Distribution of PCBs in sediments of the Červený potok, stream contaminated by technical PCB mixtures Delor, Czech Republic

The results of measurement of polychlorinated biphenyls (PCBs) in surface bottom sediments contaminated by technical PCB mixtures Delor collected from the Červený potok (stream in the Litavka River catchment), Czech Republic in 2008 are presented. The sediment samples of two different grain size fractions (< 2 mm and < 200 μm) were analyzed for 8 congeners of PCBs using Soxhlet extraction and gas chromatography (GC-ECD). Total concentrations of PCBs ranged from 15.3 to 997 ng g^-1 (dry weight) in < 2 mm fraction and from 29.9 to 952 ng g^-1 in < 200 μm fraction, where PCBs 28, 52, 101, 138, 153, 180 and 194 were found in all the samples. The highest levels of PCBs were found in sediment collected from the area below the discharge of municipal wastewater treatment plant and local engineering industry in the Komárov village. High percentage of PCBs 28, 153 and 138 (22-74%, 5-22% and 5-20% respectively) indicates the contamination by PCBs commercial mixtures Delor 103 and Delor 105 (an equivalent of AROCLOR 1242 and 1254). The result of PCA analysis indicates that the more highly chlorinated PCB congeners tend to be more associated with finer organic carbon particles of the < 200 μm sediment fraction.