Document 155J7N6qExxvZK7O966m7mkZZ

FILE NAME: Union Carbide (UC) DATE: 1975 Sept 29 DOC#: UC051 DOCUMENT DESCRIPTION: Memo RE Visit to the 18th International Congress Occupational Health - Brighton, England, Sept 14-19, 1975 MEMO R A N D U M UnionjCarbide Corporation Metals Division Niagara F a lls , New York September 29, 1975 To: R. E. Byrne, Or. B. L. Ingalls 0. L . Myers W. C. Thurber From: H. B. R hodes./ Copies: Subject: F ile V is it to the 18th Int ernational Congress on Occupational Healt h y Brighton. England. September 14-19X_19Z5 r The w riter attended the above noted conference in Brighton. There were 22 papers d ire c tly relatin g to asbestos presented and about another 15 on occupational lung cancer generally attributed to J^ rs arf as s i l i c a T alc was covered in several o f these. Abstracts o f a ll papers are available*and a complete set o f papers w ill be published in some months. The conference was attended by over 2000 delegates, including most o f the big names in the asbestos controversy. I had the opportunity to ta lk inform ally with a number o f them and th eir current views on the toxicology situ atio n w ill be summarized.' in aeneral the conference produced only one bombshell in the asbestos _ nan!L9hCenr M Wasserman o f Is r a e l. I t was 1n a d iffe re n t session on l?o !la a d M th sdt h a t Uhave0beenH^ were several^mong^small" t i l l dproport1 on"had r E S li kinhoet rates were not in the two regions o f Israel where the plants which K lfd ll b l f t or i ;? e llc lt e d ? 4 STdreS the conclusion that the cause was non occupational exposure to asbestos. A^/. The London Times reported th is Muriel Newhouse wrote le tte r s o f rebuttal which we a ssu m e ^ H be published. Bob Mereness w ill report d e ta ils via AIA/NA. . I O verall, the mesothelioma situation for occupational exP ? ^ r? ^ ^ J ues to look discouraging. The vlJioSs Jarts of the availab le information on the incidence of th is disease in var u n of the world. They found the incidence extremely high in three situ a tio n s. H 1. Among in su lators. | 2. Among those who work or liv e in c it ie s with ship yards. 3. Among thpse who work or liv e in certain c it je s with large asbestos  The evidence for a gradation o f e ffe c t for the various types of asbestos continues to be c o n flic tin g , except for the mining and m illin g operations. Here a clear pattern from c ro c id o lite , amosite, ch ry so tile to anthophylite 1s found. They conclude that th is pattern is generally true with some possible exceptions. The data used in th is study went up to 1972. Mr. John Marsh, (Raybestos-Manhattan) mentioned to me that there are a substantial number of new cases reported that could a lte r the rate of incidence considerably. . The TBA paper updating th e ir m ortality studies that followed was almost unbelievable. I t was read by Dr. R. Doll who mumbled so fa s t that nobody understood a word he sa id . I t was backed up by slid e s con tain in g large tables o f unreadably small fig u re s. Bob Mereness 1s to get a copy o f the paper as are a number o f others who couldn't understand 1 t. I had the opportunity to discuss the Rochedale researches with Dr. Lewinsohn. The key controversy with Dr. S e llk o ff revolves around the reading o f the x -ray s. A panel o f fo u r, including Lewinsohn 1s now reading them and the resu lts are being correlated. A meeting to discuss the re su lts is scheduled for January. I t looks lik e th is w ill not be ready 1n time to help in the U .S . OSHA revisio n . . The discussions with Lewinsohn and h1s TBA associates brought out c le a rly another key-point that I do not believe ever re a lly spelled out in the OSHA hearings. This factory that forms the basis for the 2 fib e r lim it is ju s t now getting th e ir fib e r levels down to 2 fib e r s . A ll of the m ortality data that is being argued over is fo r exposures well above t h is . j This point was also emphasized by Dr. Steve Holmes,(Dr. Holmes' te s t ifie d a t the OSHA hearings.) The lim it is not r e a lly 2 fib ers but 100 fib e r - years based on an assumed 50 year exposure. This 1s tied to a very c r it