Document M41oJZeLgeKpBnVdB1amYLaJM

Mortality Among Employees of PVC Fabricators Leonard Chiazze, )r., Sc.D.; William E. Nichols, Ph.D.; and Otto Wong, Sc.D. A cross-sectional mortality study of 4,341 deaths occurring among current and former employees of 17 PVC fabricators during 1964-1973 is presented. The objectives are: (1) to iden tify any angiosarcoma deaths among the employees of these fabricators, and (3) to examine the distribution of deaths by cause. No angiosarcoma deaths were found among the study group. Sex-race-cause-specific Proportionate Mortality Ratios (PMR's) were computed, using the corresponding U.S. mor tality as the standard. Among white employees, there appears to be an excess in total cancer mortality, particularly that of the digestive system. Observed deaths were found to exceed the expected in cancers of the breast and urinary organs among white females. Deficit mortality was observed in cirrhosis of liver among both male and female white em ployees. I he January 1974 disclosure of three deaths from angio sarcoma of the liver in a single vinyl chloride polymerization plant and the attention focused on this new occupational disease are well known A significant amount of information from animal ex perimentation and observation on humans engaged in the produc tion of vinyl chloride followed 1 However, there was no informa tion regarding the possible adverse effects on employees engaged in polyvinyl chloride (PVC) fabrication, where potential exposures were thought to be low and to result from the release of unreact ed monomer trapped in the resin. This issue was considered of great import because of the very large number of workers believed to be engaged in fabrication. In March 1974, representatives of PVC producers, who are members of the Organization Resources Counselors (ORC), Oc cupational Safety and Health Standards Croup, contacted ORC about the feasibility of a study of health risks to employees work ing with vinyl chloride and polyvinyl chloride. Since the National Institute for Occupational Safety and Health (NIOSH) was con ducting a study of vinyl chloride and resin producing employees, the scope of the proposed ORC study was limited to employees of from the Division of 8ioftati9t<$ nd Epidemiology, Department of Community Medione and international Health, Georgetown University School of Medicine Washington, DC 20007 IDr* Chtaue and Wong) and Organization Resouces Coun selors Inc Washington, DC 20006 (Dr NtchoHI companies engaged in the fabrication of PVC resin into finished products A number of alternative study designs was considered, and it was decided that a proportional mortality study would best meet the urgent need for information The study concentrated on deaths occurring during the ten-vear period 1964-197 3 among ac tive fabricating employees plus retirees Since it was not possible to identify those employees with only vinyl chloride exposure, the study focused on deceased employees who worked anywhere in those plants where PVC fabrication was carried on The primary objective of the study was to determine whether or not any angio sarcoma deaths had occurred among employees of the fabricators under study. A secondary objective was to examine the distribu tion of all deaths by cause. The relatively few producers of vinyl chloride monomer and ot PVC resin are generally medium to large companies. PVC fabri cators, however, range from large plants of major companies to very small |Ob shops Even in a large plant, there may be few em ployees who are in the vicinity of PVC resins The range ot com pany plant size and number of exposed employees help to explain the wide range of estimates of total employment dependent upon PVC resins. Fabrication is geographically disbursed, with at least some operation in almost every state. Typical fabrication products include coated wire, upholstery fabrics, floor and wall coverings, pipe and other construction materials, toys, recreational equip ment, phonograph records, containers and container lining, and a myriad of noveltv items Since the fabrication of PVC resin into finished products is often a part of diversified product lines in a plant, raw materials other than resin are utilized Thus, emplovees may be