective Cohort Study The population at risk for the retrospective co hort study consisted of the 4806 males ever em ployed at this plant from its opening in 1942 until December 31, 1973. In the absence of individual data on race, everyone was assumed to be white because the company indicated that less than 2% of the population had been nonwhite. Date of birth and detailed work histories at this plant of all jobs and dates worked by each individual were coded. By follow-up of all study members from the first date hired at the plant through December 31,1973, it was determined that 4174 were alive and 559 had died. The 73 (1.5%) persons lost to follow-up were considered alive throughout the study. The 16 (3%) deceased persons for whom no death certificates could be located were assumed dead, cause of death unknown. A modified life table analysis (NIOSH) was used to obtain person years at risk of dying by five year age and calendar time periods. United States white male death rates specific for five year age and calendar intervals were used to calculate the expected deaths and standardized mortality ratios (SMR's). SMR's were tested for statistical significance using the Poisson distribution (one sided). The cohort was young; by December 31, 1973, only 30% of the cohort, if alive, would have been over 54 years of age. However, 63% of the cohort had been hired before 1954 and thus had the oppor tunity to achieve 20 years' latency. Two separate analyses of the cohort were made. Initially, all members were considered at risk from their first date of employment at the plant. This analysis yielded 556 observed and 550 expected deaths (Table 1). Risk of death due to malignant neoplasms of the central nervous system (SMR * 209) and respiratory system (SMR * 149) were both significantly elevated. A second "over tenyear latency" analysis was carried out by beginning person-years at risk only after an individual had achieved the tenth anniversary of his first date of employment at the plant. Results similar to those in the first cohort analysis were found but with slightly higher SMR's. Respiratory system cancer had an SMR of 156 based on 39 observed cases. Because our previously published analysis (1) of just the presumably VCM-exposed workers at this plant 160 Table 1. Observed and expected death* among chemical tim worker cohort. Cause (ICDA-7 Code) Observed Expected SXP. All causes All malignant neoplasms 556* 550.2 101 (140-205) Digestive system (150-159) Respiratory system (160-164) Central nervous system (193) Lymphatic and hematologic 109 24 42 9 92.5 lie 25.6 28.2 14S-' 4.3 20? (200-205) Other cancers 9 11.4 78 25 23.0 108 Five person*, including three of the original 339 deaths, at* not included in the cohort analysis because of missmj ion histories. < 0.01. *p < 0.06. also found an SMR of 156 after 10 years latency, these results indicate an excess lung cancer risk no: solely due to VCM exposure. Case-Comparand Study The second objective of this study was to deter mine whether an excess risk existed for a particular histologic type of lung cancer. Because no historical data exist on histology-specific lung cancer inci dence or mortality rates and because histologic classification is somewhat variable between pathol ogists and over time, a case-comparand design war chosen to accomplish the second objective. Medical records and pathology reports were ob tained on all deceased members of the cohort whose death certificates mentioned cancer or respiratory disease. For 45 cohort members, primary or un specified lung cancer was reported on at least one of these three records. A few persons who died after December 31, 1973, the cohort ending date, were included. Of the 45 cases, 42 were bom in Kentucky or an adjacent state. Histologic material was re quested. The worker case group consisted of the 27 of the 45 deceased individuals for whom histologic specimens were available. As a comparison group, the lung cancer case? (comparands) most closely preceding and succeed ing the chemical plant worker case in the chronolog ically ordered hospital pathology logs were selected that matched in age at diagnosis, sex, race, and county of residence. For four cases, only one matched comparand could be found. Histologic material was reviewed by a panel of pathologists unaware of the employment histories (case versus comparand status) of the deceasedThe histologic type distributions, according to the Environmental Health Perspective* UCC 084264 *'kuh, ,, jmi-'`inr "s Jatenn errisJtr,;.; to deter^rticular rifi! ^Per inci- listolopc n pathol$ign u a, vere obrt whose piraton>' or unst one of ed after e, were -Mucky was ref the 27 stoiogic r cases icceedmologelected e, and atched mel of tones *d. i ,oe S'vet ,f.tru*' Administration classification scheme (U), compared between the cases and comparands. T:.r results of the majority opinion of the pathol. pjnt.| are listed in Table 2. The panel found a ,l-..f.cantly (p < 0.05, chi-square) higher percentJ of urge cell undifferentiated (type 4) cancers L- v the worker cases than among the community * 'Trarands (3(Kr vs. 10%). hi using the SMR for respiratory system cancer jin in the retrospective cohort study and the curved and expected histologic distribution of cancer deaths based on the case-comparand ;y. Table 3 demonstrates the calculation of his -. specific lung cancer SMR's (column C). If the ' cx-es for which histologic specimens were availj.