Document B8K12RdnnYZYELBNOgm2bGOxL

March 7, 1940 Mr. C. H. Chase, Secretary-Manager Washington State Apple Commission Wenatchee, Washington. Dear Major Chase: This morning I spent neerly two hours with Dr. Kchce. He gave me a copy of a paper soon to he published which summarizes ills latest work bearing on the lead tolerance question, and I am inclosing it. He stated as a generalization that on the basis of results to date, he has no answers capable of practical application to the immediate problem. Dr. Kehoe would be extremely dubious as to the advisability of a further raising of the lead tolerance at least until there is conclusive evidence as to the nature of lead poisoning itself. The material inclosed outlines a study now in progress in wnich he establishes that the body sets up an equilibrium between intake and output of lead when larger quantities of lead are ingested over a period of time. The issue is, does lead poisoning result from 1. Such an eouilibrium adjusted to such a high level of lead tha e blood stream Itself becomes toxic, or, 2. An overthrow of this equilibrium when the intake of lead exceeds a certain critical amount. In other xvords, it is not known what takes place when lead poisoning occurs; there is no explanation yet as to the physiologic mechanisms involved. Dr. Kehoe placed great importance on this question. He pointed out his view is necessarily somewhat different from that of the Public Health Service; what it must do i3 to try to adapt itself to the urgency of an immediate 05 situation, while the purely scientific point of view taken O by him must depend on complete factual evidence covering HO every point involved in the matter. He made the statement, CO "No person knows, and no combination of persons know, what o o the tolerance should be on the basis of fact." o I hope this conveys the gist of what he said without doing w too much violence to its accuracy. . Sincerely yours, '* / , ,