Document 5XNOOEEEGejJL1w2qdEEMg0z

B a l t im o r e C it y H o s p it a l s Fr e d e r ic G. Hu b b a r d DIRECTOR 4940 EASTERN AVENUE BA LT I M O RE, M A RYLA N D 2 1 2 2 4 October 12, 1971 IN REPLY REFER TO: Dr. Robert A. Kehoe Professor Emeritus of Occupational M edicine Kettering Laboratory Department of Environmental Health University of Cincinnati Eden and Bethesda Avenues Cincinnat i, Ohio 45219 Dear Dr. Kehoe: o - It was indeed a pleasure and a privilege for me to visit the Kettering Labora tory last week. 1 do want to thank you for your great kindness in showing me about the laboratory during the late afternoon. I shall cert ainly take your advice about certain respiratory exposure data relat ive to lead. We did not get a chance to discuss the necropsy data which you are now collect ing. 1 am wondering whether you are finding any signifi cant differences from the data reported by Tipton and Schroeder and by Mossman and Barry. There is a great deal of scatter in the data reported by them. I mentioned briefly during my discussions with the students and staff after the lecture our recent experiences with the determination of total porphyrin in blood. It seems to me that this has great potential, part icularly in the practical medical sur veillance of groups such as children and occupational ly-exposed workers in whom it might well replace the urinary ALA measurement. W hile the measurement of porphyrin in blood does not have the apparent specif icit y for lead effect that the measurement of ALA in urine has, it has some pract ical advantages. The variations encountered in urinary collect ions would be obviated. The determination of total porphyrin in blood can be made either by fluorescence or by spectrophotometry. In either case, analysis is less time consuming than the analysis of urine. On the other hand, it does not appear that the total porphyrin in blood is stable for more than a few hours. I think that the measurement of total porphyrin in blood may also have some biologic significance beyond its pract ical usefulness. 1 am at present trying to work out the interrelationship between total blood porphyrin and blood lead concentrations. I would very much like to learn your reaction to these observations. 0020209 j x . R. A. Kehoe O ct . 12, 1971 Again, it was a great plea sure to have a chance to meet with you and 1 want to thank you for your generous hospitality. Yours sincerely, JJCj ov D. / 0020210