Untitled

Due to the low concentrations of persistent organic pollutants (POPs) in seawater, a special method of analysis is needed. The aim of this work was to prepare the detailed procedure for the determination of POPs in seawater and establish the level of pollution by selected POPs (seven PCBs, DDT and its metabolites, HCH isomers, HCB) of the surface and near bottom water from the Baltic Sea. The levels of toxic substances were analysed using capillary gas chromatography (GC). The average values of EHCH, HCB, EDDT and E7PCBs in the surface water were 0.35 (±0.13) ng dm!3, 0.06 (±0.02) ng dm!3, 0.14 (±0.05) ng dm!3 and 0.98 (±0.44) ng dm!3, respectively. The average concentrations of EHCH, HCB, EDDT and E7PCBs analysed near bottom water were 0.44 (±0.16) ng dm!3, 0.09 (±0.02) ng dm!3, 0.17 (±0.08) ng dm!3 and 0.95 (±0.57) ng dm!3.

Fig. 4. Concentration of ΣDDT in surface and bottom water from the Southern Baltic. A trend towards the concentration decrease in the last years was identified for HCH isomers and DDT and its metabolites. The concentration of HCB in the Baltic Sea water has been similar for the last 20 years. A decrease of PCB concentrations in the Baltic Sea was not so clearly detected. The highest pollution (despite atmospheric transport) into the Baltic was brought by the Vistula River. This elaborate method was sensitive and appropriate for determination of persistent organic pollutants in seawater.