oy ‘ = 4 eer Mf tse 4 er = Thvroird Absorzed Dose Assessment for Rongelap and Ucirik Resicents E.T. Lessard, J.R. Naidu, &.P. Miltenberger 3rooxhaven National Laborazoary 410800 Sarety and Environmental Proceccion Division Upton, New York 11973 & N.A. Greenhouse University of California Lawrence Berkeley Laboratory Berkeley, California 94720 & L.V. Xaplan Brookhaven Summer Stucenc Program Brookhaven Nacional Laboratory and Yale University ABSTRACT The incernal thyroid absorbed dose from Castle 8ravo fallout affeceing Rongelap and Ucirik Acolls, Marshall Islands, snderendent approaches encompagsing 1) is reassessed using the single sooled urine radto- chemical analysis of March 1954 and currenc uptake, rerencion and excrerion models, 2) airborne concentrations and areal activities of the iodine isotopes derived from hiscoric soil samples and, 3) airborne concentrations and areal activities of che todine isotopes derived from weather cata obtained during the thermonuclear test experiment at Bikini Atoll and current Factors such as solubilicy of fodine isotopes, the possible contribution from neutron induced activity, the impact of cthy- roid seekers other than iodine isotopes on dose, and confidence levels tty fallout daposirion models. for vaLues of derived quantities such as airborne activity concentracions are also considered. aAddicionally, these thyroid absorbed dose estimates are compared to che incidence of chyroid nodules reported for the accidentally exposed people. BEST COPY AVAILABLE Research carried out under the auspice of the U. ander Contracce No. DE=AC02-76CHOOOL16. S$. Deparcmenc of Energy