Document v1w1nMmZOdagG4GY2DyrzqeKE

t NATIQ8AL INSTITUTE OF AHfHHITIS A PlBfABQLIO DISEASES -* Pop A. I*wrence Victor H. Archer July 29s 1953 Analysis of 3anpa.es for 210 After spending considerable time in developing a method, we have analysed the nine water and urine-: upedifeeas- which yon have subaittedi We modified vfce dithissone lead determination method so that tb# separated lead is deposited, on a,glass pl2hehet and coanted in a gas flow proportional counter* We ran enough controls and a spiked sasple to convince ourselves of the validity of the-method* The spiked sample showed 86$ recovery* ''o' jxLm to run s o t norc-spiked apples and. publish the method* ,"Par-a'"-relahle count, one should have nt least .twice; the back ground which in this case is approximately *53 epat* If a 2k hr*-urine sample were concentrated and analyzed* it should contain at least ICO dpa ( 91% equivalent to .$*9 X 10 13 gpam of Fo 210* this would represent the lead formed by the decay of 0*0? microcurics of rnden* PeSQl.ts Of andlydess Sample asm 100 ml analysed Water (1) Water (2) `Wpter (3) P* Lawrence 0* Ponder J* . Johnson. B# Rilport <J* ..Orhem - Distilled Eg) epa 61 *h dkgd* Blfgd, 1^*2 33.1 lb.6 2?*ij. Bkgd* Bkgd* f1 K*. wv\i * '.^i. ij pc A 10~4 2lt hr. urine pc X KT4 Dally absorption 2.0 Calculations not 5.U 16*2 2.1* 7.2 li*5 . 13.5 -The estimated 2l*:hr. urine content was obtained by dividing by lO0s multiplying % 1800 (1800 ml* taken as average 2h hr* urine output), multiplying- by 2 (geometry of counter), and dividing by 2,2 X 106 (conversion t-o microcuries)* The estimate of amount in body is based on the following information supplied by Pr. T?. A Kehoe (data obtained from one normal individual exposed daily to finely divided lead oxide for two years)* An equilibrium, with respect to the tvodtouai concentration ilenc on plateau for the rest of the period* In the two years, the Dr* Kebbe*s work was dose with, stable load, bat- ?b 210 should behave exactly the same since there is enough stable lead 'present in the tody to act as a. carrier* iTsin?; the above figures,-- -at equilibrium (6 ir*c* or more of exposure) '[Of, of absorbed lead is retained and' 60% is excreted per day# 0f that excreted, *3S is in the urine# The urine excretion than represents one third of the- daily intake* The amount of daily absorption of lead is thus aprroxLxately three tires the emouri ' usd in the nrins* To make an estimate of t& amount of lead 210 in the body of an individual exposed for over six nonius, one could take (proportion ` retained) of txe a' ount absorbed daily, and. multiply by the total -pusher cf days exposed* Assuming ih~t ene ihird of 1-}.j & load .210 fomed'by radon decay in the bod;/: is excreted in the urine, then the lower, limits of tbbirathod would be the amount of lead 210 formed by the ebsorpitoa and decay -between 0.2 and 0*3 mierocuries. of redon. per day in chronic exposures* For acute. exposures* the lower linit would px'twbly 1* severs! times higher because of less excretion* I an sure th.it you un^rcteaSd the ^ c nt-.it Iv& and-' .prel'isainary nature cf this data ud: crlcalationr* 7 c :-i-::lyses were performed on mall m civic-n (100 nl*), nant of the counts wore loss than twice bachground so that the statistical error In countiu y was large , the data cf Kehoets was oViairted from only one individual, the, lead in Ms experiment was administered by a possibly different route, and the ekenieal for wae probably different* Kb 0019717