Document Y48pd45QMejp68rgqznZxX2O

REVIEW OF ASBESTOS-HEALTH LITERATURE Over the past decade, the occupational and environmental health hazards of -* a asbestos have received as much if not more attention from the worldwide medical profession than any other toxic substance known to man, with the possible exception of automobile emissions and the by-products of cigarette smoking. While the medical literature now contains more than 4,000 articles and learned papers on asbestos-related disease, only a small percentage of this vast accumulation can be considered of significance in our understanding of the problem. It is the purpose of this review to identify those papers that are of special importance, to briefly report on the findings contained therein, and to provide a cross-reference of the papers with regard to thati general areas of the problem with which they deal. No attempt will be made to comment critically on the contents of the papers reviewed. General Reviews While numerous comprehensive reviews of the asbestos-health problem have appeared in the popular press (Brodeur, Sherrill, Porter, etc.), these have all been argumentative in tone and cannot in any way be considered scientific papers. Only three general reviews of the overall issue have been published in learned journals or by scientific organizations of high repute. These are Dr. George Wright's (1) "Asbestos and Health in 1969," the National Academy of Sciences pamphlet "Asbestos: (2) The Need For and Feasibility of Air Pollution Controls," and the rather abbreviated "Report of the Advisory Committee on Asbestos Cancers to the Director of the (3) LnteiT.atiov.al Agency for Rescarcivon Cancer." A fourth.general review. A;785i "Preliminary Aiy Pollution Survey of Asbestos," was prepared in 1969 by Litton Systems .^ Incorporated for. the old National Air Pollution Control Administration (predecessor to the EPA), but it is marely a non-critlcal literature review and cannot be placed in the same category as the above three papers and documents. It was, in essence, superseded by the NAS document, which was also prepared for the EPA. The Wright, NAS and IARC documents all examine the various aspects of the problem, and in general agree that the occupational health hazards of asbestos are serious but controllable, and that the general public is not presently in danger from exposure to asbestos in the environment. Early Studies and Asbestos is ........ . :t -- ` ...... f....... As some critics of the industry are fond of pointing out, the first mention of asbestos-related disease in the literature occurred nearly 70 years ag^'^^By 1930 - (6> asbestosis was a generally recognized occupational hazard of asbestos exposure, hut it was not until 1947 that the first major link between asbestos and lung cancer was (7) ....... ' established. Mesothelioma, on the other hand, was identified as an asbestos induced occupational disease even later, the first important study on this disease appearing (10) in 1960. ; A i 7 S6c - --------------- ---------------------------- Asbestos and Lung Cancer In 1947, E.R.A. Merewether, Chief Inspector of Factories in the United Kingdom, reported 31 lung cancer deaths among 235 persons known to have died with asbestosis (7) between 1924 and 1946. This discovery of a high incidence of lung cancer among -3- asbestosis sufferers lead to the launching of one of the most important of all asbestos- health investigations. Commonly referred to as the Knox-Doll studies, this research centered on employees at a single asbestos textile factory' in Great Britain. The first (8) results were published by Boll in 1955, with subsequent updates being issued in 1965, 1966 and 1968, the last being entitled "Mortality from Lung Cancer and Other Causes (9) among Workers in an Asbestos Textile Factory." V. Since Knox-Doll, numerous other investigators have reported a lung cancer link with asbestos, the work of Dr. Irving J. Selikoff being the most widely quoted. Mesothelioma J .,1 In 1960, Dr. J. C. Wagner et al published "Diffuse Pleural Mesothelioma and Asbestos Exposure in the North Western Cape Province," in which they reported finding (10) 33 cases of this rare tumor in a part of South Africa important for crocidolite mining. Of considerable significance was the fact that 16 of the cases had not worked at the mines,, but had only lived in the vicinity or had had household exposure. Wagner's paper is considered to be the first major evidence linking mesothelioma with asbestos exposure, although a number of earlier obscure German papers had also noted the relationship. Because many of the cases reported by Wagner had not been occupationally exposed, a number of investigators launched studies to determine if the general public was at hazard to mesothelioma from asbestos in the general environment. The most important (11) of these were by Newhouse and Thompson (the case of the woman who developed mesothelioma from washing her husband's clothes comes from this stud}'), Stumphius (12) (13) (14) (15) and Meyer, Bo row et al, I.ieben and Pistawka, and McDonald et al. Doth Newhouse and A 1 786 1 4 I Lieben found numerous non-occupational mesotheliomas; Stumphius found a number of cases among non-asbestos handling shipyard employees: Bo row found two noa-occupational cases out of 17 (notv increased to two out of more than 50) in the Manville area; and McDonald, whose studj' involved the entire Canadian population, found no cases in the neighborhood of Canadian chrysotile mines nor in the household of people working in those mines, although he did find non-occupational cases associated with insulation ~/ork. \ McDonald also reported that only 14-16% of the cases had "definite" or "probable" asbestos exposure. From the strictly occupational standpoint, the most important studies have been those of Newhouse on a British asbestos textile factory*"Selikoff on the insulation wcurkers^"7^ on an amosite insulation plant0,.7a)nd on the J-M Manville plant (unpublished); Mancuso on 4 American textile workers; and McEwen on shipyard workers in Scotland (it is this study upon which Selikoff has based his predictions of an epidemic of mesotheliomas among U. S. World War II shipyard workers)."