Document avvE5MaOVVVgp65GB9GgrVxa

^ WEST ALUS MEMORIAL HOSPITAL Xiik eta WEST UN'COIN AVXNVS. WEST AUJS. ssa, WWSi S. <5. E. Wright Chief, Laboratory Division ` liavy Environmental Health Center . 3333 Vina Street Cincinnati, Ohio 45220 . Sear Jir. Wright: -;.V This is a reply to your letter of November 5~th; HAVENYIRHLTHCEN, 5/GH:Z11, 6260,10, Inclosed are copies of Our blood and urine lead procedures. The procedures involve a simple chelation and extraction process followed by aspiration into the atomic absorption system, in our case the Vartan AA 5. tx n ip He recommend that blood specimens for lead analysis be collected in the special Orange Too Vacutainer Tube prepar by Becton, Dickinson 6 Co.. This tube #3200 X F532 cental sodium heoarin and 0.1 ml of Triton X-JGO. Blood col 1ecta in this tube is comoleteiy hemolysed if shaken immediately j after drawing and, as a result, clotting is keot to a I ainimun. The tubes are certified as lead free. .Although the literature indicates that the pH of the blood be adjusted to 3.0 before chelation with ammonium oyrollidin difchiocarbanate (A?0C), w.e nave found no appreciable difference in.the values determined if this adjustment is emitted. Literature also recommends use of the 2170 A resonance line as the most sensitive. Studies *how, however that measurements made with this resonance line are not ' linear. He use only the 2333 A resonance line. As Indicated in the procedure vie use only certified AA standards. Because we were not able to fir 1 acceptable commercial controls, we preoare our own controls for our quality control program. Spiked specimens are not acceotable nor are specimens using animal blood. After analysis we pool the blood from industrial workers exposed to lead according to arbitrary concentration levels, ie t N 30683 DUP040013698 WEST ALLIS MEMORIAL HOSPITAL m west mxoy< a v en v c w es t a l u s , Wis c o n s in . ph o n e; j ms o 2. ,` * , * % . * . * .** . * ' i /- % us 0 * 20, 21 - 40, 41 - 60, 61 - SO, and 81 * TOO mcg/dl* ' *" The pools are kept frozen during collection. When a liter, or better two liters, of a given level has been collected, the blood is thawed, filtered through gauze and cloth with suction to remove all docs and fibrin, poured into plastic tubes or vials in 7 to 10 ml aliquots, and the aliquots frozen. The mean and standard deviation of each pool lot Is determined from the aliquots. Vials of the frozen control are thawed as needed for our quality control program. At least one control aliquot is run with each set of lead determinations. If kept frozen the pool controls maintain the mean value indefinitely. Our studies have shown that a refrigerated pool decreases in value after about two weeks. It Is this pool control that we use in our round robin program. We have also made these controls available to other,laboratories at cost for their*quality control programs. .-We discourage the determination of lead on urine specimens unless the patient is being treated and the doctor is interested in an evaluation of the lead excretion. Our experience shows very little correlation between blood and urine lead--levels in patients exposed-'to lead. Urine read is a poor indicator of lead exposure. , .. ;;' In our program the hemoglobin valuers... determined on all blood specimens analyzed' 'for'lead in crder"'td~d2termine the ratio of lead concentration to the grams percent hemoglobin. The ratio, which we call the lead index, is far more indicative of lead toxicity than the lead level alone. An individual with a lead level of 83 mcg/dl 3od a hemoglobin of 16 graS will have an index of 5; a second patient with a lead level of 60 mcg/dl and a hemoglobin of 10 gms- has an index of 6. The second patient has a greater lead toxicity than the first and there is need for greater concern for the condition of this patient. Toxic levels are often present when the Index approaches 6,0, Vie routinely reoort the lead level, hemoglobin, and index for each analysis. He are in the orocess of evaluating our Reference Program pf October in which 16 laboratories participated. Me will be happy to send you a copy of the tabulated data from this Study and will'be glad to include your laboratory in any & . 've DUP040013699 WEST ALLIS MEMORIAL KT^-fTAL `A WCT tWST JXiCOLM a v e n u e. WEST AIUS, WISCONSIN Mar. PHONE: JM-JZ09 3. future programs. Some consideration Is being given to round robin program on a monthly basis but this would have ~e Involve some financial contribution from the participants i hope I have provided the information you seek. If there r.ro any further guest ions concerning our orogram or our .nalysis procedures, please feel free to contact us. Me i' happy to be of service. Sincerely, , Nt H. 3. Conion, H.O. Director of Laboratories JC/dr cvx DUP040013700