2001-2012 우리나라 연안 퇴적물과 이매패류 중 잔류성유기오염물질(POPs)의 공간 분포와 경년 변화

Abstract

Persistent organic pollutants (POPs) are of great concern in coastal environment, due to their bioaccumulation potentials and toxicological effects. In this study, polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethane (DDTs) and hexachlorocyclohexanes (HCHs) were measured in sediment and bivalve samples collected from Korean coastal waters during 2001–2012, to evaluate the contamination status, spatial distribution, temporal trends and ecotoxicological risks of POPs in coastal environments of Korea. PCDD/Fs, PCBs and DDTs were detected in almost all the samples, except for HCHs, suggesting widespread contamination of POPs in Korean coastal waters. In general, the concentrations of PCDD/Fs, PCBs and DDTs in bivalves were higher than those measured in sediment, due to bioaccumulation potentials of POPs. Total concentrations of PCDD/Fs, PCBs, DDTs and HCHs in sediment ranged from 0.15 to 18.9 (mean: 1.61) pg TEQ/g dry weight (dw), from 0.33 to 53.2 (mean: 1.82) ng/g dw, from 0.02 to 21.2 (mean: 1.00) ng/g dw, from 0.02 to 11.8 (mean: 0.24) ng/g dw, respectively. In bivalve samples, total concentrations of PCDD/Fs, PCBs, DDTs and HCHs ranged from 0.06 to 7.70 (mean: 0.20) pg TEQ/g wet weight, from 2.5 to 71.5 (mean: 7.76) ng/g dw, from 0.15 to 52.6 (mean: 5.01) ng/g dw, from 0.09 to 13.7 (mean: 0.72) ng/g dw, respectively. The concentrations of PCDD/Fs, PCBs and DDTs in sediment and bivalves from Korean coastal waters were lower than found in other areas around the world. The overall spatial distribution of POPs was similar to each other, indicating that they have similar contamination sources and environmental behavior in coastal waters. The highest concentrations of PCDD/Fs, PCBs and DDTs were observed in southeastern part of Korea (Ulsan, Onsan, Busan, Masan, Jinhae Bays), which are the locations close to the largest industrial complexes and harbors. This result indicates that intensive industrial and shipping activities are major contamination sources of POPs in Korean coastal waters. The POPs in sediment and bivalves from eastern and western parts of Korea showed relatively lower contamination status than southeastern coastal areas, because these areas are far away from the contamination sources of POPs. Among target contaminants, only a decreasing trend of PCDD/Fs in sediment for 12 years was found in the present study. This result is associated with a strong regulation on PCDD/Fs in flue gas from waste incinerators in Korea. This finding suggests that legislative action is effective to reduce PCDD/Fs in coastal environment of Korea. No significant temporal trends were observed of PCBs, DDTs and HCHs in sediments and bivalves. To evaluate ecotoxicological effects of PCDD/Fs, PCBs and DDTs in Korean sediment, sediment quality guidelines (SQGs) such as probable effect level (PEL) and threshold effect level (PEL) from Florida State were used in the present study. All of the sediment samples did not exceed the PEL values for PCDD/Fs, PCBs and DDTs. Although the concentrations of PCBs and DDTs exceeded the TEL values with less than 5% of the sediment samples, half of sediment samples (46%) had exceeding values of PCDD/Fs for the TEL, implying ecotoxicological potential risks to marine organisms in Korean coastal waters.