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Concentrations of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) in air and soil, their fugacities, and the experimental soil-air partitioning coefficient (KSA) were determined at two background sites in the Gt. Hungarian Plain in August 2013. The concentrations of the semivolatile organic compounds (SOCs) in the soil were not correlated with the organic carbon content but with two indirect parameters of mineralization and aromaticity, suggesting that soil organic matter quality is an important parameter affecting the sorption of SOCs onto soils. Predictions based on the assumption that absorption is the dominant process were in good agreement with the measurements for PAHs, OCPs, and the low chlorinated PCBs. In general, soils were found to be a source of PAHs, high chlorinated PCBs, the majority of OCPs and PBDEs, and a sink for the low chlorinated PCBs and γ-hexachlorocyclohexane. Diurnal variations in the direction of the soil-air exchange were found for two compounds (i.e., pentachlorobenzene and p,p'-dichlorodiphenyldichloroethane), with volatilization during the day and deposition in the night. The concentrations of most SOCs in the near-ground atmosphere were dominated by revolatilization from the soil.

Enantiomeric fractions (EF) of PCB 95, 132, 149, and 174, alpha-HCH, o,p'-DDD, and o,p'-DDT were analyzed in 112 soil samples using two-dimensional gas chromatography and triple-quadrupole mass spectrometry. To assess the soil conditions that facilitate enantioselective fractionation of chiral compounds, EF values of selected PCBs were further correlated with a wide range of physicochemical and microbial soil parameters in an attempt to identify the influential factors and their mutual relations. It was evident that soils where nonracemic ratios of investigated compounds were found were more carbon rich but they also contained significantly more humic and fulvic acids and total nitrogen. These specific physicochemical properties were accompanied by significantly increased values of all key biotic variables, the amount of microbial biomass, and its respiration activity (both basal and substrate-induced). Therefore, the shifts from racemic ratios appeared to be associated with more sustainable and active soil microflora. Among other abiotic characteristics, most significant differences were detected in the soil texture. Soil samples with significant shifts contained increased amount of clay component and correspondingly decreased proportion of sand fraction. These differences can also be associated with more intensive microbial activity, because clay content and texture with an increased amount of microaggregates are known to be favorable for soil microflora and its viability.