Document m0NN7Vv06J5mda15gdR4MDn0

( 1.* ch 15, 1943 /v. Ludvig Heltoer., Chairman Cc^ni:`2- cc Cancer Research ;-;_2rioc?1 Cancer Institute Bethesda, Maryland D2.12T Dr*- H^htc em . - ' Xa analyzing the results or a. recently completed f inhalation experiment on asbestcsis, X vaa startled to discover * - // that a oral! group or. XX white nice that had been Inhaling asbes tos dust iron 15 to 2*1 ccaths shewed sc excessive Incidence (31.8?) t/ cf pulmonary cancer- Shin experience was quite at variance vlth the- results. In.all our previous leng-tars dust exposures which were summarised and published by VcrvaXGfanG Xarr lit the American. Journal cf Pathology r January 1933. X would have attached little significance- to this recent binding because or the snail ember cr C animals Involved, bnt Tor the Tact that the literature no*./ contains some 10 reports of pal no nary cancer in cases or human astestosis^ Xrorr these X have heretofore attributed to selection or material as ve have found no cases of pulmonary tenor In surveys of employed . asbestos vorlara. Severer, Gloyna, Marswgther and other Scgiiah. observers contend that asbestos ha a a specific carcinogenic action, cr, the lungs, the question. Is of ccnsiderah?." incortar.ee in. induo-- ... trial medicine- because cf the associated compensation aspects- xr.C from. a scientific view point,, it interests no a great, deal- _ Zn tlsv of this recent finding X have- reanalyzed the results cf a large no--her cf dust inhalation, experiments that we have carried cs during the past 25 years. The* Incidence of pelnonary turners is. shown in the appended table. It. would appear that, except in nice, tuners have been generally uncommon. In the strains . of different species that we had used. Guinea plga have shewn oc casional adenomas. of the lung whose incidence is not influenced by dust exposers or by the type of dust involved. However, in white * l rice that survived for 15 cr core months in our dust rooms, various \ ferns cf long tumors were much sore frequent. The average incidence cf such timers in a group of 1*43 nice exposed to 4 different quartz-- 'cctAinieg du3ta waa 1S.S? but this appears small in contrast to _ls> Incidence of Sl.S? in the asbestos nice. In 51 younger nice sat died or vere killed after exposures of 10 cr 11 months there* c only one instance cf pulmonary tumor. Therefore*, cither ago or .. ration cf dust oxcoaure oust be Imr.crle.nt_ I.cdvtr Hektoer _o_ March 15/ 1943 Eoue or thes>e errperinentc vas planned to study caccirogenic effects. Mice vers only used as there was scece in the dust rccc3 and nar.y of these arinalc that died after short exposures vers discarded, `without autopsy as they could not have developed a sufficient arount of dust reaction tc bo of interest. 'The strain cf nice kept in the laboratory ha3 charged free tins to tine by in-- - portation of cev stock- At one tine vs did procure froa Dr- Kaud Slyo sene cancer susceptible stack but . as these aniaals failed to react to Inhaled quarts ve lost Interest In the subject- *' Obviously under such conditions, the results with asbestos near. nothing but in view of the. considerations which X have cited, X believe they should. be checked. A decioire answer to this question would, be- of rsaX practical value- ?rca what v have learned about the action of asbestiforo alcerals in the living body, X would ckeuically as la the* case with quartz and other force of free silica. Cn crushing or grinding, asbestos fibres, loose care tic ally all their irritating'capacity; quartz on the other hand,bsccr.es nore Irritating an the particle siza decreases- Asbestos provokes fibrosis only in the lungs cf certain steclss; cuartz excites such reaction in asy organ of ary species cf aninsl that vs- have tested. Asbestos so ere to have no specific action upon pulrcnary epithelium but in sons species, it caase** an unusual tyre of diffuser fibrosis which, ccapresses and distorts the epithelial--lined respiratory bronchioles but often faile to obliterate thee, -ceverar, this rechscisa would cot appear to be the one respcnsibl for the- reuse tenors for* this la one of the species which, develops no % fibrosis cc exposure- rcssibly, - the lack of reaction is due to sup-- * ericr upper respiratory protection against inhaled foreign bodies. Xke lungs of nice, exposed to asbestos dust for two years reveal relatively few fibre and all of these are short and coated to fom that peculiar structure breve a3 the asbestos body. " \ - HcOctcen March 15, lSvo , b'culd aCteupt to obCa* a 00 aie-v for each croup- The exposures / *-culd arrarently have to be continued for 15 to 24 nor.th*. Cur routine Ln such experiments providea for dustleg S hours a day, 5 daj3 a vee'-;. * We have all the accessary eqdpuent for such ex periments and a trjltod' laboratory personnel- i*unda are baching fcove/er. Cur previous study of esbeatosis which continued for a period of 7 years was financed by the Asbestos Association- Since this group of esszseS-acturers has already invested $iO>CCC, I cannot ash then for further* contributions - X discussed the natter vlth .* *>r*- Fhcdee at the Manorial Hospital who favored and was cf the cpicicn that it was vorthy cf consideration by your comittce.- X an therefore applying; for a grant of ->5,C0G to cover the cost of the * - first year5c expense- .. * * , ; ' ***.','*. X'had told Dr- Wheels3. that X vculcl bo willing .to do . the entire expert.next for thin amount and ordinarily X cfccdd- How--, ever, cn ny- return fron Ksw Xorb, X found two proposals for investigs-- tins of ether IrduatriaX dust a each of which yield the laboratory 5.000 a year- is X bars only twsr cluat rociss at the present tine- free for new vor;c, X cannot afford to tie up or.o of than fox- two years for half -- *"* e ano*'*nf * SLU yon be- favorably impressed with this proposal X would appreciate aay criticises or suggestions- Sincerely years. ITT ij Xercy 17- Gardner, X- D. Director 010255 l 3 ____3 - -$ A a r c tr n f P itIp tfv M o d u lu s M odo/os