Accumulation features and temporal trends (2002-2015) for legacy and emerging per- and polyfluoroalkyl substances (PFASs) in finless porpoises bycaught off Korean coasts.

Legacy and emerging per- and polyfluoroalkyl substances (PFASs) were measured in livers of finless porpoises (Neophocaena asiaeorientalis; n = 167) collected in Korean waters from 2002 to 2015 to investigate their occurrence, bioaccumulation feature, temporal trends, and ecotoxicological implications. Perfulorooctane sulfonate (PFOS), perfluoroundecanoate (PFUnDA), and perfluorotridecanoate (PFTrDA) were the predominant PFASs found in the porpoises. The concentration of 6:2 chlorinated polyfluoroalkyl ether sulfonate (F-53B), an alternative to PFOS, was comparable to that of PFTrDA. Perfluorooctane sulfonamide (FOSA), a precursor of PFOS, was also detected in all the porpoises examined. All PFASs, including F-53B, accumulated to higher concentrations in immature porpoises compared with mature specimens, implying substantial maternal transfer and limited metabolizing capacity for PFASs. A significant correlation was observed between PFOS and F-53B concentrations, indicating similar bioaccumulation processes. Based on prenatal exposure and toxicity, F-53B is an emerging contaminant in marine ecosystems. Significantly increasing trends were observed in the concentrations of sulfonates, carboxylates, and F-53B between 2002/2003 and 2010, whereas the FOSA concentration significantly decreased. During 2010-2015, decreasing trends were observed in the concentrations of FOSA and sulfonates, whereas concentrations of carboxylate and F-53B increased without statistical significance, likely due to a gap for the implementation of regulatory actions between sulfonates and carboxylates. Although PFOS and PFOA were found to pose little health risk to porpoises, the combined toxicological effects of other contaminants should be considered to protect populations and to mitigate PFAS contamination in marine ecosystems.

Accumulation and time trends (2003-2015) of persistent organic pollutants (POPs) in blubber of finless porpoises (Neophocaena asiaeorientalis) from Korean coastal waters.

Accumulation of persistent organic pollutants (POPs) in marine mammals is of great concern and is associated with declining populations. The concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) were measured in blubber of finless porpoises (Neophocaena asiaeorientalis) collected from Korean coastal waters in 2010 and 2015, to assess the concentrations, time trends, and ecotoxicological effects. Among the POPs measured, DDTs were detected at the highest concentrations, followed by PCBs and PBDEs. Significant age- and sex-dependent accumulation of POPs was evident for porpoises collected in 2010, but not for those collected in 2015. This finding may be a function of stabilization of POP concentrations over time. In our study, accumulation patterns of POPs were dependent on consumption patterns and physico-chemical properties of the contaminants, and on the metabolism in the porpoises. Significant reductions of POPs were found between 2003 and 2010, likely reflecting the impact of domestic and global regulation of POPs. However, no changes in most POPs were found between 2010 and 2015, suggesting a trend toward stabilization. Approximately 10 % and 27 % of porpoises exceeded previously proposed threshold levels for PCBs and DDTs, respectively, implying a potential health risk.

Tissue-Specific Accumulation and Body Burden of Parabens and Their Metabolites in Small Cetaceans.

Parabens have been of global concern due to their endocrine disrupting properties. However, few studies have reported tissue-specific distribution of parabens in wildlife. In this study, we measured parabens and their metabolites in organs and tissues (blubber, muscle, melon, stomach, kidney, liver, gonad, brain, uterus, and umbilical cord, total n = 94) of common dolphins ( Delphinus capensis) and finless porpoises ( Neophocaena asiaeorientalis), to investigate tissue-specific accumulation and body burden. Among the target compounds, methyl paraben (MeP) and para-hydroxybenzoic acid (4-HB) were detected in all organs. Compared to common dolphins, finless porpoises had significantly higher concentrations of MeP and 4-HB due to their near-shore habitat. Higher concentrations of MeP and 4-HB were found in the kidney, liver, and stomach than in other organs, indicating selective accumulation of parabens in certain organs. Significant correlations between MeP and 4-HB in liver/kidney suggested metabolic transformation of the former to the latter. Detection of parabens in brains, umbilical cords, and uteri suggests that these chemicals cross biological barriers such as the blood-brain and placental barriers. The body burdens of total parabens were in the ranges of 13000-90600 µg and 19800-81500 µg for common dolphins and finless porpoises, respectively.

Accumulation of butyltin compounds in finless porpoises (Neophocaena asiaeorientalis) from Korean coast: tracking the effectiveness of TBT regulation over time.

The concentrations of butyltin compounds (BTs) were measured in the livers of finless porpoises (Neophocaena asiaeorientalis) caught off the Korean coast in 2003 and 2010, to assess the effectiveness of legislative action against BTs. The concentrations of BTs ranged from 65.1 to 1432 (average: 370) ng/g wet weight, within the ranges reported by previous studies. The levels of BTs in almost all the samples exceeded the suggested threshold value, implying potential adverse health effects from the BT exposures. Concentrations of BTs were significantly correlated with body length, weight, and age of finless porpoises, but were not correlated with sex. Spatial differences in the concentrations of BTs were not observed between Yellow and South Seas, while there was a significant decrease in BTs between the sampling years of 2003 and 2010. Our result indicates that the effectiveness on TBT ban has reached to marine mammals in the coastal waters of Korea.

Occurrence and accumulation features of polycyclic aromatic hydrocarbons and synthetic musk compounds in finless porpoises (Neophocaena phocaenoides) from Korean coastal waters.

Reports of the occurrence and accumulation patterns of polycyclic aromatic hydrocarbons (PAHs) and synthetic musk compounds (SMCs) in marine mammals are scarce. In this study, the concentrations and accumulation profiles of PAHs and SMCs were determined in blubber from finless porpoises in Korean coastal waters. Total concentrations of PAHs and SMCs ranged from 6.0 to 432 (mean: 160) ng/g lipid weight and from 17 to 144 (mean: 52) ng/g lipid weight, respectively. Residue levels of PAHs were lower than those reported from other studies, while residue levels of SMCs were relatively higher than those reported in other studies. Naphthalene was the most abundant PAH and HHCB was the dominant SMC observed in finless porpoises. The concentrations of PAHs and SMCs were not correlated with each other, but were significantly correlated within the same chemical groups. No correlations were found between body size and residue levels of PAHs and SMCs.

Contamination status and accumulation features of PCDDs, PCDFs and dioxin-like PCBs in finless porpoises (Neophocaena phocaenoides) from Korean coastal waters.

Data on the concentrations and accumulation profiles of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in cetaceans are scarce. In this study, concentrations and accumulation profiles of PCDD/Fs and DL-PCBs were measured in the blubber of finless porpoises (Neophocaena phocaenoides) collected from Korean coastal waters. Total dioxin-like toxic equivalent (TEQ) concentrations (6.5-31 pg/g lipid weight) in finless porpoises were lower than those reported for cetaceans and pinnipeds from other countries. Significant gender-specific differences were found in the concentrations and accumulation profiles of PCDD/Fs and DL-PCBs and this difference was associated with maternal and lactation transfer of contaminants from mature females to their fetus. All of the PCDD/F homologue groups were detected in all of the samples and the proportions of PCDFs were higher than those of PCDDs. The dominant congeners found in finless porpoise blubber were 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF and OCDD for PCDD/Fs and PCB 118 for DL-PCBs. The accumulation profiles of PCDD/Fs in finless porpoise in our study were different from those found for cetaceans from other countries. Total TEQ levels in finless porpoises in Korea were below the suggested threshold values for adverse health effects in marine mammals.