Assessment of potential biological activities and distributions of endocrine-disrupting chemicals in sediments of the west coast of South Korea.

The west coast of Korea has experienced environmental deterioration for more than half a century. In the present study, we specifically aimed to: i) evaluate potential toxicities of contaminants in sediments that cause effects mediated through the aryl hydrocarbon receptor (AhR) and estrogen receptor (ER); ii) determine spatio-temporal distributions of polycyclic aromatic hydrocarbons (PAHs) and alkylphenols (APs); and iii) identify causes of greater potencies of samples. From 2010 to 2014, sediments were collected from 12 major estuarine and coastal regions along the west coast of South Korea. In vitro cell bioassays were performed to determine AhR- and ER-mediated potencies using H4IIE-luc and MVLN cells, respectively. Fifteen PAHs and six APs in sediments were identified by GC/MSD. Results of bioassays generally showed a low-to-moderate degree of contamination, however, greater AhR- and ER-mediated potencies were measured at some locations. Concentrations of PAHs and APs varied among locations, which indicated that sources were independently affected by the surrounding environment (e.g., industrial complex and cities). Results of bioassays were generally well correlated with concentrations of putative causative chemicals. Benzo[k]fluoranthene, dibenz[a,h]anthracene, and benzo[b]fluoranthene were the major AhR agonists, explaining approximately 30% of the bioassay-derived benzo[a]pyrene equivalent concentration (BaP-EQ). Unknown AhR and ER agonists and potential mixture effects remain in question. Overall, the present study provides baseline information on chemical contaminations and potential toxicity of sediments in a fairly wide geographical region of the west coast of South Korea.