Contamination Status and Temporal Trend of Persistent Organic Pollutants in Gwangyang Bay, Korea

Abstract

Twenty surface sediment samples from Gwangyang Bay in Korea were analyzed for persistent organic pollutants (POPs) such as polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and alkylphenols (APs) to determine contamination status and temporal trend. The concentrations of ∑PCB, ∑DDT, ∑HCH, ∑CHL, and ∑APs in sediments were in the range of 0.03~0.46 ng g-1, 0.03~0.37 ng g-1, nd~0.26 ng g-1, nd~0.18 ng g-1, and 3.24~19.8 ng g-1, respectively. Among the compounds analyzed, PCB 180, p,p’-DDT, β-HCH, trans-chlordane, and nonylphenol were detected with relatively high concentrations and high frequency. There is no significant correlation between TOC content and POPs concentration despite the fact that the concentration of POPs is largely influenced by TOC content. Relatively high PCB concentration in the sediment was found near a steel mill and urban areas. Similar to PCB, higher CHL and AP concentration were also found at the inner bay compare to the outer bay, implying the sources of these compounds located in the inner part of the bay. Other pesticide compounds were evenly distributed except for some sites. Temporal trends of PCBs, DDTs, and NPs showed that their concentrations decreased about 2~10 times from 2001 to 2010, while HCHs and CHLs concentrations remained comparable.