Document XO2LvDbJk924O12kb9VEOGOKw

FILE NAME: Union Carbide (UC) DATE: 1974 May 20 DOC#: UC225 DOCUMENT DESCRIPTION: Memo RE Answers to Questions Addressed to Irving J. Selikoff, M.D. k X' C/ ASBESTOS INFORMATION ASSOCIATION NORTH AMERICA 1660 L. Streel N W / Wisnmglon. DC 20036 (202) 223-885 20 May 1974 Memorandum For: MEMBERS Subject: Answers to Questions addressed to Irving J . Selikoff, M.D., Mount Sinai School of Medicine Reference: A. Minutes of Special Board of Directors Meeting, February 21, 1974, New York City, forwarded March 6, 1974 B. Executive Director letter to Dr. Selikoff dated February 26, 1974 C. Executive Director letter to Dr. Selikoff dated March 6, 1974 (not to all) Enclosed are answers from Dr. Selikoff with regard to the 13 questions included with Ref. A and submitted to Dr. Selikoff by Ref. b. Enclosure received j m ^ 22 1974 j j DEDICAI PtPfffMEMT j ViD M a y 2 1 1974 Union Carbide 287 QUESTIONS . What is your opinion of the position taken by the Advisory Committee on Asbestos Cancers of the Inter national Agency for Pose-arch on Cancer of the World Health Organization to the effect that "There is no cancer hazard resulting from the ingestion of asbestos fibers present in water, beverages, food, or in the fluids used for the administration of drugs."? Would you comment on the two recent reports issued by the FDA with reference to the use of asbestos filters, both of which would indicate that asbestos filters do not add asbestos fibers to the filtered liquid? The first report was by Mr. Philip McGrath to^Dr. Armand Casola, dated July 10, 1973, showing that an asbestos filter, far from adding to the contamina tion, almost eliminated asbestos from a liquid v?hich had been deliberately heavily loaded with the material. The second report, from Dr. J. Richard Crout to the Acting Director, Bureau of Drugs, would indicate that the use of asbestos-containing filters bears no rela tionship to the presence of asbestos fibers in finished parenteral products. Would you comment on the possible carcinogenic effects of other filter madia, such as the polymers in membrane filters, diatomaceous earth, and activated carbon? QUESTIONS Page 3 8. You have been quoted as saying that asbestos--related disease can be contracted from very minimal exposure to asbestos -- one or two days, for example, bo you have evidence that this is really a serious problem or has your position been exaggerated in the press? 9. Do you believe that asbestos is the only cause of mesothelioma? Are other possible causes being ` investigated by the Mt. Sinai Environmental Laboratory 10. You have predicted an epidemic of mesothelioma among World War II shipyard workers. How many actual cases are you finding or are you aware of per year in this industry? 11. You have talked of the two- or three--fiber Time Weighted Average of the insulation workers, but have said little about peak exposures. Isn't it likely that these are of even greater importance in the causation of disease than the medium or low average exposures? Are you undertaking any investigations in this area? OUZ3t i o :js Pacjc 4 4- ey^o;M-i:3 - S a n C e H C a n d * V e l ? iron- cac-'s of lung cane*-- o^cn-^a" fs3jeST:os;s, yet most have asbescosis. ^ o ,, It "thisexPiaed? lrec^' 13. insulation v o ters t? L 1UB those workers ~whoSdo.nt * * 1 the m s t +y '5 /^ X, i ' MOUNT SINAI SCHOOL OF MEDICINE ofTbcCtty University ofMew York r i F T H AV EN UE AND I00TH S T R E E T . N E W YORK. N T tOOI9 DtftarlmmltfC*munityMtJtcme May 14, 1S74 Mr. R. H. Mereness, Executive Director Asbestos Information Association 1660 L Street, N. W.* Washington, D. C. 20036 Dear Mr. Mereness: I regret we didn't have time to discuss outstanding questions at our recent meeting; clarification of such outstanding problems is often the most useful part of a meeting. I have briefly commented below concerning the several questions raised: 1. I know of no comparable studies which provide information con cerning the relative occupational hazard of crocidolite, chrysotile, amoslte. I am aware that Dr. Enterline's study of JohnsWanville asbestos cement workers exposed to crocidolite in addition to chrysotile provided data interpreted by him as suggesting that exposure to these fibers was associated with additional hazard. I consider that such interpretation is insecure, in view of many uncertainties and variables. 