4.3 Internal Dose - Brookhaven National Laboratory Cesium. It is a curious fact that Brookhaven's studies were not utilized by DOE-1982. Brookhaven had chosen whole-body counting, a definitive method independent of assumptions concerning diet, to follow cesium in the Rongelap population (Conard et al 1980; Lessard 1984 b,c; Miltenberger et al 1980), and one of primary importance in the present case where cesium accounts for 95% of the dose. The cesium-137 body burden fell from about 670,000 pCi in 1958-65 to about 175,000 pci in 1979. It is of interest that body burden fell by 75% in 20 years, whereas the half-life of cesium is 30 years. Perhaps a change in eating habits or a larger degree of environmental loss of the radionuclide than has been established were at work. are In any event, the Brookhaven estimates for whole-body dose (1978) .027 rem, and for Tables 1,2). the ensuing 30-year period .245 rem (Note ll, The 30-year dose was calculated by extrapolating the curve for the previous dozen years. A more conservative assumption would be that the dose will fall only as a result of spontaneous decay by cesium-137. In this case, the 30-year dose would be .56 rem for whole-body, red marrow and bone surfaces. We do not have an independent field check on the accuracy of the whole-body field measurements. The point may be made, however, that it was this team that discovered the precipitous rise in body-burden of the Bikini settlers in 1977-78 and who therefore called for their removal from Bikini Atoll (Conard et al, 1980; Miltenberger et al, 1980). Strontium. Strontium-90 daily excretion was determined by urine analysis and the committed effective dose equivalent calculated therefrom. Three autopsies have confirmed such calculations (Conard et al 1980, p. 115). The annual whole-body dose for 1978 was less than .001 rem (Note ll, Table 2); the subsequent 30-year committed effective dose based on spontaneous decay alone whould be .015 rem. The corresponding tissue doses are: red marrow, .079 rem; bone surfaces, .179 rem. Transuranics. Although only 104 of some 270 determinations have been looked at, it is clear that the results cannot be used as they stand now. A full discussion is presented in Note 12; here we deal briefly with the conclusions. Plutonium-239 was measured in urine samples, collected in 1981 at Rongelap, using the fission track method (ORAU, 1987). The data appear to be bimodally distributed over a range extending from 1 x 10-3 pCi/d (the practical limit of detection) up to 5 x 10-9 pCi/d. Neither sex nor age appears to play a primary role in determining this result. 32