Distribution of Polychlorinated Biphenyls in Surface Waters of Various Sources from National Capital Region Delhi India

Abstract

This paper presents the concentration of twenty eight polychlorinated biphenyls (PCBs) including twelve dioxin-like PCBs (dl-PCBs) congeners in surface water of rivers canals lakes ponds and drains from National Capital Region (NCR) Delhi (India). The total concentrations of 28 PCBs were ranged between 14-1768 ng L^-1 with a mean of 332±42 ng L^-1. The concentration of dl-PCBs was ranged between <1-146 ng L^-1 with the mean of 40±4 ng L^-1 and accounted 12% for total 28 PCBs. The toxicity equivalent calculated using WHO toxic equivalency factors (TEFs) was presented and discussed.  In terms of the homolog distribution it was dominated by 3–5 chlorinated biphenyls. The tetra-PCBs (65%) dominate the PCB homolog followed by tri-PCB (47%) and penta-PCB (21%). The concentrations were lower than the guideline values; however levels at some locations were higher. Further in-depth study is proposed to determine PCBs its bioavailability and bioaccumulation through tissues of aquatic biota to assess the risk of these contaminants on the ecosystems and human health more thoroughly.

Keywords: polychlorinated biphenyls (PCBs) dioxin-like PCBs surface water Delhi India