Integrated chemical and effects-based assessment of sediment contamination in the Saemangeum coastal area, South Korea.

This study conducted an integrated chemical and effects-based assessment of surface sediments from the Saemangeum coastal area, a large reclaimed coastal system on the west coast of South Korea, to characterize sediment contamination and assess potential ecological risks. Eight bioassays encompassing receptor-mediated and baseline toxicity endpoints were employed to characterize sediment toxicity. Target analytes included 29 polycyclic aromatic hydrocarbons and 20 metal(loid)s. Among the bioassay endpoints, non-persistent aryl hydrocarbon receptor (AhR)-mediated activity showed the highest responses, ranging from 5.1 to 90 %BaPmax (mean = 32 %BaPmax), with elevated activities observed near industrial complexes. In the bioluminescence inhibition assay for Aliivibrio fischeri, saline extracts caused substantially greater inhibition (mean = 33%) than organic extracts (mean = 2.3%), suggesting that metal(loid)s were the primary contributors to baseline toxicity. Potency balance analysis identified benzo[b]anthracene (BbA) as the predominant AhR contributor, accounting for ∼90% of the total non-persistent AhR-mediated activity. Nontarget screening identified 11 AhR agonist candidates, several of which were associated with combustion sources. Enrichment factors of Cu, Hg, Ni, and Zn were significantly correlated with bioluminescence inhibition. Integrated chemical and effects-based risk assessment indicated that non-persistent AhR activity, BbA, Cr, and As were the primary contributors to the potential ecological risk of sediments from the Saemangeum coastal area. The integrated chemical and effects-based approach presented in this study provides a practical framework for environmental monitoring and ecological risk assessment of coastal ecosystems.