Comparative study of sediment and mussel aromatic compound content in European coastal environments. Relationship with specific biomarkers

Abstract The distribution of selected Polycyclic Aromatic Hydrocarbons (PAHs) has been investigated in sediments and mussels ( Mytilus sp.) of different European coastal environments (Baltic Sea, Arcachon Bay, Mediterranean Sea) by gas chromatography coupled to mass spectrometry (GC-MS). Contrasted contamination levels were observed. The lowest PAH contents were observed in sediments collected in pristine areas, such as those found in Corsica, Sardinia, the Balearic islands, or in the middle of the Baltic Sea. The most contaminated sediments were sampled in large harbours (Ajaccio, Port Vendres, Barcelona, Kiel). These contaminants mainly originate from uncomplete combustion of organic matter and are linked to industrial activity. The sediment PAH distribution was observed to be governed by the organic carbon content and the grain size distribution of the sediments. Similar to the sediments, the most contaminated mussels were sampled in or near large harbours. Mussel total parent PAH concentration was generally significantly correlated with sediment total parent PAH concentration. The bioavailability of hydrocarbons is governed by their water solubility, their origin (petrogenic / pyrolytic), their lipophilic character and parameters linked to the studied areas such as water turbidity or the location of the bivalves in the water column. The comparison of individual PAH concentrations in sediments and mussels allowed to show the preferential biotransformation of benzo[ a ]pyrene relative to benzo[ e ]pyrene by the bivalves. Some biological parameters were also determined to estimate the impact of chemical contaminants on organisms. Generally, mixed-function oxygenase activities were significantly correlated with sediment PAH concentration.