Document M426Mjk5Zz12Odk749Ex0GpQz

i>o Th!i tnoHrtol fctft b**n (*wctt*iuc*d with permission o* fh# copyright owner, Furrier reproduction Is prohibiteJ DEFENDANT'S EXHIBIT PUBLIC HEALTH REPORTS VOL. JSO JAKUiifiY 4. IBM NO. 1 EFFECTS OF THE INHALATION OF ASBESTOS DUST ON THE LUNGS OF1 ASBESTOS WORKERS A Preliminary Study By A. J. Lanza, AitiUatU MtdicaJ Director, William J. McConnell, Atrittani Medical Director, and J. W'iLuam Fehkel, CKemi-.i, Metropolitan Life Imu ranee Co. INTRODUCTION In 1929 the Metropolitan Lire Insurance Co. was approached by officials representing the osbes'tos industry in the United States, who were, clesirons of ascertaining 'whether asbestos dust was an occupa tional hazard in their establislumenIs and, if so, what was the naturo of this hazard and what should be done to prevent or control it. About this time several articles had appeared in English medical, journals describing a pneumoconiosis duo to asbestos dust. While in one or two isolated instances tlbe occurrence of this type of pnoumoconiosLa hod been described in American journals, the industry itself appeared to be quite uninformed of tho existence of any such occupational disease. The hazard of silica duBt, with special reference to the lungs, has long been appreciated, and a great deal of Btudy and research has been applied to the problem (ian the metal mining and certain other industries) in Great Britain, tho United States, the British Do minions, and in other countries. The nature of the effects of Bilks dust expressed in tho term "silicosis", with the resultant extraor dinary predisposition to pulmonary tuberculosis, is well known. These effects' have been associated with the inhalation of dust con taining iree silica in varying amounts. The effects upon the pul monary tissue of dusts containing combined silica--silicates--are still a fertile field for investigation, but evidence is accumulating that certain of these dusts produce pathological results quite distinot from true silicosis. The xsame "asbestoais" has been applied to the pneumoconiosis caused by asbestos dust and it will bo so used in this report. Chem ically, tie asbestos of commerce is a hydrated magnesium silicate consistiDg primarily of silica (combined silica) 44.1 percent, mag nesia 43.percent, and water 12.9 percent, while ferrous iron and nickol axe present in small quantities. This commorcial varioty of 101OM*--SB-- Li. SC-ALL-01005 SCF-FA-0265