2. There is very little information, especially in humans, con . c e m l n g the relative toxicity of asbestos fibers identical in all respects except for "size" (? length, ?diameter, ?surface area). Dr. Langer of our Laboratory has found, for example, that the overwhelming number of fibers in the lungs of asbestos workers who die of asbestosis or mesothelioma are very small, most in the submicron range. Relatively few are visible by light microscopy. Ruth and his colleagues found approximately as many experimental mesothelioma with chrysotile fibers shorter than 3p as with those longer. These results have not been con troverted. Further evidence on this matter can be extensively provided, but this is hardly the occasion for it. ' 3 3. I see no reason not to use asbestos-containing filter media, provided the end-product does not contain more asbestos than the initial ingredients. I would not support the use of such materials, however, if they added to the concentration of asbestos. 03329 Mr, R. H. Mereness - 2 May 14, 1974 4. There are no reliable data on the total number of mesotheliomas in the United States each year. Data are currently available only for occupationally exposed asbestos workers where studies indicate that approximately 5% of deaths are due to pleural or peritoneal mesothelioma. Some measure of the annual number of mesothelioma deaths among these workers can be obtained by re viewing data concerning newly hir,,,, asbestos workers each year 1930-1960. Calculations could even include such variables as age distribution, duration of employment. The Public Health Service has estimated that there are now some one million workers who are currently employed ir. asbestos trades or who were previously employed but who are now either retired ' or working elsewhere. Without knowing their age distribution and year of onset of asbestos work, only rough projections are Although mesothelioma may occur as a result of neighborhood or family exposure, or as the result of "bystander" exposure in shipyards or the construction industry, few data are available that would allow reliable quantitative estimates to be made in such circumstances. Should any studies be planned to provide information concernin'* the number of mesothelioma cases in the United States, I would" hope that an appropriate design would bo used. Otherwise, re sults would be questionable and conclusions potentially mislead ing, as has been the case in some studies that have been made. 5. There are no reliable data one way or the other concerning cancer haaard that might be associated with the ingestion of asbestos fibers in water, beverages, food or in fluids used for the admin istration of drugs. The question is an important one and it is in my opinion, wrong to state that there is no cancer hazard ' present. We simply don't know, one way or the other, and the phrasing of the statement as it now stands, is misleading. 6. It would not be at all surprising that an asbestos filter would sharply decrease the amount of asbestos in a liquid which had been deliberately heavily loaded with fiber. I fail to see why an experiment had to be done to document such an obvious con- The pertinent experiment would be whether or not asbestos-free liquid passed through an asbestos filter becomes contaminated th fiber from the filter. Such experiments have been done in Dr. Langer s laboratory and they show that the filtrate becomes contaminated* p 30 L Mr, R. h . Mereness May 14, 1974 *ubnitted suggests that uncertainty still exists on w i i c S r t L- l i a\ thUSht " sufflci t l y obvious that we were reluctant to publish what seemed self-evident. Perhaps we were wrong and should record the data. P * ere 7. is ! ? f B "* thiS qUeStin - that other carcinogenic potential to the filtrate - filters r 6 ne and data should be obtained. Thus, if mono:9er were ^ be leached from PVC-contaimng r ^ ^ T t h e ^ l ^ 7 * 1 'lah t0 investi^ t e the natter, that miwht ho w 3e 'elS f Poiycyclic aromatic hydrocarbons bo o i l * , ' Z r " . " '1''" ' Clrbo"- f . wool. crcloogenic potential It t l Z Z Z l Z " " "" !'