exposed to toxic agents other than vinyl chloride Consoquently, in the current study, it is not possible to isolate only the effect of vinyl chloride Some departures from expectation mav be due to exposures to vinyl chloride, to one or more other agents, to some combination, or to employee characteristics other than occupation. Materials and Methods The decision to focus on a cross-sectional mortality study rather than on an historical cohort study derived from several con siderations First, the primary study objective was to determine relatively quickly whether or not any angiosarcoma deaths could be identified among the study group, and this was best ac complished by examining causes of death among relatively recent Rxnfittd from jourml of Occupational Modlcino Soptomdaf 1977 Volume 19. HO pp 023-629 QENC 20308 i e,, past ten years) decedents The desirability of identifying an historical cohort for follow-up was realized, hut it was deter mined that it would not be possible to identify clearly and com pletely the necessary cohort of workers within a reasonable period of time, it at all As a consequence, this study is based upon a 141 deaths which occurred during the period 1964-1973 amontt turrent or former employees of 17 companies engaged in PVC fabrication A total of 55 plants supplied data on all identitiable deaths sm< e, as was mentioned earlier it was not possible to iden tify those emplovet's with only vinyl i hloride exposure tor the study In order to be included in this study, a de< easi'd employee fell into one of the following categories h employee died while ac tively employed, (2) employee died .liter retiring trom the com pany with retirement bonetits, and 1' employee died alter ter minating employment but with vesting in a company-sponsored life insurance plan Deaths nr r urrmg among termer employees with less than the number oi v ears rin essyrv tor insurant e vesting were not inr luded in plant rer orris and were therefore not available tor this studv An attempt was made to rnmpensate tor at least some ot the 'leakage 1 due to employees leaving the industry prior to the time they were vested in any insurant e program by using the following procedures Once death records tor a given company were iden tified, death certificates were obtained and separated into two groups as follows: (It all deaths with cancer (ICDA 140-205 up to 1%7: ICDA 140-209 for 1%8 on), or liver disease (ICDA 580-586 up to 1967. ICDA 570-576 for 1968 on), or suspected liver con dition mentioned on the death certificate, and '2* all deaths from causes other than cancer or liver disease Death records men tioning cancer or liver disease and giving a hospital as place of death were segregated and sorted by hospital Where there were several death records for a single hospital or several hospitals in the same area, arrangements were made for a Registered Records Administrator (RRA) to visit the hospitals, review medical records, contact the hospital pathologist and review pathology records to determine whether there were any angiosarcoma cases in the hospital's pathology records If so, an attempt was made to deter mine whether or not the angiosarcoma possibly could be related to vinyl chloride exposure This procedure enabled us to identify whether any employees, who had left the industry prior to vesting in an insurance program and remained in the local area had died from angiosarcoma of the liver The hospital inquiry procedures turned up five deaths from angiosarcoma of the liver ac cording to company employment records, none were employed at any time in PVC fabricating plants. These deaths were reported to OSHA, NfOSH. and CDC for inclusion in the nationwide angiosarcoma survey Death certificates not mentioning a hospital as a place ot death required an additional step to determine whether death occurred in a hospital or tf a recent hospitalization had occurred prior to death. The certifying physician was queried by mail for in formation on recent hospitalization of the decedent and whether there was any indication that he or she had cancer or liver disease Additionally identified hospitals were contacted as above Originally, it was planned that death certificates would be ob tained from life insurance