of this radionuclide are not known. of Fon, 13765 and 99sy observed, Fe body burdens were probably ~ small (9). | 1957. However, based on the levels The Rongelapese returned to the atoll in mid-July, Whole body counting and urinalysis measurements one year later disclosed significant body purdens of several radionuclides, the most notable being 13 Tos, It is probable that 556 body burdens increased similarly. | the concentrations of ne. in a selected species of fish and in soils are listed in Table 20 Activity in the fish is based on wet weights for comparison with previous work. Pooled samples were used in the analyses to xeduce the effect of withinsample variation. The 556 values for soil samples collected in 1963 at both Kabelle Islet and Rongelap Islet are averages of samples collected at depth increments of O-1.3 cm and 1,3-2.5 em. Specific activities are not given for soils since varying amounts of pre-1954 plant detritus could significantly alter the stable iron content but not the ar activity. In this instance, activity per unit weight of soil is a better index of changes which occur as a result of input or loss than is specific activity. | | The decrease in Se specific activities in Mulloidichthys, sp. (goatfish) at Rongelap ‘between 1959-1961 corresponds to an ecological half-life of 11 months, identical to that observed by Jennings (11). Higher specific activities may have occurred