Anthropogenic radionuclides in seawater of the Far Eastern Seas

Large quantities of radioactive wastes have been dumped in the Far Eastern Seas by the former Soviet Union and the Russian Federation, and small amoun ts of radioactive wastes have been dumped by Japan and the Republic of Kore a. In order to investigate the concentrations of anthropogenic radionuclide s in the nine dumping areas, a second expedition was conducted in 1995 by J apan, the Republic of Korea, the Russian Federation and IAEA, following the first expedition in 1994. The results show that Cs-137, Sr-90 and Pu239+24 0 concentrations in surface and bottom waters at dumping areas do not signi ficantly differ from the values observed in background areas, and from hist orical values. There is no clear effect of possible contamination due to ra dioactive waste dumping. The concentrations and water column inventories of Cs-137, Sr-90 and Pu239+240 in the Far Eastern seas are controlled by phys ical oceanic processes such as horizontal transport and biogeochemical proc esses such as scavenging. (C) 1999 Elsevier Science B.V. AU rights reserved .