^ GI Cancer .. Selikoff was the first to report an increased rate of GI cancer among occupationally (17) (20) exposed employees. Since then a number of other investigators, such as McDonald and (1C) (9) Newhouse, have also reported increased rates, while still others, such as Knox-Doll, have not. The NAS document considers the evidence inconclusive, while the IARC report considers that a "small excess risk" exists from this disease. Asbestos (Ferruginous) Bodies The general public health scare rc asbestos arose out of two events: (1) the finding of non-occupationally exposed mesotheliomas in the vicinity of asbestos mines and A 17862 D factories, and (2) he discovery of coated asbestos fibers (asbestos bodies) in the lungs (21) of city dwellers. Approximately five years ago, there was widespread controversy over "asbestos bodies." Some researchers claimed that we were all in peril because of this fact,(22w) hile other investigatiors sought to place the issue in its proper perspective by (23) showing that not all asbestos bodies actually had a core of asbestos, and should therefore (24) more properly be called ferruginous bodies. The controversy largely subsided when Selikoft^C^ross and others found uncoated free asbestos fibers in human lungs, yet could find no link to disease. Selikoff further found no increase in the number of asbestos bodies in human lungs in New York City between the 1930's and the 1960's, despite the growth in the use of asbestos. .(26)In Great Britain, on the other hand, ) Uni did find an increase over the years P^^oday, the presence of small amounts of asbestos in the lungs of most members of the general public is accepted as fact without attributing to it any particular importance.(2) Asbestos Mining and Milling While no epidemiological studies have been conducted of employees in the United States asbestos mining and milling industry, the Canadian, South African, Italian and Finish industries have all been examined, with varying degrees of detail. Certainly the most comprehensive mining study has been that of McDonald et al in the chrysotile producing region of Quebec! ^Studying more than 10,000 past and present miners, McDonald established that the overall mortality rate of the cohort was less than that of the general Canadian population, that mesothelioma was not a significant cause of death among the miners, unci that an excess of lung cancer was limited to those workers that have the highest cumulative exposure. Ip South Africa, Webster :Ji\l Sluis-Cremcr^3' A i 7863 -6- looked at both the crocidolite and amositc mining industries, the most striking discovery being the relatiyePabsence of mesotheliomas among amosite and crocidolite miners in the a Transvaal district"as compared to the large number found in the crocidolite producing . region of the South West Cape. Vigiliani has studied chrysotils miners in Ita^aricl Kiviluoto and Meurman have examined the Finish anthophyllite mining industry.(30) Textile Manufacturing In the asbestos manufacturing industry, the production of asbestos textiles has received more attention than all other segments of the industry combined. The reason for this is relatively simple -- textile production was in the past probably the dustiest of all asbestos manufacturing operations and hence the most likely to result in substantial cases of disease among the employees exposed. The most important studies have^een those of Knox-Doll, \Newhouse, Mancuso'and Enterline. All reported greatly, increased rates of asbestos-related disease among the cohorts studied. Selikoff's unpublished study of Manville workers and Enterline's study of J-AI retired employees(32D)oth included textile workers in the cohorts, but no attempt has been made to separate their mortality rates from the rest of the employees studied. 0 special interest in Enterline's study was the fact that maintenance workers showed a greater excess mortality from asbestosrelated disease than did production line employees. Asbestos-Cement Manufacturing Dr. Hans Weill's ongoing study of asbestos-cement workers in two plants in New Orleans is the first large scale investigation of this most important segment of the (33) industry. The results of this research are as yet preliminary but seem to indicate a risk considerably loss than has been demonstrated in the textile manufacturing and insulation application and removal industries. fv In a report given at the Lyon conference in October 1972, Entcrline presented F a breakout of data Trom his retired employee shady on workers in rigid shingles and sheet and asbestos-cement pipe operations.- Both subgroups from the larger study shov/ed (34) excess mortality from asbestos-related disease. In an earlier paper. Enterline reported on his study of more than 12,000 % United States asbestos "Building Products" workers, in which he found an excess of (31) lung cancer and respiratory disease (asbestosis) but no overall mortality excess. Asbestos Friction Materials Enterline studied 7,500 asbestos friction materials workers from 11 U.S. plants and found an excess of lung cancer, GI cancer, and respiratory disease, bu|f no overall mortality increase! iTo other papers have been produced in this area. Insulation Manufacturing Selikoff's study of amosite insulation workers (the famous Patterson study)(,17) in which he demonstrated high rates of all asbestos-related diseases, is the only research conducted in this segment of the industry thus far. Other Manufacturing The vinyl-asbestos floor tile, packings and gaskets, asbestos felts, asbestos paper, and asbestos reinforced plastics segments of the industry have not been examined thus far. Insulation Application Trades The asbestos insulation workers are the only major group of end product users that have been examined extensively, Selikoff's two ongoing studies being the prime (17) examnlos. iV, 7 & 6 '0 -8- As a subgroup of the overall insulation application and removal trades, shipyard workers have received special attention. The most important research conducted in . , 1* 2 {IV (19) (35) (36) this area has been that of Selikofi, McEwen, Harries and Murphy. The special attention paid to this group lias stemmed from the supposition that the uncontrolled use of asbestos insulations during the Second World War contaminated entire shipyard areas, thus \ extending the hazard of .asbestos inhalation to many more individuals than merely those handling the material. The McEwen and Harries studies have been important in this regard. Dust Levels and Disease Because asbestos-related disease is both dose and time related, the diseasefbeing found today is a result of conditions existing 20-30 years ago and longer. Efforts t3 determine the highest level of exposure that will result in no disease, i.e. to find a "safe" exposure level, are hampered by two factors: 1. Very few dust counts were taken before the mid-SO's. Thus, most studies have estimated past exposure levels in relative terms, i.e. "low, medium or high." 2. Within the