atolls. Concentrations of !37Cs in these four samples ranged from 1.1 to 1.6 pCi/g. Strontium-90 and 239°249Pu were measurable in the samples analyzed. Concentrations were less than a picocurie in all samples but one, the surface soil from site #3 on Bigen Island. 239°240Py per gram. Soil at this site contained 3.8 pCi of Americium-241 was detected in only a few of the soil samples. Utirik Atoll] The two predominant radionuclides in plant samples from Uttirik Atoll were 40K and 137Cs (Appendix Table 8). Of the 19 samples analyzed, the edible portion of the three Pandanus fruit samples contained the greatest amounts of 137¢s (average 14 pCi/g). Values of 9°Sr in the plants ranged up to 2.1 pCi/g. Plutonium-239,240 values were below the limits of detection in the five plant samples analyzed. Soil samples from Utirik Atoll contained !37Cs, 99Sr, and 239°249py jn most of the samples analyzed for these radionuclides (Appendix Tables 9 and 10). Americium-241 and ©°Co were also detected in many of the surface soil samples. Cesium-137 values ranged up to 5.3 pCi/g and averaged about 3 pCi/g in the nine surface soil samples. Soil samples from 5-10 cm below the surface contained less than 0.5 pCi of !37Cs per gram. In the surface samples analyzed, 9°Sr values ranged from 0.5 to 3.2 pCi/g while 239°24°Puy values ranged from 0.08 to 1.3 pCi/g. Americium-241 and ©°Co values were less than a pCi/g. Rongelap Atoll Most samples of marine organisms from Rongelap contained “°K and ©°Co with 40K the predominant radionuclide (Appendix Tables 1] and 11). Cobalt-60 was pre- sent in less than pCi/g amounts, except in the Tridacna clam kidney which contained from 7.6 to 16 pCi/g. Samples of terrestrial organisms also contained 13