*.r are considered representative of all 45 lung vw cases, it appears the excess lung cancer risk ir; ars limited to types 3 and 4, adenocarcinoma i' 1 large cell undifferentiated, with the greater -A due to the latter. Approximately 13.5 of the :i -* excess lung cancers among the plant workers -aid be due to adenocarcinoma and large cell differentiated carcinoma.'' I: appears that there is a histology-specific ex.V-- lung cancer risk among workers at this plant *.'1 that this differential distribution of cell types is Table 2. Cut and matched comparand histologic distribu tions. ologir type Veterans Ad Frequency ministration Community classification Worker comparand code cues cases Epidermoid cell undifferentiated Adenocarcinoma Large cell undifferentiated Other Total 1 2 3 4 -- 6 (2241) 15 (30%) 6 (22%) 15 (30%) 7 (26%) 14 (28%) 8 (30%) 6 (10%) 0 1 ( 2%) 27 (100%) 50 (100%) not an artifact of the geographic region nor of the pathologist's techniques. The fact that this risk occurs for adenocarcinomas and for large cell undif ferentiated lung cancers makes it veiy unlikely that it is due to cigarette smoking. Serially Additive Expected Dose Model The third objective was to test whether any presumed occupational chemical exposures were associated with the excess lung cancer risk at the plant. It was decided to analyze the previously mentioned cohort data in a serially additive ex pected dose (SAED) model (10), obtaining for each lung cancer case the observed and expected doses of each chemical, conditional on certain characteris tics. The purpose of the SAED model is to compare the observed exposure of each case in a study with the exposures of fellow workers close to the case in year of birth, and in age at commencement of work at the company. If the total work force in the plant under study is referred to as the cohort, then each case can be thought of as belonging to a subcohort of workers with approximately the same year of birth and age at commencement of work in the plant. In each year that a case worked at the plant, his exposure can be compared with that of the other members of his subcohort who were working in that year. Company personnel compiled estimated exposures on a scale of 0 to 5 (5 being the highest exposure) for each of 19 chemicals (Table 4). Each job was as signed an exposure rank for each calendar year of the study (Table 5). These exposure data were then linked with work histories identifying the jobs each worker had in the plant and the calendar time involved. The analytical method is based on esti mating exposure dose by multiplying the exposure level by the number of days worked at that level. These "doses" are accumulated over a calendar year for a case to yield the observed dose and for Table 3. Histologic specific tuns cancer ri*k among plant personnel. Total Epidermoid Small cell Adenocarcinoma Large cell Histologic distribution Observed 01) Expected (B) 100% 22.2% 22.2% 25.9% 29.6% 96%' 30% 30% 28% 10% Histologic specific SMR C - 149 (AJB) 149 110 110 138 441 Excess cases among those pathologically reviewed (O)* 8. O' 0.6 0.6 1.9 6.2 *D (27 A) - (27 B x 100/149). (45 A) - (45 B x 100/149). 'Specif,; cell types do not add up to total because of "other" type lung cancer among comparands. October 1981 Total excess cases (E)b 14.F 0.9 0.9 3.2 10.3 161 UCC 084265 ! his subcohort to yield an expected dose for each year that a case works. The methodology has pre viously been described in detail elsewhere {10), In addition to testing the total-dose hypothesis, the SAED analysis facilitates examination of the observed and expected doses for each year of exposure before death. Exposures to 19 chemicals Tabic 4. Expo*urc ratine* end to dutifj job*. Rating Exposure No exposure Minimal exposure to low levels (chemical in building-- not handled, low vapor pressure and dust level, probably works on different floor) Moderate exposure (works around the chemical, but exposure is minimal) Works in areas where subject to occasional high excursions (normally exposure is minimal but occasional spills, leaks, or dust exposure may occur) Works in areas where level is high (exposure levels in the area are frequently high; might consider that some risk is involve*if chemical is very toxic) Intimate contact, skin or high inhalation (such as poly cleaners in earlier years handling slurry) Table 5. Chemical exposure ratings specific for job identification number and calendar year for a given chemical. Chemical #1, Exposure ratings job identifi cation number 1942 1943 1944 194S 1946 1973 1 000222 2 55565S 3 22 1 100 84 4 4 4 1 .1 1 were assessed; seven of the chemicals were, howete excluded from the formal analysis because so fet persons were exposed to them at levels 3, 4 and 5 (Table 6). The SAED model analysis resulted in the ob served minus expected cumulative dose differences per case in Table 7. The differences for PVC dust are striking in comparison with the other expo, sures. For the large cell undifferentiated caneg and adenocarcinomas combined and for large cell undifferentiated cancer by itself, the differences in exposure to PVC dust are three to four times as large as those estimated for vinylidene chloride, the Tabic 6. Frequency ofjob categories having at least one jtm of expooure greater than specific exposures levels.* Acrylic add Acrylamides Acrylonitrile Acetylene Acrylates Bisphenol A Butadiene Caprylyl chloride Chlorinated solvents Chloroethyl vinyl ether Diethyl maleate Mercuric chloride Methanol Phenol Toluene Vinyl chloride Vinylidene chloride Vinyl acetate PVC dust No. at each exposure level 1 2 3 4$ 13 4 3 0 0 14 4 4 0 0 36 25 13 6 1 20 17 10 3 1 39 30 21 8 2 7 2 0 00 23 15 9 5 1 25 9 6 6 3 30 18 7 4 4 22 6 4 1 0 14 6 0 0 0 15 7 5 3 3 30 21 14 2 2 2 1 0 00 2 0 0 00 55 40 29 21 4 20 14 8 5 2 26 18 10 0 0 56 32 19 9 6 E g., for acrylic acid, employees could have worked in 13 different job categories that had exposure levels o; one or higher in at least one calendar year between 1942 and 1973. Table 7. Observed minus expected cumulative doee differences per lung cancer i Chemical All lung cancers Pathologically reviewed cases Adenocarcinoma and large cell Acrylonitrile Acetylene Acrylates Butadiene Caprylyl chloride Chlorinated solvents Mercuric chloride Methanol Vinyl chloride monomer Vinylidene chloride Vinyl acetate PVC dual -652 -353 -322 -330 -547 -868 -507 -430 -1428 -341 -707 763 -402 -289 -251 -207 -258 -672 -425 -618 -795 210 -480 2448 -446 291 -83 -406 -270 -150 -211 -456 26 804 -217 3225 Large cell -128 -167 -339 -622 -1139 749 -62 -1078 907 1525 328 4526 162 Environmental Health Perspectives UCC 084266 i however, iae so few 3, 4 and 5 in the ob> lifferences ^VC dust her expoed cancer large cel] erences in " times as loride, the tft one year leveli.