Document n9mXgVOdnGMO0bKdLGdd98GMm

Dr.med. 7.Tolf-Dietrich Hegelxnaier Stuttgart-Sued Auf dem H sig st llu Stuttgart, Germany, April 2U, 1950 To the President of the Kettering Laboratory for Applied Physiology, University of Cincinnati, Cincinnati, Ohio. Sir : I have the honor to enclose herewith copy of a letter which I addressed to you on March 17, 1950. Since I am very anxious to finish ny work at an early date and since your reply trill be of great importance to me, I dare to address you again in the hope to receive 'an early reply. Thanking you again for your cooperation and assistance I am Respectfully yours, Enclosure: Copy of letter, dated March 17, 1950 N April 25, 1950 Air Hail Dr. med. Wolf-Dietrich Hegelmaler, Stuttgard-Sued, Auf dom Haigst, ' Stuttgard, Germany. Dear Doctor Hegelmaler* H.' I shall attempt, "briefly, to answer the question raised in your letter of March 17# although I fear I shall not do so to your entire satisfaction* I must apoliglze fin? the long delay in replying, which has been occasioned by a rather heavy work schedule# My primary reason for objecting to the use of milk as a prophylaxis for lead Workers, stems from the fact that there are such better vays of protecting the lead worker# Assuming that the use of silk sight be somewhat advantageous in this regard, for which there is no evidence, it is 3till a poor way to provide safety, for it is a substitute for the adequate control of environmental conditions In my work in the lead trades over a period of a goodly number of years, I have been hurt and distressed b y the willingness of employers, and also by industrial physicians, to justify the existence of hazardous exposure, on the ground that conditions have been improved since the earlier period of industrial operations. In general, the control of occupational lead exposure by sound engineering means is not too difficult. There are situations in which it Is troublesome, but most of the situations , respond to intelligent engineering in an entirely satisfactory manner. Inasmuch as I have been responsible fon the hygienic conditions in the most hazardous of all of the lead trades, namely, the manufacture of tetraethyl lead, X sea well aware of the fact that sound methods of industrial hygiene and of engineering control can solve the problem in a wholly satisfactory manner* Therefore, there is no point in palliative and in apologetic types of prophylaxis* Therefore, I am opposed to the use of milk as a substitute for appropriate professional methods There can be very little question that provision for the use of milk among industrial workmen who are poorly fed is a great advantage, in relation to many types of intoxication* That milk has any other, or more specific, effect than that of Its nutritional benefit, M s never been demonstrated by anyone. It has been alleged, after the fact, in this country, that its beneficial effect may be exerted through Its relatively high content of calcium, Which is alleged to be beneiflcal in tending to immobilize lead in the skeleton* Our metabolic observa tions have shown that neither mobilization nor demobilization of lead can be achieved by efforts to influence the calcium metabolism, and therefore there Is,at the present tlma no scintilla of mechanistic evidence for the beneficial effect of milk, otter than its well known n u 'rient capacity. In experimenta which we have conducted with human Dr. med. Wolf-Dietrich Hegelmaier - 2} - April 25# 1950 subjects to whom soluble lead vas administered In knovn quantities over long periods of time, the administration of milk in quite large quantities vas demonstrated to have no effect upon the lead metabolism. It neither influenced the absorption from the alimentary tract or the disposition of lead in the tissues of the body after absorption. This is in keeping vith our general observations in the course of vhieh ve have found only one therapeutic agent that is capable of influencing the rate of excretion of lead from the body, namely, BAD* Bhder separate cover I shall send you a reprint of our preliminary observations on this material, together vith seme other reprints discussing some of our experiments and the lead metabolism* I should not vant you to believe that ve have spent much time or effort in the investigation of the role of milk. On the contrary, ve have not been very greatly concerned vith this problem. Bather our concern has been vith the more fundamental question of the limits of lead absorption vhieh are compatible vith human safety. Most of our experimental effort over the .past tventy years has been directed to this point. The result has been that ve have been able to set up criteria for safety in the lead trades that can be folloved vith complete success* If the exposure and lead absorption of vorkmen can be kept vlthln certain limits, we can be quite sure that there vill be no cases of lead poisoning. There Is, of course, a larger question than the one referred to above* It vould be of the utmost value If ve could demonstrate whether or not there are any long-term effects of slow absorption of lead. In apparently safe quantities over a long period of time. We have been engaging in several clinical studies of plant populations