Distribution and Sources of Polychlorinated Biphenyls in Air, Dust, and Sediment from India

Abstract

Persistent organic pollutants, such as polychlorinated biphenyls (PCBs), pose a serious risk for human health and the environment. In this study, PCBs contamination and sources of ambient air, road dust, and sediments in the most polluted city in India, Raipur, has been measured over the period 2008–2015. The seasonal variations of particulate matter (PM), elemental carbon (EC), organic carbon (OC), and carbonate carbon (CC) were studied, and maximum concentrations were detected in the December–January period each year. Total PCBs concentrations in the ambient air (associated with PM), road dust, and sediments samples during 2008 were in the 186–645 pg m−3, 102–537, and 241–538 ng g−1 range, respectively. 2-chlorobiphenyl (PCB-1) and 4-chlorobiphenyl (PCB-3) were the dominant chemical compounds identified. A substantial vertical migration of the PCBs in the sediments was observed. Concentration variations (spatial and temporal), correlations, and sources of PCB are discussed. In particular, an average increment rate of 6.2%, 4.9%, and 5.4% of PCBs concentration in the particulate matter (PM10), road dust, and sediments, respectively, was observed over the 2008–2015 period. The reported data points to India's low degree of accomplishment of the Stockholm Convention's requirement to phase out the use of PCBs in equipment by 2025 and ensure elimination of PCBs by 2028.