past 10 years, the accepted method for determining exposure has changed from particle to fiber counting. Efforts at determining a conversion factor for converting past particle counts to their equivalent in fibers per cc (3Ga,3Gb) have been generally unsuccessful. Thus, it has not been possible to accurately translate past dust data into modem terms for the purpose of setting standards. Gibbs, using data from the McDonald studies, has suggested that standards Attempts at determining safe exposure levels have, thus, been relatively few. Selikoff et3d. have concluded that the time weighted average exposure of insulation workers is less than 5 fibers of asbestos per cubic centimeter of air. However, no dust counts were taken by the Mount Sinai group earlier than 19G9 nor has the data leading to this conclusion been published in a scientific journal for professional scrutiny. The most important study yet published in this area has been the 196S report of the Sub-Committee on Asbestos of the Committee on Hygiene Standards of the British Occupational Hygiene Society. Entitled "Hygiene Standards for Chrysotile Asbestos Dust," the paper recommended the establishment of the now famous "two fiber standard." (3 6c) The United States two fiber standard, scheduled to go into effect in 1976, is based largely on this report. Among those studies that have sought to establish a relationship between past (20) (36) (32) (33) particle counts and disease are those by McDonald, Murphy, Enterline and Weill. Asbestos in the Environment Various investigators have demonstrated the existence of asbestos in ambient (37,3S) air and water. None of this research has established a link between the quantify of asbestos discovered and any increase of disease among the general public. Speculation on this point, however, has run rampant. The concensus of both the NAS and IARC reports is that current levels of asbestos in Lhe-environment present no hazard to health. One possible source of asbestos in the environment that has been thoroughly (39) investigated is emissions from brake lining wear. Lynch in 1968 and Jacko et al in MO) 1973 reported that brake lining wear was an inconsequential factor in ambient asbestos air pollution. A i 7867 - 10 - been banned by the-EPA, the study is now of only academic importance. The natural action of wind and water on serpentine rock formations release small though detectable amounts of asbestos into ambient air and water, but precise data as (37) to the contribution of these "natural sources" to ambient concentrations is unavailable. (41) Selikotf has investigated the asbestos content of parenteral drugs. Other studieson asbestos ingestion and injection are due for publication shortly. Variables on Pathogenicity One difficulty in finding a solution to the asbestos-health probelm has been t^.e scarcity of data relating to the manner in which asbestos causes disease, especially the various types of cancer associated with asbestos exposure. Selikoff has established a synergistic relationship between cigarette smoking, asbestos inhalation and lung cancer. Buggescea mat trace metais attacneo to me lioer are ms prune cause oi carcmogenisis. Many researchers have concluded that crocidolite is more hazardous than either chrysotile or amosite, and that amosite is perhaps more hazardous than chrysotile.(3) Timbrell suggested that the varying aerodynamic properties of the different types of (44) asbestos fiber in the human lung may account for their differing biological potency. (45,45a) (4G) Stanton and Gross, on the other hand, believe that fiber size is of primary importance in the carcinogenicity of asbestos and other fibrous materials, the smaller EM sized fibers being less, if at all, hazardous. Research Needs Despite the tremendous amount of data that has been published on the healch effects of asbestos; most studies do little more than confirm observations already reported upon by previous investigators. A number of vital questions still remain unanswered. Among theseare: 1. Is there a safe exposure level for protection against the various asbestosv. related diseases? If so, what is it? Does it vaiy from disease to disease or from type of asbestos to type of asbestos ? 2. What is the true relationship between asbestosis and lung cancer only in individuals who already have asbestosis, while others maintain that it doesn't matter) ? 3. What are the relative cancer risks following exposure to only one variety of asbestos ? 4. How does asbestos cause or contribute to the causation of disease, especially cancer? 5. What other causes of mesothelioma are there, in addition to asbestos exposure 6. Can asbestos cause other diseases in addition to asbestosis, lung cancer, mesothelioma and GI cancer (it has been suggested that asbestos can cause ovarian cancer in women and also cancer of the larynx and esophagus) ? 7. Is it possible to detect asbestosis early enough so that it is reversible? A i 78 63 Conclusion According to Dr. Premysi Pelnar of the Institute of Occupational and Environmental Health in Montreal, approximately 90 percent of all information and data now available on asbos toS-healtliis the result of medical studies undertaken within the past ten years. Nonetheless, major sections of the asbestos manufacturing industry have not been investigated at all, or have been investigated by only one researcher, whose results are therefore not comparable with other studies nor, consequently, are they refutable. Until we have answers to all the unanswered questions, and until we know through scientific investigation that this or that use of asbestos is safe or unsafe, the asbestos industry will continue to be plagued by its own uncertainty and the unfounded speculation of those who would question the unknowns rather than examine them. | \ ti i o REFERENCES 1. Wright, G. W. FAsbestos and Health in 1959," American Review of Respiratory Disease, 100:457-469,'1959. __ a * O Committee on Biologic Effects of Atmospheric Pollutants. "Asbestos: The Need for and Feasibility of Air Pollution Controls," National Academy of Sciences, ISBN 0-309-01927-3, 1971. * 3. "Report of the Advisory Committee on Asbestos Cancers to the Director of the International Agency for Research on Cancer,'1 Brit. J. Ind. Med., 30:1S0-186, 1973. "Preliminary Air Pollution Survey of Asbestos: A Literature Review," U.S. Department of Health, Education, and Welfare; National Air Pollution Control Administration Publication No. APTD 69-27, 1969. 