Methylphenanthrenes in the Southern Baltic as markers of petrogenic pollution

Mono- and dimethylphenanthrenes were determined in recent (0–10 cm) sediments collected at about 30 stations in the southern Baltic Sea from 1995 to 2001. The stations were located in the Szczecin Lagoon, the Pomeranian Bay, the Bornholm Deep, the open sea (without the Bornholm and Gdańsk Deeps), the Gdańsk Deep, and the Gulf of Gdańsk including the Wisła (Vistula) Lagoon. The results were related to the unsubstituted PAH content. The annual load of methylphenanthrenes in relation to unsubstituted PAHs in the Rivers Odra and Wisła was estimated. Methylphenanthrenes are more abundant in the Odra estuary than in the Wisła estuary, and more abundant in the coastal sediments than in the open sea sediments. The results indicate that methylphenanthrenes related to the lower molecular, unsubstituted PAHs are a good measure of petrogenic pollution in the southern Baltic.