Dioxin-like Polychlorinated Biphenyls Contamination and Distribution in Soils from the Modern Yellow River Delta, China

Abstract

The concentrations of 12 dioxin-like Polychlorinated Biphenyls (dl-PCBs) were determined from 37 soil samples collected from the modern Yellow River Delta (China) in March 2006. The PCB concentrations were determined by dual capillary GC-ECD. The total dl-PCBs concentrations were in the range of 108.7 to 2153 ng/kg with an average of 800.5 ng/kg. The toxic equivalency (TEQ) in this area varies from 2.3 × 10^{− 5} to 9.5 × 10^{− 5} ng-TEQ/kg, so the delta is slightly polluted by PCBs. PCB118, the main congener, accounted for 46.7% of the total dl-PCB. More than 60% dl-PCBs were penta-PCBs. The spatial distribution of the dl-PCBs is discussed in detail. The distribution of the PCBs suggests that water runoff is the main source of the total contaminant burden in the delta, and that atmospheric precipitation plays an important role.

Keywords:

• Dioxin-like polychlorinated biphenyls (dl-PCBs)
• modern Yellow River Delta
• soil
• concentration
• distribution trends

Acknowledgments

This work was supported by National Natural Science Foundation of China (NSFC grant No. 20577030). The authors are grateful to NSFC for providing financial assistance to undertake the research project titled “The sources, distribution, transportation, transformation and fate of dioxin-like and atropisomeric polychlorinated biphenyls (PCBs) in soil.” The authors thank Dr. Pamela Holt for editing the manuscript.