Polycyclic aromatic hydrocarbons (PAHs) constitute a large group of organic compounds that make constant threat to the environment. Their contents from natural sources are low. The processes of incomplete organic fuel combustion are the main sources of PAHs. In Upper Silesia (Poland), large amounts of PAHs are emitted into the air as a result of coal combustion in home furnaces and liquid fuel burning in combustion engines (low emission). PAHs get into surface water because of the surface runoff and point source wastewater discharges from certain industries. The following study presents PAHs concentrations in raw municipal wastewater. The tests were performed out of the heating season. The samples were collected from the combined sewer system. The analyses of PAHs were carried out with gas chromatography coupled with a mass detector (GC-MS). The concentrations of 16 PAHs sum (EPA list) ranged between 1.025 and 3.056 μg/L. Phenanthrene dominated in nearly all the analysed samples. The contents of PAHs, which are priority hazardous substances according to the directive, were high in the analysed samples. The obtained results and the analysis of diagnostic ratios for the emissions of PAHs into the air helped to reach the conclusion that traffic emissions were the main source of PAHs in the examined wastewater.

The research determined the concentrations of selected polycyclic aromatic hydrocarbons (PAHs) in water and sediments of Kłodnica River reservoirs and distribution depending on number of rings, ecotoxicological impact on studied ecosystems and possible sources of origin. Samples were subjected to qualitative and quantitative analysis by gas chromatography coupled with a GC-MS mass detector, using a ZB-5MS column and electron ionization. The sum of 16 PAHs in water ranged 0.111–0.301 μg/L (mean 0.200 μg/L) in Dzierżno Duże, 0.0410–0.784 μg/L (mean 0.303 μg/L) in Dzierżno Małe and 0.0920–1.52 μg/L (mean 0.596 μg/L) in Pławniowice. While in sediments respectively: 17.5–37.2 μg/g (mean 26.8 μg/g), 4.33–8.81 μg/g (6.43 μg/g) and 2.27–9.50 μg/g (5.30 μg/g). The concentration of PAHs in sediments of reservoirs, which spatial management of the catchment area accounts for over 90% of agricultural and forest land, was up to eight times lower than in sediments of the reservoir which is 69%, while built-up and transport areas are 24%. In sediments of Dzierżno Małe and Pławniowice PAHs with 5 and 6 rings dominate, while in Dzierżno Duże – 2 and 3 rings. Higher concentrations of PAHs with higher molecular weight, found in the bottom water layers, confirm the role of the sedimentation process in the transport of these compounds in reservoirs. Assessment of sediment quality, based on ecotoxicological criteria, showed that PAHs may cause toxic effects in Dzierżno Duże, while in Dzierżno Małe and Pławniowice can cause sporadic adverse effects. The likely source of PAHs in reservoirs is low emissions.