that the concentrations of 239+240py, 24lam, and 60Co were consistently higher in the edible tissues of invertebrates than in the flesh of fish collected at comparable atoll locations. Highest levels of 60co were associated with the kidneys of each species of clams. Concentrations of 297Bi, 137cs, and 90Sr in the edible mucsle and mantle tissue were very low and, in most cases, were undetectable in the samples analyzed. " SUMMARY Over 1550 fish representing species from all trophic levels collected from regions of Bikini lagoon between 1977 and 1984. were Concentrations of gamma-emitting radionuclides accumulated in the different tissues organs of these fish were determined. and A number of samples were selected for the radiochemical analysis of 995r, !13mc¢q, 238,239,240py, 24iam, 210po, 210ph, and 210Bi. Activities of these radionuclides were measured in the tissues using appropriate alpha-spectrometer systems or low-background beta detectors. All the radionuclide concentration data are tabulated in the Appendix. . Over the 8-year period, a reasonable amount of data was developed to define adequately the range in concentrations of the different radionuclides in edible muscle tissue and other organs of fish from the lagoon at Bikini Atoll. Unless there is some unforeseen impact on the lagoon that would significantly alter the environmental concentrations of the different radionuclides, there is little reason to expect that concentrations of the different radionuclides in fish in future years will exceed the upper concentration limits determined over the last 8-year period. . The present mea’ levels of radionuclides in edible muscle tissue of fish can be used with a reasonable degree of confidence to predict the magnitude of future radiological doses to individuals from the marine fish-food pathway at Bikin’ Atoll. J0005 1b 22