Comparative study of plutonium and Americium bioaccumulation from two marine sediments contaminated in the natural environment

Abstract

Plutonium and americium sediment-animal transfer was studied under controlled laboratory conditions by exposure of the benthic polychaete Nereis diversicolor (O.F. Müller) to marine sediments contaminated by a nuclear bomb accident (near Thule, Greenland) and nuclear weapons testing (Enewetak Atoll). In both sediment regimes, the bioavailability of plutonium and 214Am was low, with specific activity in the tissues < 1% (dry wt) that in the sediments. Over the first three months, a slight preference in transfer of plutonium over 241Am occurred and 241Am uptake from the Thule sediment was enhanced compared to that from lagoon sediments of Enewetak Atoll. Autoradiography studies indicated the presence of hot particles of plutonium in the sediments. The results highlight the importance of purging animals of their gut contents in order to obtain accurate estimates of transuranic transfer from ingested sediments into tissue. It is further suggested that enhanced transuranic uptake by some benthic species could arise from ingestion of high activity particles and organic-rich detritus present in the sediments. © 1991.