carriers. In practice, both company and life insurance records were used because of record retention prai tices and retrieval problems in the insurance carriers All available death certificates were examined by a trained nosologist for men tion of angiosarcoma anywhere on the certifu ate, and no angio sarcomas were found on the death certifu ates Underlying cause of death was classified according to the eighth revision ot the In ternational Clussituation of Diseases - Over the ten-vear period under studv plant size was found to have changed drastically in many cases. In one instance a plant employing 100 employees in 1973 emploved tower than 10 in 1964 At the other extreme, one plant employing 5,000 people m 1964 had only 2,000 in 1971 Some companies had gone out ot business Such developments show not only the rapid changes taking place hut also the difficulty of determining average industry employment The 17 companies covered in this report ranged from single plant, small companies (one with 70 employees) to multiplant large companies (one with over 7 000 employees) Average numher ot employees clustered between 100 and 500 Although total employment is difticult to determine prei iseU it is estimated to have been between 65,000 and '0 000 at the end oi 1971 Since the population at risk could not he determined mortality fates as measures of risk could not he calculated Rather results were summarized >n terms ot Proportionate Mortality Ratals I'Mk ad lusted tor the age distribution of the study group The PMR uses relative frequencies ot specific causes ot death bv age in a i ornparison population to obtain expected numbers of deaths trom that cause in the study population Selection of an appropriate comparison population poses some difficulties since it would he desirable to have a cause of death distribution for a similar group or workers dying during the same period, hut not subjected to the factor under study But such a comparison population was not available, and the study used mortality tor the United States, specific tor color and sex, for comparative purposes 1 Despite recognized deficiencies, the PMR can provide (lues on unusual distributions ot causes of death where true rates cannot he calculated Results Table 1 gives the distribution of deaths among the employees of the 17 PVC fabricators within each of the ten years An increase in the proportion of deaths taking place in later years of the decade may reflect a variety of factors, such as an increasing employee population, less complete availability of records for earlier years (eg, tn one company, there were no records for the first four of the ten years', increase in duration of exposure, etc However there is no reason to believe that anv unavailable death records lor earlier years would be concentrated in a tew causes and thereby bias the distribution of deaths tor those years ToMo 1. -- Dtstrlhutloo of Oootho Among EmpfayOM of 27 PVC Fohricoton Inr Yoor of booth. 1944 1973. Vw of Ooott 1964 1966 1966 1967 196* 1969 1970 1971 1972 1973 Ttfa* No. 375 349 400 429 499 449 46S 471 52* 430 4141 % 75 SO 92 99 116 103 107 109 122 99 100 GENC 20309 Tibi* 2. -- Dhtribvtiii ot 0*ath> Amonj Employ**, o* 17 PVC Fabrkttofi by Cotof ind S*i 1964-1973. Roe* Toll! White Nonwhite Unknown To* 4341 3849 204 288 MM* 3676 3248 ISO 248 fonab 663 601 24 3S Unknown 2 0 0 2 The distribution of deaths in the sludv group bv ra< e and 'ex is given m Table 2 Most deaths B4 '%) occurred among males The vast maioritv '88 7%) ot decedents were white and there were 288 8 8%) for whom race could not he determined Table 1 >hows this distribution of deaths hv age For both white male* and white female employees, more than halt ot the deaths occurred among those aged 85 and over 58 Do and 5 1 9% for white men and white women, respectively) The corresponding proportions ot deaths which occurred alter age 85 in the United States population m 1988 were 59% and 72% respectively) The higher proportion ot deaths among white women over 85 m the US population compared to the employee population mav indicate that relatively fewer women work to retirement age than do men While the numbers of deaths among nonwhite employees are too small for any definite conclusions, the