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

We have measured the concentrations of Pu-239.240, Pu-238, Pb-210, and Cs-1 37 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 an d Kara Sea and sediment samples from the Pechora Sea of the Russian Arctic. Mean concentrations of Cs-137 and Pu-239.240 in bivalves on which measurab le concentrations were found are slightly higher than the values reported f or the east, west and Gulf coasts of US. The mean concentrations of Cs-137 and Pu-239.240 in 27 surficial sediment samples from the Pechora Sea are lo wer than the corresponding values from the Ob and Yenisey Rivers and Kara S ea, The Pu-238/ Pu-239,Pu-240 activity ratios on 16 of these sediment sampl es varied between 0.015 and 0.056, The best-fit line between the concentrat ions of Pu-238 and Pu-239.240 yielded a mean Pu-238/Pu-239,Pu-240 activity ratio of 0.035, suggesting that most of this Pu is derived from global fall out and that there is virtually no detectable input of Pu from either the E uropean nuclear effluents, close-in fallout from the nuclear test sites or from the dumped nuclear reactors in the Kara Sea or adjoining marine system s. (C) 2000 Elsevier Science Ltd. All rights reserved.