Concentration of uranium and thorium in molluscs inhabiting Gdansk Bay, Baltic Sea

The concentrations of U and Th were determined in the soft tissue and shell of Mytilus edulis, Cardium glaucum, Mya arenaria, Macoma balthica and other benthic invertebrates from Gdansk Bay. Results of these investigations show that the concentrations of U and Th in some molluscs are species specific. For Th, unlike U, significant site-dependent variations in concentration were noted. Results show some dependence in concentrations of metals analysed with size and age of molluscs. The regression analysis of the data indicates that discrimination factors for U with respect to Ca significantly decrease with an increase in the concentration of Ca in the soft tissues. 39 refs.; 3 figs.; 4 tabs