Polycyclic aromatic hydrocarbons in recent sediments and mussels (Mytilus edulis) from the Western Baltic Sea: occurrence, bioavailability and seasonal variations

Surface sediments and mussels, Mytilus edulis, collected in the Baltic Sea in March 1995, October 1995 and August 1996 have been analysed for polycyclic aromatic hydrocarbon (PAH) content. The analyses have been performed by gas chromatography coupled to mass spectrometry (GC–MS). Total sediment PAH concentrations range from 3 to about 30 000 ng/g while total mussel PAH concentrations range from 90 to about 3900 ng/g. Molecular indices based on isomeric PAH ratios differentiate the pollution sources, pointing out differences between Germany and Poland. Most of the contamination originates from high temperature pyrolytic inputs with some slight overimpositions of petrogenic and diagenetic PAHs. Mussel and sediment total PAH concentrations have been found to be moderately correlated (r2=0.51 for March, 0.58 for August and 0.98 for October). Bioaccumulation factors (BAFs) have been calculated and have shown higher values for the mussels sampled in March. Differences of BAFs have been observed for the different compounds resulting from different uptake pathways and metabolism abilities of Mytilus edulis.