Document peEXmQVOg1x8woEJ3djg18g9k

August 2, 1948 Dr. E. T. Johnstone, 10^1 Roosevelt Building, Los Angeles 14, Calif. Dear Led: In accordance with your letter of July 29 I am sending you a reprint of the published article on the screening method of lead analysis about which I told you, in Detroit. I believe the published article will give you all the information you need, but I do want to make one point. This is a very precise analytical procedure. The results obtained will be equivalent in accuracy to those obtained by the more elaborate techniques, except for the fact that bismuth Is not excluded, and therefore the result may be too high. The low results may be accepted as wholly satisfactory and precise, and therefore only the high results will need to be re-examined. I do want also to warn you that due allovnace will have to be made for the significance of the analytical results on spot samples . Urines of small volume will not always yield the information which is desired, and therefore one has to be careful In putting his reliance on an analysis of a single sample. For this reason, this method is particularly adapted, not so much to diagnostic work but to plant observations where one makes frequent determinations on samples obtained from the sajae individual. In onr opinion, in diagnostic work it Is always advisable to analyze a sample of urine and a sample of blood, since occasionally a sample of urine shows a low lead concentration in the presence of a high concentration in the blood. This is rare, but since it occurs it presents a possibility for error in connection with a medico-legal case. Ve believe that one^ technique should be so carefully chosen that no such err >r occurs in connection with litigation or compensation cases. It was certainly good to see you, and I hope it will not be too long before we meet again. Sincerely yours. FAX ef Enc . .Robert A. Kehoe, M. D. N22087