Document 5DqGNbMqvj04106qVaKqRL6je

m.*' ir k INDUSTHIAL H rGICNG fOUI-DATlON OF AMERICA. IMC. INf.inUTE 4400 FIFTH AVENUE PrrrsouRCM 13. Pa. August J. 1753. UEUOKA NDUhi ON RESEARCH PROJECTS r OK JOHNS-MANVILLE CORPORATION ... ^ j -- I PLAI Structure and Dual Characteristics ot Hy-5ort> A study of tho structure and dual characteristics of Hy-Sorb would require three atop* (1) x-ray diffraction to determine If crystalline frsc silica l present and. If ao, tho amount (2) screen analysis to glvo Information on Uio amount of fines, and (3) field studios to deter tulno the amount of dust actually disseminated Into tho air under actual working conditions. r The first two Items are simple routine procedures and require no special consideration. To conduct the flold studies It would be necessary to \ V /) * know companies which are using lty-borb and obtain their cooperation to Kr * ' permit sampling during actual uoe of the material. It would, ot course, be * possible to simulate working conditions but It Is believed that actual in-plaut teats would have greater weight, e Laboratory teste have been used la which tho dlsso.idn&llon of d\.*l *\ X * Is measured after the dust Is dropped through a certain distance, buch lasts provide valuable information whan studying several compounds l order to obtain comparative data. ,. , * The results for aay one compound would bo of * * i \ *. t \ \i # iwtii11 or a**** .a ( relatively Hula vi*.lui* unlen* it were possible to compare it to soother com X pound, .ntico only ono aubsmucc la lavolvod this teat might nail be cui.iUsd. hclatlvn ioxlclty o( 'marine and Fresh V ater L'into r.aceoui Larth bluce the (nforuiniloa desired la relative toxicity, the Intratracheal Insufflation toal Is well suited lor this purpose. It Is proposed, therefore, to * stud) six dusts: namely, natural, calcined, and (lux-calclncd marine dlato- e mac ecus earth and the corresponding Crash water dlatomaceous earth. The . rat would be used as the experimental animal and the dust administered In a single doao. Sufficient animals would be used In each group to permit aacri- lice at 3, 6 and IZ months with the remainder being held lor 18 months. Thus, comparative Information would be obtained on rotative short-time effects as * well as long-tin.e effects. V The Relative Toxlcltv of Vsrloua Asbestos Fibers V V 4 1 * /.gain, sloes (he objective la la obtain relative toxicity data, the V > Intratracheal Insufflation teats should give meaningful information. The pro I \ cedure in general would parallel that for th marine and fresh water dlntomacoou* % 74 % earth previously outlined. The study could be limited to croctdollle, chrysotUe and amoslte and we would wish to work clooely with you la selecting tho material (or the test. * i *#n *. <--*. MCHNf AC.' III''*. I.-IC. Toxicity of Mnsalva Hose by Inhalation of Dlato:>.llo It U bollcreJ that Information obtained by th* tatratrnchetil insuf- ' Halloa tests ot the dlatoinoeuouo earth previously outlined would jtro a partial answer to this question. Periodic Intratracheal insufflation tests would give additional information, However, actual iahalatloa tools would bo required (or a more precise evaluation. The design ol equipment (or tost procedure (or . exposing .s a Irani s Intermittently to massive concentrations o( the dust can * - readily be accomplished. In order to hare a baola (or comparison It would ho . i necessary to cooduct chronic exposures. This, la tarn, would necessitate fixing a proper level for the chronic exposure#. If the intratracheal lasuf- r 5 ** ' . . : flallon tests wore conducted first, those data would ho helpful In selecting ' exposure levels. However, if such tests nre not conducted first, it Is possi ble that information available oa exposures la industry would provide the nec essary Information, Threshold Limit for Flux-Calcined DUIomaceous Earth Products The threshold limits of 5 million particles per cubic foot for quarts was established from human experience through iahalatloa. So far. ao one has ever established a toxicity limit for fibrosis-producing dust through soi.csl experimentation. It Is, of courso, possible through animal experimentation to obtain comparative results which would bo helpful In Indicating the possible magnl- t i Ml/UHtHMI, HV&II.XC rm,.. U*HOU ' AMI MICA ltc. A. > t*..de of & threshold lor tMa dust In comparison with slllcn dvst. This problem ' In particular wo leal should bo given vory carafut consideration br.fore atten.pttag to snsv/er the '.ucatlon by animal arporlmcnLatloa. \>hlto undoubtedly meaning!?.! and worthwhile Information could b obtained, a caTcf-.tl apprslaal of the limitations of such data should be understood. #*** ^ y/ f Possible Relationship-of Asbestoais and Cancer of the Lung V The results published by certain lorestigaior* Indicating a high loci- dance ol lung caoeer la persons sufforiug from aabestosts, apparently are at rariance with the experience of some other observers. Thors srs several a possible explanations for the divergence of these'ob'servatlons. It Is possible that variations In the typo of operation or the characteristics of the flber'may play a role, and confirmatory information is needed regarding the diagnosis of both the asbestosis and the cancer of lung. Until the necessary data are * obtained by means of a scientific epidemiologic study, the difference of oplnloa will continue to exist, and no convincing evidence will be available to either side. It Is proposed, therefore, that the study to be undertaken will include: 1, A critical review of tho literature with detailed stndy of cases reported by hieretrcthor and Heuper, who claim a high Incidence of lung ^ cancer among workers showing asbestosis. 2, A detailed study of the operations la which these workers were involved with reference to the exact type of fiber to which they were exposed, duration of exposure, and luformatloa relating to age, sex nod race. Results t i iMOUcra*u Mraic>JK r<3Mfioiio.. c. .................... .... .^c - of tnepropuscd study on the relmlvf tonicity of chxyautlls, amooltc tnu c/o- .. "- - , ^ . * '^ tiuorn would Le correlated wllh this portion of tUe survey. *; * ' # ' J'*; . . 3, bcellsllcal stud/ u( both asoestosls nod carclnon^a cases to determine W.'--'X5-*. . - -- . . . , the oasis u a which the diagnosis was made. * * *'. *. ..." * **:i" * ' . 4. A parallel statistical study o( a sufficiently large group of unaffected . workers to-serve as a control. - ` . ~ ~ ' * "" ` ....................................... f ileioro undertaxing such aa extensive epidemiological survey. It v will be 'aeccssary to determine whether the required areas for Investigation are Available. We would wish to know how many plants wo sight have access . > 'to, and to what exlost.tho information outlined above might be accessible. L- \ Xl is Anticipated that a proper study of this sort would reveal infor mation pertinent to the problem of aabeatoala, .as well ag contributing specific * * knowledge r egarding the possible connection between pulmonary* carcinoma and aatmstosia. > .. V $ i