Document p2eQ7OYRLRY9Yd6BaE2X5OLdX

October 26, 1967 George D. Clayton, Chairman Committee on Air Quality Criteria American Industrial Hygiene Association 14125 Prevost Detroit, Michigan 48227 Dear George: With some surprise, I find myself, through your recent correspondence of October 10, addressed to the Committee on air Quality Criteria, to be a fullfledged member of this Committee. It may be through my misunderstanding, as the result of the somewhat hurried nature of our verbal exchange on this matter, but in any case 1 am surprised, and not happily so. The fact is that 1 simply cannot take the time that is necessary to do this job well, and I want to with draw before I am drawn into this responsibility. I did not take your request of me, in connection with lead, to be that of preparing such a document as will clearly be required in an official statement, if It Is to be issued at this time. Rather, Z thought you wanted me to assist in determining when such a document should be prepared on the basis.ox satisfactory evidence, and of aiding in its preparation. This I am entirely willing to do. The information is not sufficient at present to enable one to establish a specific criterion (or criteria) for the quality of the ambient air in this instance. One could point out how a standard must be arrived at, and how the criteria for that purpose must be established, but this would be an academic exercise. 1 have done this in a published article. A present statement might be useful in delaying this procedure until the proper time, but it would be worthless otherwise. The fact is, however, that no such standard is required at this time other than for the regulation of the lead content of the ambient air for the sake of regulation. There is no public hazard that needs regulation. Let me point out to you and to the Committee the obstacle that exists to this issue in relation to lead. The real issue is the extent of the absorption of absorbable lead in the respiratory tract. This varies in present estimates from 10 percent of that inhaled (under substantially ideal conditions with respect to the compound of lead Inhaled and the size of the dispersed particles) to 50 percent of that inhaled. Until this has been resolved, there is no sense in talking about criteria for the quality of the ambient air with respect to lead. Experiments are either underway, or are soon to be undertaken, and until these have been carried out, successfully, there will be no sound basis for regulatory action. The fact that two of the States, to my knowledge, have adopted standards for the ambient air (for purposes other than dealing with the potential threat of lead In the ambient air), is no reason for encouraging other States and jurisdictionsto go and do likewise or differently. We can contribute nothing to this problem by issuing a document to deal with the industrial, occupational or unusual situations. What is required here, primarily, is sound information on the degree of the potential hazard of lead in the ambient air, as it relates to the general population. The Guide issued on lead is George D. Clayton Page 2 October 26, 1967 sufficient for occupational purposes. (It is true that there are localized problems of atmospheric contamination with lead from smelters and similar industrial processes, in relation to domestic animals. However, in my view, it is not wise to deal with these under the heading of general air quality criteria. Others may see this differently, but I will not be a party to any such views.) With respect to the other substances in the air, such as those dealt with in the papers which you forwarded to me, as well as others that may come up in the future, I cannot take the time, at this stage in my life, to examine these in the manner that is called for if my name is to be attached to them. I am in substantial agreement with the policies of the Committee as expressed in the Rationale, and I believe the other two are sound, but I am not signing my name to any such document, at present, until I can review the available evidence, including that which has been obtained recently. You should know, I think, that when I say that I haven't time for many things that I've been doing previously, I mean that I have systematically neglected my own work, in favor of a lot of administrative and other professional work for many years. I must now get at assembling and studying the data accumulated over a period of years, and if I accept other responsibilities as they come I shall never get my own job done. For this reason, I must ask your indulgence in withdrawing from this Committee assignment, as I have done in the case of Z 37 of A.S.A. I wil.l be most happy to review any of these papers if you (or the Committee) wish me to do so, and to express ray views. I will not find it possible to prepare any of them. Especially would I be pleased to review any statement that may be issued on lead, for I shall be working over the literature on lead, together with our publications in the past and the unpublished results of many observations and experiments over the past several decades. I hope to publish a monograph on lead within the next few years. I believe you know that I am ready to assist A.I.H.A. in every feasible way, and that I will help in this without being the prime mover. Sincerely, RAK:wp Robert A. Kehoe, M.D. Professor Emeritus of Occupational Medicine 0023024