Document v1o6YMw4ddpR5zj0ZzYpkj9GZ

11. Inhalation Experiment -rdth n%lrig-'s flouts1* /labegtoa Curt the first inhalation -cxpcricer.t conducted at the Saranac laboratory with asbestos dust was begun Is l?2o. Animals inhaled, the dust for periods up to nearly three Tears and seme guinea pigs lived for about four years after their first exposure to dust* 1 preliminary report giving observations after 29 months of exposure appeared in the February, 1931 issue of 7KZ JODRHit OP USDSTRlkL KTCIEHE.* it that tine observations covered a period of only 2-1fk years and the conclusion* as to the ultimate effects of inhaled asbestos dust vara provisional. Results of the completed study shor that most of the conclusions dr*sn in the preliminary report vers substantiated. i complete rtrrie* of this experijusnt follows. 12. the dust inn; material was a coasarcial variety of asbestos dust known as Xing's floats and res composed of short, flbori? and particles of variable size. It van obtained froct the Thetford, Quebec plant- of th* isbestos Corporation of iaerica. 13. rhg~do5t cocposltioa (table 2) reveals that the amount, of fibrous chrysc-- til* was only lia per cant, a rather lev nalu*. However, there was suf ficient fibrous material to produce a characteristic fibrosis, lit. The dust coocsotrrtlgn at first was quite lor aad for impinger samples takan soon after the experiment *** started, th* average light field count* by tb* standard technique v*^ only 6.0 sdilion particles per cubic foot of air. In appreciable amber of larg* ptrticlw (or fibers) also war* present, u STUDIES OH EXPERDfflnilL FXEaeCCSIOSIS. 71. Inhalation of Aabecto* Dust., Osrdner, I.C., md OaalAgs, D.E, J. Ind, Hy*., 13* 65-tfl, 97-Uii, 1531.