Characterization of 241Am and 134Cs bioaccumulation in the king scallop Pecten maximus: investigation via three exposure pathways

Marc Metian (1, 2) , Michel Warnau (2) , Jean-Louis Teyssié (2) , Paco Bustamante (1)

1 LIENSs - LIttoral ENvironnement et Sociétés
2 IAEA-MEL - Marine Environment Laboratories [Monaco]

In order to understand the bioaccumulation of 241Am and 134Cs in scallops living in sediments, the uptake and depuration kinetics of these two elements were investigated in the king scallop Pecten maximus exposed via seawater, food, or sediment under laboratory conditions. Generally, 241Am accumulation was higher and its retention was stronger than 134Cs. This was especially obvious when considering the whole animals exposed through seawater with whole-body concentration factor (CF7d) of 62 vs. 1, absorption efficiencies (Aol) of 78 vs. 45 for seawater and biological half-lives (Tb½l) of 892d vs. 22d for 241Am and 134Cs, respectively. In contrast, following a single feeding with radiolabelled phytoplankton assimilation efficiency (AE) and Tb½l of 134Cs obtained were higher than those of 241Am (AE: 28% vs. 20%; Tb½l: 14d vs. 9d). Among scallop tissues, the shells always contained the higher proportion of the total body burden of 241Am whatever the exposure pathway was. In contrast, the whole soft parts presented the major fraction of whole-body burden of 134Cs, which was generally associated with muscular tissues. Our results showed that the two radionuclides have contrasting behaviors in scallops, in relation to their physico-chemical properties.

Mots clés: bivalve; scallop; radionuclide; bioaccumulation; uptake; depuration

Domaines: Ecotoxicologie

Marc Metian, Michel Warnau, Jean-Louis Teyssié, Paco Bustamante. Characterization of 241Am and 134Cs bioaccumulation in the king scallop Pecten maximus: investigation via three exposure pathways. Journal of Environmental Radioactivity, 2011, 102 (6), pp.543-550. ⟨10.1016/j.jenvrad.2011.02.008⟩. ⟨hal-00593369⟩