Polyaromatic hydrocarbon (PAH) distributions in the Seine River and its estuary

Dissolved and particulate PAHs were quantified throughout the Seine River and its estuary. Samples were collected in October 1993, covering a salinity gradient of 0.2‰ to 34.8‰. Two mooring stations were occupied at the river mouth to ascertain the influence of tidal cycles on the dispersal of riverborne PAHs. Total particulate PAH concentrations ranged from 2 to 687 ng l−1 (or 1 to 14 μg g−1). Concentrations were correlated to the suspended matter load and distributions could be explained by estuarine mixing. PAH levels decreased from ebb to flood tides. PAH concentrations in the dissolved phase (4 to 36 ng l−1) were, in general, an order of magnitude lower than in the particulate phase. The partition coefficient of individual PAHs (Koc) were comparable to those previously reported for the Rhône River suspensions.