ic a l second condition that concentrations do not exceed 10 fib er/cc measured over a 10-15 minute period. These c r ite r ia do not consider mesothelioma. The TBA paper was followed by Dr. Murial Newhouse with her la s te s t thinking on her cohort of 3600 asbestos te x t ile workers. She had fit t e d a distribu tion function that had worked for other cancers and was predicting a 10-15% death rate from mesothelioma. This was in addition to 20% from lung cancer. This is a very substantial number and the re st o f'th e B ritish experts that I talked to questioned, the v a lid ity o f the extropolation. In terestin gly enough, Dr. S e lik o ff arose and commented that he f e l t she was high by a facto r o f about 2. I t was interesting to note in a ll o f these discussions that the workers had heavy exposure for a le a st some period but no real attempt was made to correlate variations in ex posure, Dr. Newhouse, however, continues to talk about a dose-response e ffe c t in mesothelioma. * Several other papers o f p articu lar interest in th is seminar related to a cooperative 6 ffo r t to compare asbestos fib e r counts by the techniques used in various countries. The general feelin g was that the methods le f t , considerable to be desired but in the lig h t o f our experiences the comparisons looked pretty good. A key difference found was with the 01189 l U .S. PAT samples that everybody but the U .S. laboratory ca n te d very low. We can understand the problem from our own experience and have a real question in our own minds as to whether the PAT samples are re a lly much more than a numbers game. The S e lik o ff e t . e l . paper on TJC was well presented but looked lik e the same data as was given in Miami, Dr. Fishbein expanded on the short fib e r question to the extent that Dr George Wright got red and climbed a ll over him a fte r the paper. George in sists that there is no evidence that the short fib ers are toxic and a great deal of evidence that they are not. Dr. S e lik o ff him self fin a lly had to come over and smooth things out. As a consequence, I was only able to learn that they do have additional data but could get no d e ta ils . The brake lin in g paper from Mt. Sinai followed the same pattern as TJC with lim ited data and lo ts o f concern. Dr. Lewinsohn commented privately that the 0/1, 1/0 and 1/1 x-ray changes that the Mt. Sinai group feature so prominently 1n th e ir s ta tis tic s are often more In the eye o f the reader than in the film .' Kou Have to get Into the 2 level before there is no question th at a change has occurred. The U.K. public response was that dust was controlled in th is application 1n the U.K. ' The cro cid o lite vs other asbestos question was addressed by * one paper from South Africa- that argued that amoslte plus chrysotile caused as much asbestos!s as c ro c id o lite . The s ta tis tic s were based on the number o f miners who came back out o f the-bush to make compensation claims a fte r working for several years 1n the asbestos mines. There was considerable question regarding the v a lid ity o f the cohort but I t did bring out sonic background on ths cro cid o lite situation* When the question of regulations came up in England 1t looked lik e the blue asbestos from South A frica would be replaced by better amoslte and chrysotile from Rhodesia. I t was s a c rific e s much lik e the spraying o f insulation 1n the U .S .A . and then the Rhodesian sanctions upset the whole pictu re. In summary, I get the overall Impression that there 1s a great deal of concern that the mesothelioma and even the asbestosis picture w ill get worse before I t gets b etter. There is a growing feelin g that sh ort, Intense exposures which overwhelm the lu n g x le a rln g mechanisms may be enough to cause serious harm. The question o f how a9ue and depends to a considerable extent on the Individual s u s c e p tib ility . The only one I found who would take a firm stand on the 2 fib e r lim it was Alex Cross of Cape Asbestos and AIC who f e l t i t was safe for mesothelioma as w ell. knew. I f anyone would lik e to look a t the ab stracts, please le t me H3R:pl H. B. Rhodes