snapper. These differences appear to be independent of location and the level of contamination and much more dependent on species. Arithmetic mean concentrations of 239+240py, 238py, ang 24lAm in edible muscle tissue from all fish collected at Bikini between 1977 and 1984 are shown in Table 10. during different periods The results also show that there has been essentially no change in the mean concentration of 238+240py quring the years of collection. Mean concentrations of the transuranic radionuclides in the flesh of fish from Bikini Atoll are a fraction of a pCi/kg wet weight. Barring any major impact on the lagoon environment that might affect the availability of the transuranic radionuclides to marine organisms, mean concentrations in the flesh of fish collected”over the next 10 to 20 years should not differ greatly from present-day values. equivalent to radionuclides the in bone the marrow of individuals fish-flesh-ingestion The 30-y committed-dose from the transuranic pathway (using 200 g/d as the ingestion rate and the mean value for flesh concentration) ranges from 3 to 6 mrem. This range results from increasing the adult gut-transfer coefficient for plutonium? from 1 x 10-4 to 5 x 1074. In fish with relatively high body burdens of 239+240py, the 238pu to 239+240py activity ratio in the muscle and other internal organs was usually higher than the activity ratio found in the material ingested by the fish. In many cases, the error associated with the measurements of 238pu was large, and it could be argued that the differences among the samples were not real. Table 10. Summary of transuranic concentrations in the flesh of all fish from Bikini Atoll. pCi/kg wet wt 4 Arithmetic mean Range in values 1977-1978 0.39+0.34 1977-1981 0.37+0.32 1977-1984 0.29+0.30 1977-1984 <0.007-1.1 0.020+0.021 <0.002-0.08 0.18+0.28 <Q.01-1.1. 4 If the radionuclide concentration was below limits of detection, the value Of the concentration was not included in the average. 9000513 | eee 19