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 eaximum permissible concentration for radionuclides in food or drinking water of man. Of the wide spectrum of radionuclides concentrated in the surface layers of the soil, strontium-90, antimony-125, and cesium-137 ere the principal nuclides entering into the soil solution. The principai nuclides in the land plants and plant- eating animals such as coconut crabs and the indigenous rats are cesium-137 and, to a lesser degree, strontium-90. Bottom sediments contain mainly strontium-90 and europium-155. The radionuciitdes in the lagoon water have not been detected but are probably present in minute amounts. Planktonic orgaSisms contain traces of manganese-54, cobalt-57,60, zinc-65, zirconium-95, ruthenium-106 and cerium-144. The principal nuclide found in the Marine algae is cerium-144. In the marine invertebrates cobalt-60 and zinc-65 occur most commonly. Corais 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 strontium-90 in the body of the natives reflects a diet of both marine and terrestrial origin. . Cote, D.W., S.P. Gessel, and E.E. Held. 1961. of the tension lysimeter in coral atoll and Glacial till soils. Ounning, G.M. (ed.). Use Soil Sci. 25: 321-325. 1957. Radioactive contamination of certain areas in the Pacific Ocean from nuclear teats. U. $8. Atomic Energy Commission, U. 3. Government Printing Office, Washington, D.C. pp. 60 Fosberg, F.R. 1959. Long-term effects of radioactive fallout on plants. Atoll Research Bulletin No. 61. National Academy of Sciences-National Research Council, Washington, D.C. il pp. ---. 1959. Plants and fallout. 1448. Held, E.Z. 1960. Nature 183(4673): Land crabs and fission products at Eniwetok Atoll. Pacific Sci. 14(1): 18-27. Miller, C.F., and P. Loeb. 1958. Ionization rate and photon pulse rate of fission products from elo neutron fission of U235. U. S$. Naval Radiological Defense Laboratory, San Francisco, USNRDL-TR-247. 91 pp. report Robinson, M.K. 1954. Sea temperature in the Marshall islands area. U. S. Geological Survey professional paper 260-D. pp. 281-291 Stone, W.S3S., M.R. Wheeler, W.P. Spencer, F.D. Wilson, J.T, Nevenschwander, T.G. Gregg, R.L. Seecof, and C.L. Ward, 1957. Genetic studies of irradiated natural populations of Drosophila. ACKNOWLEDGMENTS the This work was performed under contract ousber AT(45-1)540 between the U. S. Atomic Energy Com- mission and the University Page 169 of Washington. genetics of Drosophila. Sg essoesi6. In Studies io” niv. of Texas, , Publ. 1954. Circulation systems of Bikini and Yon Arx, W.S. U. 8S. Geological Survey profesRongelap lagoons. pp. 265-273. sional paper 260-8. Walker, R.B., £.E. Held, and 3. P. Gessel. 1961. Radiocesium in plants grown on Rongelap Atoll Cohn, S.H., J.S. Robertson, and R.A. Conard. 1960. Radioisotopes and environmental circumstances: The internal radioactive contamination of a Pacific island communtty exposed to local fallout. In R.S. Caldecott and L.A. Snyder (eds.), Radioitgotopes in the Biosphere. Univ. of Minnesota Tinting Dept., Minneapolia. pp. 306-330. . soils. In Recent Advances in Botany, Prog. of the Sth latern. Bot. ,, 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.

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