Monitoring of the total content of polycyclic aromatic hydrocarbons (PAHs) in arable soils in Poland

The paper provides comprehensive information on the level of contamination of arable soils in Poland with polycyclic aromatic hydrocarbons (PAHs). Extensive monitoring studies were carried out to determine the content of the 16 priority PAHs in 216 soil samples collected in 2005 throughout arable lands (0-20cm layer) in Poland. Locations of sampling points reflected the differences in regional industrialisation and urbanisation as well as in the characteristics of soils. The content of Sigma 16PAHs ranged from 80 to 7264 mu gkg(-1) with a median of 395 mu gkg(-1) and with a dominance of 4-6 rings hydrocarbons (74% of total PAHs). Soil properties affected the PAHs content to a limited extend. The organic matter content was the only parameter correlated significantly (although weakly) with the concentrations of Sigma 16PAHs; the strength of this relationship was more pronounced in soils with elevated OM content. The various molecular markers pointed to a prevailing pyrogenic origin of the PAHs in Polish arable soils, with minor contribution from liquid fuels combustion and traffic emissions. Two different Polish systems for classification of agricultural soils (providing for the content of Sigma PAHs and Sigma 13PAHs) indicate that the percentage of contaminated arable soils in Poland does not exceed 10%. Multivariate methods enabled an evaluation of spatial trends in Sigma 16PAHs concentrations, an identification of regions with very low PAHs content (East part of the country), and a recognition of small industrial/urbanised areas of higher risk. (C) 2008 Elsevier Ltd. All rights reserved.