with this idea in mind, vith substantially negative results * These are not wholly conclusive, but they represent our best experience up to this time. My opinions on this subject are set forth in some of cur articles, but are perhaps best represented in a comprehensive way in a report issued by the American Public Health Association some years ago on the general subject of lead absorption and lead poisoning# This report, so far as my viewpoint 13 concerned, is up to date, vith the single exception that at that time I was unable to satiefy myself on the subject of the therapy of lead intoxication. At that time we had no absolutely conclusive evidence on the inadequacies of the hypothesis of Aub and his associates on the relationships obtaining between the calcium and lead metabolism* We have since had ample opportunity to convince ourselves that this hypothesis ba3 no foundation in fact, and that indeed, the lead metabolism and the calcium metabolism are substantially independent of each other, except for the fact that both lea* and calcium tend to find their way into the skeleton in relatively high concentration. It is quite apparent from oui observations that lead can be absorbed into the skeleton and excreted out of it entirely independent of what is happening to calcium at the same time* I trust that the information in this letter, together with that which Dr# ned* Wolf-Dletrich Hegelnsaier - (2) - April 25, 1950 I an sending you separately, will be useful to you, but If I can answer any other questions, I should be glad to try# Cordially yours, ' Rotert A# itehoei M# !d . . RAK ef Dictated but not read. Reprints under separate cover# . - Occupational Lead Exposure and Lead Poisoning Safe Occupational Lead Exposure ' Exposure to Lead . . t ". Influence of Dithiopropanol (BAL) on Human Lead Metabolism Lead Poisoning,.Symposium A Spectrochemical'Study of the Normal Ranges of Concentration.of Certain Trace Metals in Biological-Materials' Experimental Suudies -on the Ingestion of Lead Compounds UNIVERSITY OF CINCINNATI DEPARTMENT O F PREVENTIVE MEDICINE AND INDUSTRIAL HEALTH THE KETTERING LABORATORY COLLEGE OF MEDICINE-- EDEN AVENUE CINCINNATI 19. OHIO April 2 5 a 1950 Air M8.1 ---- '' ' CABLE ADDRESS: KETLAB. CINCINNATI TELEP H O NE: CAPITOL 1414 Dr. ned. "Wolf-Dietrich Hegelmaier, tut l'.card-Sued, Auf den Haigst, Stuttgard,!Germany. Dear Doctor Hegelmaier: I shall attempt, brief ly, to answer the question Raised in your letter of March 17, although I fear I shall not do so to your entire satisfaction. I must apoligize for the long delay in replying, which has "been occasioned "by a rather heavy work schedule. My primary reason for objecting to the use of milk as a prophylaxis for lead porkers, stems from the fact, that there are much "better ways of protecting the lead worker. Assuming that the use of milk might "be somewhajt advantageous in this regard, for which there is no evidence, if is* still a poor way to provide safety, for it is a substitute for the adequate control of environmental conditions. In my work in the lead trades over a period of a goodly number cf years, I have been hurt and distressed by the willingness of employers, and also "by industrial physicians,to justify the existence of hazardous exposure, on the ground that conditions have been improved since the earlier period of industrial operations. In general, the control of occupational lead exposure by sound engineering means is not too difficult. There are situations in which it is troublesome, but most of the situations respond tq intelligent engineering in an entirely satisfactory manner. Inasmuch is I have been responsible for the hygienic conditions in the most hazardous of all of the lead trades, namely, the manufacture of tetraethyl lead, I am well aware of the fact that sound methods of industrial hygiene and of engineering control can solve the problem in a wholly satisfactory manner. Therefore, there is no point in palliative and in apologetic types of prophylaxis. Therefore, I am opposed tq the use of milk as a substitute for appropriate professional methods. . There can, be very little question that prevision for the use of milk among industrial workmen who are poorly fed is a great advantage, in relation'to many types of intoxication. That milk has any other, or more specific, effect than that of its nutritional benefit, has never been demonstrated by anyone. It has been alleged, after the fact, in this country, that Its beneficial effect may be exerted through its relatively nigh content of calcium, which is alleged to be beneifical In tendirig to immobilize lead in the skeleton. Our metabolic observa tions have shown that neither mobilization nor demobilization of lead can be achieved by efforts to Influence the calcium metabolism, and therefore there is, at the present time no scintilla of mechanistic evidence for the beneficial effect of milk, other than its well known nutrient!capacity. In experiments which we have conducted with human N 6026.03 Dr. med. "Wolf-Dietrich Hegelmaier - (2) - April 25, 1950 subjects to 'whom soluble lead was administered in known quantities over long periods of time, the administration of milk in quite large quantities was demonstrated