5. Murray, H. M. Statement before the committee in the minutes of evidence, pp. 127-125. In Report of the Departmental Committee on Compensation for Industrial Disease. London: H. M. Stationery Office, 1907. f li 5a. Auribault, M. "Sur L'Hygiene Et La Securite Des Ouvriers: Dans Les Filatures ' Et Tissages D'Amiante," Bulletin of the Inspector of Factories. 14:120-132, 1906. .6 Merewether, E.R.A. "The Occurance of Pulmonary' Fibrosis and other Pulmonary' Affections in Asbestos Workers," J. Ind. Hyg. 12:193-222, 239-257, 1930. 7. ' Merewether, E.R.A. "Asbestosis and Carcinoma of the Lung," In Annual Report of the Chief Inspector of Factories for the Year 1947. London: H.M. Stationery Office, 1949. 79 pp. * .8 Doll, R. "Mortality from Lung Cancer in Asbestos Workers," Brit. J. Ind. Med. 12:81-86, 1955. * 9. Knox, J. F., S. Holmes, R. Doll and I. D. Hill. "Mortality from Lung Cancer and Other Causes among Workers in an Asbestos Textile Factory," Brit. J. Ind. Med. 25:293-303, 1968. .10 Wagner, J.C., C.A. Sleggs and P. Marchand. "Diffuse Pleural Mesothelioma and Asbestos Exposui'e in the North Western Cape Province," Brit. J. Ind. Med. 17:250-271, 1950. * 11. Ncwhouse, M. L. and H. Thompson. "Mesothelioma of Pleura and Peritoneum Following Exposure to Asbestos in the London Area," Brit. J. Ind. Med. 22:201-259, 1955. 12. Stumphius, J. and P.13. Meyer. "Asbestos Bodies and Mesothelioma," Ann. Occuo. Hyg. 11:253-293, 1953. A i 787 1 1i.u Bo row, M., A. Conston, L. L. Livornese and N. Schalet. "Mesothelioma and Association with Asbestosis," J.A. M.A. 201:537-591, 1957. 14. Lieben, J. and 11. Pistawku. "Mesothelioma and Asbestos Exposure," Arch. Environ. Health 14:552-303, 1957. * 15. McDonald, A.-D7 ar.d J. C. McDonald. ''Epidemiologic Surveillance of Mesothelioma in Canada," CMA Journal 109:359-362, 1973. * 15. Newhouse, M. L. "A Study o? the Mortality of Worker's in an Asbestos Factory," Brit. J. Ind. Med. 26:294-301, 19S9. * 17. Selikoff, I.J., E.C. Hammond and H. Seidman. "Cancer Risk of Insulation Workers % in the United States," presented at IARC Conference on the Biological Effects of Asbestos, Lyon, France, 1972. * IS. Mancuso, T. F. and A.A. El-Attar. "Mortality Pattern in a Cohort of Asbestos Workers," J. Occup. Med. 9:147-162, 1967. * 19. McEwen, J., A. Finlayson, A. Mair and A. A. M. Gibson. "Mesothelioma in Scotland," Brit. Med. J. 4:575-573, 1970. * 20. McDonald, J.C., A.D. McDonald, G.W. Gibbs, J. Siemiatycki and C.E. Rossitlr. "Mortality in the Chrysotile Asbestos Mines and Mills of Quebec," Arch. Envirda. Health 22:677-636, 1971. \ 21. Numerous investigators have reported on this phenomena, including J. G. Thompson (South Africa), Anvilvel & Thuribeck (Montreal), Ashcroft (England), Ghezzi et al (Milan), Meurman (Finland), Laager et al (New York), and others. 22. Thompson, J.G., R. O.C. Kaschula and R.R. McDonald. "Asbestos as a Modem Urban Hazard," S. Afr. Med. J. 37:77-81, 1963. 23. Gross, P., L. J. Cralley and R. T. P. deTreville. "Asbestos Bodies: Their Nonspecificity," Amer. Ind. Hyg. Assoc. J. 23:541-542, 1967. 24. Gross, P. "Today's Pressing Question: How Safe is Urban Ambient Air?" Arch. Path. 82:195, 1966 (letter to the editor). 25. Langer, A.M., I.J. Selikoff and A. Sastre. "Chrysotile Asbestos in the Lungs of Persons in New York City," Arch. Environ. Health 22:348-361, 1971. 26. Selikoff, I.J. and E.C. Hammond. "Asbestos Bodies in the New York Population in Two Periods of Time." In Pneumoconiosis: Proceedings of the International Conference, Johannesburg, 1969. Cape Town: Oxfoi'd University Press, 1970, pp. 99-105. 26a. Um, C.H. "Study of the Secular Trends in Asbestos Bodies in London 1936-1965," British Medical Journal, 1971. A i 7872 -------------------- * 27. Webster, I. "Malignancy in Relation to Cx'ocidolite and Amosite," presented at IARC Conference on the Biological Effects of Asbestos, Lyon, France, 1972. -3- 2S. Sluis-Cremer, G. K. and'R. S. J. duToit. "Amosite anc! Crocidolite Mining- and Milling as Causes of Asbestosis," presented at IARC Conference on the Biological Effects of Asbestos, Lyon, -Trance, 1972. 29. Vigiliani, E.C., I. Ghezzi, P. Maranzana and B. Perais. "Epidemiological Study of Asbestos Workers in Northern Italy," Med. Lavoro 59:4S1-4S5, 1963. 30. Meurman, L. 0-, R. Kiviluoto and M. Hakama. "Mortality and Morbidity of Employees of Anihophyllite Asbestos in Mines in Finland," presented at L^RC Conference on the Biological Effects of Asbestos, Lyon, France, 1972. \ * 31. Enterline, P.E. and M.A. Kendrick. "Asbestos Dust Exposures at Various Levels and Mortality," Arch'. Environ. Health. 15:131-lSo, 1967. * 32. Enterline,- P.E., P. DeCoufle and V. Henderson. "Mortality in Relation to Occupational Exposure in the Asbestos Industry," J. Occup. Med. 14:897-S03, 1972. 33. Weill, H., C. Waggenspack, C. Rossiter, W. Bailey and M. Ziskind. "Radiographic and Physiologic Patterns Among Wo rivers Engaged in the Manufacture of Asbestos! Cement Products: A Preliminary Report," presented at Conference on Respiratory Disease in Industry, 1972. *. * 34. Enterline, P.E. and H. Weill. "Asbestosis in Asbestos Cement Workers," presented at LARC Conference on the Biological Effects of Asbestos, Lyon, France, 1972. * 35. Harries, P.G. "Asbestos Hazards in Naval Dockyards," Ann. Occup. Hyg. 11:135-145, 1968. 36. Murphy, R. L.H., B.G. Ferris, W.A. Burgess, J. Worcester and E.A. C-aensler. "Effects of Low Concentrations of Asbestos, " New Eng. J. Med. 285:1271-1278, 1971. 36a. Ayer, H.E., J. R. Lynch and J. H. Fanney. "A Comparison of Impinger and Membrane Filter Techniques for Evaluating Air Samples in Asbestos Plants," Ann. NY Acad. Sci. 132:274-275, 1965. 36b.. Gibbs, G.W. and M. LaChance. "Dust-Fiber Relationships in the Quebec Chrysotile -ndustry," Arch. Environ. Health. 2S:69-71, 1974. 3Gc. Sub-Committee on Asbestos, Committee on Hygiene Standards, British Occupational Hygiene Society. "Hygiene Standards for Chrysotile Asbestos Dust," Ann. Occup. Hyg. 11:47-69, 19GS. *, 4 . Nicholson, W. /. and F. L. Pundsack. "Asbestos in the Er.vi ronmonl," presented at IARC Conference on the Biological Effects of Asbestos, Lyon, Fi*ancc, 1972. ' O T. . Cunningham, II. M. and R. Pontefract. "Asbestos Fibers in Beverages and Drinking Water," Nature 332:332-:;::::, 1971. y ^ 7 3 I i9 39. Lynch, J. R. "(Brake Lining Decomposition Products," J. Air Pollut. Control Assoc. 18:324-826, -196S. * 40. Jacko, M.G., R. T. DuCharme and J.H. Somers. "Brake and Clutch Emissions Generated During Vehicle Operation," presented at Automobile Engineering Meeting of Society of Automotive Engineers, Detroit, 1973. * 41. Nicholson, W. J., C. J. Maggiore and I. J. Selikoff. "Asbestos Contamination of Parenteral Drugs," Science 177:171-173, 1972. - iV; 42. Selikoff, I.J., E.C. Hammond and J. Churg. "Asbestos Exposure, Smoking, and Neoplasia," J.A.M.A. 204:106-112, 1968. 