Monitoring and risk assessment of polychlorinated biphenyls (PCBs) in agricultural soil collected in the vicinity of an industrialized area

Samples of agricultural soils possibly contaminated by polychlorinated biphenyls (PCBs) were collected from Anseong, Korea. The agricultural areas chosen have possibly been contaminated by nearby factories, either directly or via atmospheric deposition, and require monitoring. The concentrations of 29 out of 209 PCB congeners were determined at five sites using high-resolution gas chromatography/high-resolution mass spectrometry. Total concentrations of the 29 PCB congeners in soil samples obtained from each study site were 106.65, 149.15, 222.67, 166.15, and 118.28 pg g−1 dry weight, respectively, with pentaCBs and hexaCBs giving the highest concentrations of the congeners studied. The total toxic equivalent (TEQ) for 12 PCBs from each site was 0.05, 0.11, 0.08, 0.05, and 0.04 ng kg−1 dry weight, respectively. These values were mainly due to high TEQ values for PCB 126 (3,3′,4,4′,5-pentachlorobiphenyl) from each site (at 0.05, 0.10, 0.07, 0.04, and 0.03 ng kg−1 dry weight, respectively). The TEQ values are much lower than the action level of 20 ng WHO–TEQ kg−1 recommended by the World Health Organization, but PCB concentrations in this area should be monitored nonetheless, since these manmade compounds bioaccumulate, thus threatening the ecosystem and human health.