Marine radioactivity in the Arctic: a retrospect of environmental studies in Greenland waters with emphasis on transport of Sr-90 and Cs-137 With theEast Greenland Current

The waters around Greenland have received radioactive contamination from th ree major sources: Global fallout, discharges from the nuclear fuel reproce ssing plant Sellafield in the UK, and the Chernobyl accident in the Former Soviet Union (FSU). The global fallout peaked in the early 1960s. The radio logically most important radionuclides from this source are Sr-90 and Cs-13 7. Th, input of global fallout to arctic waters was direct deposition from the atmosphere and indirect delivery through river run off and advection fr om the Atlantic Ocean via the north-east Atlantic current system. The water borne discharges from Sellafield which were at their peak between 1974 and 1981 contributed primarily Cs-137, although some Sr-90 was also discharged. The Chernobyl accident in 1986 was characterised by its substantial atmosp heric release of radiocaesium (Cs-134 and Cs-137). Other sources may, howev er, also have contributed to the radioactivity in the Greenland waters. Exa mples include La Hague, France, and radioactive discharges to the great Sib erian rivers (Ob, Yenisey and Lena) from nuclear activities in the Former S oviet Union or the local fallout from the Novaya Zemlya nuclear weapons tes t site. Dumping of nuclear waste in the Kara and Barents Seas may be anothe r, although minor source. From measurements in Greenland waters carried out since 1962 the transport of radionuclides with the East Greenland Current is calculated and compared with the estimated inputs of Sr-90 and Cs-137 to the Arctic Ocean. This study focus on Sr-90 and Cs-137 because the longest time series are available for these two radionuclides. (C) 1999 Elsevier S cience B.V. All rights reserved.