43. Crailey, L. J., R. G. Keenan and J. R. Lynch. "Exposure to Metals in the Manufacture of Asbestos Textile Products," Amer. Ind. Hyg. Assoc. J. 23:452-461, 1967. 44. Timbrell, V. "Physical Factors as Aetiological Mechanisms," presented at IARC Conference on the Biological Effects of Asbestos, Lyon, France, 1972. >:s?. * 45. Stanton, M. F. "Some Aetiologic Considerations of Fiber Carcinogenesis," pretented at IARC Conference on the Biological Effects of Asbestos, Lyon, France, 1972. 45a. Stanton, M.F. "Fiber Carcinogenesis: Is Asbestos the Only Hazard?" J. Nat. Cancer Inst. 52:633-634, 1974. 46. Gross, P., and R.A. Harley. "The Locus of Pathogenicity of Asbestos Dust," ArchEnviron. Health 27:240-242, 1973. NOTE ON REFERENCES: (1) In some cases. Dr. Selikoff's study of the insulation workers being a prime example, numerous papers have appeared over the years dealing with the same study. The paper or presentation referenced above is not necessarily the first to appear on the study, but will more often be the most recent or the most comprehensive of those that have been published. (2) Even in a short review of this nature, the number of references is extensive. For this reason, papers and presentations of primary importance are marked with an asterick. 7 87 At w ir ".nr*:: i:j n^nnncrr^Monsaon PLAINTIFF'S EXHIBIT UC-171 P,*nS'v?!S R^iroil^r. C83?n;r'7Il'I?A!-t5 KWtVBIPAMY ikrtjtut* i-LAriT r. o. nox ?SM. CH'.msroH. wr.st w$;ii. K. J. Sexton, H.D. o.i. 29 November 19G3 Nodical Department - riant 512 Ori(i.i"i opt Industrial Hygiene - Plant 512 AMwrUf (fNir fir. I.. II. Dickinson Mr. N. S. Eastman Hr. t . ** C. C'ia'i'hrauiM Hr. B. A. i Infer !!' . Ih F. ting IV. i;. II. l est iv. i;. U. I.emchl IV. J. w. Terry *kM Construction Insulation Flop Hr. P. E. Henry Building 511-2'Hii Hr. R. A. Neal Hr, 1). P.. Matheny"^ Hr. N. II. Ketcham Hr. L. H. Weddell - Safety Dept. Mr. F. G. Comerford In accordance v.'ith Mr, P. E. Henry's request of Ihnr.-.hv, 7 Nov 63, J hive investigated the fabrication of "Carey-Temp" pipe covering, 'llii.r. operation is carr ied out with band saws and, on the basis of visual ol'tvuvnlion alone, it lias been decided that there should be no health lur.ird associated with this particular type of operation. * 'C 9 This investigation took place during the morning cf Thur-ca\y .Pi 1! ;v 63, in the oampiny of Hr. K. B. lanliam, Fort-man of the Fabrirutinn Tnr.'il at ion !.`-hc?p, and consisted merely of observing the process of the rutting of h ilf sections of eight inch diameter "Carey-Temp" pipe covering with a Puri saw. P ) el fort was made, at tliat time, to determine the actual CMnc.cnLr.ition <>| o':i)sph< ric dust 1-ling produced during this operation. It should not lo I- -ssary la perform this specific test so long nr. working conditions ate m* ill - i-.l appncciah.lv from tlroso observed on this date. However, a rroi.- (ii>i>yigh -v 11 ill ion of thc-v conditions will be performed if (1) i*' is rp.-r: :: r i al'y i ! ".ilcd. (2) employees begin complaining about reactions such a. n 1 ' :*-'l, it . . (3) i thick- r material, i.e.,rrorc than two inches in d.inm-1: i' I i Lull 1 for fabrication, or (l) the fabrication shop logins cu't.i"-' : ;h ur-.-l lull-seel .inn from large blocks of ''Carey-Temp". Very truly ym-s, TV(L. V) I Id B. r.. IV.-ri ll idust ri a .1 1 iygicnis..:. A2405 r\ o iniv;:;rKi,M. nvcru.'i: mh vi.v V Lot .sti net ion Insulation Shop - building 5 11-20)1? Kcjxort 63-IH-3-G-1 I SUtlilMY:' 'llio Construction Insulation Slop (Building 2010), riant I>12 location, t- uiin-.-lv fabricates larg<; quantities of insulation bloc): with ventilated Ivin! s-v.r.. Tlu' nv.nc efficient procedure of fabrication has replaced an. older, live hon.-rei, practice of using simple handsaws to do the job. However, it hir., .it lb: scire lime, cirated a lx iltii liazord resulting from exposure to excessive'coiuv.ntr.itions of alnospheric dust. 'I h : hazard to health lias l.ecn evaluated and report I p> vi'iuv.! y ' with the result Dial: one material, "Therrrobestos" was clearly identified with the h.av.-.n>J (exceeded TLV)-and anotlier nutcrial, "Kayla", was safe to f\:iri: i:-r (within TLV). The pivsent rciort (the third on this subject) via a initialed in an .iLt -mpt to supply answers to three basic questions: (1) was there any 'n^v in the original evaluation of "Kaylo", (2) can supplementary exhaust v i 1 it ini ivdu'-e llie "ThcmeUu.tos" bicard to within safe aeccptfil.de limit"-, an I ( ') r a ]tu;:ard to health produced in the fabrication of a third material, i.r:-, "Carey-, 'lamp". *. r Ihe information uncovered in the pr esent evaluation r;i! t he following facts: 1. "I.aylc" insulation blocks can lx: safely fabricated v.i'h tlie existing equipment. 2. "'Ibcrmobcstcs" insulation blocks cannot le r-if'-lv f i! ri-rated Jl the present time with existing equipment, but ov.il-l i.safely fabricated if the exhaust ventilation is inpi-'V'd. 3. Thu TLV (Thresliold Limit Value) for "Carey-T* :>n" is- identical v-ith tint established for both "Kaylo" and "Thennob os", i-e., 20 mppcf (million particles per cubic foot) of air. i. "Cfircy-Tcmp" also cannot be safely fabricate-1 with th existing equipment, but could be if .improvements are mu'. in *': ventilation system. 5. 'I lie original "downdraft" exinust ventilation rule;, a oil her land saw, do not meet the recoinncndcd capture voIvii.y jatc of ',000 fpm (feet per minute). V f>. `i h-; uipplrmentary "overhead" cxhiusl venli.lul i "n n I'Mi !>i;i-l : r-`:>, is in improvement ani.1 lb" rates do meed: lb- i v-i;:*-teP.-1 capture velocity rate of li,0b0 1pm. * 1.11. H'l'Ml:; G2-III-1-c:,-1 and r>2-l il-?-f,-l A 24 05 *' 71 it: "haylo" insul.ition material 1ml Lo !>_ n:-*va hi-it rd 3. The Construction Insulation Gltop requested lhal j new instil-it:ion nvl terial, i.e., "Carey-Temp", be evaluated. * ili'.'. .investigation of 6 Mar 1963 was conducted liecaurc. 1. The Construction Insulation Glop recently hid it-ji.nl.bvl i supplementary exliaust ventil.it ion on Loth bur! r>v.::; -uvl. desired to know if this additional control method v.vild re-luce the "Thcnnobestos" dust concentrations to within Safe acceptable limits. A comparison of the reasons listed above discloses tint each wjs di I Cerent in content and concerned actually with different investigation:-, but all were interrelated in part, i.e., each was concerned with the s-tv- environment, 1.1 .n same location and the same specific methods of fabrication, fonse-j i- nlly, the sampling, procedures, utilized in each instance, bisically were identical and in accordance with the following, condensed explanation: first: Two methods of fabrication, i.e., cutting, aiv.l edging, and cutting a radius, were evaluated at each land saw r since this is standard practice followed in the fabrication of any insulation material. Second: The environmental conditions of both preo'd in: r>ports, i.e., 62-IH-l-G-l and 62-111-2-0-1, were dupl i.calr*; in that all outside.doors to the building were closed. 