Document 91bpjVOJ6o32pow64xMYywy0V

FILE NAME: US Gypsum (USG) DATE: 1973 Jul 31 DOC#: USG085 DOCUMENT DESCRIPTION: Letter to M Ehrmann from Dr Selikoff regarding research on toxicity of asbestos M O U N T SINAI S C H O O L OF oj The City F IF TH A V E N U E AND IAATH S T E C T * N E T MEDICINE Universtyoj New York Y O K . N Y. 1901 Dtpmrtmtntof Community July 31, 1973 Mrs. Marie Ehrmann Libran an-in-charge Research Center Library United States Gypsum Company1000 East Northwest Highway Oes Plaines, Illinois 60016 Dear Mrs. Ehrmann: There is a vast literature reporting results of investigations into the comparative toxicity of chrysotile asbestos, in relation to other fibers. In summary, no significant difference was found; all varieties show important fibrogenic and carcinogenic activity. At your request, we will provide some of the most pertinent references. Insofar as human effects are concerned, it is conceivable that the animal models do not reflect a difference which might exist among the fiber varieties; this possible difference is the subject of investiga tion in a number of ways. Dr. McDonald considers that his studies in the chrysotile mines in Quebec have shown less lung cancer and mesothelioma than other asbestos-exposed groups. Very worrisome is his observation that more heavily exposed chrysotile miners had five times as much lung cancer as those more Lightly exposed(l). This would provide clear evidence of the carcinogenic effect of chrysotile asbestos, since the individuals concerned had been exposed only to this fiber variety. Too, review of x-rnys among thase men has shown numerous cases of asbestosis, demonstrating the fibrogenic effect. In addition to mine and mill employees, studies have also been under taken of factory populations thought to be exposed only to chrysotile. This is more complicated, since it is difficult to be absolutely sure that the populations concerned never had any exposure, however small, to other fiber varieties. One such study was reported by Dr. Thomas . Mancuso in 1963, and an important cancer risk of the population in vestigated was found(2). Another study has been reported at scientific meetings by Dr. Joseph K. Wagoner of the National Institute for Occupa tional Safety and Health, while this has not yet appeared in the scien tific press, I am sure that you will be able to obtain a copy of the manuscript from Dr. Wagoner. Mrs. Morie Ehrmann -2 7/31/73 i 1 Or. Joseph Wagoner, Acting Director Division of Field Studies & Clinical Investigation National Institute for Occupational Safety and Healt 550 Main Street Federal Building, Room 7033 Cincinnati, Ohio 45202 In obtaining information on the question, advantage may be taken of another set of circumstances. Amosite and crocidolite, the other two major fibers used in commerce, are not mined in North America, and must be imported. Records of these imports have been kept by the Department of Commerce. We find that only trivial quantities of these fibers were imported until the 1940's and of these small amounts, crocidolite was not used in any insulation materials, although amosite was. Therefore, experience of asbestos insulation workers during the 1940's and 1950's (especially, the former) cannot be ascribed to other than the one asbestos fiber that was in regular use in insulation materials during the 1930's - chrysotlle. Since lung cancer rates, as well as the occurrence of mesothelioma and deaths of asbestosis, were demonstrably increased among these men during the 1940's and 1950's we may infer the chrysotlle-associated risk among them(3-5). Since the problem is an important one, Z expect that more information will become available within the next several years. Sincerely yours, IJS:jlr 1. McDonald, J.C., McDonald, A.D., Gibbs, G.W., Slemiatyckl, J. and Rosslter, C.E. Mortality in the chrysotlle asbestos mines and mills of Quebec. Arch, ^lvxron. Health. 22(6)677-686, June 1971. 2. Mancuso, T.F. and Coulter, E.J. Methodology in industrial health studies. The cohort approach, writh special reference to an asbestos company. Arch. Environ. Health 3(2):210-226 (Feb.) 1963. 3. Selikoff, I.J., Churg, J. and Hammond, E.C. Asbestos Exposure and Neoplasia. J.A.M.A. 188:22-26, 1964. 4. Selikoff, I.J. , Churg, J. and F.aramond, E.C. The occurrence of _ asbestosis among insulation workers in the United States. Anns. N.Y. Acad. Scs. 13?.(1):139-155, Dec. 31, 1965. 5. Selikoff,* I.J., Hr.nmond, E.C. and Churg, J. Asbestos exposure, smoking and neopliisia. J.A.M.A 204(2) :106-112 , April 1968