Residues of persistent organic pollutants in Estonian soils (1964–2006)

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.