Levels and trends of PCBs, chlorinated pesticides and petroleum hydrocarbons in mussels from the NW Mediterranean coast: comparison of concentrationsin 1973/1974 and 1988/1989

A mussel watch survey was conducted in 1988-1989 along the Mediterranean co ast of France and Italy, between Sete and Genoa, in order to assess contami nation by organochlorine pesticides, PCBs and petroleum hydrocarbons. Resul ts show concentrations of DDTs (average 130 ng g(-1) dry wt,) and PCBs (ave rage 527 ng g(-1) dry wt.) higher in coastal areas receiving river discharg es and close to large cities. Concentrations of total aliphatics (average 4 70 mu g g(-1) dry wt.) and PAHs (average 233 mu g g(-1) dry wt.) were gener ally higher also near large harbours, namely Marseille, Toulon and Genoa. P AHs in mussel samples from Genoa and Monaco were mostly of pyrolytic source s, likely forest fires and exhaust gases from cars, whereas PAHs in other s tations were mainly of petrogenic sources. Comparison of chlorinated hydroc arbon concentrations measured in 1988-1989 with those measured in a similar survey carried out at the same sites in 1973-1974, shows that DDTs and PCB s decreased by a factor of approximately 5 in 15 years. This decrease is in agreement with the ban on DDT implemented in 1975 in western Europe and gr adual cessation of PCBs production in the 1970s and 1980s. Nevertheless, th e residues of these compounds measured in mussels confirm the well-known lo ng persistence of DDTs and PCBs, which are still present in relatively high concentrations in a few areas. (C) 1999 Elsevier Science B.V. All rights r eserved.