distribution or deaths by age among nonwhite men is roughly comparable to that tor the total United States. Tables 4 and 5 show the distribution ot deaths for selected causes by sex for whites and nonwhites, res pet tivelv Among white men, nearly 60% of the deaths are from diseases of the cir culatory system (ICDA 390-458) and 20% are deaths trom cancer (ICDA 140-209) The corresponding percentages for the total U S population of white males in 1968 (midpoint or the study period) were 54% for diseases of the circulatory system and 16% for can cer Digestive and respiratory cancers account tor somewhat less than two-thirds ot all cancer deaths among the white males m the studv group as compared to about 59% ot all cancer deaths among U S white males in 1968 For white women, over 46% of the deaths are from diseases of the circulatory system {compared to 57% for ail U.S. white women in 1968). and 30% were trom canrer (compared to 18% for ail US. white women in 1968) Somewhat over half of the cancer deaths among white women in the1 study were from cancers of the breast and digestive system. about the same proportion as for all US white women in 1468 About two-thirds ot the deaths tor both nonwhite men and women were trom diseases of the circulatory system and from cancer The numbers ot deaths for most causes among nonwhitrs, however, are quite small making interpretation difficult and are presented mumlv for completeness Age-adjusted PMRs for white male and white temale employees of the 17 PVC fabricators are presented in Table 6 tor selected causes of death There were no similar analyses tor nonwhite*' because for nearly all causes, the numbers ot deaths wore too small to produce stable PMRs Expected numbers of deaths have been calculated on the basis ot the sex-cause-age spec'tic distribution of deaths among U,S, whites in 1%8 applied to the total number ot deaths hv age among white men or white women m the studv group The midpoint of the studv period '1%8* was selected for the standard, since it is representative ot the studv period and provides US mortality data coded according to the eighth revision of the International Classification ot Diseases % /)e</ec/ numbers are deaths tor mdivuiu.il causes to he ex per led m the study group if the proportion of total deaths ascribed to a given cause were the same as tor the corresponding U 5 ra< '--ex group, while accounting for differences between the age distributions of deaths m the study groups and deaths tor the United States. A PMR larger than unity would indicate that the relative proportion of mortality from that particular cause in the study population is higher than would he expected based on the 1968 U 5 mortality experience, Due to the nature of the data, for mal significance tests and interpretation in probabilistic terms are deemed inappropriate, In addition to the numerical value of the PMR itself, the ob served number ot deaths is also of interest. The larger the number of deaths observed, the more reliable the PMR, There were two deaths of unknown age among the white males, one a digestive cancer (ICDA 153) and one an unspecified cancer UCDA 199) These were included in the age groups with the lowest relative frequency for those causes, that is. less than 35 vears for total can cer and digestive cancer and 65 and over tor other and un specified cancer Such an assignment has a trivial effect on the ex pectation but is the most conservative wav or handling these unknowns, since it serves to increase the expectation (and hence lower the PMR) bv the least amount Rased upon both the number of deaths and the value ot the PMR, there seems to be an important excess in total cancer mor tality among the white males m the study group, The distribution bv specific cancer site suggests that any excess appears to be t on* Cobr sox White MM Fwntlt NMlilt MM Fcnata Unknown Milt Femilt Unknown T*M 1 -- DttrtetiM of Outta A*o*f EmtoyM of 17 PVC Fibrtwtan by Ao, Color. Sox, 1*64-1973. Ml ~"i! 5 IMv 39 IS" 5 39-44 S% Ac* 45-94 Sr % 59 64 iir % 69 & iw Sr % 3248 601 100 100 107 24 33 136 40 42 42 365 112 752 23 2 1186 581 70 too 166 123 20 5 312 519 ISO too 24 100 21 6 11 7 25 0 24 m 2 83 28 156 5 20 8 39 21 7 6 25 0 68 371 5 208 246 1 00 3$ 100 2 100 20 I 