Biota contamination by PCBs and trace metals in the freshwater estuary of the River Seine (France)

We studied the impact of urban and industrial activity upon the occurrence and the distribution of pollutants in the fresh estuary of the River Seine. Contamination was investigated under dry weather conditions, by determinat ion of PCB and trace metal levels upstream and downstream of Rouen and the pollutant content of organisms with different positions in the trophic web. PCB contents of roach were higher downstream than upstream of Rouen. Cd le vels showed a regular four fold increase from upstream to downstream of Rou en. Cyprinidae (ablet, roach) showed similar PCB or even higher trace metal levels than their predators (Percidae). This result suggests that contamin ated food intake was not the main pathway for pollutant accumulation.