Transfer of radionuclides to man from greylag geese Anser anser and Wigeon Anas penelope grazing the saltmarshes at Ravenglass

The greylag goose and wigeon are both traditional quarry of wildfowlers. Populations of these birds in the Ravenglass estuary feed and roost on saltmarshes containing radioactivity originating from the Sellafield reprocessing plant. There is therefore, via the meat, a potential pathway for the transfer of radionuclides to man. The birds' intake of gamma-emitting fission and activation products, including 60Co, 95Nb, 95Zr, 106Ru, 144Ce, 134Cs, 137Cs, 154Eu, 155Eu and 241Am, was investigated by examining their concentrations in vegetation from feeding areas and in their faeces. Muscle and liver tissues were also analysed. Only 134Cs and 137Cs were detected and quantified in breast muscle; 58 Bq kg−1 and 158 Bq kg−1 fresh weight were recorded for goose and wigeon respectively. Estimated transfer coefficients for 137Cs were very similar for both species; 5·9 × 10−1dkg−1 for greylag goose and 5·7 × 10 −1 d kg−1 for wigeon. A single person would have had to consume in excess of the total number of wigeon shot or the total population of geese to obtain even 1% of his or her Annual Limit on Intake. In a ‘worst case’ scenario, wigeon could have transferred 5·63 MBq (152 μCi) of 137Cs inland from the tidal areas of the estuary but, because they never fed above the tide line, they, in fact, transferred no radionuclides inland during the study period.