Emergent contaminants in sediments and fishes from the Tamsui River (Taiwan): Their spatial-temporal distribution and risk to aquatic ecosystems and human health.

The occurrence of emergent contaminants, 24 polybrominated diphenyl ethers (PBDEs), di(2-ethylhexyl)phthalate (DEHP), dibutyl phthalate (DBP), butyl benzyl phthalate (BBP), diethyl phthalate (DEP), dimethyl phthalate (DMP), di-n-octyl phthalate (DnOP), bisphenol A (BPA) and nonylphenol (NP), was investigated in sediments and fishes collected from the Tamsui River system to determine the factors that influence their distribution and their risk to aquatic ecosystems and human health. The concentrations of total PBDEs, DEHP, DBP, BBP, DEP, DMP, DnOP, BPA and NP in sediments were 1-955, ND-23570, <50-411, <50-430, ND-80, ND-<50, ND-<50, 1-144, 3-19624 µg/kg dw, respectively. The spatial-temporal distribution trends of these compounds in sediments could be attributed to urbanization, industrial discharge and effluents from wastewater treatment plants. The PBDE congener distribution patterns (BDE-209 was the dominant congener) in sediments reflected the occurrence of debromination of BDE-209 and the elution of penta-BDE from the treated products. The concentrations of total PBDEs, DEHP, DBP, BBP, DEP, DMP, DnOP, BPA and NP in fish muscles were 2-66, 17-1046, <10-231, <10-66, <30, ND-<30, ND-<30, 0.4-7 and 3-440 µg/kg ww, respectively. The species-specific bioaccumulation of these compounds by fish was found and four species particularly showed high bioaccumulation potential. BDE-47 was the predominant BDE congener in fish muscles, suggesting high bioavailability and bioaccumulation of this compound. The results of biota-sediment accumulation factors showed that BDE-47, 99, 100, 153 and 154 had relatively high bioavailability and bioaccumulation potential for some fish species. The ecological risk assessment showed that the concentrations of BPA and NP in sediments were likely to have adverse effects on aquatic organisms (risk quotients > 1). The human health risk assessment according to hazard quotients (HQs) and carcinogenic risks (CRs) revealed no remarkable risk to human health through consumption of fish contaminated with BDE-47, 99, 100, 154, 209, DEHP, BPA and NP.

Exposure of arc-furnace-plant workers to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs).

This study aimed to evaluate serum polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) levels in electric-arc-furnace workers according to their corresponding occupational exposure. In addition, the ambient PCDD/Fs of the work environment were measured to provide additional support for the exposure and accumulation inside the electric arc furnace. The ambient PCDD/F concentrations inside the electric arc furnace were 1.557-1.917 pg-TEQ/Nm(3), 5-24 folds higher than those outside (0.080-0.385 pg-TEQ/N m(3)). In addition, higher average serum levels were measured in the workers with high occupational dioxin exposure (24.0 pg WHO-TEQ/g lipid) than in those with lower occupational dioxin exposure (13.8 pg WHO-TEQ/g lipid). Higher PCDFs/PCDDs ratios were found in serum samples from high-exposure groups than in low-exposure groups. The higher ratio of PCDFs/PCDDs was also found in ambient samples consistent with other metallurgical processes reported previously. Our results suggest that PCDD/Fs exposure exits in the smelting process of electric arc furnace, and the occupational hygiene should be taken more seriously concern in that workplace.

Characteristics of nonylphenol and bisphenol A accumulation by fish and implications for ecological and human health.