'third: Each dust sample was collected in the operator's breathing . zone as he worked in the fabrication process. fourth: The complete fabrication of "Carey-Temp" in -u.l-M ion blocks was evaluated in two ways: First, with all available ventilation in operation and second,with only the original downdraft ventilation in operation. .,;p"r inlized : impling pi\acedurv` wei e utilized al: ' 'i ;-vf ions ( I the 1 liter tv'> invest ig.aVions, in an endeavor lo ev-iT.i-.ile t.lv . *. , 1 > -nt srv fMiiusl "''ntilat.ion system 'which had l>een inst illed as rocomivn. 1 '. i v.\:re r; tolb I i t: The complete fabrication of "Tlvivvd.-rrivu' dion M i-ks was evaluated in two w Fi.ruTl., wi.lh tI ' I'tibb' vriii ilution in operation und sc-'>nd,wilh >*nly Sir original, downdraft ventilation in I'perut. irn. ond: 'Mv' complete fVibric.it. i'wi of "Car-',y-T.,.:i| " it.-' t ' i-.n Id; Is war; evaluated while utilizing, all available ::h . i t vent flation. J I. ir; necessary to explain that "Kaylo" insulation blocks ws*?. not iiv Juled -i'.: a jort of this evaluation since the initial investigation, (pcrlormed \ without supplementary exhaust ventilation) disclosed only on* exposure exceeding, tho TLV of 20 mppcf of air and, tharofere, it could be assumed That any ventilation that might be added should be more than adequate in controlling the hazard. LVAIDATIONS: ;$ A. Atmospheric dust exposui'es: 1. The concentrations of inhalable dust, present in the'breathing zone when fabricating any one of the three types of insulation materials, were deteimined in accordance with the following procedure: a. Three locations and nine different conditions of exposure, as described on Tage 9, were selected for evaluation. b. Atmospheric dust samples were collected through the use of the impingement* principle of air sampling. The midget impinger apparatus (described on Page 5 ) served as the instrument of use. c. The concentration of dust collected in each sample was catal-lishe-'rt r through the use of standard light field microscopic counting tecliniques as described on Page 5 . 2. 'The size ol the particles of inhaled dust was determined, lor loth "Kaylo" and "Thermjbestes", in the initial survey of 1962 in accordance with the procedure described on Fage 5. Consequently, no effort wo:; .expended to repeat the determination for any of the insulation materials since the sawing tecliniques as well as equipment, i.e., saw blades with three teeth to the .inch operating at 2200 linear feet per minute, were identical cn loth occasions and, therefore, the size of the particles should not be expected to deviate to any great degree from the prior recorded values. 3. 'Die composition of the dust, i.e., percentage crystalline free silica or percentage asbestos was determined for both "Kaylo" and "Thennolor.tos" in the .initial survey of 1962. Consequently, no effort was expended to l'epcat this determination since the nnterials used on loth occasions, wore reported as being identical in composition. However, since the composition of "Carey-Temp" was not established at any earlier date it was deemed imperative tliat it be determined and reported at this time. This was accomplished as described on Page 5. H. local exhaust: ventilation controls: 1. The velocity of the air lxaing exhaust'd through the vent il.it. ion Iv-.vl openings on loth hand saws (01 and II2) was measurcd through the use of a : Model 60 Anemotherin air meter. 2. Pour variable conditions of interest were evaluated: a. 'Hie velocity of air through tl>e downdraft hood on Lot 11 saws with all other loods on the system closed off. * This means to strike against, as (in this application) the striking or flashing cl atmospheric dust port idea against the bit tom of a small impinger flask containing a specific volume of dust-free water as a collecting medium. A24053 O zr-tr-'tr lmi.JiS'i'i |! il: A i1 , 'll r'i i I O'] in fl-irrh lflGi?, stilted lint. iin. inli da' bu hi.- i> i' i vMuced j.n tli'.' (.'onstmclion Insulat ion Slop ulici lover " I n.t ;:r insulation blocko fabricated. In July 1QG2, a eecond svuvoy was conducts-1 $ in ordar to evaluate three new "ThermoL-e'Jtos" ralcrlulH which had h-icn rigidied hv' !.h-.' minnfael.ii! <t fc'p evaluation. Hi in cinycy revealed that, nl t lror.ii Mu? inh ilutiwn h.i;:arJ to health had been substantially reduced fboin lint c-v "inten 1 during the first survey, the atmosplieric dust concentrations be mi.-, rirt-'l during fabrication of tliwe new products, were still in excess of the Thr- :-1. >j.i l.irait V.ibi.v; ciu designated in the first report, Thoi eforc, all recorunend U inn shvebl r-i'llin exactly as stated in lhe initial import of March 1%2. Jh". r. nufoctwrer and Union Carbi kPurrha aing Hep n 'mTt oxpivev;ed a deal of concern alien: the findings revealed in this initial re|ort 'non it was uncovered tbit, the rn'iiufacturer's Research Icpart front also b.i 1 rv-itu it oil those initi:rials and w.i:; not able to produce resul ts com)\irat>lc with Miis r.iiliinc-l in lh- ivpvrt oT I'.irch 19G2. Tliat is to say, the a tuns; Iv-rio lust con-:i-nti.itions imported by the manufacturer, when pioccssinp, '"Ihoi-i:-l's` in--.nl.it ion b.Ux-1.'w to substantially higher thin those i>'veale i in !"!: i p-IH-1-r~.l. lhis revelation disclosed the n^e-J Jor a non exlvn.'-ive. ilu-.it wmi <:f thi:; p:ubloir. .-is to resolve all differences of opinion relative to the atm:spheric dust e:qosuros in this environment. ^.r nils decision in favor of further evaluation, prvrvti ! ll.j pi'.'ducticn of a much r;\cre extensive study tlian was originally plane-d, a study which eventually -.'iicompossed llirce separate intervals cf dust ramp ling., n iLysis, <anl cvalulion before all of the unanswered health problems ecu 11 1 .? ? o >'. vc.l. Dlf.Cbfj.t 1 Mi 1: .Th'-sr* Mirce inv'':;t.if:at:inn:; were actually initialed for the geneid | u ,*ver-. of loth clarifi.-- u.ion and identification - purjosclv for ol.iri.1 ic d bn ' I-.? actu >1 Ivi.-.aiM to health (if any) connected with the fabrication of fhr - different incut at ion mtcriil-- .and identification of acceptable measures ior u:s in reducing, all. "xposures to within safe .acceptable limits- However, each inveslig it ion oc-.