* ire level 45 0 0 8 8 0 5 ~ 0 3 2 0 0 -1 5 0 9 0 0 1 1 2 0 1 J 0 0 3 2 0 0 4 2 0 6 rked in 13 e or higher i. ell 4 next most evident chemical. The significance levels ofthe larger of these differences are found in Table g for the total cumulative doses and also for cumula tive doses until 10 years before death. Statistical agnificance was observed only for exposure to PVC dust. Latency analysis for PVC dust (Fig. 1) shows a peak for the difference between observed minus expected dose during the period 5 to 16 years before death. As the diagnosis of the disease of interest becomes more narrowly defined as a patho logically homogeneous entity, the dose difference per case increases, yet the implied latent period stays constant. Discussion The first objective of this study was to determine if the excess lung cancer risk among employees exposed to VCM also existed for the total plant population, including those persons not exposed to VCM. The retrospective ephort mortality study showed that respiratory system cancers occurred approximately 50% more frequently among the em ployees of the entire plant than would have been expected based on age, sex, race, and calendar year specific United States death rates. A similar excess had been previously shown to exist among the subcohort of employees exposed to VCM (1). Thus, the excels lung cancer risk at the plant appeared to be independent of VCM exposure unless one hy pothesized that it was due to extremely low levels of VCM that could have permeated throughout the plant. Potentially confounding variables are age, sex, calendar year, race/ethnicity, migration, urban res idence, cigarette smoking and socioeconomic status (SES). In the retrospective cohort study, age and calendar year cannot confound because they are adjusted in the results. All persons in the study are male and 98% are presumed white. White male specific rates were used for comparison to control those potential confounders by subject category re striction. Ethnicity and migration (both inter- and intracountry) effects are considered minimal for all three study designs because 42 ofthe 45 cases were born in Kentucky or an adjacent state. Urban resi dence is mainly associated with an excess of epidermoid and small cell undifferentiated lung can cer (15) rather than the histologic types of lung cancer found in excess in this study. Excess lung cancer risk is associated with low socioeconomic status (25,17), measured either by education (rela tive risk of 1.2 for persons with fewer than eight years of school) or by occupation (relative risk of 1.3 for laborers). Since the cohort consists of a mixture of socioeconomic status levels, there is probably insignificant confounding due to SES at the plant considered as a whole. Furthermore, recent infor- Table 8. Probability value of paired f-teiti of cumulative difference* between observed and expected doee* for luni cancer cases. 10 or more Total years before (all yaars)* death All cases (.V - 45) PVC dust All pathologically reviewed cases C.V > 27) PVC dust Adenocarcinoma and large cell (A? 15) PVC dust Vinyl:dene chloride Urge cell (N - 8) PVC dust Chlorinated solvents Vinyhdene chloride 0.185 0.026b 0.037* 0.267 0.068 0.360 0.201 0.253 0.047* 0.061 0.333 0.177 0.435 0.322 "Twelve chemicals were tested for each lung cancer group, thus, under an assumption of independence of tests, one would eniect or.* test to be significant at the 0.08 level. V < 0.05. October 1981 Figuxe 1. Observed minus expected dose differences per esse smong lung cancer cases for PVC dust. 163 UCC 084267 mation indicates that these risk gradients may be partially due to smoking patterns (18, 19), which would affect epidermoid and small cell undifferenti ated lung cancers. The second objective of this research was to determine whether an excess lung cancer risk of a particular histologic type existed. The case-comparand study showed that there was an excess of adenocar cinomas and large cell undifferentiated lung cancers among the cases occurring among plant employees compared to other lung cancer cases from the same community. Because the pathologists reviewed both sets of slides without knowing which were those of plant employees, it is unlikely diagnostic biases occurred. Histologic specimens were more difficult to find among the cases which died earlier and which were older on the date of death. However, community comparands were matched with the cases on age and date of diagnosis and had to have specimens available themselvesphence a biased ascertainment by histology between cases and comparands would be unlikely. The choice of community comparands makes it unlikely that a community wide pollutant was responsible for the excess risk at the plant for types 3 and 4 lung cancer. Consequently, it can be inferred from Table 3 that the excess lung cancer risk in the cohort was limited to adenocarcinoma and large cell undifferentiated cancer. Adenocarci nomas, accounting for a minor proportion of this excess risk, have been shown to be weakly, if at all, related to cigarette smoking (lb, 20-29) Large cell undifferentiated carcinoma of the lung is the only major histologic type that has appeared to be unrelated to cigarette smoking. Thus, ciga rette smoking was probably not a major confound ing variable. However, the role of smoking as a promoter or cocarcinogen cannot be ruled out. Nev ertheless, the conclusion of this phase of the inves tigation was that an excess risk occurred among plant employees for types 3 and 4 lung cancer, especially type 4. The third objective was to test whether one or more particular chemicals used at the plant were responsible for either the excess risk of all lung cancer or of the types 3 and 4 or just type 4 lung cancer. The SAED model was specifically devel oped for this objective. The major hypothesis was tested for each chemi cal in the SAED model by using the one-sided t-test of the observed minus expected cumulative doses over all years before death and ten or more years before death (Table 8). PVC dust was the only chemical that was statistically significant. These results suggest that an excess of types 3 and 4 lung cancer exists at this plant and is related to PY( dust exposure. The suggestion of PVC dust being a lung carte, ogen is biologically plausible. Almost all PVC par., cles produced by the emulsion system, one of tit systems at this plant, are in the respirable nn;(23). These particles could settle in the lungs arc conceivably by themselves cause lung cancer. 