1 St 26 500 5 20 5 13 2 00 32 12 9 4 103 00 48 194 131 521 S 21 1 18 47 4 00 00 (Mhh *x 2 01 00 00 00 12 48 2 S3 1 30 0 QENC 20310 Tibti 4. -- DMribMIo* f Obithi (roil) SolocM Carnot Amonf Employ*** O* 17 PVC Ftbritxton by Sox, Whitt Only. 1964,1973. Can* 1 DwHt ICDA 8tR R*e, All Cants All Cancan 140 209 Buccal Cavity and Pfurym Digestive System Stomach Intestine Rectum liver ResorfJtory System Lung Bone. Connective Tissue Sinn Breast Breast Genital Organs Urinary Organs Brim 4 Other NffrtkrS System Other 4 Unspotted Lynvhonvt leiAamut Diabetes Oiuasti at it* C*cult<ey System Ctrtbrgmsai** Cartas* ai liver CtoUhrttasis. Ctoteyftrt* CtatM|rtr| Accidents Pwetaimt, an* VKtanct Accidents Suicide All 0th* Carta (Residual) 140 149 ISO 159 151 153 154 155 160 163 162 WO 174 174 130 187 188 189 191192 190. 193 199 200-203 208-209 204 201 250 390458 430-434 571 524-575 E8004999 E8004949 E950-E959 Male FtmttB No. % No \ 3248 100 00 601 100 00 666 20 50 181 30 12 15 0 46 3 0 50 209 643 53 8 82 41 1 26 s 133 73 2 25 24 3 99 25 077 8 1 33 6 0 18 0 Q 205 631 12 200 191 5 94 12 200 24 0 74 51 8 49 0 -- 44 7 12 44 1 36 19 3 16 36 1 11 11 l 83 16 0 49 4 0 67 56 1 72 18 300 42 129 9 1 50 19 0 58 1 on 42 129 11 183 1931 5949 281 46 76 289 990 66 10 98 42 \ 29 J 050 7 0 22 3 050 188 5 79 48 799 134 4 13 38 6 32 40 123 2 0 33 372 11 45 74 1231 Ttbi* 5. -- Oittnbuttan *t Ouths from Soloctotf CausM Amortf Employ*** of 17 PVC Fabricator! by Sox. Noiwbito Only, 1964-1973. Cause f DmA ICDA Ith Rev. All Cann All Cancers Bum! Cavity ant Rharyra Otgesirve System Stomach Intestine Rectum lmr Respiratory System Lung Bone. Connective Trswe. Skin Brcsft Breast Gemtit Orgata Unnary Organs Brim & Qttta Nervous $y*l*m Qtt* 4 Unseacitad IrinoMm lat^ermas Outvies Oumes at the Circulator System CentorandcoNt Dream Cintasrs of tftr CtatetithiaM. Chotseyitrtts. 4 " Ctatangdrs Accidents, fasomet, 4 Violent* Aoriam Sutcide All Other Cun (RfMtueO 140 209 140149 150-159 151 153 154 155 160*163 162 170-W4 174 180187 188*189 191 192 190. 193-199 200-203. 206-209 204-207 260 390451 430431 571 574-575 800-5999 C800E949 E950-E959 Me* Female Ne. % Ne. % 180 100 00 24 00 00 39 21 66 8 33 33 0 0 00 13 7 22 4 1667 3 1 67 0 0 2 1U l 4 16 l 0 56 0 0 1 0 56 0 0 7 3 89 0 0 7 3 89 0 0 0 0 3 U5Q 0 0 3 12 50 4 2 22 0 0 3 167 0 0 1 056 0 0 6 3 33 0 0 4 222 0 0 2 111 4 16 2 1U 0 0 81 4500 8 33 33 19 1056 3 167 12 50 415 0 0 00 33 1833 1250 17 944 4 16 2 t 11 0 0 22 1222 4 16 67 centrated in digestive system cancer, given the large number of deaths (31% of all cancer deaths). For each of the sites within the digestive system, observed numbers of deaths are greater than ex pected Although, except for intestinal cancer, the observed num bers of deaths are small. The PMR for liver cancer is rather high, out a definite conclusion is difficult with only six observed deaths. On the other hand, the PMR for cirrhosis of the liver suggests a deficit in mortality from that cause. For white women, the PMR for total cancer appears high, as it did for white men, with cancer of the digestive system and, perhaps, cancer of the breast contributing a fair amount to the ex cess. The PMRs for individual sites within the digestive svstem are based upon small numbers but suggest an increase in intestinal cancer. The PMR for urinary cancer, though based upon onlv 11 deaths, seems strikingly high and may be an indication for further investigation On the other hand, in contrast to the observation m white men, the PMR fot respiratory cancer among white women is very close to unity Similar to the observation in white men. mor- tahtv from cirrhosis of the liver seems to be in deficit. but the corresponding observed number of deaths is quite small Among both white male and female employees, diseases of the circulatory system account for a large percentage of total deaths In each case, observed numbers of deaths are close to expected. There appears to be a somewhat different pattern among men and women for deaths due to accidents, poisonings, violence with the number of deaths somewhat low among men and high among women. There were 39 cancer deaths among nonwhite men, somewhat greater than expectation, although the numbers by site are too small for meaningful analysis. Mortality