Document e1MnNN7nK1G71Z89owJ7dDwDG

FILE NAME: Raybestos-Manhattan (RBM) DATE: 1940 DOC#: RBM016 DOCUMENT DESCRIPTION: Letter from Johns-Manville to Raybestos with Excerpt from the Digest of Industrial Hygiene I u V. \ * --^ X;; s1.'* *."* J ohn's -Manvulle Co rpo ratio n r * n z . m - - r * o eajt ro a tiz ra a r a i a jrrw TOSS.XX Exzcwrrvs Omczs ay 10, 1910. Sumner Simpson, Esc., President,* Raybestos-Hanhattan, Inc., . Bridgeport, Connecticut. Re: Dr. Gardner*s Experiments. Dear H r . Simpson; I an sorry I was away when you telephoned me a few weexs ago. However, my secretary informed-me of the natter about which you wished to speax to se. be In the interested in *lr same connection, I believe you will the attached excerpt from Hygiene Foundation Digest of April, 1910, covering current natters in the field of industrial hygiene. I have not read the original article, but it is apparent from the Digest that Dr. Gardner is already publishing, with out seeding our advance approval, certain conclusions which his reports to us have indicated were arrived at as a result of the experiments underwritten by the textile group. I shall appreciate your comments on this situation Sincerely, 's y Enc. Vandiver Brown, General Attorney. C$472.5" , , // to EXCERPT FRCli AIR EXGIZKE FOGKDAIIOH "DIGEST OF INDUSTRIAL EEGIEIIE Literature-News---Developments " April, 1940 273. %, Recent Develaogents la Relation to Silicosis. L. Gardner. Iad.iiea., 45-4^ (February, 1940). U* Experimental worx in progress at the Saranac Laboratory seens to lead `to the conclusion that inhaled asbestos fibres are irritating not because they are silicates but because they are stiff fibres ,which mechanically irritate the lungs. Yihen asbestos is ground very riheiyjso that~few of T h e fibres are longer thhn 2 m e r ens__rr-isgg th the 'Lrfita ting'*^ op erty'"af"'the ascestog is^pra'ctically^de_stroyed.'" Inhalation, exper*32Snts vdth t m s f lme~ asbestos" In a concentration of 125 oillion particles per-cubic foot over a period of three years has not produced fibrosis -- in previous experiments exposure to one third this concentration of long fibres has produced well carded fibrosis in two years. This phenomenon is directly opposite to that found in silicosis, where with decrease in particle site, reaction becodes dare vigorous. Irritation, f r o a the asbestos fibres seeds to be more closely associated with the physical, rather than the chemical, composition as~'in'the case of1rre erfH i cal There' are many experiments whose re sults are'difficult to reconcile with the solubility hypothesis. In vivo, cellular reactions begin 15 to 30 minutes after injections; in vitro, traces of dissolved silica are found by the most sensitive methods only after 12 to 24 hours. There Is soma experimental evidence that free silica ha3 a specific toxicity. Fine silica injected into the veins or hearts of cer tain animals acts lixe a strong poison. This has not been observed with particles*of larger size or with suspensions of other minerals. These toxic effects can be neutralized by the addition of different substances, for example, coiiodial aluminum hydroxide arr. ferric hydroxide. Lore and more experimental evidence seems to demonstrate the physiological in significance of particles over 3 microns. Finally there is a discussion of the similarity between the silicotic and tuberculous reactions in the lung. " 00ttiso ' v w