-Si- Summary_ 1. Chemical separations by ion-exchange resin column and precipitation techniques were made during January to April, 1957, on selected samples collected at the Pacific Proving Ground in June 1954 and September 1956, The radioactive isotopes contained in the separated fractions were identified by determination of rates of decay, maximum beta energies, 2, and gamma energies. The distribution pattern of radioactive non-fission pro- ducts in plants and animals at the Pacific Proving Ground was studied by means of gamma spectrometry on whole samples. gamma peaks of Minoo , Co?!, C08, C060 | and Zn 65 The were used for identification in this survey. 3. In a soil sample from Belle Island, Eniwetok Atoll, collected September 19, 195€, almost all of the radioactivity was due to fission products, with Ru 106_p,106 and trivalent rare earths accounting for approximately 90 per cent of the total ac- tivity. Of the non-fission radioisotopes only cobalt was detected -- at a level of one to two per cent. 4, Ina clam kidney sample collected at Belle Island, Eni- wetol Atoll, September 22, 1956, fission products accounted for only 3.5 per cent of the total radioactivity. Fe, Co, Mn?“ and Fe? comprised the remaining 96.5 Co’, C078, per cent of the radioactivity. 5. In two fish liver samples collected at Bikini Atoll September 22 and 23, 1956, Oe fission products were not present. ro o* ' / { fl