1; fact, one case of supposedly PVC dust-induced pne> moconiosis has been found in a worker (24), an: pulmonary granulomas (25, 26) have been induct in animals exposed to PVC dust. In a large proper tional mortality study of 4341 deaths that occum< among PVC fabricators, persons expected to bt exposed to VCM and PVC dust demonstrated! slight (PMR = 117) excess lung cancer risk (2h VCM gas is easily inhaled, and possibly would fat in contact with tissue only a short time before being either exhaled or absorbed into the bloodstream. However, VCM becomes entrapped in the PVC dust and can be released slowly over time. Thu-. PVC dust particles in the lung may slowly relea* VCM to small adjacent areas of the'tissue, prolong ing the contact time of that chemical to tissue. Lf this latter hypothesis is true, then it begs thr question of why almost all of the liver angiosarcoma cases occurred among polymer reactor cleaners vh received extremely high VCM doses while the lung cancer cases occurred frequently among the les.heavily exposed workers. In fact, there was ik relationship between VCM and lung cancer in thfc analysis; yet, one would expect the lung to be the major route of entry for VCM regardless of the cancer site. REFERENCES 1. Waxweiler, R. J., Stringer, W., Wegoner, J. K-, Jones. J. Falk, H., and Carter, C. Neoplastic risk among workerexposed to vinyl chloride. Ann. N.Y. Acad. Sd- 271: <0-t* (1976). 2. Maltoni, C. Vinyl chloride carcinogenicity: an experiment model for carcinogeneaia studies. In: Origins of Hums' Cancer. H. H. Hiatt, J, D- Watson, and J. A. Winner.. Eds., Cold Spring Harbor Labs., Cold Spring Hartior. N.Y., 1977. 3. Thomaa, L. B., Popper, H., Berk, P. D., Selikoff, 1. and Falk, H. Vinyl chloride induced liver disease--from idi* pathic portal hypertension (Banti's syndrome) to mri" sarcomas. N. Engl. J. Med. 292:17-22 (1975). 4. Nicholson, W. J., Hammond, E. D., Seidman, H.. Selikoff, I. J. Mortality experience of a cohort of w>l chloride-polyvinyl chloride workers. Ann. N.Y. Acad. So 246: 225-230 (1975). 5. Duck, B. W., Carter, J. T., and Coombes, E. J. Mortal::? atudy of worker* in a polyvinyl chloride production plar.: Lancet 2:1197-1199 (1975). 6. Berry, G., and Roaaiter, C. E. Vinyl chloride and mortaln? Lancet ii: 416-417 (1976). 184 Environmental Health Perspective! UCC 084268 Pv in8 care;. PVCpj,,. one oft.., able nr., lungs u. cancer. j'Jcedpne ` <*>. r': -H induce & pro^r 1 occunvted to b istrated * . ur, " ould U fore beiry xistrean; the PV( W. Thu-. v reW prolongtissue. begs the >sarcomi ners wh< the lung - (>t M G - Lsngner, R. R., and Holder, B. B. Vinyl >eionde exposure in a controlled industrial environment. Vtk Environ. Health SO: 333-339 (1975). . Eeuitable Environmental Health, Inc.: Epidemiologic atudy rf vinyl chloride worker*. Final report submitted to the gmufaetunng Chemists Association, 1978. , Foi A. J.. and Collier, P. F. Mortality experience of eorken exposed to vinyl chloride monomer in the manufac ture of polyvinyl chloride in Great Britain. Brit. J. Ind. Med 34:1-10 (1977). Smith, A. H.. Waxweiler, R. J., and Tyroler, H. A. Epidemiologic investigation of occupational carcinogenesis uung a seriallv additive expected doee model. Am. J. Epid. 112: 787-797 (1980). Fox. A. J-. and Collier, P. F. Low mortality rates in industrial cohort studies due to selection for work and arrival in the industry. Brit. J. Preven. Soc. Med. 30: 223-230 (1976). 2 Baffler. P. A.. Wood, S., Clayton, E., Suarez, L,, and ~ Kilian. D J. Mortality experience of workers in a vinyl chi-ride* monomer production plant. J. Oceup. Med. 21: 193-203 (1979). ;> Byrtn. D.. Engholm, G., Engiund, A., and Westerholm, P. Mortality and cancer morbidity in a group of Swedish VCM and PVC production workers. Environ. Health Perspect. 17:167-170 (1976). :t Vesner, R., Gelftnan, N. A., and Feinstein, A. R. A reappraisal of histopathology in lung cancer and correlation of cell tvyt - with antecedent cigarette smoking. Am. Rev. Resp. Dis 107: 790-797 (1973). * ; Haenszel. W,, Loveland, D. B., and Sirken, M. G. Lung cancer m -rtality as related to residence and smoking histories. I. White males. J. Natl. Cancer Inst. 28:947-1001 H962). 1C Kitagawa. E. M., and Hauser, P. M. Differential Mortality in the United States: A Study in Socioeconomic Epidemiolo gy. Harvard University Press, Cambridge, Mass., 1973. 17. Guralnick, L. Mortality in 1950 by occupation and industry. Vital Statistica-Spedal Reports 53, 1-5, U.S. Dept. HEW, 1961-1963. 18. Sterling, T. D., and Weinkam, J. J. Smoking characteristics by type of employment. J. Occup. Med. 18: 743-754 (1976). 19. Winkelstein, W., Jr. Contemporary perspectives on preven tion. Bull. N.Y. Acad. Med., 51: 27-28 (1975). 20. Doll, R., and Hill, B. Mortality in relation to smoking; ten years' observations of British doctors. Brit. Med. J. 5395: 1399-1410 (1964); ibid. 5396:1460-1467 (1964). 21. Weiss, W., Boucot, K. R., and Seidman, H. Risk of lung cancer according to histologic type and cigarette doeage. J. Am. Med. Assoc. 222: 799401 (1972). 22. Auerbach, O., Garfinkel, L., and Parka, V. Histologic type of lung cancer in relation to smoking habits, year of diagnosis and sites of metastasis. Chest 67: 382-387 (1975). 23. Jones, J. H. Worker exposure to vinyl chloride in vinyl chloride and polyvinyl chloride production and fabrication. NIOSH Technical Report Draft, January, 1978. 24. Szende, B., Lapis, K., Nemes, A., and Pinter, A. Pneumo coniosis caused by the inhalation of polyvinyl chloride dust. Med. Lavoro 61: 433-436 (1970). 25. Frongia, N., Spinazzola, A., and Bucarelli, A. Experimental lung damage from prolonged inhalation of airborne PVC dust. Med. Lavoro 65: 321-342 (1974). 26. Agarwal, D. K., Raw, J. L., Srivaatava, S. P., and Seth, P. K. Some biochemical and hiatopathological changes induced by polyvinyl chloride dust in rat lungs. Ind. Tox. Res. Center Report, Lucknow, India, 1978. 