Document rpDX450XkamZxN7N1bdkK8Xja

O O D 4-2908 CABLE A D D RESS: W I FPO D EPA RTM EN T OF RESEA RCH Cr D EV ELO PM EN T 1151 W EST FI FT H ST R EET AZUSA, CALIFORNIA June 19, 1958 Robert A. Kehoe, M. D. Director of Kettering Laboratory of Applied Physiology College cf Medicine Uni ver si t y of Cinoinnat i Cincinnati, Ohio Subject: Toxicology of Lead Dear Dr, Kehoe: Wc hope that you will forgive the liberty we are taking in address ing a letter directly to you on this most interesting subject. Recently I was in communication with the State of California, Department of Health, talking to Paul Kaplan. I asked him certain questions regarding the processes of elimination of lead from the human system and he referred me to you. He stated that he felt quite sure that if I mentioned his name you would understand the importance of our problem. Several years ago I attended a lead poisoning symposium by the E. I. du Pont de Nemours & Co. here in Los Angeles. At the symposium Dr. S. L. Rankin of the Medical Research Department of the du Pont Compan presented some very excellent data and information on the rate cf elimination of lead poisoning from the human system. His treatise, however, was directed toward the assimilation of lead poisoning through the respiratory system, particularly where workmen were brought into contact with TEL in gas phase. I recall his mentioning that there is apparently a lethal dosage from which there is no re covery but that if the lethal dosage level is not reached there is an excellent chance for complete recovery of the victim. This would indicate that the prosesses of metabolization and other biochemical processes within the body do reduce the lead level in the blood so that it is eliminated from the system. Do you have any pertinent literature and/or data on this subject? Can you cite some pertinent references? We have one other question which is of interest to us but realize that you may not have any' in formation on the subject. Has any work ever been done to your know ledge on the possible absorption of lead to produce lead poisoning through the skin on the hands where soluble organic lead soaps such as lead naphthenate are being used in very' low percentage ratios. For example, suppose that a cutting or metal working oil contained 0.20% lead in the form of lead nap.hthena t e. In your opinion is there any particular hazard involved? Robert A. Kehoe, M. D. - 2 June 19, 1958 Any information or help that you can give us on this subject will be deeply appreciated. Very truly yours, SIG;gc Director of Research & Development 0005062