Fish populations constitute an important part of aquatic ecosystems. Thus, their accumulation of nonylphenol (NP) and bisphenol A (BPA) may pose risks to ecosystems and human health. This study analyzed the concentrations of NP and BPA in four types of fishes (i.e., wild/farmed freshwater fishes and wild/farmed marine fishes). Wild freshwater fishes contained higher concentrations of NP and BPA than the other three types of fishes. The concentrations of NP in the wild freshwater fishes ranged from 1.01 to 277 µg/kg ww, with bioconcentration factors (BCFs) and biota-sediment accumulation factors (BSAFs) ranging from 74.0 to 2.60 × 10(4)L/kg and from 0.003 to 18.3, respectively. The wild freshwater fishes contained relatively low amounts of BPA, varying from ND to 25.2 µg/kg ww, with the BCFs and BSAFs ranging from 1.00 to 274L/kg and from 0.003 to 3.40, respectively. Five fish species particularly showed high BCFs and BSAFs, indicating that they could be an important source of NP for higher trophic levels, most likely resulting in ecological risks. The demersal fishes showed a greater ability to accumulate NP than the pelagic ones. The fact that the 95th percentile values of the risk quotient (RQ) for NP and BPA were higher than the acceptable threshold indicated that these two compounds would have adverse effects on aquatic organisms in Taiwanese rivers. The consumption of wild marine fishes had the highest 95th percentile values of hazard quotient (HQ) for NP and BPA among the four types of fishes, particularly for the population aged 0-3 years. However, the 95th percentile values of HQ for NP and BPA were all less than 1, suggesting that exposure to NP and BPA through fish consumption posed no remarkable risk to human health in Taiwan.

Influence of water quality parameters on occurrence of polybrominated diphenyl ether in sediment and sediment to biota accumulation.

Polybrominated diphenyl ether (PBDE) concentrations in sediment and fish from 12 principal rivers in Taiwan were investigated to determine their association with water quality parameters as well as the biota-sediment accumulation factor (BSAF) in fish with different living patterns. The highest PBDE concentration in sediment was found in the Bajhang River (261 ng g(-1) dryweight (d.w.)) and the lowest in the Beinan River and the Da-an River (0.17 ng g(-1) d.w.). The PBDE concentrations in fish samples ranged from 1.28 ng g(-1) d.w. (Oreochromis niloticus niloticus) in the Yanshuei River to 33.7 ng g(-1) d.w. (Varico rhinos barbatulus) in the Da-an River. We conclude that PBDEs contamination in sediment was significantly affected by NH(3)-N, pH, and DO. The BSAF results showed a parabolic trend from low- to high-brominated BDEs. Fish easily accumulated the congeners BDE-47, -100, -119, -126, and -154 from sediment. The BSAF decreased in the following order: PeBDE>HxBDE>TeBDE>other BDEs. Principle component analysis showed that demersal fish have different PBDE sources than do pelagic fish. We conclude that living and feeding habits are critical factors affecting PBDE accumulation in fish.

The potential role of water quality parameters on occurrence of nonylphenol and bisphenol A and identification of their discharge sources in the river ecosystems.

Nonylphenol (NP) and bisphenol A (BPA) have attracted great attention due to their estrongenic activities and occurrence in different environments. This study investigated concentrations of NP and BPA in water and sediments of 16 major rivers in Taiwan to determine their association with water quality parameters on their distribution. The sources of NP and BPA discharged into river environments were also identified. The results showed that concentrations of NP and BPA were in the range of 0.02-3.94 and 0.01-44.65µgL(-1) in water and 6.59-47797.69 and 0.37-491.54µgkg(-1) dry weight in sediments. High levels of NP and BPA in water and sediments were measured in sampling sites near highly industrialized and urbanized areas. Construction of the sewage system and wastewater treatment plant has decreased these chemicals discharged into Love River. Dilution effects and erosion of surface sediments in the high-flow season resulted in lower concentrations of NP and BPA detected in sediments of most rivers than those in the low-flow season. Occurrence characteristics of NP and BPA in water and sediments were mainly related to organic carbon contents in sediments and several water quality parameters such as dissolved oxygen, pH, concentrations of ammonia-nitrogen and total organic carbon in water. Effluents from NP/BPA-related factories appeared to be the major discharge sources of NP and BPA. Use and waste of BPA-containing products in household activity was the another discharge source of BPA, but handling NP-containing products became an important source of NP only in the low-flow season.