Abstract
Ambient concentrations, congener patterns and multi-media distribution of PCDD/Fs and PCBs were determined in air, water, sediment andmussels in a semi-enclosed marine ecosystem (Thau lagoon, France). sum2,3,7,8-PCDD/F and sum7ICES PCB air concentrations (0.2-1.4 and31-57 pg m-3, respectively) were typical of rural areas. Concentrations in the water column were very low for PCDD/Fs (163-476 fg L-1)and low for PCBs (138-708 pg L-1). PCDD/F and PCB concentrations found in surface sediment (0.15-1.6 and 2.5-33 ng g-1 d.w., respectively)and mussel (13-21 pg g-1 d.w. and 10-39 ng g-1 d.w., respectively) were medium levels. PCDD/F congener patterns observed in air,water particulate phase and sediments were similar suggesting direct coupling among these compartments and atmospheric inputs of PCDD/Fsinto the lagoon. Conversely, for the same set of samples, similar patterns were not observed for PCBs in the mentioned compartments.