*lnS " * 8, i i S L T t o r * S ! ,S '^ " r !i*t*d '" *** folloi" occupational w ^ n ,,fcf-T " ,hirty * " * before. However, thin was not Minimal exposure, since it occurred in an asbestos factor* S? montht is*eXposed to such uncontrolled conditions for three T n o ? ' W i m a r aad traCSd Sae thirty yea" ^ter. This again, exposure of bett<!r CatC^ lzed " S v r n ' S ^ . " ''05'1" ' *' 0'i" 1" - poses * Ptoblem, 9. R e S i e r n ^ 116^ tha! asbestos is the only cause of mesothelioma. Dr f.s ! cass in the South Africa Mesothelioma Registry by oi'clis s t u ^ e d ^ 3 !lle^ r lDdiCated that approximately 15% I f f studled by them had no recorded history of either envfrTM course r ccupational asbestos exposure. Experimentally, of ~ course, other agents can produce mesothelioma, as well. investiBating other possible causes of mesothe- -Pr#" f prioritl " d ^ " ited resources h a v T s o far not allowed us to investigate this interesting question. 10. lhlil.liZvaoJi reef arly SeeinB Cases oi mefithelioma with occupational ePluyaat in shipyards during World War II. These 2 e n l v S i 1***1' !Ver* and hapPen to be referred to us because q S S i r t h o nN o r ? f i r rhintereSt in the disease' We did " ake in- fa*mLI I shipyard to see whether records there could thia TM an appropriate population-based study but t l l l o T Z t I ? ? '* KSi* " arly. we have proposed that an Investi gation be undertaken by the U. s. Navy and this, too, has been 03331 Hr. R. H. Xlereness - 4 - Way 14, 1974 E Howcver' the nav5' through the federal Bureau of nW C"pensatCS a11 cases of mesothelioma who woiked in navy shipyards in World War H , provided that they had no asbestos employment since. 7 Very worrisome data were reoorted several months ago by Dr John . ff h * ni8rh Carley Hospital m Lancashire/ He5found m a male autopsy study in Bai-ow, where a very lar-e majority o/th,. th* ;/h0P: lafiln Wrked in that approximately one! lo"ienllv l l l i S i PiaflUef and that W r o x i a a t e l y 6% had radio-, for/f d pleural plaques (of the current shipyard work force). Prospective observation of a group of 235 men with ifeural STS'JSSSJIL""- shmedth*` 70" "" * " * < do or. Harries' treatm!!! ! * S especlal3y sin=e *e still have no successful treatment for this condition. . a l l o w / * / r C e M / aPprpriate industry sources that would we would be if" ! i / rge Ch0rt of 40-1945 shipyard workers, ha hi * pleased to undertake such an investigation and will " " fUl of mesothelioma among such people. `O' espected incidence U ` L S ! f ! ! ! ! ly af ! f that peak * - ^ aures may be of considerable i t ^ i 1 W We/ htd avera* es * at all tell * y" have made a series of measurements concern ing peak exposures, and have reported these. 12. tLlT l investigated asbestos-associated lung cancer other ! i eT S/ 0rkerS` We V Uld lherefore expect to find con- c!!!!! t! f ' at ast hist<>lotically, in cases of lung a we see. However, lung cancer may occur among workers I t T " 1'," " " * `1 " * " * ot p n l c o J " asbestosis. As you know, not all occupationally exposed asbestos workers develop radiological evidence of pulmon'ary f i S o s i ! It is of interest, further, that Dr. Churg found varying levels of pulmonary fibrosis (asbestosis) among cases of afbestosassociated lung cancer studied l.y him, and recently reported. Some cases ha very little fibrosis, and others had a good deal. 13. w! r!W lnv*stiBatil,S this question, prospectively. In 19G3, the iff1"!'5 v e r .1>10 ^ s t o s insulation workers and recorded men ! * * raj xolo6ical pulmonary fibrosis among them. These c!!d!d ^ i n e d under observation and all deaths have been re lation "t *.Kint<iid t0 anal>'zc the experience of these men, in re extent of fibrosis in 1963. Analyses will take a~o !osif! f ! S ' t0tal e*Pore and duration from onset of ex- ' posure, into account. Sincerely yours, M.D.