Residues of persistent organic pollutants in Estonian soils

Organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were analysed in selected Estonian soils. The sample collection included agricultural-rural (Ahja, Eerika), industrial-urban (Kohtla-Järve, Muuga, Kunda), and reference sites (Lahemaa and Vilsandi). The PCB concentrations were greater in Ahja-1982 and Kohtla-Järve station 1, while Eerika, other Kohtla-Järve, Muuga Port, Kunda, Lahemaa, and Vilsandi Island concentrations were low. Organochlorine pesticides were slightly higher at Kohtla-Järve stations and PBDEs at Kunda stations. Overall, the predominant contaminants were PCBs (0.43–89 ng/g dw), followed by OCPs (0.21–16 ng/g dw) and PBDEs (< 0.01–3.2 ng/g dw). The occurrence of 4,4'-DDT in some samples indicated recent contamination by DDT of Estonian soils. The PBDEs in Estonian soils were reported for the first time