Exposure screening of some aquatic animals to persistent pollutants on the Rhone river, France

Abstract

The Rhone river is contaminated with nuclear, chemical, urban and agricultural wastes. This study is an investigation of the level of exposure to polychlorinated biphenyls (PCBs), radionuclides of top predators of this river, Great cormorant (Phalacrocorax carbo sinensis) and European eel (Anguilla anguilla). Low concentrations of PCBs were found in liver and muscle of cormorants and eels from the Rhone river in 2000 and in 2001 : the total PCBs contamination was about 2 µg/g lipid for both cormorants and eels from the Rhone river. All measurements of artificial radioactivity in cormorants from the Rhone river were below the detection limit. Two 7-ethoxyresorufin-O-deethylase (EROD) activity experiments on caged eels were conducted in the lower Rhone river. EROD activity was induced and could be correlated to persistent pollutants as PCBs or others dioxin-like pollutants, or polycyclic aromatic hydrocarbons (PAHs). These results suggest that cormorants and eels are at least, slightly contaminated with PCBs and not with artificial radionuclides, despite the high level of nuclearization of the valley.