to have no effect upon the lead metabolism. It neither influenced the absorption from the alimentary tract or the disposition of lead in the tissues of the body after absorption. This is in keeping with our general observations in the course of which we have found only one therapeutic agent that is capable of influencing the rate off excretion of lead from the body, namely, BAL. Under separate cover I shall send you a reprint of our preliminary observations on this material, together with some other reprints discussing some of our experiments and the lead metabolism. I should nqt want you to believe that we have spent much time or effort in the investigation of the role of milk. On the contrary, we have not been very neatly concerned with this problem. Rather our concern has -been with the more fundamental question of the limits of lead absorption which are compatible with human safety. Most of our experimental effort over the pst twenty years has been directed to this point. The result has been tljiat we have been able to set up criteria for safety in the lead trades that can be followed with complete success. If the exposure and lead absorption of workmen can be kept within certain limits, we can be quite sure that there will be no cases of lead poisoning. There is, of course, a larger question than the one referred to above. It would be of the utmost value if we could demonstrate whether or not there are any long-term effects of slow absorption of lead, in apparently safe quantities over a long period of time. We have been engaging in several clinical.studies of plant populations with this idea in mind, with substantially negative results. These are not wholly conclusive, but they represent our best experience up to this time. My opinions on this subject are set forth in some of our articles, but are perhaps best represented in a comprehensive way in a report issued by the . American Pdblic Health Association some years ago on the general subject of lead absorption-and lead poisoning. This report, so far as my viewpoint is concerned, is up to date, with the single exception that at that time I was unable to satisfy myself on the. subject of the therapy of lead intoxication. At that time we had no absolutely conclusive evidence oi) the inadequacies of the hypothesis of Aub and his associates on the relationships obtaining between the calcium and lead metabolism. We have since had ample opportunity to convince ourselves that this hypothesis has no foundation in. fact, and that indeed, the lead metabolism and the calcium metabolism are substantially independent of each other except for the fact that both lead and calcium tend to find their way into the skeleton in relatively high concentration. It is quite apparent from our observations that lead can be absorbed into the skeleton and excreted out of it entirely independent of what is happening to ^calcium at the same time. I trust that the information in this letter, together with that which Dr. ined. Wolf-Dietrieh Hegelmier - (2) - April 25 1950 I am sending you separately, will be useful to you, but if I can answer any other questions, I should be glad to try. Cordially yours, RAK ef Dictated but not read. Reprints under separate cover. Robert A. Kehoe/, M. D^- \> stnT .' . Dr.ned. D'olf-Dietrich Hegelmaier O'- V' Stuttgart-Sued . >y-' Auf dem Haigst ijf s Stuttgart, Germany, March 17* 1950 s. . - To the President of the Kettering Laboratory for ' Applied Physiology, 5 University of Cincinnati, `. Cincinnati, Ohio. ; - . Sir: l . In a scientific work I a m `presently occupied with the problem of the significance of milk allocations to workers of graphical trades, in particular lead workers. Since many years, milk is used in Germany ;as prophylaxis for lead workers. Recently,'however, certain doubts have come up with regard to this question and some German trade ;doctors are mentioning the word of the "Milk Lie". r. ` I understand that- in the United States and in particular in y our'laboratory milk is disapproved as prophylaxis for lead workers. M y attention wa.s called to your research work in this field through articles inthe "Zeitschrift Deutscher Me-- tallhuetten- und Bleiarbeiter"-by Dipl. Chem. IT. Lowicki and Dr. Milesch. Since, however, both articles only mention your results without giving details sand since, according to iry knowledge^ you are the only institute that has dealt with this question, I rould greatly appreciate if you would give me a little more detailed information about your research work in connection with the significance of milk as prophylaxis for workers of graphical trades and in particular lead workers. I . would be most grateful if you would advise me as to literature and statistical material published.;in this field. I am particularly , interested in those publications which may be available to me in Germany, but would also appreciate any indications as to articles published in other countries. ] , : ./ ' Ary information received from y o u will be most Valuable to mej may I, therefore, ask you to send me an early reply? Thanking you'in advance for your cooperation and assistance in this matter I am '` . '- Respectfully yours, A % 1 -H ''Mm Dr.med Wo: trich Hegelmaier 01763.