27. Chiazze, J., Jr., Nichols, W. E,, and Wong, O. Mortality among employees of PVC fabricators. J. Occup. Med. 19: 623-628 (1977). thU o be the S Of the ones. J.. w orkery. "1: 40-ts rimental .Human msten. Harbor. I . ind m idioanpo- and vinvl =d. Sd. rtality plant. talky? October 1981 165 UCC 084269 * < according to the ILO U/C Classification. All these platelet aggregation and conversion of fibrinogen u cases were found among PVC exposed employees. The pattern of radiologic abnormalities described is very similar to that reported in the case in which the lung biopsy revealed fibrosis and granuloma fibrin with polymerization. Occlusion of small ve*. sels results, and ischemia stimulates new collage: biosynthesis. Similar abnormalities of the immunologic statu? l. Ana and ( 33: It t MW 4 tous reaction, with inclusion of PVC particles. were found in another study of 22 workers exposed G*mi The same study reported the presence of less to vinyl chloride, with Raynaud's syndrome and. ir. marked radiologic abnormalities, of the linear- some cases, acroosteolysis. Latent cryoglobulinemia nvl c fOSK 3. Souti reticular type, in a much larger proportion (32%) of was detected in 18 cases, with increases ofimmunu K. a the population examined; these changes were pres noglobulins, IgA and IgG (18). disea ent both in VC monomer exposed and in PVC exposed employees. While the prevalence was higher in smokers than nonsmokers, 65 of the 388 Circulating cryoimmunoglobulins are a promi nent feature of idiopathic pulmonary fibrosis in and increased IgG levels have been shown to be I'ap* of Vi tural pubL x-rays with linear-reticular opacities were found in characteristic for bronchoalveolar lavage fluid of 4. Szcn persons who had never smoked. such patients. ns e In another large epidemiologic study (8), expo Interstitial pulmonary fibrosis is a possible effect sure to respirable PVC dust was found to be of vinyl chloride exposure. The occurrence of more Lave 5 Lilia Fisc associated in a proportion of exposed workers with dramatic and specific abnormalities in other orgar. mo the presence of small rounded opacities on the chest systems--liver, spleen and peripheral circulation- NY radiograph and a decline in mean ventilatory capac ity. 's The question of pulmonary effects due to vinyl chloride monomer continues to be of great interest. has probably prevented more focused attention or. pulmonary effects of vinyl chloride in the past. | Long-term effects of vinyl chloride include well documented carcinogenicity. Lung cancer has be-- 6. Lilii Pulr or T. LilL< Moc The multi-organ effects of vinyl chloride include the peculiar syndrome of acroosteolysis, sclerodermalike skin changes, vascular changes affecting the arteries, arterioles and capillaries of hands and found to occur with an increased incidence u. several mortality studies (20-22). Abnormalities ir sputum cytology tests have been found to be mort i frequent in VC/PVC-exposed workers than in other ! pol} 5. Wej G. prtx S Mill fingers, liver and spleen capsular fibrosis, liver chemical industry employees and in smokers (14<. Cha fibrosis, abnormalities of the sinusoidal vessels in the liver, and portal hypertension. Ward (16) inves tigated the immunologic status of 58 workers from a VC polymerization plant. The findings included hyperimmunoglobuiinemia, cryoglobulinemia, cryo* fibrinogenemia, in vivo complement activation via the classic pathway, with C4 and C3 conversion and an increase in the B cell lymphocyte population. In experiments on mice, Suzuki (24) has describee | hyperplastic changes of the alveolar lining cells and ; pulmonary tumors in the majority of exposed animals. The ultrastructure was thought to indicate that the tumors originated in type II alveolar cel.? Alveologenic tumors were also described in several other experimental studies (25-27). Interestingly, other known carcinogens, such as polycyclic aro chic 4.'-; 10. Bor of exp 11. Lit SOK Svs J5. aid; ibnc Immunofluorescent examination of skin, muscle and lung biopsy specimens revealed the presence of circulating immune complexes, with deposition on the vascular endothelium and occlusion of small matic hydrocarbons, nitrogen mustard and chro mates, produce pulmonary tumors in experimental animals similarly, originating in the type II alveolar cell. tur* 22-Z 13. Will akin vessels. Immunoglobulin, complement and fibrinogen The effects of vinyl chloride-poly(vinyl chloride deposition in the subintimal regions of the vessel exposure on the respiratory system of exposed were found in areas with subintimal fibrosis and workers seem to indicate two patterns of nonmalig- luminal occlusion. nant effects: a granulomatous reaction to P\C Grainger et al. (IT) have accumulated evidence dust, with inclusion of PVC particles in macro suggesting the following mechanism: the vinyl phages and histocytes and associated interstitial chloride metabolite cyclic chlorethylene epoxide, an fibrosis, and an interstitial pulmonary fibrosis due alkylating agent with high biological activity binds to vinyl chloride monomer effects on protein ma to IgG producing structural conformational changes cules and the immunologic mechanisms triggered that promote aggregation of IgG molecules. The by the altered protein. modified IgG may also become antigenic. The IgG The long-term carcinogenic effect, with a significant aggregates are cryoprecipitable and may initiate increase in the incidence of lung cancer, also is o. complement activation. Precipitation of IgG aggre concern, although the magnitude of this effect has gates by cold leads to complement activation, not yet been completely evaluated. 168 UCC 084270 Environmental Health Perspective* Octo mogenti small vtv v Co%v: Sic statu, s expose ie and, ir, ulinemii mununu- * promi"&sis (;>, vn to bt fluid of ile effect of more er organ ilation-- ntion on ast. jde well ias be-\ ence it, lities in * more I ','in other r.-^ed ells and xposed ndicate ir ceJi. several singly, ic aro' chroTiental veolar >ride) :posed malig- PVT lacrostitial s due .nolegered ficant is of t has REFERENCES *niiid. A.. Pomniier de Santi, P. Garbe, L.t Payan, H., md Chsrpin, J. Polyvinyl chloride pneumoconiosis. Thorax S 19-25 (19*8). jujwingelo. G., Manno, M., Marcer, G., Bertolucci, G., ' omi*nani, C., Saladino, G., Simonalo, L., Saia, B. Polyvi- rvl chloride pneumoconiosis: epidemiological study of exworkers. J. Occup. Med. 21: 540-545 (1979). ioctar, C. A.. Copland, L. H., Thoniley, P. E., Hurley, J. F.. and Ottery, J- An epidemiological study of respiratory diiwase in workers exposed to polyvinyl chloride) dust. Paper presented at Conference to Reevaluate the Toxicity of Vinyl Chloride Monomer, Poly(vinyl Chloride) and Struc tural Analog*. Bethesda, Md., March 1980; not received for publication. I Saende, B.. Lapid, K., Nemes, A., Pinter, A. Pneumoconioris caused bv the inhalation of polyvinyl chloride dust. Med. Uvoro 61: 433-436 (1970). , Li*. R,, Anderson, H. A., Nicholson, W. J., Daum, S., Fuchbein, A., and Selikoff, I. J. Prevalence of disease among vinvl chloride and polyvinyl chloride workers. Ann. N.Y. Acad. Sci. 246: 22-41 (1975). ,; Libs. R-. Anderson, H., Miller. A. and Selikoff, I. J. Pulmonary changes among vinyl chloride polymerization workers. Chest 69: 2, Supplement, 299-303 (1976). T Lilia. R., Anderson, H. A., Miller, A., Selikoff, I. J. Modifications pulmonaires et exjfosition au chlonire et polvchlorure de vinyle. Med. Hyg. 35:1542-1545 (1977). Wegmen. D. Discussion in: Lange, C.