Document o9NkVy7wmVNyB7LpD0NdjGD5X

EDWARD CORSI INDUSTRIAL COMMISSIONER THOMAS F. MOORE. JR. PIRST OEPUTY (NOUSTRlAL COMMISSIONER ABRAHAM H. GOODMAN DEPUTY INDUSTRIAL COMMISSIONER LOIS B HUNTER OEPUTY INDUSTRIAL COMMISSIONER EDWARD A. NYEGAARD OEPUTY INDUSTRIAL COMMISSIONER STATE OF NEW YORK DEPARTMENT OF LABOR ALBANY NEWYORKOFFICE 80 CENTRE STREET February 17, 1950 NEWYORK, N.Y. Division of Industrial Hygiene and Safety Standards Dr. Robert A. Kehoe The Kettering Laboratory College of Medicine Eden Avenue Cincinnati 19, Ohio Dear Dr. Kehoe: Many thanks for your letter of February 9tb. The information v:as exactly what we were looking for, Y,e are getting in touch with Mr. Kleiner of Becton, Dickinson & Co. and wall make some arrangement with him for obtaining their new lead free tubes. Naturally, we will run the necessary blanks to insure the accuracy of our determinations. Me vail be happy to let you know the results of cur experience with these tubes. Cordially yours, - 7 -- Senior Industrial Hygiene Physician JES:DG February 9, 195(-> Dr. John E. Silson, Senior' Industrial Hygiene Physician, Division of Industrial Hygiene and Safety Standards, liev York Department of Labor, 8o Centre Street, Albany, Nov York. Der.r Doctor- f 11sons I am very glad to reply veil as I can to your letter cf February 2, concerning the means of collecting samples of blcod for the determination of lead. As you are probably avare, ve have studied the problem of lead concentration in the blood in relation to a sizable number and variety of types of occupational lead exposure In this connection, I may say,at this time, that ve feel quite certain as to the significance of the lead concentrations in the blood, in relation to hazard. I'vlll give you our impressionson this for such use as they may be to you. I should like to point out that ve have been making parallel observations, using tvo highly precise methods of analysis, over a period of seme y e a r s , and that; vhat X have to say is the result of the systematic uopli- cation of these methods, vi t h due recognition of the magnitude of the analytical errors of the methods. The range of normal values in the blood can nov be stated vith utter- precision, in terms of the methods available at this time, as ranging from some tiling under 0*01 mg. of lead per hundred grams of vhole blood up to and including 0.05, ox- occasionally C.055, mg. per hundred grams of vhole blood. The experimental error of either method vhich ve use is such that an occasional value as high as o.OO may be obtained in the case cf an apparently normal individual vith no knovn occupational lead exposure. Values-in excess of this, hovever, are an expression of unusual lead exposure, vhether occupational or non-occupational. When the results obtained on the blood of an individual or of an occupational group are consistently above these normal values, one may assume that there has been occupational lead exposure. I should point out also that the mean value for the blood findings on a normal individual, as the result of repeated observations, or on a group of normal individuals, is slightly less than G.03 rag. per hundred grams. Therefore, vhen the results of a series of observations on a single individual, or on a group of individuals, yields a mean value vhich is statistically different from the figure, 0.03, then one is dealing vith an abnormal group. In our experienceY^gsults above 0.07 are obtained consistently on an individual, oryobtained as the average or mean result on a group under study, then the occupational exposure is of the potentially hazardous type, and should be regarded vith some suspicion. On the other hand, signs and symptoms of lead HE 0007389 N 7872.01 Br. John E< Silcon - (2) - February 9, 1950 intoxication do not appear, with any degree of frequency or severity, In an Individual or in groups of individuals, until the figure of 0.Go mg* per hundred grams of whole blood has been reached or exceeded. The values range far above t h e s e , and may be as high as 0 .1., o.fi, or even 0.8 rag. per hundred grams. There is no level of lead concentration in the blood w hich is certainly associated with signs or symptoms of illness, but the higher values among groups of industrial vorlcmen are associated with a higher incidence and more severe forms of lead intoxication. With reference to your specific question, we have worked with the B and D people on their-vacutainer tubes, from the tine they first had the idea of producing these for use. The tubes first made available were rather badly contaminated, and following their methods of cleaning, they were not greatly improved. Nevertheless, the equipment