Alkylphenols, polycyclic aromatic hydrocarbons, and organochlorines in sediment from Lake Shihwa, Korea: Instrumental and bioanalytical characterization

Lake Shihwa is an artificial lake, located on the west coast of Korea, that has experienced environmental deterioration since 1994, when it was formed by construction of a sea dike. This study used instrumental analysis and in vitro bioassays to characterize organic contaminants in sediment collected from 11 stations on Lake Shihwa. Alkylphenol (AP) concentrations in Lake Shihwa sediment ranged from 20.2 to 1,820 ng/g nonylphenol and from 4.69 to 50.5 ng/g octylphenol, on a dry weight basis. Maximum concentrations of polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides, and polychlorinated biphenyls (PCBs) were 30.8, 2.26, and 12.3 ng/g (dry weight), respectively. Significant estrogenic activity was associated with fractions containing APs. Mass-balance analysis suggested that reported concentrations of APs account for less than 20% of the estrogenic activity observed. No significant dioxin-like activity was associated with fractions containing classic aryl hydrocarbon receptor agonists, such as PCBs, but the mid- polarity fractions containing PAHs and most polar fractions yielded significant dioxin-like activity. Overall, most of the in vitro bioassay responses appear to have been caused by unidentified and/or undetectable compounds associated with Lake Shihwa sediment.