Polycyclic aromatic hydrocarbons in peat cores from southern Poland: distribution in stratigraphic profiles as an indicator of PAH sources

Polycyclic aromatic hydrocarbon (PAH) concentrations were measured in 44 peat samples taken from different stratigraphical layers of 12 mires located in four regions of southern Poland (the Sudeten and Tatra Mountains, Silesian Lowland and Orawa Basin). Relationships between PAH concentrations and botanical composition (genus) of the peat and its geochemical properties (contents of ash, nitrogen, organic carbon, humic acid, fulvic acid and exchangeable cations, as well as pH) were explored. The total concentration of 15 USEPA PAHs and benzo[e]pyrene was between 39 and 384 ng g-1 in all samples except those from Lasówka, a fen in the Sudeten Mountains, where an extremely high PAH concentration (3746 ng g-1) was recorded. The concentrations of PAHs apart from perylene were influenced by the location and type of mire, indicating that most of these compounds were of anthropic origin. In some samples the perylene concentration greatly exceeded the total concentration of the other 16 PAHs measured. The high concentrations of perylene in deeper peat layers may have arisen through sorption from water during peat formation, or through biogenic processes.