•Long-term exposure to TDCPP affected sex hormone levels in female zebrafish.•Significant levels of TDCPP and BDCPP were detected in the gonads.•TDCPP affected gonad development.•Long-term exposure ...caused reduction of fecundity.•TDCPP is an estrogenic endocrine disruptor that impairs fish reproduction.
Tris(1,3-dichloro-2-propyl) phosphate (TDCPP) is an organophosphate flame retardant that is detectable in the environment and biota, prompting concern over its risk to wildlife and human health. Our objective was to investigate whether long-term exposure to low concentrations of TDCPP can affect fish reproduction. Zebrafish embryos were exposed to low concentrations (0, 4, 20 and 100μg/L) of TDCPP from 2h post-fertilization until sexual maturation. Exposure to TDCPP significantly increased plasma estradiol and testosterone levels in females, but had no effect in males. TDCPP exposure also caused a significant reduction in fecundity as indicated by decreased egg production. Real-time PCR was performed to examine selected genes in the hypothalamic–pituitary–gonadal (HPG) axis and liver. Principle component analysis (PCA) showed that sex hormone levels and fecundity were related to the mRNA level of several genes in the HPG axis. Furthermore, hepatic vitellogenin (vtg1 and vtg3) expression was upregulated in both females and males, suggesting TDCPP has estrogenic activity. Histological examination revealed promotion of oocyte maturation in the females, but retardation of spermiation in males. Reduced egg quality (e.g., egg diameter) and increased malformation rates were observed in the F1 generation. Chemical analysis showed significant levels of TDCPP and its metabolite bis(1,3-dichloro-2-propyl) phosphate in the gonads of males and females. In conclusion, long-term exposure to low concentrations of TDCPP impairs fish reproduction.
Stereoisomers of 1,2,5,6,9,10-hexabromocyclododecane (HBCD) and 1,2-dibromo-4-(1,2-dibromoethyl)-cyclohexane (TBECH) were determined in sediments and 30 marine species in a marine food web to ...investigate their trophic transfer. Lipid content was found to affect the bioaccumulation of ΣHBCD and ΣTBECH in these species. Elevated biomagnification of each diastereomer from prey species to marine mammals was observed. For HBCD, biota samples showed a shift from γ- to α-HBCD when compared with sediments and technical mixtures; trophic magnification potential of (−)-α- and (+)-α-HBCD were observed in the food web, with trophic magnification factors (TMFs) of 11.8 and 8.7, respectively. For TBECH, the relative abundance of γ- and δ-TBECH exhibited an increasing trend from abiotic matrices to biota samples; trophic magnification was observed for each diastereomer, with TMFs ranging from 1.9 to 3.5. The enantioselective bioaccumulation of the first eluting enantiomer of δ-TBECH in organisms at higher TLs was consistently observed across samples. This is the first report on the trophic transfer of TBECH in the food web. The estimated daily intake of HBCD for Hong Kong residents was approximately 16-times higher than that for the general population in China, and the health risk to local children was high, based on the relevant available reference dose.
Plastic waste are introduced into the environment inevitably and their exposure in the environment causes deterioration in mechanical and physicochemical properties and leads to the formation of ...plastic fragments, which are considered as microplastics when their size is < 5 mm. In recent years, microplastic pollution has been reported in all kinds of environments worldwide and is considered a potential threat to the health of ecosystems and humans. However, knowledge on the environmental degradation of plastics and the formation of microplastics is still limited. In this review, potential hotspots for the accumulation of plastic waste were identified, major mechanisms and characterization methods of plastic degradation were summarized, and studies on the environmental degradation of plastics were evaluated. Future research works should further identify the key environmental parameters and properties of plastics affecting the degradation in order to predict the fate of plastics in different environments and facilitate the development of technologies for reducing plastic pollution. Formation and degradation of microplastics, including nanoplastics, should receive more research attention to assess their fate and ecological risks in the environment more comprehensively.
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F0B7Large amount of plastic waste enters the environment due to inappropriate disposal.F0B7Ocean gyres, farmlands, reservoirs, beaches are potential hotspots for plastic wastes.F0B7Plastics degrade in the environment due to chemical, biological and mechanic processes.F0B7Physicochemical and mechanical properties alter due to oxidation and chain scission.F0B7Microplastics are generated as a result of the fragmentation of plastics.
