Levels of PAHs in the soils of Belgrade and its environs.

Polycyclic aromatic hydrocarbons (PAHs) were analysed in 39 soil samples (0-10 cm upper layer) collected in Belgrade, the capital of Serbia. The sampling sites were randomly selected from urban, urban/recreational and rural areas; the samples were collected in April and December 2003 and July and October 2004. The sum of the 16 PAHs corresponding to the recreational zone (298 microg/kg) was close to the urban zone (375 microg/kg). Mean soil SigmaPAH concentration from rural areas was 18 microg/kg dry weight. Comparing to values observed in the urbanized locations around the world, the overall levels of PAHs in this study are low. The PAH ratios obtained pointed to a domination of pyrogenically formed PAHs in the examined soils. The dominant PAHs in soil samples in urban zones were fluoranthene, benz[a]anthracene, phenanthrene and pyrene, mostly emitted from noncatalyst vehicles which are still in use in Serbia. The total carcinogenic potency for each sampling site was calculated. Regardless of the used carcinogenic activity factors, carcinogenic potency of 7 sites were 3-9 times higher than the reference ones indicating the increased carcinogenic burden of soils from these sites.