Document MYvQLzr1bewVoG4Onq3yZmGL

r. .. %. * *^ 9* COPY is PLAINTIFF'S !* exhibit \CTSG /S3 ir st Progress Report on Asbestosis Experiments at the Saranac Laboratory. ITay 5> 1937. To furnish a 'center understanding of the disease, asbestosis, and to provide standards as a basis for its diagnosis by x-ray films, a group c: animal experiments has now been started. It is expected that anatomicalchanges rill be produced in the lungs of animals inhaling fibrous asbestos which Trill cast shadows on an x-ray film comparable to those seen in human beings. Since the animals can be killed as seems advisable it rill be possible to compare the anatomies changes in their lungs with the shadows seen in the films. To make certain whether the fibrosis in the lung is due to the chemical composition of asbestosis or whether it is the result of a mild irrita tion in the rails of the air spaces resulting from the action of a fibrous foreign body (L.e. its physical structure) injection experiments are in progress. If no fibrosis results from accumulations of asbestos in other organs it may probably be assumed that chemical stimulation of the tissues is not responsible for the pulmonary fibrosis. As a further check on the physical vs. the chemical hypothesis, the action of ground serpentine is being compared with that of chrysotile. Since they both have the same chemical composition the comparison should be instructive whatever the result. To check fhe effect of mere fibrous structure, a search for other f ** wTOUS r.erals was made. Hone other than those classified as asbestos could be d iscovered which had the same structural composition, -owever, because of our interest in the action of gypsum, a sample of satin spar (fibrous) and also one of soda tremolite were selected for comparative testine. Finally, the action of various members of the asbestos group, amphibo-le, amesite, crocidoiite and anthophyllite are all being compared with that of chrysotile. I * is woo early_to report more than ;e fad -a *Whe experiments have - beer._s tarred. For the inhalation of chrysotile, a dust,furnished by Lr. Fisher from a plant at ilanville, V.. J. is be ins employed. As it was received, the dust war not sufficiently fine for experiments of thi *a. ^ Ir. the dusting oom we placed 3C guinea pigs, 20 rats, S rabbits and 3 cats. Yore of he latter will be procured as they become available. S> O i A dust concentration of apcrcximately 175 million particles ?ar ;ubic foot o: air is no'.t being maintained. This may later be chanced. Crar rCl' of *.hr particles rre less than 5 microns ;r. ilama ter. Since significant results car.ncc be expected to develop until exposures have been continued for from 1 to 2 years there csn be little to report before the expiration of that tine. The various injection experiments are further advanced although it is too early to report any results. For this purpose all dusts have been analysed, chemically and.. petrographically. They rare then ground and fractionated by aliutriation. Only particles 1 o } microns in diameter were used. Their composition '.vac train hacked by the same methods of analysis. The various tests are a'oulated for your information. ChT*vsctile fT^etford') a. Intravenous Injections. Have proved difficult. 7 rabbits have died, apparently from mechanical effects, without receiving significant quantities of the dust. Further attempts are in progress. b. Intraperitoneal Injections - 5 guinea pigs, March 31, 1937 One killed after one month. No gross fibrosis. a. Intravenous Injection. L rabbits still in progress. Have each received 11 doses totalling 0.55*grams. Mo fatalities'. b. Intraoeritoneal Injection. 5 guinea pigs. Feb. 5, 1937 2 killed after 12 and 30 days respectively. Dust plaques without gross fibrosis. .-.me site Intravenous Injection. L rabbits still in oroeress. Have each received 11 doses totalling 0.55 gr=ms Mo fatalities. b. Intraperitoneal Injection. 5 euinea Digs on Feb 5 1937 ` 2 died of infection. 1i vxsiiiled after 1 month. Most of the dust absorbed; no fibrosis. -3- i- r ii e a. intravenous Injection. 4 rabbits-have each received full dose of one gran in 10 inject! :r.s. None killed. ...... -Intraperitoneal-injection. 7 guinea 'p'igs 1 2 died of infection. .......... 1 killed after 1 month. Pigmented dust ... ^ plaques without fibrosis." Anthorhvllite a. Intravenous Injection. 4 rabbits have each received full dose of 1 gran in 20 injections. 2 killed after 3 1/2 to 6 months respectively. No evidence of fibrosis in the lungs, spleen, liver or bone narrow. b. Intraperitoneal Injection. 5 guinea pigs. 3 killed after 1, 4 and S months respectively. Disappearing reaction with gross evidence of fibrosis. ' Servertine a. Intravenous Injection. 4 rabbits have each received full dose of 1 gran in 20 injections. A. 11 alive and well. b. Intraperitoneal Injection. 5 guinea pigs. 2 killed after 1 and L months respectively. Soft pigmented dust plaques Without fibrosis. Fibrous Ovrsun - Satin Scar a. Intravenous Injection. L rabbits have each received 11 of 20 injections, or a total of 0.55 grans. No fatalities. - ..... r b. Intraperitoneal Injections - not cade. Soda Tre^olite a. Intravenous Injection. 4 rabbits have each received . total dose of 1 gram.in 20 injections. All alive and well. b . Intraperitoneal Injection. 5 guinea piss. 1 killed after 1 month. Snail oismectec dust *">o <-> * r I IU rlacues without : ir o s i s . Mone of these early results is regarded as significant and no conlusions rill he dram until the observations have been con or at least one year. It. is not yet clear whether the difi with intravenous injections of chrysotile are merely a matt technique or whether this substance is essentially toxic. 7'e are attempting to discover the cause.