13 - Les contaminants organiques

This booklet on organic contaminants in organisms in the Seine estuary follows up that devoted to the transport and fate of these substances in the estuary's water and sediments. The measurements taken in organisms, especially in mussels, raised awareness of the estuary's contamination by organic contaminants, especially PCB. In the framework of the Seine Aval programme, assessment of PCB contamination status was extended to the key species in the estuary. These measurements and knowledge of the food webs made it possible to build a model for PCB bioaccumulation in seabass. PAH behaviour in food webs is different from that of PCB due to hydrocarbon metabolization. However, it remains difficult in an estuary to draw the link between the high levels noted for some contaminant groups and the biological effects observed related to highly varied substances.