-E., Juhe, S., Stein, G.. and Veltman, G. Further results in polyvinyl chloride production workers. Ann. N.Y. Acad. Sd. 246:18-21 (1975). h Miller, A , Teustein, A. S., Chuang, M. and Selikoff, I. J. Changes in pulmonary function in workers exposed to vinyl chloride and polyvinyl chloride. Ann. N.Y. Acad. Sci. 246: e52 (1975). I" Berk, P. D., Martin, J. F. and Waggoner, J. G. Persistence of vinyl chloride induced liver injury after cessation of exposure. Ann. N.Y. Acad. Sci. 246: 70-77 (1975). II Lange, C.-E., Juhe, S., Stein, G., Veltman, G. Die . sogenannte Vinyl-chlorid-Krankheit--Eine berufsbedingte Svstemsklerose? Inter. Arch. Arbeitsmed. 32:1-32 (1974). L' Walker. A. E. A preliminary report of a vascular abnormalr.y occurring in men engaged in the manufac ture of polyvinyl chloride. Brit. J. Dermatol. 93 (SID: 22-23 (1975). 13. Walker, A. E. Clinical aspects of vinyl chloride disease: skin. Proc. Roy. Soc. Med. 69: 286-290 (1976). 14. Frongia, N., Spinazzola, A., and Buearelli, A. Lesioni polmonari sperimentali da inalazione prolungate di PVC in ambiente di lavoro. Med. Lavoro 65: 321-342 (1974). 15. Agarwal, D. K,, Kaw, J. L., SrivasUve, S. P., Seth, P. K. Some biochemical and histopathological changes induced by polwinyl chloride in dust in rat lung. Environ. Res. 16: 333-341 (1978). 16. Wsrd, A. M., Udnoon, S., Watkins, J,, Wslker. A. E., Darke, C. S. immunological mechanisms in the pathogene sis of vinyl chloride disease. Brit. Med. J. 1:936-938 (1976), 17. Grainger, R. G,, Walker, A. E., Ward, A. M. Vinyl chloride monomer-induced disease: clinical, radiological and immuno logical aspects. In: Induced Disease, Drug, Irradiation, Occupation. L. Preger (ed.), Gruhe and Stratton, New York, 1980, p. 191-214. 18. Langauer-Lewowicka, H., Dudziak, Z., Byczkowska, Z., and Marks, J. Cryoglobulinemia in Raynaud's phenomenon due to vinyl chloride. Int. Arch. Occup. Environ. Health 36: 197-207 (1976). 19. Crystal, R. G., Fulmer, J. D., Roberta, W. C., Mots, M., Line, B. R., and Reynolds, H. Y. Idiopathic pulmonary fibrosis: clinical, histologic, radiographic, physiologic, scin tigraphic, cytologic and biochemical aspects. Ann. Intern. Med. 85: 769-788 (1976). 20. Tabershaw, I. R. and Gaffey, W. R. Mortality study of workers in the manufacture of vinyl chloride and its polymers. J. Occup. Med. 16: 509-518 (1974). 21. Ott, M. G., Langner, R. R., and Holder, B. B. Vinyl chloride exposure in a controlled industrial environment. Arch. Environ. Health 30: 333-339 (1975). 22. Waxweiler, R. J., Stringer, W., Wagoner, J. K., and Jones, J. Neoplastic risk among workers exposed to vinyl chloride. Ann. N.Y. Acad. Sci. 271: 4048 (1976). 23. Mshorn. C. Precursor lesions in exposed populations ss indicators of occupational cancer risk. Ann. N.Y. Acad. Sci. 271: 444-447 (1976). 24. Suzuki, Y. Pulmonary tumors induced in mice by vinyl chloride monomer. Environ. Res. 16: 285-301 (1978). 25. Kepiinger, M., Goode, J. W., Gordon, D. E., Calandra, J. E. Interim results of exposure of rats, hamsters, and mice to vinyl chloride'. Ann. N. Y. Acad. Sd. 246: 219-224 (1975). 26. Lee, C. C., Bhandari, J. C,, Hause, W. B., Peters, P. J., Woods, J., Dixon, R. L. Inhalation toxirity of vinyl chloride (VC) or vinylidine chloride (VDC) in rata and mice. Pharma cologist 18: 245 (Abstr. 718) (1976). 27. Holmberg, B., Tronevi, T., and Winell, M. The pathology of vinyl chloride exposed mice. Acta Vet. Scand. 17: 328-342 (1976). October 1981 169 UCC 084271 4 1970 through 1978. The annual incidence rate for this period was also 0.25, almost double the expect ed rate of 0.14 per million in the United States (8). There are several possible explanations for these observations. New York is more industrialized than many other states, and it is possible that the exposed cohort might be larger. Increased recogni tion and reporting of this entity might also be a factor. Finally, relatively few workers have been exposed for a long time to high levels of vinyl chloride monomer. As Fox and Collier (17) point out, more than half of the people who have ever been exposed to VCM in the manufacture of PVC in Great Britain are currently employed in the industry; approximately 75% of men who have been employed in the industry have been employed for less than 10 years; only 8% have been employed for 20 years or longer; approximately half the persons who have teen exposed to VCM have been intermittently exposed; and only 10% of those who have been constantly exposed have been exposed to high concentrations. Thus it is possible that we are only beginning to sec the full impact of industrial exposure to VCM. This suggestion is supported by the observation of Monson et al. (18) that the relative frequency ofall cancers appears to be increasing with time in vinyl chloride workers. Other factors must also be considered in examin ing the frequency of ASL in our society. Working conditions in the manufacture of PVC have un doubtedly been influenced since the early 1940s. This was largely due to the recognition after 1957 that exposure to high concentrations of VCM can cause acro-osteolysis (19) and Raynaud-like phe nomena, and in the early 1970s that high concentra tions ofthis chemical increase the risk of dying from ASL (9). A reasonable assumption is that earlier workers were probably exposed to higher concen trations of VCM than those who entered this industry during the last decade. Interestingly, it has recently been suggested that the age at diagno sis and latency period for ASL might be increasing (15). If verified, these preliminary observations Table 1. Angioaarcoma of the liver (ASL) in reaidenta of New York State (excluding New York City), 1970-1978. of ASL Exposure Case Age Race* Sex diagnosis history6 Metastatic site Other tumors Type Year of Site diagnosis 1 60 W M 1970 Direct, VC Adrenal, omentum 2 45 W F 1970 Possible, VC Kidney, scalp, dura -- 3 45 W M 1970 Bone, adrensd -- 4 18 B F 1970 -- Spleen, lymph nodes -- 5 55 W F 1971 -- Spleen, omentum, adrenals. -- 6 7 68 4/12 w w M F 1971 1971 lymph nodes -- -- Lungs, adrenals, skin Lymphosarcoma Ileum 1955 -- 8 9 31 77 w0 F M 1972 Possible, VC Heart', brain, lungs, adrenals 1972 -- Spleen, marrow, lymph nodes -- --* 10 61 w F 1973 Direct, AS -- Fibromyxolipo- Knee 1969 urcoma 11 12 47 62 w w M F 1973 Direct, ThO, Brain, lymph nodes 1973 Possible, VC Spleen 13 63 w M 1973 -- Spleen, pancreas, adrenals, Mesenchymoma Liver 1973 -- Transitional Bladder 1973 brain, bone, lungs, lymph nodes cell carcinoma 14 69 w M 1973 _ -- -- 15 16 17 18 19 20 31 45 62 66 73 43 w w w w w w F M F M M M 1974 Possible, VC 1974 -- 1974 1975 Direct, VC 1975 1977 _ _ -- -- ---- Spleen, brain, lungs, duodenum -- --* -- -- -- 21 54 w F 1977 -- -- -- 22 23 24 63 83 46 w w w M F M 1977 1978 1978 -- -- -- -- -- -- -- --- W - White; B - black, O - oriental. 