Vertical distribution and fate of trace metals and persistent organic pollutants in sediments of the Seine and Marne rivers (France)

Trace metals: Cd, Cu, Cr, Ni, Pb and Zn and persistent organicpollutants: polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs) were investigated in a fraction ofsediments characterized by a granulometry < 200 km. Coresfrom 17 to 54 cm depth, were collected at two sites of theSeine river upstream (Port a l'Anglais) and downstream (Saint-Cloud) from Paris and at one site of the Marne river (Saint-Maurice). Marne river sediments displayed higher Cu andPb levels than those of the Seine river. Except for Cd and Cr,contents did not vary notably in the Seine river sediments.Metal contents, except Pb, were significantly correlated withthe sediment fraction which granulometry is < 50 km,particularly at Port a l'Anglais (p < 0.001). Correlationcoefficients between Cr, Cu, Ni and Zn contents and clayfractions of the cores ranged from 0.85 to 0.99 at both sitesof the Seine river. PCB levels varied widely, ranging from 27to 689 kg kg super(-1) and were highly correlated with bothsediment fraction < 50km and particulate organic carbon(POC) ratio. PAH levels ranged from 2.30 to 41.3 kg g super(-1) and displayed the highest values close to dams; theyshowed no correlations with sediment fraction < 50 km and POC.