from cerebrovascular disease appeared high (PMR 2.111 but the finding was based upon only 19 deaths. Discussion The present study was designed with two objectives. The first was to determine whether or not any angiosarcoma deaths had GENC 20311 TtM* S. -- Obttrvtd and Eipttted Outfit for SoloetMl Ciuwt Among Employoot of 17 PVC Fabricator! fey Soi. Wtilto Only, 1964-1973. Cam if Doom All Cancan Buccal Gavrty and Pharym Digestive System Stomach Intestine Rectum Liver Respiratory System Bone Connect rve Trssue Skin Breast Breast Gemtal Organs Urinary Organs Brain A Other Nervous System Other & Unspecified Lymphomas Leukemias DiatwIB D seeses a* the Circulatory System Cerebrovascular Du-- Cirrhosts of Liver Cholehthtaw. Cholecystitis, and Cholarvrtrs Accidents, Rotsonmf, an} Violence Accidents Smut* tea* itii aw. 1*0-209 140 149 ISO 159 151 153 154 155 160 163 162 170 174 174 130 137 188 139 191 192 190 193 199 200 203 208 209 204 207 250 390451 00438 571 574 575 E800999 E800-E949 E950-C959 Obarved 666 15 209 41 73 25 6 205 193 24 0 44 36 16 56 42 19 42 1931 289 42 7 188 134 40 Malt Expected 561997 16875 16? 143 31 507 52 528 19631 4 190 176 657 165 566 15117 -- 52 828 33 131 13 885 34 607 32 382 23 364 49600 1832 515 292 074 62 821 6 349 265 541 189 268 52 325 fm* 1 19 089 1 29 1 30 139 1 27 1 43 1 16 1 17 159 -- 0 83 1 09 1 15 162 130 081 085 105 099 0 67 1 10 071 071 0.76 0b--rued 181 3 S3 8 24 8 0 12 12 61 44 19 11 4 18 9 1 11 281 68 3 3 48 38 2 FeM Expected 13/699 1896 35 342 4 981 15 344 3 877 0 633 11 888 11 224 35 661 32 397 23 297 4 537 3 499 9 622 7 631 5 005 15 436 309 232 71.965 12 343 1.713 40 855 2/931 9171 1 31 158 1 50 1 61 1 56 206 -- 1X 107 1 43 136 0 82 2 42 1 14 1 87 1 18 020 071 091 0 92 0 24 168 1 17 1 36 0 22 ' PM9 is the rjtro of ttimtO to eipKttd Bfiort the tioecled mUw n chlcuUttO on the SJII5 of tte distribution d Oootfn Iv the total U S n 1964 tpaciftc tv colv i*i cauw ind aye occurred among employees of the PVC fabricators under study. Since no angiosarcoma deaths were found among the employees studied, the first question has an unequivocal answer A secondary objective was that of examining the distribution of deaths by cause among the employees under study. Implicit in that ob|ective 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 comparison population as well as the analytic methodology 4 On the basis of a proportionate mortality analysis, there appear to be excesses in total cancer mortality among both white men and white women in the study, when compared to the distributions of deaths for the total United States specific for color and sex and adjusted for age Excesses in cancer mortality appear concentrated in cancers of the digestive system 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 employees is higher than that for the total U.S. There are, however, several reasons why definitive interpretation is difficult. It has, for example, been suggested that a Proportionate Mortality Ratio based on an exter nal population may not be sufficiently discriminating in screening for potential hazards,4 In addition, an analysis using PMRs fails to take account of the absolute risk of dying in the population under study * Further, a number of studies have suggested an overall favorable mortality for industrial working populations, even in those where well-defined hazards increase risk for a specific cause.7 * Factors such as these are meant to suggest that proportionate mortality analysis must be interpreted cautiously, with the intention of providing leads for further investigation. Results consistent with those of previously published studies would be of particular interest. With no comparable working populations in the fabrication industry, potential contrasts may be found in studies of vinyl chloride workers. Monson, et al, provided a proportionate mortality analysis of 161 deceased workers (all presumably white males) in two plants, one where vinyl chloride monomer is produced and one where it is polymerized into polyvinyl chloride.