210Po in the North-West Black Sea ecosystem

210Po is a natural radionuclide which contributes 2-3 orders of magnitude more than anthropogenic radionuclides to doses received by humans from ingestion of seafood. Data on 210Po in the Black Sea were very scarce. This paper introduces an extensive set of data and related results obtained by the authors on 210Po in water, bottom sediments, algae, macro- and mesozooplankton, mollusks and fishes from the Ukrainian area in the North-West Black Sea in the period 1998-2004. 210Po concentrations in surface water of the open part of the sea in the summer season were around 1 Bq.m-3. In the bottom sediments they ranged between 10 and 500 Bq·kg-1dw, with maximum 210Po concentrations in the area of the Western cyclonic gyre. Concentration factors for this radionuclide, estimated on a wet weight basis, had values of 1.5·103 for macrophytes, 4·103 for total zooplankton, 103-104 for entire fishes, depending on their ecological groups affiliation and 6·104 for mussels (Mytilus galloprovincialis). These values are comparable to those of similar species from other areas of the World Ocean. Amongst the investigated species, the highest doses from 210Po were estimated for the mussels. Amongst the fishes, pelagic species (Sprattus sprattus phalericus, Engraulis enchrasicolus ponticus) are estimated to receive the highest doses from 210Po