Document 6wGxQyMXgNd09RvQbvnL0Mn4o

72 [l^L- QUESTION AND ANSWER SESSION FOLLOWING DR. SELIKOFF'S PRESENTATION In the asbestos products factory In which mon employed for only three months were found . u have a significant Increase in lung cancer, were smoking histories obtained? (Dr. Selikoff) The answer is 'yes*, and those data are now being analyzed, but I would be amazed if we found any lung cancers or any more than a trivial number among those who did not smoke cigarettes. Wo have failed to see any significant increaso in the incidence of lung cancer among asbestos workers who do not smoke cigarettes. Wo have bean following 2,066 non smoking insulation workers from January 1967 through 1971 and wo have only seen two lung cancers among then. On the other hand, of 9,590 cigarette smoking insulation workers, we have found 145 lung cancers whereas only some 30 were expected. Bronchogenic carcinoma is almost limited to ciga rette smoking asbestos workers. This is not true of peritoneal mesothelioma; it is not true of asbestosis; and it is probably, although our data is too scant yet to be sure, it is probably not true of pleural mesothelioma. Eut of lung cancer - there is no question - this will not occur by and large among asbestos workers who do not smoke cigarettes. I would like to ask Dr. Solikoff if he thinks the new standard should include both a total dust count - if there is a new standard - both a total dust count and a per cent fiber count. At least in our experience, we seem to vary comparatively. A standard set on one rather than the other could be quite mis leading. . Ray Murphy has asked me a vary embarrassing question. He asked me to give an opinion where I can't give it even on fiber counts. Ho now asked me whether I would do it on total counts rather than just fibers. The answer is, "I don't know." But I'm not very impressed (if I can upstage Duncan Holiday a bit who is going to review this tomorrow morning) - we're not very impressed with asbestos standards which rely upon dust counts being done. Kay I give you some data? Very depressing data, if you think these are depressing. On June 7, 1972, the asbestos standard came into effect. And it said that every company using asbestos had to do at least one dust count, one dust count, in the next six months. That is, by December 6. We, on December 7, did a survey of insulation workers in the United States ar.d we now have some 5,000 odd replies. Each man was asked about tho dust counts that ho personally had seen in tho six months whon every company was supposed to do a dust count. In the Unitod States Insulation industry, fewer (than 3% of the in sulation workers saw even one dust count 'done from June 7 to December 6, 1972. Obviously thon, dependence upon dust counting as a means of control in this unusual industry has many deficiencies. 0. It is really one quostion in two parts, perhaps. The fibers at tho Turner Asbestos Company (Xnox-Holmes study), what were these and could you comment, would you comment on the possible differences that you think may bo between crocidolite and chrysotile and amosite? A. The fibers in Turner Brothers, since it was a textile operation, were largely chrysotile. We can give you no information con cerning crocidolite because nono of the workors studied by us had any crocidolite exposure. They had chrysotile exposure and many of them had amosite exposure. Indeed, in the plants, in the factory making the Navy insulation, this was almost entirely ' amosite. So our data apply only to amosite and to chrysotile ar.d, unfortunately, I can give you no information on the relative hazard of crocidolite. I would suggest, however, that if crocidolite is more dangerous than amosite or chrysotile, it is ' going to be almost as bad as bis-chloromothylether. (Laughter) Q. Dr. Selikoff, are you aware of a particular type of asbestos liber mined in Ontario called Headman? fibers which have been found to be relatively inert, by Paul Gross and others? A. I presume that you mean the fibers mined in Quebec, not Ontario. (No, rained in Headman Mine in Ontario.) No, I do not know these particular fibers ar.d I would be delighted to know of an asbestos fiber which is comparatively inert. Q. They claim - and Paul Gross and others have done experimental work - and they have found that this particular fiber which is chrysotile has boen, in experimental work, found to be inert. A. Well, I would be delighted to see those, indeed I'd be delighted to rce those in industrial use. . Thank you. Dr. Selikoff. '! ' ' . I.