Document 82BBrkME9Vjre9GpEomDjywpk

December 1, 19^7 Dr. J. S. Felton, Superintendent, Health Department, Monsanto Chemical Company, ? 0. Box V , Oak .nidge, Teim . Dear Dr. Felton: lour letter of October 29 brings me to recognize that Monsanto Chemical Company is still concerned with Clinton Laboratories. I make mention of this, since I thought that they were no longer involved, and since some discussion some time ago of my acting as an occasional consultant there on their behalf has not been referred to lately. This is not especially important to me, and I mention it only to point out that if there would be any advantage in our getting together at some time, 1 should be very glad to arrange accordingly. Meanwhile, I am very glad to answer your questions as well as I c a n F i r s t , the matterof the interpretation of analytical results on the blood and urine of exposed personnel must be based upon the use of methods of analysis which have an extremely high degree of precision. In general the samples obtained are required to be small, and therefore the analytical precision must be correspondingly great. Furthermore there must be a background of experience which enables one to interpret the results on a broad base. Let me say at the outset that there is no concentration or range of concentrations in the b l o o d , urine or tissues which in and of themselves, denote toxicity. All that can be said is that lead intoxication does not occur until a certain range of concentrations has been reached. Above such a level Intoxication need not occur, but it does occur with a frequency which increases the higher the concentrations go above a safe level. Our observations have established the fact beyond any question that safety requires that the lead concen trations in the urine should not regularly go much above 0.1 mg. per liter in the urine, or u.u6 mg. per 100 grams in the b l o o d . There is more to it than this, but if an individual gives results regularly above these levels, his lead exposure is potentially hazardous. In our experience individuals should be promptly removed from exposure when the lead concentration in the urine remains regularly above 0.15 nig* per nod1115 wou^ correspond roughly to O.uJ or 0.075 mg. per 100 grns7. xibhd intoxication occurs with a rather high frequency among individuals who give results above u.20 mg. per liter in the urine and/or u.oS mg. per loo grams of blood. lou will observe that the range of values in the blood is rather narrow and it is partly for this reason that it is necessary to have information on the u r i n e . ho treatment Is required for any individual who is not ill, regardless of the levels of lead concentration in the blood or excreta. The only treatment required is removal from exposure. There is Indeed no treatment of any kind which can be used practieably to bring about the more rapid elimination of absorbed lead from the body. Various methods employed or advised for employment In the past have been shown to be Dr. J. S. Felton - (2) - December 1, 19^7 valueless in terms of achieving any quantitatively important effect. V e have recently found that the administration of B.A.L. has a profound effect upon the lead content of the blood and that of the urine, decreasing the former sharply while increasing the latter comparably. Even this, hcvever, has no practical usefulness at the present time, since the effect is fleeting and the total effect is too slight to be of any practical significance. I should be very glad when the opportunity presents itself to show you the kind of results that can be obtained by the application of analytical methods in correlation with medical observations. By the suitable application of these methods one can be certain at all limes of the safety or the degree of hazard of people who are under his supervision, and he can act accordingly. Vie have followed certain groups of workmen through their normal operations and through dangerous operations of industrial production, so that new it can be said that ve are pretty clear on just what can be done anc what has to be done. I hope to be able to get this material published in the not too distant future. Unfortunately, however, there are so many things to be done from day to day that I have b e e n 'unable to find the time to study and put this material together for publication. I trust that what I have said will be helpful. If you should care to raise further questions, I ohall do my best to answer them. C ord is.11 y y cur s , AK ef Lober t A. K e h o e , M. L. CONTRACT W 3 5 -0 5 8 ENG 7 t Monsant o Chemical Company CLINTON LABORATORIES P . O'. BOX W OAK R I D G E , T E N N E S S E E October 15^7 Pr, Robert A. Kehoe Kettering Leboretory of Applied Physiology College of Medicine Eden Avenue Cincinneti 19, Ohio Peer Ttr, Kehoe; As you m.sy recell from previous letters end lend de terminetions yoxi did for this office during the drys of the Menhpttrn Pistrlet Project, we hove sererrl of our employees engaged in lend work. Our blood end urine lend determine tic-no hrve continued but T would like to h*ve your present feeling ps to the intrenretsticn of the velues. In other words, vhrt do you feel to be the lowest blood pnd urine levels indicative of beginning lead toricity? ifhrt is the renge where observa tion of the pet lent solely should be carried on? At whet rsnge should the worker be teken off the job svey from lend exposure? At whrt renge should, the rrtient ctuelly be treated for leed poisoning if he is otherwise psymptometic but shows high blood or urine levels? Your current opinion would be very greptly erprecieted end would rid us considerably in guiding the leed workers we hpve. In edvnnce, my deepest thonks. 7erv cordially yours,