This study concerns freshwater bioindicators of radiocontamintion, in a metallic multipollution context. Metals, such as cadmium (Cd) and zinc (Zn), are widely represented in aquatic ecosystems, and their concentrations can induce physiological effects. This chronicle exposure generates both metabolic and behaviour stress of individuals, and can also yield to detoxification mechanisms induction. The main goal of this work was to estimate the influence of metals on the radionuclides (57Co, 110mAg, 134Cs) bioaccumulation by two different bivalve species (Corbicula fluminea and Dreissena polymorpha), by studying the contamination level, the kinetic of the radionuclide transfer and the soft-body repartition.
As the exploratory feature of this study, two parts have been developed: (i) testing the problematic suitability in a really biomonitoring situation, and (ii) analysing the metal/radionuclide interaction mechanisms under controlled and standardised conditions (laboratory).
For the different experimental conditions explored (laboratory and field), radionuclide bioaccumulation by freshwater bivalves has been influenced by metal exposure. This result was obtained after assessing a decrease of the organisms contamination level by radionuclide and their accumulation rate, an increase of their depuration rate and tissue and cellular rapartition changes.