Document 39d2zwmvep4nOB6e4BLbgek6

V Mr, Hugh M Jackson, Manager Industrial Health Program Johns.Manville Corporation 22 East 40th Street Hew York 16, Hew York Dear HughJ Please find eneloeed memoranda concerning laboratory atudlee on each of the six subject* cited la your letter of July 13* Delay in forwarding these data to you was caused by mention schedules and other absences from the office of certaltr. staff members. We have purposely in this stage deleted costs and starting Ume estimates as we wished to hare a clarification of the technical aspects of the studies and a mutual agreement of procedure of research. The starting dates and coats can easily be appended at a later date. l will be in Hew York a few days the week.of August 10 and also August 31, If you and Dr, Smith would llks to have me meet with you either of those dates, Z will be pleased to arrange for it. Kindest personal regards Slocerely yours C, Richard Walmer, M,D Managing Director CRWtfna cc: Dr, Kenneth Smith cc of memorandum also enclosed to Dr. Smith -n_ HVGIc.NL jNDATION Or AMERiw^. MRLLCN IIMSTITUTC 4400 FIFTH AVENUE PiTTsrauRGi-i is. Pa. August i, l';53 MDMOKANBUht ON RISIaKCH PROJECTS rGR JOHNS-MANV2LLE CORPORATION /Hf S.J- Strueture sad Dual Characteristics of Mv-5orb A study o< the strueturs sad dust characteristics of Hy-Sorb would rsqulrs three stops (1) x-ray diffraction to determine U crystallise fras silica la prasaat sod, if so, Lhe amount (2) screen analysis to give Information on the amount of fines, and (3) field studies to determine the amount of dust actually disseminated Into the air under actual working conditions. The first two Items are simple routine proceduras and require no special consideration. To conduct the field iludles It would ce necessary to.. \ * , 4 snow companies which are using )fySorb and obtain their cooperation to Vy- \ permit sampling during actual use of the material. It would, of course, he * possible to simulate working conditions but It la believed that actual lo-plaui tests would have greater weight. Laboratory testa have been used In which Lho dlsss.i.lnatlon of dust is measured after the dual is dropped through a certain distance, buch tests provide valuable Information when studying several compounds In order to . obtain coo.pr stive data. Thu results for any one compound would be of > V \ relatively llitle value ubUs* it were possible lo compare it to auotoer com pound. wince only oq auiiAaet le Involved this test i- l^nt well be omitted. ^*jlel^e_tj|>jdcUv_of_j^erine^eed Fresh V ster 'ta:o rsetoc* i.arth Moce the information desired Is relative toxicity, the in tret riches! Insufflation test Is well suited (or this purpose. It Is proposed, therefore, to slud> six dusts: narr.oly, natural, cslcteed, and flux-calcined marine dlatoinaceeus earth sod the corresponding fresh water dlatomaceous earth. The rat would be used aa the experimental animal and the du: i administered In a single dose. Sufficient ealmals would be used In each group to permit aacrl- m flee at 3, 6 and 12 months with the remainder being held for 18 months. Thus, Comparative Information would be obtained on relative short-time effects as well as long-tin.e effects. V The Pdative Toxtclt*- of Various. Asbestos Fibers Again, since the objective Is to obtain relative toxicity data, tbs ^ lntratrachaal Insufflation tests should give maaoiogful Information. The pro cedure In general would parallel that for the marine and fresh water dlatomaceous previously outlined. The study could be limited to crocldollte, chryeotlle and auv.oslle and we would wish to work cioeely with you la selecting the oiaterlal for the test. 4 Toxicity of hiasalve Dote br Inhalation of Dlatomlf It la believed that laformatloa obtained by the Intratracheal Insuf flation testa of the dUtomeeeous earth previously outlined would give a partial Qiwir to this question. Periodic intratracheal Insufflation test* would give additional information. However, actual inhalation teats would bo reqelred for a more praclaa evaluation. The design of equipment for toat procedure for exposing animals intermittently to aaaalvo concentrations of Ibo dual can readily be accomplished. la order to bare a baala for comparison it would bo < i # aeeeaaary to eoeduct chronic exposures, This, la tore, would aeeeaaltato Using a proper level (or the chronic exposure*. If the lotratracbeal Ineof- flatloa teat* were conducted drat, these data would be helpful In aelectlag exposure levela. However, if such iaats are not conducted first, U la petal* ble that information available on exposures ia taduatry would provide the nec essary Information. - Tbraahold Limit (or f*lux-Calctnd Dlatomaceous Earth Products The threshold limits of 5 million particles per cubic foot for quarts was estabUahad from human exparience through Inhalation. So fax, no oaa baa ever established a toxicity limit for flbrosla-prodoclag dual through * aoLr.tl experimentation. It la, of courae, poaatble through animal experimentation to obtain comparative resulta which would be helpful la Indicating the possible mngnl- ti.de of e threshold (or thl* due: In comparison with ftlllcft d-st. Thi problem in particular we (eel should be given very careful consideration before attemptfog to tfliwer the question by animal experimentation. While undoubtedly meanlr^f-.l c.-.d worthwhile information could be obtained, ft careful appraisal of the limitation* of such data ehould be understood. Possible Relationship of Asbestosls end Cancar of the Lung v The results published 07 certain investigator* indicating a high Loci* d nee of lung cancer la person* suffering from asbestos!*, apparently are at variance with the experience of some ether observers. There are several possible explanations (or the divergence ( these observations. It la possible that variations in the type of operation or the characteristic* of the fiber'may play a role, sod confirmatory Information i* needed regarding the diagnosis o.` both the asbestos!* and the cancer of lung. Until the aaeeaaary data are obtained by mesa* of a scientific epidemiologic study,' the difference of oplnloa xriU continue to exist, and so convincing evidence will be available to either side. Zt la proposed, therefore, that the study to be undertaken will Include: 1. A critical review of the literature with detailed study of case* reported by Merewefihsr and Keeper, who claim a high incidence of lung # cancer among workers showing aabestosla, e 2, A detailed study of the operations in which these workers were Involved with reference to the easel type of fiber to which they were exposed, duration of exposure, and Information relsting to age, sex aad race. Resell*  o( tnc pmpnsed study on the relative toxicity of chryeulUc, jux.obUc *r,u cro' labile fiuer* would L correlated with this portloo of u.e survey, J. blalisllcal stud/ of both asweeioeis 4od C4tcinoniA c*a to dl<rcr.la the dsis wo v*i.ic:i Uie diagnosis wn made, 4, A parallel statistical etudy of a sufficiently largo group of unaffected worker# to serve a# a control. lict'oro aasertaxlag s-cb an extensive epidemiological survey, it will bo accessary to determine whether the required area# for investigation are available. Wo would wish to know how many pleats wo might have access to, end to what extent the information outlined above might bo accessible, Xi Is eaticipatod that a propor study of this sort would reveal Infor mation pertinent ie the probleu. of asbestosis, as well as contributing specific knowledge regarding the possible connection between pulmonarr carcinoma and ashestosls,