Bhupander Kumar, S. K. Singh, V. K. Verma, Richa Gaur, Sanjay Kumar and C. S. Sharma
A preliminary assessment of levels of polychlorinated biphenyls (PCBs) in surface waters was carried out and discussed in this paper. Total concentrations of ΣPCBs ranged between 1.03-21.79 ng L-1 with the mean and median value of 12.91ng L-1 and 11.26 ng L-1 (±1.61 ng L-1), respectively. Average concentration of twelve WHO’s dioxin like-PCBs (DL-PCBs) was 7.67±1.18 ng L-1 and accounted for 67.1% of ΣPCBs. The 2, 3, 7, 8-tetrachloro dibenzo-p-dioxin (TCDD) relative toxicity equivalency (TEQ) for DL-PCBs was calculated using WHO toxicity equivalency factors (TEFs), and ranged between 0.001-0.135 ng-TEQ L-1 with an average value of 0.048±0.011 ng- TEQ L-1. The group homolog of PCBs was dominated by 4-6 chlorinated biphenyls. The observed concentrations were lower than the guideline values for eco-toxicological risk
