PAHS IN ARCACHON BAY, FRANCE - ORIGIN AND BIOMONITORING WITH CAGED ORGANISMS

The concentration of polycyclic aromatic hydrocarbons (PAHs) has been determined in superficial sediments and caged mussels (Mytilus gallopr ovincialis) of Arcachon Bay, France. The bay sediments are uniformly c ontaminated at moderate to high levels (900-4100 ng g(-1)), with a low er contamination level at the entrance to the bay (approximate to 30 n g g(-1)). This pollution is mainly pyrolytic and related to anthropoge nic activity. Caged mussels exposed to sediments with a contamination level of <2000 ng g(-1) are contaminated at moderate levels (300-500 n g g(-1)), but those exposed to sediment contaminated at a higher level ( > 3000 ng g(-1)) have accumulated more PAHs (> 2000 ng/g). This may result from a different equilibrium between uptake and depuration of the xenobiotics at the sites with greater levels of contamination or f rom higher levels of bioavailability of the contaminants at these loca tions. The bioavailability of the contaminants is also discussed in te rms of organism exposure and contaminant origin. (C) 1998 Elsevier Sci ence Ltd. All rights reserved.