Distribution and behavior of radionuclides and trace elements in marine sediments from coastal areas of Japan

The concentrations and inventories of cesium 137, the sedimentation rates of lead 210, the origin of the marine sediments and the sedimentary environment in the coastal areas of Japan were studied. The marine core samples (26-62cm) were collected from 11 coastal areas (15 stations, 16-455m of water depth) of Japan mainly faced the Pacific from 1985 to 1991 using the gravity core sampler (10cm in diameter). The samples, dried up at 105degC and pulverized into small particles, were analyzed to determine the concentration of radionuclides and trace elements such as Mn, Sc, Sb, lanthanoids, Th, and U. The results were reported as the distribution of each nuclide including vertical profiles as function of each sampling site together with sedimentation rates. (S. Ohno)