Seasonal-spatial distributions, congener profile, and risk assessment of polychlorinated biphenyls (PCBS) in the surficial sediments from the coastal area of Bangladesh

ABSTRACT

A comprehensive congener specific assessment of polychlorinated biphenyls (PCBs) was conducted for the first time in Bangladesh. All 209 PCB congeners in the surficial coastal sediments from the coastal areas of Bangladesh were analyzed by GC-MS/MS. The total concentrations of PCBs (∑PCBs) varied from 5.27 to 92.21 and 4.61 to 105.3 ng/g dw in winter and summer, respectively, and the ranges were comparable to or higher than those recorded in the sediments from the coastal areas of India, Korea, China, and Taiwan. The seasonal difference in the levels of PCBs was not statistically significant (p > 0.05). The spatial distribution revealed that the areas with recent urbanization and industrialization (Chittagong, Cox’s Bazar and Sundarbans) were more contaminated with PCBs than the unindustrialized area (Meghna Estuary). Moderately chlorinated (4–6 Cl) homologs dominated PCB profiles. A set of congeners based on their detection frequencies and abundance were identified and categorized as potential environmental marker PCBs, which can be used for the future selective monitoring studies where there would be limitations on whole congener assessment. Ecotoxicologically, the sedimentary PCB concentrations exceeded some of the existing environmental quality standards, suggesting a potential threat to the aquatic organisms in the Bangladeshi coastal areas.

KEYWORDS:

• Polychlorinated biphenyls (PCBs)
• surficial sediment
• risk assessment
• coastal area
• Bangladesh

Acknowledgements

The authors are thankful for the kind help from the members of Dhaka University, Bangladesh, during the field sampling.

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Additional information

Funding

This study was supported by the FY2016 Asia Focused Academic Research Grant from the Heiwa Nakajima Foundation (http://hnf.jp/josei/ichiran/2016ichiran.pdf). The authors are also grateful for financial support for Dr. Md. Habibullah-Al-Mamun from the Research Collaboration Promotion Fund provided by the Graduate School of Environment and Information Sciences, Yokohama National University, Japan (Grant No. 65A0516).