Document rpzaMOVkX9wYOMa6BDKmErRBq

FILE NAME Talc TALC DATE 1971 DOC TALC123 DOCUMENT DESCRIPTION Excerpt from Barry Castleman's Master's Thesis - Asbestos on Health DRAT'S # 20. Po ID 0-0 79 ASBESTOS ON HEALTH by Barry Castleman An essay submitted to the Johns Hopkins University in conformity with the requirements for the degree of Master of Science in Engineering Baltimore Maryland October 1971 42 For the proofing came past 10 years during which spray fireto be extensively used it was not uncommon to see extensive snowfalls of asbestos- containing material over widespread areas of New York and other metropolitan cities In some cases the fireproofing was even done with no attempt to enclose the spray area by tarpaulins or other means 136 Sampling around construction sites where extensive spraying of asbestos fireproofing was in progress demonstrated a significant contribution to asbestos air pollution In some instances chrysotile asbestos levels approximately 10 times background were observed A few months after this report was made the use of sprayed asbestos insu- lation was totally banned in Boston and Chicago and severely restricted in New York Los Angeles Detroit and Philadelphia 138 Another suspected significant source of asbestos fiber was abrasion of brake linings Lynch examined the emissions from automobile brake wear and found that practically all of the fiber was destroyed by the heat of friction 139 Schulg and Williams 115 analyzed 51 different samples of commercial talc and found tremolite asbestos present in greater than trace amounts in 17 In fact three of the talcs were composed 80 of tremolite Wright stated that 140 talc provides a potent asbestos at least equivalent to source for supplying respirable sized that of fibers that could produce ferruginous bodies It is difficult of having fibers inhaled to conceive of a better way than the use of cosmetic talcum powders This line of thought is contradicted by results of the many body prevalence in populations studies of asbestos that asbestos bodies are more These have established and in individuals with numerous prevalent in males usually in men with assumed asbestos bodies it was to asbestos occupational exposure Talc with or without inclusion of tremolite asbestos may be harm- is no evidence to show that it is a ful but there the extent that the major forms cause of disease to of asbestos are Conclusion Selikoff and coworkers 141 estimated that than 100,000 workers regularly there are fewer using asbestos United States trades in the in the construction than 3,000,000 other build- Yet more work in the same structures A ing trade employees large number of workmen have similar indirect occu- in pational exposure there are people with shipyards 142 In addition family and neighborhood exposures 134. 135. 136. Mourman L. Environ Res 2 30 1969 Lynch J.R. and H. E. Ayer J. Occup Med 10 21 1968 Nicholson W.J. A.N. Rohl and E.F. Ferrand Paper presented at Second International Air Pollution Conference Washington D.C. 1970 137 138 139. 140. U.S. Department of Health Education and Welfare Air Quality Criteria for Particulate Matter PCA Publication 49 Washington D.C. 1969 pp 13-14AP New York Times News Service July 14 1971 Lynch J.R. A.P.C.A. Journal 18 824 1968 Wright G.W. Amer Rev. Respir Dis 100 467 1969 141 142. 143. 144 Selikoff I.J. E.C. Hammond N. Heimann Paper presented at Second International Air Pollu- tion Conference Washington D.C. 1970 Harries P.G. Ann Occup Hyg 11 135 1968 Hourihane D.O'B L. Lessof and P.C. Richardson Brit Med J. 1 1069 1966 Schepers G.W.H. Ann N.Y. Acad Sci 132 246 1965 145 Kuyper L.N. Pneumoconiosis Proceedings of the International Conference Johannesburg 1969 London Capetown Oxford Univ Press 1970 p 42 146 Cremer G.K. Environ Res 2 310 1970