Polycyclic aromatic hydrocarbons in Baltic Sea bivalves

Concentrations of parent polycyclic aromatic hydrocarbons (PAHs) in the bivalves Macoma balthica and Astarte borealis were studied as an indication of the state of the Baltic Sea. Samples were collected between 1999 and 2001 from the Gulf of Finland, the Eastern Gotland Basin, and the Southern Baltic Proper PAHs were quantified by liquid chromatography with fluorescence detection. The sum of 12 PAHs varied between 44 and 298 ng/g (ww), with the most contaminated bivalves found in Hano Bight (the Bornholm basin). High-molecular-weight PAHs predominated among the PAHs. The PAH profiles of M. balthica differed from those determined in sediment from the same area. Both pyrolytic and petrogenic origins were indicated. Toxic equivalency factors evaluated as benzo[a]pyrene equivalents (BaPEs) were used to assess the PAH contamination. BaPEs were higher than values for M. balthica found in the southern Part of the Gulf of Finland in 1995 and much lower than values measured in 1987 after the most serious oil spill in the Gulf of Finland in the past 25 years.