Sources of ¹³⁷Cs, ⁹⁰Sr and ⁹⁹Tc in the East Greenland current

Concentrations in water of ⁹⁹Tc, Chernobyl-¹³⁷Cs (¹³⁴Cs), total ¹³⁷Cs, and ⁹⁰Sr from depth profiles, including several water masses at 71 °N between East Greenland and Jan Mayen and in the Denmark Strait from 1988 and 1990, are discussed in the background of changing sources. A major surface water mass in the area is the Polar Water reflecting the radionuclide concentrations in the upper layer of the Arctic Ocean. It appears that the present levels may well be explained by pre-1970 sources including early Soviet discharges and global fallout, the European reprocessing facilities, mainly Sellafield, and a Chernobyl contribution. There is no indication of significant additional sources in the present material. However, the effect of additional sources may be masked under the fluctuating European contribution adding significantly to the uncertainty.