금호강 퇴적물 내 잔류성독성물질의 분포 및 잠재적 독성 평가

초록

Geumho River is a major tributary of Nakdong River and is affected by the effluent of the wastewater treatment plants and surrounding urban and industrial areas. In this study, we investigated distributions of persistent toxic substances (PTSs) and evaluated potential aryl hydrocarbon receptor (AhR)-mediated activities in sed-iments from inland creeks (n = 7), Geumho River (n = 13), and Nakdong River (n = 3). Target PTSs included 15 traditional polycyclic aromatic hydrocarbons (t-PAHs), 7 alkylphenols (APs), 10 styrene oligomers (SOs), and 20 emerging PAHs (e-PAHs). Concentrations of sedimentary t-PAHs ranged from 27 to 360 ng g-1 dry mass (dm) (mean = 120 ng g-1 dm), APs ranged from below detection limit to 730 ng g-1 dm (mean = 120 ng g-1 dm), SOs ranged from 36 to 270 ng g-1 dm (mean = 110 ng g-1 dm), and e-PAHs ranged from 53 to 300 ng g-1 dm (mean = 140 ng g-1 dm). Significant AhR-mediated potencies were detected in organic extracts of sediments ranging from 30 to 230% BaPmax (mean = 120% BaPmax) in the H4IIE-luc bioassay. The targeted AhR-active chemicals partially explained the total AhR-mediated potencies in sediments, ranging from 0.6 to 362% (mean = 40%), indicating that unknown AhR agonists widely distributed in sediments in the study area. Contributions of t-PAHs, SOs, and e-PAHs to the total AhR-mediated potencies in sediments were 7.7%, 0.5%, and 32%, respectively (on average). Results for EPA PMF model indicated that PAHs in the sediments were mainly originated from coke oven, coal combustion, and vehicles. In some sites, fresh APs and SOs seemed to be introduced from point sources such as WWTP. Results for principal component analysis (PCA) revealed that the relatively great concentrations of PTSs were found in WWTP area and urban area. Overall, the present study provides baseline information on distributions and sources of PTSs and potential toxicity in river sediments of the urban areas in South Korea.

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