-uiTod ior clc.*-r.ly identifiable reasons as explained below: lb- investigation of 24 Jan G3 was conducted bcean;. : l. ilr- Johns Kinvillc Company sulmiU.ed a ropsi ' . ' i-v Mi ir 1 's earch I'- rartment, which c'-n! lin' d dat a lh ' .'I : 1 I .i ' 1 t.h-it submitted by tliir, cJej's* I!> nt in ! <'| ort 1 . * 1' -1 . ?. This dup-u tir.cnt desired to clarify the war'-mi '. ' discrepiiK-y botween the tun wp'irl::- .ml ta : i My it 'v,>: .-, Mi- actual conditions as th-y <::Lsl in tlw > ' :i.-\ -v o Mum id . lb- invest i p. 'In mi of 2S and 2G ! ! f..< vi; : u.ln- I ! i- : : t- In I lie pr-ceding inventigai i mi, I lie l;. > iiv ul " i i. i i.ils i;i '|'ic:,t > mi, i.c., "flier.ivDl and "1 ayjid' r . luped >a idv'TtcnLly durijig the r.u:>- aticrruon, a |i<' 1 u oiii .-h - is not in beeping 'with an att'inpt In nfijmilat.- 11 ? nvliti'in ' the ci ii'.inal report. In 'In' original ivpo -: , i ;. i.iiori.il is cvaJuded on separate c^:M-ioir. so as t > | i . clu:- Mr* | .::.ibi.l.i t v that any one sa q le might oxitaii. i'.i a : i-..-.?d bv loth ojorations. A24054 m V > Xsrsjtrji in i rj.nMAU u?nne.cipormnrJCM c.-'tsswu'tst UNION CAnniBK ClIflMVHOALS COMPANY IMOTitutk plant p. o. box zmi. chmuston. wist virffcifw Mr. S. C. Giambruno Cr^9r tmiir. Industrial Delations oi# 2 3 October 1963 Oriffoni opi. tfcjical Department - Plant SI? l#Nr Wf* c*^r * Mr. II. Dickinson Mr. J. W. Perry sntji . Insulation Block Past Suivcy Ur. 11. S. Listman Mi'. P. E. Henry Construction Insulation Shop >f Mr. K. A. Huber Mr. P. P. King Mr. R. A. Neal Mr. n. R. llitheny^r-^SL Plant 511 c It. i;. M. Ikv.t Mr. II. H. Ketcham A It. ('. IJ. Dame hi Mr, L. L'. VJeddell - Safety Dapt. i *. *r Enclosed is a very excellent and veiy complete Industrial Hyricne lrparl on the potentia l hasordousness cf "Thcrmobestcs", "Kaylo" and "^arev-Temp" insulation blocks which have been processed in the Construction Depir'.rtcnt1 s Insulation Shop. The rejort points out definitely that ''Thcnnober.los" and 'Tamy-Temp" insulation blocks cannot be fabricated safely with existing equipment, bit that "Kaylo" insulation blocks can be fabricated safely. Mi'. Peele's . jvconnicndaticns are quite definite and I am sure that you will wish to comply with them. I believe this, particular project should be considered completed. If there are any comments, suggestions or criticism, please direct these to no. Very truly yours, O'! r,.i;;:hi. 1 .nr. b-.urv:; Sexton, M.D. Medical Director A2405b V b. Ih'.: velocity of air tl trough tlvc downdraft 1kdo:I on both saws with all other hoods on the system open. : it c. The velocity of air through the supplementary overhead licod on both ' saws with all oilier hoods on the system closed off. d. The velocity of air through the supplementary overhead hood on Loth saws \:ith all other hoods on the system open. PEOCEDUl-lS: Hath sampling and airalytical methods were as follows: d/'jn'ijUG: 1. All samples used in determining the'actual concentrations in air were collected with a midget impinger apparatus, sampling 0.) cubic feet: of air per minute through impinger flasks containing 15 milliliters of double distilled dust-free water. 2. A11 samples used in obtaining particle size distribution d Hi ..ere collected on millipore filters connected to a small battery-operated pump. ANALYTICAL: >. r 1. Inch dust sample was evaluated through the use of a counting procedure reTcrtrcd to as the light field microscopic counting tccliniquo."- 2. "lhe particle sizing techniques were derived from two separate : -.necs. Tirst, tlic sample was prepared for sizing in accordance with a icnivment mounting method.* Second, the actual sizing was accomplished in accordance v;ith the recoimtendod technique depicting the use of a filar micrometer, and a standard microscope while using both the *i3>1 (high and dry) and the 97X (oil immersion) objectives.$ 3. The evaluation and free silica determination of "Carcy-Tcmp" miterial was accomplished through the use of two methods. First, through information supplied by Hr, L. D. Dnnenc, Director of Pescaiuh of the Philip Carey Manufacturing Company and second, Lhrcugli cwuli .jc>e-.l analysis performed by Mr. Thomas H. iXirkan, Chief Chemist lor ti c Tnjdcuu foundation, Inc., Saranak Lake, N. Y. I J.dULTS: Leo Pages 0, 9, 10 and 11. Dri.nl.'-r and llulrh: " I ndnsl rial Dusl", 2ixl Ldition, pp. 15T-153, McGraw-Hill. IImI. Company, 1 no. , H' w York , 19.VI. Pant us, II. J., Talvitic, M. A., Praser, D. A., and Keenan, R. G.: "Use of Membrane Filters in Air Sampling", A.t.H.A. Quarterly, Vol. 10, p. ?G9, Scptcm'ror, lfJ!.7 t Di'inVer and Hatch: "Industrial Dust", 2nd Edition, pp. 1GG-179, McGraw-Hill Look Company, Inc., New York, 19b't. A 2 4-0 5 G V iK'in.i' ir.: I,, Kola live to dust exposures from Graph. Ill E Tables on Pages 8 G 3: , *$ 1. "Thenr.'b:stos" insulation blocks should not le fabricated v;hcn using only Lhc original downdraft exliaust ventilation. 2. "Kaylo" insulation blocks could be fabricated safely when using only the original downdraft exhaust ventilation if existing leaks, observed on the 111 hand saw, are corrected. 3. "Kaylo" insulation blocks definitely may be safely fabricated when using the entire exhaust ventilation facilities now available, i.e., hoods ahove the blocks as well as below. ` From Graph II?- C Tables on Fages 8 E 9: 1. Methods of handling "Thenrobestos" blocks (preparatory to rawing) and scraps (after sawing) contribute greatly to specific individual exposures as demonstrated by the following facts: v a. live fabrication process, which always begins at the //? lond saw wl'vlf the simple cutting of each 18" x 38" x 4" block into three smaller blocks about 18" x 12" x M", is normally the least dusty of all the fabrication operations as revealed by the samples taken on 2'i Jan 1963. b. However, on 6 liar 1963, this operation was revealed as being one of the dustiest, regardless of the ventilation being used. c. There was only one major variable between the samples taken on -the two dates, i.e., .the method of handling the blocks preparatory to sawjug. Consideration of the p'rocedurc used on these dates reveals: (1) that on 24 Jan 1963, the blocks were rolled up to the saw after having been removed from their shipping cartons and slacked on a "dolly" for easy individual removal and (2) on 6 Mar 1963, the blocks were not removed from their shipping cartons until needed by the worker. A large amount of dust is produced when block.'