Document KGwDE2Lm2ov7VKqx0Ban7g00K

f . T .* * * UNION ASBESTOS & RUBBER COMPANY Attached hereto please find the report and e which you recently handed me referring to the asbestos dust experiment being: conducted by Dr. Gardner at. Saranac Lake. in the 'present report l find most of the Information is further in confirmation of previous results as reported in April of this year. `."hen this experimental work started in march of It'S?, Dr. Gardner outlined the' objectives a3 being two-fold: 1. To observe by x-ray examination any tendency towards development of fibrosis in the lungs of experimental animals subjected to high concentrations or asDestos dust over prolonged time intervals. 2. To determine if possible wrietner the irritation that develops from asbestos oust in the lung tissues is a result of chemical affects, or mechanical action. To date the results seem to point definitely tc mechanical action as being the cause of fibrosis. This 15' t 2o 58 UJ means simply that the shape and 3ize of the particles that accumulate in the lungs appears to be of more importance as a source of irritation*-than the chemical composition of the particles. Dr. Gardner has found, contrary to what was expected, that the finer particles cause less irritation than the coarser particles. Aninais exposed to nigh concentrations of very fine dust for twenty months have not developed fibrosis of lung tissues, whereas in previous experiments with coarser particles of asbestos dust, fibrosis developed m 15 months exposure. This appears to be an important point and something heretofore not known. ...ost of the experimental results seem to indicate tact asbestos dust is probably less likely to produce fibrosis of the lungs man other forms of silica or silicate dust. There is some evidence to show that crysotiie fleer may be more harmful than other varieties of asbestos that have been tested including Amosite. .his is not conclusive at this time however. -O further cneck the ruecnanical theory as the source of Irritation injections of coarse dust are being made UNION ASBESTOS & RUBBER COMPANY INTEROFFICE CORRESPONDENCE into ootn iun-s or each or a yroup or animals. Jit'r. these animals one run- aas bean artificially collapsed, and thus rendered inaiooiie. -he oxner lun~ xuncxions normally. if Tie necnanical tueor.- is correct, presumably, fibrosis will occur in the Iujip* that moves end mill not develop in the co Hans ed lun^.. Further experiments are now under way to yet additional information on the effects of asbestos dust in different particle sizes and possibly tnis may lead to some de finite cone. .usions as tp wnere t! ie limits :he hazard, in r e s ne c " to 'tide size be-rin and end. 'Iy personal opinion is that if this work is continued it mill likely establish a background of information that will be of considerable assistance in aesiyniny equipment and protective devices for eliminating the industrial hazard. If it can be established that only a certain ranve of particle size and only definite concentrations of dust are harmful, our problem will have been simplified to a considerable extent. R. Cryor:IS Lie-