Qualitative Distribution of Radionuclides years after contamination by fallout from a thermonuclear device indicates distinct differences between the terrestrial and marine environments. The levels of radioactivity are low, the concentrations being less than the maximum permissible concentra- Cole, D.W., S.P. Gessel, and E.E. Held. glacial till soils. Dunning, G.M. (ed.). The principal nuclides in the land plants and plant- eating animals such as coconut crabs and the indigenous rats are cesiur-137 and, to a lesser degree, strontium-90. Bottom sediments contain mainly strontium-90 and europium-155. The radiobuclides in the lagoon water have not been detected but are probably present in minute amounts. Plank-~ tonic organigms contain traces of manganese-54, cobalt-57,60, zinc-65, zirconium-95, ruthenius-106 and cerium-144. The principal nuclide found in the marine algae is cerium-l144. In the marine invertebrates cobalt-60 and zinc-65 occur most commonly. Corals and coralline algae contain some strontiun90, while the fish and sea birds are found to contain mostly zinc-65. The presence of zinc-65, cesium-137, and strontiua-90 in the body of the na~tives reflects a diet of both marine and terrestrial origin. Use Soil Sci. 25: 321-325. 1957. Radioactive contamination of certain areas in the Pacific Ocean froe nuclear tests. U. 9. Atomic Energy Commission, U. 8. Government Printing Office, Washington, D.C. 60 Of the wide spectrum of radionuclides concen- trated in the surface layers of the soil, strontium-90, antimony-125, and cesium-137 are the prin-~ cipal nuclides entering into the soil solution. 1961. of the tension lysimeter in coral atoll and tion for radionuclides in food or drinking water of man. Page 169 PP. Posberg, F.R. 1959. Long-term effects of radioactive fallout on plants. Atoll Research Bulletin No. 61. National Academy of Sciences-National Research Council, Washington, D.C. 11 pp. ---. 1959. Plants and fallout. 1448. Held, Z.E. 1960. Nature 193(4673): Land crabs and fission products at Eniwetok Atoll. Pacific Sci. 14(1): 18-27. Miller, C.F., and P. Loeb. 1958. Ionization rate and photon pulee rate of fission products from slow neutron fission of U235. U. S$. Naval Radiological Defense Laboratory, San Francisco, USNRDL-TR-247. Robinson, M.K. 91 pp. 1954. islands area. al paper 2860-D. report Sea temperature in the Marshall U. 8. Geological Survey profession- pp. 381-291 Stone, W.3., M.R. Wheeler, W.P. Spencer, F.D. Wilson, J.T. Nevenschwander, T.G. Gregg, R.L. Seecof, and C.L. Ward, 1957. ACENOWLEDGMENTS Genetic studies of irradiated natural populations of Drosophila. This work was performed under contract number AT(45-1)540 between the U. S. Atomic Energy Conmission and the University of Washington. the netic: f£ Drosophila. S7f1e pe86-316. Von Arx, ¥.8. 1954. Rongelap lagoons. Cohn, 8.H., J.S. Robertaon, and R.A. Conard. 1960. Radioisotopes and environmental circumstances: The internal radioactive contamination of a Pacific island community exposed to local fallout. In R.8. Caldecott and L.A. Snyder (eds.), Radjo- isotopes in the Biosphere, Univ. of Minnesota rinting Dept., Minneapolis. pp. 306-330. , ” Publ. Circulation systems of Bikini and U. 8. Geological Survey profes- eional paper 260-5. Walker, Ia Univ. of Texas, pp. 265-273. R.B., E.E. Held, and 8. P. Gessel. 1961. Radiocesium in plants grown on Rongelap Atoll soils. In Recent Advances in Botany, Proc. of the 9th . - Congr., Univ. of Toronto Press, Toronto, Canada. pp. 1363-1367. Weiss, H.V., and W.L. Shipman. 1957. Biological concentration by killer clams of cobait-60 froa radioactive fallout. Science 125(3250): 695.