Document EdKLxQqqBYmk2vBKMoQV8a7RL

JCIATED ETHYL COMPANY LIMITED MEDICAL SERVICES 20 BERKELEY SQUARE, LONDON, W. I jsROSVENOR 6030 TELEGRAMS: ETHYLPORT, WESDO, LONDON CABLES: ETHYLPORT. LONDON HIL1P BOYD ,fMedical Officer o ur r ef . - ' ' YOUR REF. April 24, 1956. Dr. R.A. Kehoe, Kettering Laboratory of Applied Physiology, University of Cincinnati, College of Medicine, Eden Avenue, CINCINNATI 19, Ohio, U.S..A. Dear Dr. Kehoe, In a recent personal letter to Frank Princi, I happened to mention that I was interested in fatty salts of lead, and he suggested I should write to Dr. Stevens. This I have done, and enclose a copy of my second letter, which is really part of the first, as it has occurred to me that perhaps you would prefer to know of this cor respondence. The problem is that I have been asked by certain authorities in this country to help them with the question of the toxicity of the fatty salts of lead, and I find it difficult to get any authoritative information on this subject in this country. Frank suggested I write to Stevens, as he apparently is working in this field, but I think you should know of my-enquiry. There is another point in which I am particularly interested at the present time. This relates to the rapid screening test for lead in urine. In 1953 Cholak wrote an article in the Archives of Industrial Hygiene and Occupational Medicine, suggesting an improvement in the method to identify the organic compounds of lead which might exist in the urine in the tetraethyl lead industry, alongside with the ionic lead which is alone picked up by the ordinary short method of analysis. The suggestion was to add iodine to convert the organic lead to inorganic lead before continuing the normal stages of the method. While our chemists have not yet published their findings, they have examined the whole technique, and gone one further by recovering the final lead and re-assessing it. It is their present opinion that the Kl 08102!.7 N29799 '. b H i f l b rf O A L> I 1- O , Kehoe. t 3' 24.IY.56. i<d 0) -2- Oa0 extra colour which is produced by the addition of iodine is not wholly due to the conversion of organic lead to inorganic but also possibly to an actual colour change caused by the use of iodine, and that therefore the final figure with the new technique does not truly represent the lead content of the urine. Probably I should have waited to discuss this with you until I could let you have the report on this, but I thought it might be interesting at this stage to hear whether in fact similar comments on the technique have been voiced before'. In tfyis matter, I would be most grateful for your comments, as we are having to re-assess the various screening methods we use in terms of their value and their availability in the practical circumstances of the factory routine. I shall not disturb you longer with this letter, but send you my very warmest regards. Yours sincerely, PRB/jmr K 0010218