Radiological status of the marine environment in the Barents Sea.

Abstract This paper presents the results of Norwegian radiological monitoring of the Barents Sea in 2007, 2008 and 2009. Activity concentrations of the anthropogenic radionuclides 137 Cs, 90 Sr, 239,240 Pu and 241 Am in seawater were low and up to an order of magnitude lower than in previous decades. Activity concentrations of 99 Tc in seawater were low but remain elevated compared to levels prior to the increased discharge of this radionuclide from Sellafield in the 1990s. Activity concentrations of the naturally occurring radionuclide 226 Ra in seawater were comparable to expected background values. Activity concentrations of 137 Cs in surface sediments were low, with higher values observed in sediments from coastal areas along the Norwegian mainland than from locations in the open sea. Activity concentrations of 137 Cs and 99 Tc in marine biota were low and up to an order of magnitude lower than in previous decades. Committed effective dose rates to man from anthropogenic radionuclides via the consumption of seafood from the Barents Sea were low and are not a cause for concern. Weighted absorbed dose rates to biota from anthropogenic radionuclides were low and orders of magnitude below a predicted no effect screening level of 10 μGy/h. Dose rates to man from consumption of seafood and dose rates to biota in the marine environment are dominated by the contribution from naturally occurring radionuclides.