.: aw> removed individually from the cartons as a result of the n.duial atra:.;Lon produced when one block is pulled over the surface of llv* clbar. Consequently, the dust concentrations on this date at this location were greater Ilian normal. 2. 'lhc supplementary overhead ventilation (added since the time o( tlr> preceding tv.o reports) does successfully reduce the dust cxiosurcs. However, it doer, not reduce "Thermobostos" dust ex|>oruros to within safe acceptable lim.its-wlien cutting radii. From Graph //.I r. .Table on Page 9: 1. "Caroy-Temp" dur.t concentrations for each exposure was substantially greater tbm the comparable "Thermobestos" dust concentrations and in excess of even the nost lenient TLV established for human exposures, i.e., 60 mppcf of air. A24057 2. 'll.-' oxliaunt ventilation system ns installed on 1 1 It bind r*vr.\ is incMpviMe of reducing the dust hazaitl, assoc in ted with th.- (nht\ie\l. i n ^ of "Carey-Temp", to within safe acceptable limits, i.e., 20 mpjcf of air. Relative to the exhaust ventilation system: 1. The duct velocity in the downdraft ventilation system cn loth '.ivJ rows * is far below the rcconrmended value of M 000 fpm. 2. The duct velocity in the overhead ventilation system cn both bind saws is equal to or more than'the reconmended value of * 000 fpm.. 3. The velocity in the downdraft ventilation systems for belli bnirl saws could be increased by patching all holes, leaks, etc., now in existence. -( I t Rf;C0MM]:Nl)AT10il3: *t ! 1. I'o not.fabricate 10" x 36" x M" "Carey-Tcmp" or "Thcrmolostos" insulation nuterials unless: * i a. The atmospheric dust problem can lx: reduced to bo low 20 rpprf of a .in tlnvjugh the use cf improved ventilatibn tccluiiqucs or repairs to V/* existing system, or b. The manufacturers of the two makes of insulation material:: are able to produce a product which will not release, upon fabrication 'with a land saw, dust concentrations in excess of 20 mppcf of air. i \ l i / t HUP:hi ji 23 October 11103 Submitted by: Industrial Hygienist X Or> T ^ Lv ilu.it ion cl industrial ir.r.nwi: siiir.'i:/ Almo:;pl>;ric Dust Conditions at the Construction Insulation Sirup Table III Atmospheric Dust Concentration Data Collected When Using Only Partial. Ventilation,,i.e., Only Below the Blocks II , I Cutting G Edging Insulation Blocks Cutting a Padius on Insulation Blocks l>ite Mir fi? . 25 1'rb G3 Mir G2 2N Jan (.! 6 IVir 03 Mir 02 25 Jeb f>3 Kir 02 2< .i.m r.3 ' G Mir 03 Type of Miterial Ka1y) lo Themules to:; tf It Kaylo II Thcmobestos ir ti Description of Location //3, nt i.e., II South Side of H It H 11IIm II2 It BaInf d Saw It II3, ir It fl II ft It fl It n, m II II It If ft t fl II3, tf It fl If ft fl tl 11 II", m, i.e., fl South Side of II II It Dio It III II Band tl Saw It //*, II It If fl If ft If ff II ft It If tf II l. fl n ft It fl ft fl It f Concentration in rppcf 17.10 3.30 ini.U0 GO. S3 3G.82 3.00 23.35 P3.30 GG.G3 vo. in A24059 V l1 I 11 htl'- 6 K.r (> 26 bub CO 6 Ki)' '.1 26 lob 61 Tc.i-.l-v I!2 A myiphrrb" T'-v ir - *' S-wiccnlt-it -n DUu Colluded V.lien Iking All Aviil-ihJe Vent i lation, i.e., Doth Above E Below the Blocks Cutting T. f>Jging Insulation Blocks I 1 ;i '*'.1 o of Kilrrj.il Therm ibed us Cir--'V-1 c:n| - Thetnol'/s! ' Cnrov-Tori'p Description of location /fin, i.e., South Side of the 02 Band Saw 0J ^ If * IF * H tl 11 H n I/7-i, i.e., South Side of tlv> //I Ban) Sri U j j ir it ' -i M ii ii ii ' C:n ~on 11': 1' .irm in nprcf m.ro 61. >0 17,!ii 61.20 Kite 6 Kir 6.1 6 Kir 61 26 Tub 61 26 l'ob 61 Cutting a .Radius on Insulation Blocks '/pc cf lilt c.r i.n ] The) liolr.dos TJicn-olx.':-1 os Caii'.y-'lcjiip Calry-Tomp Description of location //la, i.e., South Side of the l'2 Band Saw //'la, i.e., South Side of the fll Paul Saw II |j^ II II II 11 l II II *1 05-i, i.e., Ilorth Side of the 01 Band '-u-: v-r . ration in rrppcf 22.H2 SI.70 OS.'iO ICO. 'i0 Index__ _fo_r Gr__a_ph_s_I_I1, 11t2 E //** v 1. Sou th ' m-.l Saw - Cutting Blocks - Vt nl i lat ion On] 7 -i- /< > 11 ii n l II - L'dging " II 1 1* AM 11 m !- 11 M - Cutting a Radius _ If 11 11 n/'l: 11 ii tl it M l |l M II l r.M M 1 - Cutting Blcxdcs - II folli A!C I' 'Mi 1* ii VI 11 M - edging " II l M M If !/ 1 | <1 ir *1 It - Cutting a Radius 1 * ll n i:\/I i 1 ii M _ II If M 1 n ii Dorth : id" VI : nid Saw - Cutting a Radius - Ventilation Roll: Ad I'cJ.ci; ?<0sc V Trial o 1 2 3 J'H3 h i.i Mnliulj.oii o( I'ci'cenl i;e Crystal Line Tree Prevent in ''Theniiolwst os'*, "KnyTo" r. "Cnrcy-1 cmp" .ig Q'l.irlz by tl "Talvitiu" Metliod It). "Thennobcstos" (As Contained in Fe'Xjrt 62-III-1--G-l) Wj in Grams ('2 in Grams V'3 in Grants 1 Iree F1O2 C.500? 0.6900 o.bor? 0.0390 0.0347 0.0396 0.0069 0.0066 0.0092 Average Fei'contage Crystalline Tree S1Q2 = 6.11 G.2 5.60 o.?n "Kaylo" (As Contained in Report 62--lli-l--G--1) Trial H 1 ? 3 V.*! in Grams V.'j in Grams 'I3 in Grams " lire 0.5000 0.50U0 ' 0.5000 0.0007 0.0730 0.0563 0.0433 0.036't 0,0190. V.'.O 7..12 . 7 .nr, Average Percentage Crystalline Free Site - 7.1' ''Carcy-Tnmp" (As Reported by Mr. Thomas M. Durkan) 4 October 1963 tcmi-.MK'.ntr, [o.luMn in llel Otlv-r Coii'i' nenls Soluble in riwspltoric Acid I'ei'centage Crystalline Free as Quarts .10.(11 BB.n 99,01. 00.'ll A2406 t V ] 'No flu Ventilation Pales on Two Panel Saws l A Kite Hood Ikiing I1 it id Saw Cl iccked Description of Condition Ventilation Kite i n fpm 25 Pel, G3 G Kir G3 25 Teb CO G Kir G3 25 P?b G3 G Jhr 63 25 lei, G3 Kir 13 25 leb G3 6 Kir 63 n II2 H7 117 il 2 /2 II?. 1! 2 112 II2 DownII draft It It It Over) load II H tt Only Downdraft System in Operation It II 91 It | Downdraft E Overhead System in Operation 1 91 II 11^ M Every Hood in the System Open i II II 91 H II Downdraft E Ovei'head System in Operation t II If II It tl Every Hood in the System Open 11 If 11 11 It 91 1600 I'iGO 1200 1200 360 200 6600 us no ||000 r 25 Teb ro G Kir G3 25 Pel- CO 6 Kir 03 25 I'cb 53 G Kir 63 25 lob G3 6 Kit' 63 25 lob 03 6 Kir 63 HI n III III III n n in m m Downdraft II It tl 1 II Overhead tt ft tt Only Downdraft System in Operation 1 It II || M Downdraft E Overhead System in Operation H II 11 It II It Every.Hood in the System Open *1 11 11 II If If Downdraft 6 Overhead System in Operation 11 91 If It 11 It Lvcry Hood in the System Open 11 11 II If 11 If 2H*n 1601 1600 11 rn 1.100 6600 K no 1200 C!oru:omi.*t.ionu in nppc! of Air O' o .j wo ' o* uo . ot/* o-4 ' .on uhi Hi) O Concentration in mppcf of Air uo o* mo op o u S p "6 \ { **s *S l Jlw 02 n c 01 \tV/i mxi o Irt c: a JU yj Art trt > u n: Xv r r *o **1 V t/J w to. n \~.j'i.ti# % G Concon (.ration in mppcf of Air O C LA -I VkiIf \oJ l/> C ?a c a. m tr. T < n: 2: C Cl w n *i