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Masan Bay, located on the southeast coast of Korea, is a long and narrow inlet of a semi-closed bay that receives industrial and municipal wastewaters from the cities of Masan and Changwon. In this study, sediments collected from 28 locations on Masan Bay were analyzed for total organic carbon (TOC), nonylphenol (NP), octylphenol (OP), bisphenol A (BPA), organochlorine pesticides (HCB, HCHs, CHLs, and DDTs), individual polychlorinated biphenyl (PCB) congeners, and 16 polycyclic aromatic hydrocabons (PAHs) to characterize their spatial distribution and contamination status. Concentrations of NP in sediment ranged from 113 to 3890 ng/g on a dry weight basis (dry wt), whereas concentrations of OP and BPA were, on average, 20-110-fold less than those of NP. PAHs were predominated by 4-6-ring compounds with concentrations in the range of 54.1-1100 ng/g dry wt. Concentrations of PCBs in sediment, which were predominated by tetraand pentachlorobiphenyl congeners, ranged from 10.3 to 148 ng/g, dry wt. Among different OC pesticides analyzed, concentrations of DDTs were the greatest, ranging from 0.4 to 12.6 ng/g dry wt. NP concentrations were greater at coastal locations proximal to the discharges of creeks from inland areas, whereas the concentrations of PCBs and PAHs were greater near the sites of industrial and shipping activities. Concentrations of target analytes were not related to TOC. Although the mean concentrations of PCBs and PAHs in sediments were less than the suggested sediment quality guidelines (SQG), their concentrations in some locations were close to or above the SQG for toxic effects in benthic organisms.

The dioxinlike and estrogenic relative potencies (REPs) of 16 priority polycyclic aromatic hydrocarbons (PAHs), seven methylated PAHs, and two hydroxylated PAHs were examined using three in vitro cell bioassays. An in vitro ethoxyresorufin-O-deethylase assay with PLHC-1 fish hepatoma cells and in vitro luciferase assay with H4IIE-luc recombinant rat hepatoma cells were used to evaluate dioxinlike potency. An in vitro luciferase assay with MVLN, recombinant human breast carcinoma cells, was used to evaluate estrogenic potency. Seven of the 16 priority PAHs tested induced significant dioxinlike responses. Excluding outliers with large ranges of uncertainty, the dioxinlike REPs for the PAHs ranged from 10(-6) to 10(-3). This is similar to the REPs reported for other xenobiotics of concern including polychlorinated naphthalenes (PCNs) and some polychlorinated biphenyls (PCBs). In general, REP estimates generated in this study were similar to those reported previously. However, a comparison of the estimates of total 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents derived using assay-specific REPs with REPs reported in other studies indicated that the use of nonspecific REPs could lead to significant error in mass-balance (potency-balance) analyses. A 10-h acid treatment completely destroyed the dioxinlike activity of a PAH mixture. Among the compounds tested, only benzo[a]anthracene and dibenz[a,h]anthracene induced significant responses in the MVLN bioassay. Relative estrogenic potencies were estimated to be approximately 10(-7). Overall, this research contributes to the growing consensus regarding the dioxinlike potency of priority PAHs and PAH derivatives and provides some additional evidence about potentially estrogenic PAHs.