Document NnnenZp8Y9V4rDZRwVOpoLp

November XX, 19 3 6 Mr* Warron H. Reinhart 1^221 f'easenden Street, N*W* `Washington, D. C. Dear R!einharts . I am very glad to hear from you again and I am Interested in knowing that you are getting Into some work on lead* I gladly comply with ^our request to send along some reprints, and I am pending you one series of six articles bound together on "The llomal Absorption and Excretion of Dead", of which my supply is almost entirely ex hausted* I think it will be useful for you to have a copy of this and so I am stretching a point to supply you with a somewhat battered copy* However it is the boat I can do# We have carried on our work here beyond the point represented in these reprints, but I have not had either the time or opportunity to put together and publish our recent results# However you will find of considerable interest, I believe, the reprint on "An Appraisal of the Lead Hasards Associated with the Distribution and Use of Gasoline Containing Tetraethyl Lead* Part II - The Occupational Lead Exposure of Filling Station Attendants and Garage Mechanics", because, so far as I know, it gives the details of the first adequate metabolic studies on lead in the normal human subject* We are carrying this experimentation further In some studies of lead in gestin on human subjects. These experimenta, I believe will be of considerable importance in relation to the tolerance levels of lead in food materials, and they will be of especial importance in connection with the threshold of toxic leadr/absorption In as much as you are associated with Dr* Fairhall in some degree, I think it is worth while for me to point out that we have devoted especial attention to the question of analytical methods, and we are now operating three methods in parallel on various types of material* we are continuing our chemical analytical method as described in the Journal of Industrial Hygiene in 1953* *ts method is used only on samples containing lead in excess of one-tenth of a 2 milligram. The spectrgraphic method developed by Cholak Is perhaps the most satisfactory method In use anywhere in tlie country. Its sensitivity is very high and its accuracy both in terms of samples of known lead content and In comparison with methods employed in several other laboratories in this country and abroad, is Indeed satis factory. The "dithizone" method, a modification of which is in use in this laboratory, is being given critical study as to its general applicability, and we are finding it very useful in dealing with tissues and samples of bio-d and urine with low lead content. It bids fair to be the most useful clinical method eventually, Some of your people, particularly P, A, Clifford and H* J, Wichmann, have boen making use of the method and we have been in contact with them on certain improvements which have been developed in their hands. Incidentally wo have found that in load analyses of small samples with very low lead content, it is necessary to work in a dustles3 atmosphore, As a con sequence of this we have developed special facilities in connection with our suectrographic and dithizone work whereby all the preparation of samples and tho analyses are carried out in an air-conditioned room with walls and floors so treated as to pro ed& dust. This may seem an excess of caution but we have found it entirely necessary to do this in order to avoid occasional slight contamination of samples. I am tolling you these facts in some what more detail than Is necessary, perhaps, because I fully understand Dr* Fairhall *s apparent lack of knowledge of our work, Fairhall himself worked previously with methods which were inadequate for tire type of samples he was studying* The publication of our results, together with my criticism of his methods and of his negative results, brought about a sort of controversy which for some reason or other as soured Fairhall on me and on all my work. I am quite sure that he either believes or wishes to believe that everything W have done is incorrect and unreliable, I think this is the result of the confirmation of our results in the hands of practically every other worker in the field since our initial publication. Obviously I have no wish to contribute in any way to Dr, Fairhall*s hard foelings, and I should be glad if it were possible to do something to convince him of our essential honesty, as well as our lack of any feeling against his work. On the other hand I have been somewhat distressed by the fact that he has continued fresa time to time to publish results indicating that normal human beings are not exertting lead In their urine and faeces Two of his studies in the Journal of Industlql Hygiene, the one on leadweighted silk which he did with Helm and another on the potential hazards of rock-wool, completely ignore the observations made in at least a dozen laboratories on the normal lead content of the urine and faeces of-experimental subjects, and ether human beings. I have no idea of what to make T '4 3 of such apparent blindness to the facts, nor do I have any intention of making any further effort to understand# I merely cite these matters as evidence of the bad feeling w h i m exists toward me on his part In explanation of his lack of any Interest or reliance In bur experimental work. I am and shall continue to be very much interested in the work which Is going on In Washington in this field. Despite the large amount of work which has been done in recent years, there Is still very much to be done and In a3 much as we are primarily concerned with the problem of public health, I should like to be In as close contact with what other workers in the field are doing as I may be. With kindest personal regards, Sincerely yours, * RAKj I a Robert A* Kehoe, M.D