Evaluation of the Status of Contamination of Arable Soils in Poland with DDT and HCH Residues; National and Regional Scales

The aim of our study was to evaluate the content of organochlorine pesticides (DDTs and HCHs) in the upper layer of arable soils in Poland. 214 soil samples were analyzed for the content of three HCH congeners (α-HCH, β-HCH, and γ-HCH) and three DDT compounds (pp’DDT, pp’DDE, and pp’DDD). The median soil concentration of Σ3DDT was 24.39 μg·kg, while for Σ3HCH it was 2.85 μg·kg with the highest contribution of γ-HCH isomer. Polish criteria for agricultural soils not polluted with DDTs are met by half of the samples. In the case of γ-HCH the Polish limit value of 0.5 μg·kg was met in 6.5% of the samples. However, according to the less restrictive systems applied in other countries (Canada, Romania) none of the soil samples create a hazard due to contamination with DDTs, and only 6-11% exhibit too high concentrations of γHCH (residues of Lindane). The mean contents of DDTs and γ-HCH in soils from different provinces varied widely with the reverse interdependence of both groups of pesticides. The districts with the highest concentrations of DDT (Podlaskie, Wielkopolskie, and Mazowieckie) were characterized by the lowest mean residues of Lindane. This suggests the long-term effects of the prescriptive state system of distribution of pesticides used in Poland more than 40 years ago.