. . ,- *’ “1)” .: ti~lVERSITY OF c.ALIFORXIA LOS ALAMOS . . -. Los REFER TO: M.41L STOP: ,. “ . W-7405 -ESG-36) ‘P. O. Box 1663 . . . 1S REPLY SCIENTIFIC L.4B0RAT0RY (COSTRACT . AL.AMOS, XE\v MEXICO ,.” H-1-JNPL:75” ‘“ 692 ...... .. . ., . . . 8754-I . “ . . ,, .. . .. ““ “October 23, 1975 “ ... ,, ., . . ,4 Dr. Robert A. Conrad Medical Department Brookhaven !iationalLaboratory Upton, NY’ 11973 Dear Bob.: .. . , ,. To give you some idea’of the plutonium daily excretion level of persons who are constantl~exposed to plutonium, I have made a simple calculation, the results of.whlch,are attached”. In this calculation, I.haveassumed that the person concerned acquires 4 pCi of plutoniwn per day. This acquisitionis assumed 1) to be in a soluble form in the blood stream, and 2) to be deposited in the bone and liver, and 3) to be eliminated according to Langham’s excretion equation. For a single acute uptake of D pCi in thissoluble form, Liingham’sequation predicts a 24 hour excretion of 0.002 D Z-0.7q’on day Z after the uptake, i.e.,.U = 0.002 D 2-0974-. Forcontinuous exposure (multiple uptakes), t.~eexcretion-is ‘“ predicted to be “ ““ ‘z = 0.002 D ! n=l where Z-O.74 n D is the daily uptake in pCi Znis the number of days of exposure “Uz is the predicted excretion on day Zn in pCi/24 hr. The attachedtable is for D = 4 pCi per day and Z is from 1 to 6fIdays by daily steps and from 90 to 2190 days (6 ,years)nin.30day steps. For smaller daily uptakes you can divide the values of column !3Zand Uz,bv the desired reduction factor. After three years (lC195”days)of exposure with the calculated uptake, the total accumulated systemic body burden would be 4330 pCi and the expected urinary excretion would be 0.163 pCi/24 hr. You stated that the sensitivity detection limit of the Health and Safety (H & S) lab runs 0.01 d/roper 24 hrs or% O.005 pCi/24 hr. Since the H & S has not been able to detect any activity over their limit of detection, it just could be inferred that the 3 year accumulated intake by the 3ikini natives could not be in excess of .()~s -~X 4330 or% 130 pCi or~f).12 .+s lZ~;AL OPPOR-I”UXJ”rY1l>[PLOYER nCi/c!ay. .