* Results of that study suggest a possible excess in total cancer mortality, primarily cancer of the GENC 20312 liver However, there was a suggestion that cancers of the lung and brain also appeared with excess frequency The current study, while suggesting an excess in total cancer, particularly digestive cancer, does not clearly point to marked excesses tor cancers of the liver, lung, and brain among white men, although the PMRs for these cancers are greater than one. The observed-to-expected PMRs reported by Monson for vascular lesions aitecting the cen tral nervous system, circulatory diseases, and external causes are similar to those reported here Tabershaw and Gatfey. in a study of workers engaged in the manufacture of vinyl chloride and its polymers, conclude that no specilic cause of death was statistically significantly greater than expectations based upon Standardized Mortality Ratios SMRs) using the U S, male population as the standard ' Bv other criteria however, the authors conclude there may be an excess risk for monalitv from digestive cancer, respiratory cancer cancer of other and unspecified sites, and Ivmphomas At lower exposure levels they suggest some excess for cancers ot the buccal cavity and cancers of the other and unspecified sites The current study would seem to indicate that excesses of mor tality from cancer of the digestive system are not sex-specific and are not limited to liver cancer The ma|onty of the PMRs for cancer among both white men and white women are m excess of unity Such results must be interpreted with caution but since thev ap pear to be consistent with previously studied workers thev suggest the need for continued investigation Summary Results of a study of 4.341 deaths occurring among current and former employees of 17 PVC fabricators during the period 19641973 are presented. The study was carried out to determine whether any angiosarcoma deaths had occurred among em ployees of these fabricators and to examine the distribution of deaths by cause. No angiosarcoma deaths were found among the study population. Distributions by cause of death among white male and white female employees were compared with those for the entire U.S.. specific for color and sex and ad|usted for age by means of Proportionate Mortality Ratios There appears to be an important excess in total cancer mortality among both white male and white female employees with digestive cancer, particularly that of the intestine, contributing to the excess Among the women employees, cancers of the breast and urinary organs may also be in excess. No excesses were found for diseases of the cir culatory system. There were deficits in mortality from cirrhosis of the liver among both male and female employees and a deficit in accidents, poisonings, and violence among men. The use of the Proportionate Mortality Ratio based on an external standard requires caution in interpreting these results, but the need tor turther investigations is indicated. Thfs study wjs sponsored bv the following orgjnijotwink American (.an C>mp,inv B r Cfw>drtrh Company Diamond 5hamrix.k Corporation Firestone Fire ,md Rubrvr Company Johns ManviNe Motor Vehicle Manure furors Aw* lie ion MauMp' Cb*m*cal Company Union Carbide Corporation Uniriiv.il Incorporated References 1 Sdikotr l| and Hammond CC 'Eds i Toxiutv ot vmvl < hlnndi* -- [>)U\mvl {.blonde Ann V V At .id Sr; 2461975 2 Manual ot the International Classification of Diseases Adapted for Use in the United States Eighth Revision Washington, D C . U S Covt Printing Otnce 1967, Vol 1 \ National Center For Health Statistics Vital Statistics of the United States, 1968 * Volume II * Mortality Part A Washington. D,C US Covt Printing Ottive, 1972. pp 140-20S 4 Chiazze L, Problems ot study design and interpretation of industrial mortality experience IOM 18 169-170, 1976 5 Redmond CK and Breslin PP Comparison of methods for assessing oc- (upahonaf hazards IOM 17 111-317, 1975, 6 Mnnson RR Peters JM and Johnson MN Proportional mortality among vinvl-chlofide workers / ant of 2:197.198 1974 7 Lloyd |W and Cioeco A- Long term mortality study ot steelworkers i Methodology /OM 11 299-110 1969 8 Redmond CK, C*occo A, Lloyd |W and Rush HW Long term mortality study of steelworkers IV Mobility from malignant neoplasms among < oke oven workers, |OM 14 621-629 1972 9 Tabershaw IR and Caffey WR Mortality study of workers in the manufacture of vinyl chloride and its polymers /OM 16 509-518 1974 GENC 20313