'VC - vinyl chloride, PVC ~ poly(vinyl chloride), As arsenic, ThO* - thorium dioxide; possible lived within one mile of VC or PVC factory. 208 Environmental Health Perspectives UCC 084272 T <n of of all vinv) invin 'kin* -* un1957 1 can phentraJ from arlier ncenthis l.v, it agnoasing (tions ? 1955 1969 1973 1973 j&ivM -light be of great importance in evaluating the Ability that lower doses of VCM might be ifiociated with ASL after a prolonged latency *riod. Apart from the risk of ASL associated with industrial exposure to VCM, the possibility exists jut nonoccupational exposure might also be asso rted with ASL. Block (20) has suggested that this disorder might result from chronic low level expo sure to this chemical. Landrigan and Heath (21) found cases of ASL among workers at two poly(vi nyl chloride) fabrication plants and in residents bring nearby. A study in New York State (16) found that five individuals with ASL (but no apparent occupational exposure to VCM) lived in closer proximity to polymerization and fabrication plants than their matched controls. In a study of 10 patients with ASL in Wisconsin (22), one patient lived near a chemical company that made plastics and resins. These observations might be fortuitous and must be tempered by the preliminary evidence suggesting that no excess of ASL is found among PVC fabricators (11). At present there is no conclu sive evidence associating this tumor with nonoccu pational exposure to VCM. However, this issue and a closely related one--that chronic low dose expo sure might be associated with an increased risk of ASL--require further evaluation. To fully appreci ate the potential magnitude of this issue, one must consider both residential proximity to plants and other potential sources of public exposure. Esti mates have been made that 4.6 million people live within five miles of United States monomer and polymer production facilities (23), During the years of uncontrolled emissions, it was calculated that the average exposure level to this population was approximately 17 PPB (23). Household use of aerosol products in enclosed spaces, even in short 30-sec bursts, could result in air concentrations of VCM as high as 400 ppm which can persist several hours after spraying (9,10). The Eiologic Spectrum of Vinyl Chloride Reference has already been made to the associa tion between VCM and acro-osteolysis, Raynaudlike disorders and ASL. It is also clear that this agent can induce nonmalignant liver disease. In Russia a form of chronic hepatitis was found in approximately 25% of VCM workers (24). In addi tion, Thomas et al. (25) documented the occurrence ofportal hypertension associated with hepatic fibrosis (Banti's syndrome) in a study of the hepatic tissues obtained from 20 workers with industrial exposure. October 1981 Of great concern is the growing evidence sug gesting that the spectrum of disorders associated with VCM might include certain other neoplastic diseases, pneumoconiosis and possibly excess fetal loss. Several mortality studies have been conducted in recent years. Monson et al. (18) found an apparent excess of lung and brain cancers. A slight excess of digestive tract, lymphatic and hematopoi etic tumors was also observed. A historical pro spective mortality study of 8384 men who had at least one year of occupational exposure to vinyl chloride demonstrated that cancers of the digestive system (primarily ASL), respiratory system and brain and lymphomas occurred more often than expected in those members with the greatest estimated exposure (26). Similar results were ob served by Waxweiler et al. (27) in a retrospective cohort study of workers from four plants engaged in the polymerization of vinyl chloride for at least 15 years. Although observed numbers in each of these studies are quite small, the strength of these observations fie in their consistency. In addition inhalation studies by Viola et al. (28), Maltoni (29) and Neplinger et al. (30) have demonstrated that this chemical induces adenomas and adenocarcino mas of the lung, neuroblastoma of the brain, lymphoma and various other tumors in a variety of animal species. Two other studies are notable for the different results obtained. A mortality study of over 4000 deaths among current and former em ployees of 17 PVC fabricators from 1964 through 1973 found an excess of cancers of the breast and urinary organs among white females (31). Fox and Collier (17) studied 7000 men who were at some time between 1940 and 1974 exposed to VCM and found no evidence to support the hypothesis that cancers other than those of the liver are associated with this agent. Vinyl chloride inhalation or PVC might cause abnormalities of pulmonary function and chest x-rays (32, 33). Szende et al. (34) was the first to describe pneumoconiosis due to PVC. Although PVC dust appears to be the major offender, Lilis et al. (32) showed that inhalation of this agent induced less severe respiratory function abnormalities than simultaneous inhalation of VCM and PVC. In a more recent study of 1216 PVC production work ers, 20 cases of pneumoconiosis were found. Dura tion of exposure was about 12 years, on the average, and never less than five years (35). This study also suggests that pulmonary changes are directly related to PVC dust, while VCM exposure alone fails to cause these changes (35). Available evidence also suggests that VCM is mutagenic (36), and workers appear to have an excess of chromosomal aberrations in lymphocytes 209 UCC 084273 I t when compared to nonexposed controls (37). Selikoff (38) found that fetal death rates among wives of VCM workers ranged from seven to 14 per 100 pregnancies. Infante et al. (39) conducted a case- control study of the pregnancy outcome among wives of workers exposed to VCM and found a significant excess of fetal loss in the exposed group. While suggestive, these observations require verification, particularly in view of the many fac tors known to influence pregnancy outcome. REFERENCES 1. Alrenga, D. Primary Angiosarcoma* of the liver, Int. Surg. 60: 198-203 (1975). 