The objective of this research was to estimate the content of 16 PAHs (US EPA list) in plants (com and willow) cultivated in sewage sludge-amended soil. An ultrasonic method and dichloromethane have been used to extract total PAHs content. The solid phase extraction was performed to purify sample extracts. HPLC and UV detection were employed to separate and quantify the studied PAHs. On the basis of the obtained results a bioconcentration factor was calculated. The contents of 16 PAH in plants ranged from 5.83 to 33.8 μg/kg d.m., with a dominant share of low molecular weight PAHs. The application of sewage sludge caused an increase in the PAH content in plants in relation to the dose applied. However, even the highest doses of sewage sludge did not led to the increase of PAI-ls content in plants above the level which may be hazardous for human health. The bioconccntration factors were on the level notted by others authors and ranged from 0.04 to 0.38 for the sum of 16 PAH.

The objective of this research was to estimate bioavailable forms of choosen PAHs in sewage sludgeamended light soil. To estimate amount of bioavailable forms of PAHs the soil has been extracted with 25% tetrahydrofuran solution in water. Ultrasonic method and dichloromethane have been used to extract total content of PAHs. Influence of sludge dose on bioavailable PAHs content has been evaluated. Bioavailability of PAHs has been related to organic matter content in sewage sludge. High correlation between log Kow and level ofbioavailable forms of PAH's in soil has been noticed.

In the presented work, relations between activity of dehydrogenase and the content of polycyclic aromatic hydrocarbons in light soil fertilised with sewage sludge was studied. Sewage sludge was introduced to the soil in the following doses: 30 Mg/ha, 75 Mg/ha, 150 Mg/ha, 300 Mg/ha and 600 Mg/ha. The content of PAI-ls in sewage sludge-amended soil was proportional to sewage sludge dose. Soil fertilisation with sewage sludge stimulated the activity of the dehydrogenase enzymes. With passing of time, a gradual decrease in the activity of dehydrogenase was observed. The coefficients of correlation between activity of the enzyme and PAH content showed that an addition of sewage sludge (with PAI-I content of 5712 μg/kg) had a stimulating effect on dehydrogenase activity in doses of 75 and 150 Mg/ha.