Concentrations of ¹³⁷Cs, ^239,240Pu and ²¹⁰Pb in sediment samples from the Pechora Sea and biological samples from the Ob, Yenisey Rivers and Kara Sea

We have measured the concentrations of ^239,240Pu, ²³⁸Pu, ²¹⁰Pb, and ¹³⁷Cs in biological samples (5 isopods, 10 bivalves, 2 amphipods, 2 mussell, 1 fish fat, 6 fish liver and 2 worm tubes) from the Ob and Yenisey Rivers and Kara Sea and sediment samples from the Pechora Sea of the Russian Arctic. Mean concentrations of ¹³⁷Cs and ^239,240Pu in bivalves on which measurable concentrations were found are slightly higher than the values reported for the east, west and Gulf coasts of US. The mean concentrations of ¹³⁷Cs and ^239,240Pu in 27 surficial sediment samples from the Pechora Sea are lower than the corresponding values from the Ob and Yenisey Rivers and Kara Sea. The ²³⁸Pu/^239,240Pu activity ratios on 16 of these sediment samples varied between 0.015 and 0.056. The best-fit line between the concentrations of ²³⁸Pu and ^239,240Pu yielded a mean ²³⁸Pu/^239,240Pu activity ratio of 0.035, suggesting that most of this Pu is derived from global fallout and that there is virtually no detectable input of Pu from either the European nuclear effluents, close-in fallout from the nuclear test sites or from the dumped nuclear reactors in the Kara Sea or adjoining marine systems. Copyright (C) 2000 Elsevier Science Ltd.