Evaluation of the pollution by organochlorinated compounds (polychlorobiphenyls and pesticides) and metals (Cd,Cr, Cu and Pb) in the water and in the zebra mussel (Dreissena polymorpha pallas) of the river Seine.

The relationships between some organochlorines and metals in the water and in the zebra mussel of the river Seine have been studied in the Parisian area. The bioconcentration of PCBs by the mussel (Kb = 17 × 10³) was about 10 fold higher than for other organochlorines. The accumulation and the release response of the mussel to alterations of the water organochlorine levels occurred within a period smaller than 7 days. The correlation between the water and the mussel levels is highly significant for γHCH and PCBs (r=0.94, p<0.01 and r=0.87, p<0.05, respectively). The Pb bioconcentration (0.15 × 103) was about 20 fold lower than the Cu and Cr (3.4 and 3.0 × 10³, respectively). The Cu and the Pb levels in the water and in the mussel followed a parallel course. Cu and Pb appear to be taken up and released relatively rapidly within a 7 day period. Comparisons between the different stations along the river Seine showed that the highest pollutant evels in the water were found downstream Paris and were fairly well reflected by the mussel levels. However, when pollution reaches top values, the mussel metabolic activities are affected and thus, the bioconcentration ability too.