Ecotoxicological Risk Assessment of Polychlorinated Biphenyls (PCBs) in Bank Sediments from along the Yamuna River in Delhi, India

ABSTRACT

The River Yamuna originates from the Yamunotri glacier of the Himalayas and travels 22 km in the Delhi region. The river is used for various purposes in Delhi including drinking water supply. Twenty-eight polychlorinated biphenyls (PCBs) congeners were measured in bank sediments along the river, and their ecotoxicological risk was evaluated. Concentrations of ∑28PCBs varied from 0.20–21.16 ng g⁻¹ (dry wt.) with mean and median values of 6.63 ng g⁻¹ and 5.84 ng g⁻¹ (±0.69 ng g⁻¹), respectively. The concentration of 12 dl-PCBs concentrations varied from 0.04–2.86 ng g⁻¹ with a mean of 1.04 ± 0.11 ng g⁻¹, and their toxic equivalency ranged between <0.01–28.67 pg WHO-TEQ g⁻¹ with a mean of 10.77 ± 1.06 pg WHO-TEQ g⁻¹. CB-37, CB-44, CB-114, and CB-118 congeners were dominant among all PCBs congeners. The tri-PCBs (49%) were the main contributors to the PCB homolog followed by tetra-PCBs (35%), and penta-PCB (14%). Because there are no environmental guidelines in India for PCBs in river and marine sediments, concentrations of PCBs and their toxic equivalents were compared in a screening-level assessment with established freshwater sediment quality guidelines and found lower than those guideline values, which suggests no adverse ecotoxicological effect.

Key Words:

• polychlorinated biphenyls
• PCBs
• toxic equivalency (TEQ)
• river sediments.

ACKNOWLEDGMENTS

The authors express their sincere gratitude to the Member Secretary and Chairman of the Central Pollution Control Board, Ministry of Environment & Forest Government of India for support and guidance to conduct the study. The authors also acknowledge the help from B. Singh and R. Manjhi during sampling and G. Goel, R. Gaur, and S. K. Singh during sample process and analysis. The authors also thank HERA's editors for their editing of our article.

Notes

Editor's note: Barrage (Brit.): “An artificial dam placed in a watercourse to increase the depth of water or to divert into a channel for navigation or irrigation” (Webster's Ninth New Collegiate Dictionary 1986).