Document e12v95XVgKG2BqqEO6GnqjaMG

ti wtiwt. O/'.iV--i _/ ~ UJiV'j,'.,-. . IW.. ' 273 PASK AVt.NUE. NEW YCSK, N. Y. 22:27 7'..2.CAL 2IV.ivT:.!.2NT June 7, 29'u7 Dr. 7. J. Hall Union Carbide Europa A.A. 40, Hue Du Rhone 1211 Geneve 3 Dear Tom: I have reviewed the report, "Asbestos As A Health Hazard In The United Kingdom", prepared by I. C. layers, and in general I find that it is reasonably accurate. I do not attach very much importance to the data on the incidence of asbestosis and death from asbestosis and cancer because these are merely tabulations of events and do not take into consideration the numbers of people who were subjected to the possibility of the event occurring. % + We had been interested in the possibility that the short fiber Coalings product might have a greater hazard than the more conventional forms of asbestos bocu-se sub-micron 3ilica has been known to cause a rapidly progressive silicosis after exceedingly brief exposure. We were concerned-about whether the Coallnga material with its exceedingly fine fibril dlane-ter might have a similar effect in causation of asbestosis. We therefore made some preliminary studies in which the material was injected into the belly cavity of guinea pigs, rats ana rabbits and also was injected intratrachealy by a method which distributes the asbestos throughout the lungs of rats. The materials injected were the standard fiber, a refined fiber.and a long fiber obtained from Johns Manvllle for purposes of comparison. In the in jection study the^Coalinga refined fiber produced the most severe reaction In the belly cavity, whereas the ___________ AU 3 1 6 PtSaMkl DEPG, EXH, -3? i -*---- .3/>/-* ! '-KZY A, KENNEDY' standard fiber and the Johns .'linville fiber v.-ere es- cantiaily the`same and 1::; savors. In the infection i; v^U; ~3 ^**U &.# v^***-* CAU^CU & ,.w* 3Y<i3 * i e ^ r"* T a -s '< i# <? *5* * i V* a V'**-w**>*****-5# *V3&*** *f -'*n"W\ ,-' m. ^> *** *.****-* V*?* -- **VT*JVtC/A* ^ WAi**'*"^** o one bus i on wo ear. orav; from this crude test is chat bo -e possible -h.ao cur Coalin^a product ray be more ha.:- f.rdcu- to than lor.j fiber asbestos in that it nay .' * * --0*----ci dysostosis, a * an ear--y time at eor capo--;.. *** * *** *l*.*i ***' #*(1%**.<,**i! -* ***a**kf k*(-'**4* m,, m* *. *w*(t*w,%* *{ J l>< *i *4< . >.'. * paroicius p^r cubic foot wvre -o-ii valid -i- .'. ..old limit Value. I maintain that thl.. value is util- ^un root in terms of preventing the disease, acbesucoia. There is no evidence of asbestos!! occurring anonj people who have worked in an environment where the concentration was kept within the Threshold Lir.it Value. It is probable that the 5 million particles per cubic foot will not be acceptable for the prevention of mesothelioma. I have no idea what concentration mirhs bo effective in. preventing this disease and I would wonder whether even a limit of 1 million particles per cubic foot would bo effective an this record. ' .finally, I would eive v.y unquestionable support to the recucst of the Pneumoconiosis Research Council for "trace element analysis of the standard sample of asbestos, 2y so doir-s wa would develop techniques which could bo applied to our product from Kins City and which would be useful in making comparisons with the standards. I hope this will be helpful to you, if you hav*-* any further questions please let me know. Vary truly yours, / n b` ii yi' riJfCfy"--y^/'//L7/' Associate- Medical Dir-.ewor C. V. Demehl, M.D, ed '* 3' V\ **, 4