Bioaccumulation of 210 Po and 210 Pb in Arctic seabirds

INTRODUCTION When considering the potential radiological impacts of anthropogenic radionuclides in the environment, it is important to understand the doses incurred by biota by natural activity concentrations of naturally occurring radionuclides. Naturally occurring Po (half-life138 days) and Pb (half-life 22.3 years) are members of the U decay chain. In the marine environment, Po and Pb are principally produced within the water column through the in situ decay of Ra with additional inputs from the atmosphere via the decay of Rn and directly via release from marine sediments and riverine inputs in coastal areas. Po-210 is known to concentrate in marine organisms to a higher extent than other naturally occurring alpha emitters, particularly in certain organs and is typically the greatest contributor to dose under natural conditions. However, little is known concerning the trophic transfer and resulting activity concentrations of Po and Pb in seabirds, an important consumer group in marine food webs.