Itself is quite satisfactory, and when this equipment became available in suitable quantity, we began to make use-- of it. However, for the oast two y e a r s , we have found it necessary to clean the tubes our selves and to re- e acuate them, before making use of them in our own w o r k . Even so we have considered iJ .tu desirable to obtain duplicate sanpies of blood for analysis by parallel methods, net only to check t V, ,, U . V.. analys es but also to check the possibility of the occas: onal con.tamination of the tube. Vie still regard this as good px*c.ctice and we intend to con tinue with it in our- investigative work and in all medico-legal cases Recently the B and D people have sent 1.s a set of tubes for testing, following their use of a new, and a believed, satisfactory, method of cleaning. On an analytical study of these tubes we found them to be quite as satisfactory as those we had cleaned ourselves. We have issued a brief report on the subject-, which we have made available to the and D people ever our signature in order that they might be able to substantiate the satisfactory quality of the-'method. F or ourselves we are quite willing to make use of tubes which they supply us after cleaning by their present and new method of cleaning. Vie will contintie to make parallel observa tions on duplicate samples, since there is no method of cleaning these tubes that will give complete assurance against an occasional contamination. I would suggest, for your purposes, that you get in touch with the gentleman with whom we have had dealings in this natter (name and address b e l o w ) , that you tell him of your problem and that you arrange to be supplied wi t h tubes that are guaranteed to have been cleaned b y the newer method. I have no doubt they have tubes in stock that would not be as satisfactory, but it seems to us that if you obtain tubes cleaned in the new manner that you will obtain satisfactory results. If you do not think this will answer your problem, or if for any reason you still wish to clean your own tubes, I shall ask Mr. Cholak to provide me a description of the methods which we have used for this purpose. Ve are anxious, our selves, to get away from this necessity, since It is a nuisance. Vie will keep an eye on the results of the use of tubes as supplied to us, and if we decide that they are not good enough, ve will K ? 0007390 Dr* John E. Silson - (j5j - February 9, 1950 resume our previous procedure. On the other hand, there is no ques tion in my mind as to the desirability of the use of a technique and equipment that is similar to that issued by these p e o p l e . If the tubes are clean, and if the samples are obtained properly, the opportunities for contamination are negligible. Cordially yours, RAK ef Robert A. Kehoe, M. D Mr. Joseph J. Kleiner, Becton, Dickinson and Company, Rutherford, New Jersey. ABRAHAM H. GOODMAN DEPUTY INDUSTRIAL COMMISSIONER LOIS 6. HUNTER DEPUTY INDUSTRIAL COMMISSIONER EDWARD A. NVEGAARD DEPUTY INDUSTRIAL COMMISSIONER STATE OF NEW YORK DEPARTMENT OF LABOR ALBANY NEWYORKOFFICE 80 CENTRE STREET February 2, 1950 NEWYORK. N.Y. Division of Industrial Hygiene and Safety Standards Dr. Robert Kehoe Kettering Laboratories University of Cincinnati Medical College Cincinnati, Ohio Dear Doctor Kehoe: At Dr. Mayers' suggestion, I am writing you for some in formation on the technique of collecting blood for determination of lead concentrations, we are planning to do a fairly intensive study of the various techniques for the determination of early signs of lead intoxication in workers, and are interested in ob taining a blood lead value in addition to the other data. Since our study vd.ll require collection of several speci mens of venous blood for different tests, we were planning to use Becton-Dickinson vacutainer tubes for their collection. Our laboratory has run a fe:v preliminary tests on these tubes which indicate that they are not entirely lead free. We know of at least one plant, however, vhich has been using these tubes by breaking the vacuum, cleaning the glass and stopper, and re establishing the vacuum. Because of your extensive experience in the collection and analysis of biological materials for lead, we wonder whether you could advise us on the following points: 1) What method do you find most reliable and convenient for the collection of bloods for lead deteimination. 2) Have you had any information or personal experience on the use of vacutainers for this purpose. 3) If so, what method do you recommend for cleaning them. Vie will be grateful for any information you might be able to supply us with along these lines. Sincerely yours, 00073V hi N7872.02