2. McMahon, H. E., Murphy, A. S., Bates, M. Endothelial-cell sarcoma of the liver following Thorotrast injections. Am. J. Pathol. 23: 585-595, (1947). 3. DaSilva Horta, J. Late lesions in man caused by colloidal thorium dioxide (Thorotrast). Arch. Pathol. 62: 403-118, (1956). 4. Roth, F. Chronic arsenic poisoning in vineyard workers of the Moselle with special reference to arsenic cancer. Z. Krebsforch, 61: 287-319, (1956). 5. Lander, J. J., Stanley, R. J., Sumner, H. W., Boswell, D. C., and AACH, R. D. Angiosarcoma of the liver associated with Fowler's solution (potassium arsenite). Gastroenterol ogy, 68: 1582-1586 (1975). 6. Creech, J. L., Jr., and Johnson, M. N. Angiosarcoma of the liver in the manufacture of polyvinyl chloride. J. Occup. Med., 16: 165-151 (1974). 7. Lee, F. I., and Harry, D. S. Angiosarcoma of the liver in a vinyl chloride worker. Lancet i: 1316-1318 (1974). 8. Heath, C. W., Falk, H., and Creech, J. L., Jr. Characteris tics of cases of angiosarcoma of the liver among vinyl chloride workers in the United States. Ann. NY Acad. Sci. 246: 231-236 (1975). 9. IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man, Vol. 7. International Agency for Research on Cancer, Lyon, 1974, pp. 291-305. 10. Key, M. M., Henschel, A. F,, Butler, J., Ligo, R. N,, and Tabershaw, I. R. Occupational Diseases--A Guide to Their Recognition. U.S. Department of Health, Education and Welfare, Washington, D.C., 1977, pp. 219-221. 11. Baxter, P. J., and Fox, A. J. Angiosarcoma of the liver as the certified cause of death 1963-1973. Lancet ii: 27-28 (1975). 12. Falk, H. and Waxweiler, R. J. Epidemiological studies of vinyl chloride health effects in the United States. Proc. Roy. Soc. Med., 69: 303-305 (1976). 13. Anon. Editorial: vinyl chloride and cancer. Brit. Med. J. 1: 590-591 (1974). 14. Hammond, E. C. and Selikoff, I. J. Two deaths of a rare cancer. Occup. Health Nursing 22: 17-19 (1974). 15. Spirtas, R. and Kaminski, R. Angiosarcoma of the liver in vinyl chloride/polyvinyl chloride workers. J. Occup. Med. 20: 427-429 (1978). 16. Brady, J., Liberatore, F., Harper, P,, Greenwald, P., Burnett, W., Davies, J. N. P., Bishop, M., Polan, A., and Vianna, N. Angiosarcoma of the liver, an epidemiologic survey. J. Natl. Cancer Inst., 59: 1383-1385 (1977). 17. Fox, A. J. and Collier, P. F. Mortality experience of workers exposed to vinyl chloride monomer in the manufac ture of polyvinyl chloride in Great Britain. Brit. J. Ind. Med. 34: 1-10 (1977). 18. Monson, R. R., Peters, J. M., and Johnson, M. N. Propor 210 tional mortality among vinyl-chloride workers Lan-. 397-398 (1974). 19. Lester, D., Greenburg, L. A., and Adams, W. R. Effeeutf single repeated exposure of humans and rats to Tar. chloride. Am. Ind. Hyg. Assoc. J. 24: 265-275 (1963). 20. Block, J. B. Angiosarcoma of the liver following Tar; chloride exposure. J. Am. Med. Assoc. 229: 53-54 (19T4i.' 21. Landrigin, P. J. and Heath, C. W,, Jr., in preparation. 22. Fiechtner, J. J. and Reyes, C. N., Jr. Angiosarcoma aft)* liver in a rural population: four cases diagnosed in a ft month period. J. Am. Med. Assoc. 236:1704-1706 (I97ti. 23. Nicholson, W. J. Cancer.following occupational exposure u asbestos and vinyl chloride. Cancer (suppl.) 39:1792-1801 (1977). 24. Puschin, G. A. Affection of the liver and bile duett k workers engaged in the production of some types of piattio Sov. Med. 28:132-135 (1965). 25. Thomas, L. B., Popper, H., Berk, P. D.. Selikoff, I., ad Falk, H. Vinyl-chloride induced liver disease. New EngLJ Med., 292:17-22 (1975). 26. Tabershaw, J. R., and Gaffey, W. R. Mortality study of workers in the manufacture of vinyl chloride aid u monomers. J. Occup. Med., 16: 509-518 (1974). 27. Waxweiler, R. J., Stainger, W., Wagoner, J. K., Jon**. J Neoplastic risk among workers exposed to. vinyl chloride Ann. N.Y. Acad. Sd. 271: 4548 (1976). 28. Viola, P. L., Biogotti, A., and Caputo, A. Oncogene response of rat skin, lungs and bone to vinyl chloride. Cancer Res. 31: 516-519 (1971). 29. Maltoni, C. Preliminary report on the carcinogenicity biousays of vinyl chloride. U.S. Dept, of Labor. Informal Fan Finding Hearing of Possible Hazards of Vinyl Chloride Manufacture and Use, Washington D.C., Feb. 1974. 30. Keplinger, M. L., Goode, J. W., Gordon, D. E., and Calandra, J. C. Interim results of exposure of rats, ham sters, and mice to vinyl chloride. Ann. N.Y. Acad. Sd. 2tt 219-220 (1975). 31. Chaizze, L., Nichols, W. E., and Wong, 0. Mortality among employees of PVC fabricators. J. Occup. Med., 19:62342s (1977). 32. Lilia, R,, Anderson, H.. Nicholson, W. J., Daum. S.. Fischbein, A. S., and Selikoff, I. J. Prevalence of disease among vinyl chloride and polyvinyl chloride workers. Ajul N.Y. Acad. Sd. 246: 22-41 (1975). 33. Miller, A., Tirstein, A. S., Chuang, M,, Selikoff, I. J., and Warshaw, I. Changes jn pulmonary fiinction in worker* exposed to vinyl and polyvinyl chloride. Ann. N.Y. Aad. Sd. 246: 42-52 (1975). 34. Szende, B., Lapis, K., Nemes, A., and Pinter, A. Pneumo coniosis caused by inhalation of polyvinyl chloride dust. Med. Lav. 61: 433-436 (1970). 35. Mastrangelo, G., Manno, M., Marcer, G., Bartolucd, G. B.. Gemignani, C., Saladino, G,, Simonato, L., and Spia, B. Polyvinyl chloride pneumoconiosis: epidemiological stud}'of exposed workers. J. Occup. Med. 21: 540-542 (1979). 36. Bartach, H., Malaveille, C., and Montesano. R. Human, rat and mouse liver-mediated mutagenicity of vinyl chloride m 5. typhimurium strains. Inst. J. Cancer, 15.429-437(1973). 37. Funes-Cravioto, F., Lambert, B., Lindsten. J., Ehrenberg. L., Natarajan, A. T., and Osterman-Golkar, S. Chromo some abberations in workers exposed to vinyl chloride. Lancet, i: 459 (1976). 38. Selikoff, I. J. Paper presented at N1EHS Conference Public Health Implications of Components of Plastics Manu facture, Pinehurst, N.C., July 1974. 39. Infante, P. F., Wagoner, J., McMichael, A., Waxweiler. R J., and Falk, H. Genetic risks of vinyl chloride. Lancet, i 734-735 (1976). Environmental Health Perspective* UCC 084274