Degradation of plastics and formation of microplastics in the environment should be better understood to assess their fate and risks more comprehensively.
The present study investigated the composition profiles and levels of polybrominated diphenyl ethers (PBDEs) and five PBDE alternatives in the blubber of two species of marine mammals, Indo-Pacific ...humpback dolphins (Sousa chinensis) and finless porpoises (Neophocaena phocaenoides) from the South China Sea. Despite the fact that PBDEs were the most predominant brominated flame retardants in the samples analyzed, decabromodiphenyl ethane (DBDPE), 1,2-bis (2,4,6-tribromophenoxy) ethane (BTBPE), bis- (2-ethylhexyl) -tetrabromophthalate (TBPH), 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB) and Dechlorane Plus (DP) were all detected in both cetacean species. In addition, significantly increasing temporal shifting trends of Deca-BDE to DBDPE, Octa-BDE to BTBPE, and Deca-BDE to DP were observed in porpoise samples between 2003 and 2012 and dolphin samples between 2003 and 2011. These patterns may be attributed to the replacement of PBDEs by alternative halogenated flame retardants (HFRs) and the increasing usage of these alternatives following the restriction/voluntary withdrawal of the production and use of PBDE commercial mixtures. Our findings suggest that the study region may be a source of contamination by PBDE alternative flame retardants due to the high detection frequencies and levels of these compounds in marine mammals.
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•Brominated and chlorinated HFRs were detected in marine mammals.•Temporal shifting trends of PBDEs to its alternatives are a novel finding.•BTBPE, DBDPE and DP were first detected in cetaceans from the Asia-Pacific region.•PBDEs, DP and DBDPE were the three predominant HFRs in the blubber.
Perfluorobutanesulfonate (PFBS) is increasingly polluting aquatic environments due to worldwide manufacturing and application. However, toxicological knowledge regarding PFBS exposure remains scarce. ...Here, we showed that PFBS life-cycle exposure at environmentally realistic concentrations (0, 1.0, 2.9, and 9.5 μg/L) skewed the sex ratio in fish toward male dominance, while reproductive functions of female fish were greatly impaired, as characterized by extremely small ovaries, blocked oocyte development, and decreased egg production. Endocrine disruption through the hypothalamus-pituitary-gonad axis was induced by PFBS exposure, showing antiestrogenic activity in females but estrogenic activity in males. PFBS was found to gradually accumulate in F0 adults during continuous exposure but can be rapidly eliminated when depurated in clean water. Parental exposure also transferred PFBS pollutant to F1 offspring eggs. Although no trace of PFBS was detected in F1 adults and F2 eggs, adverse effects from parental exposure persisted in F1 and F2 offspring. These transgenerational effects implicate PFBS as an ongoing threat to the fitness and sustainability of fish populations. The dramatic impairment of fish reproduction highlights the urgency of re-evaluations of the ecological and evolutionary consequences of PFBS exposure.
A total of 211 water samples were collected from 53 key sampling points from 5–10th July 2013 at four different depths (0m, 2m, 4m, 8m) and at different sites in the Huaihe River, Anhui, China. These ...points monitored for 18 parameters (water temperature, pH, TN, TP, TOC, Cu, Pb, Zn, Ni, Co, Cr, Cd, Mn, B, Fe, Al, Mg, and Ba). The spatial variability, contamination sources and health risk of trace elements as well as the river water quality were investigated. Our results were compared with national (CSEPA) and international (WHO, USEPA) drinking water guidelines, revealing that Zn, Cd and Pb were the dominant pollutants in the water body. Application of different multivariate statistical approaches, including correlation matrix and factor/principal component analysis (FA/PCA), to assess the origins of the elements in the Huaihe River, identified three source types that accounted for 79.31% of the total variance. Anthropogenic activities were considered to contribute much of the Zn, Cd, Pb, Ni, Co, and Mn via industrial waste, coal combustion, and vehicle exhaust; Ba, B, Cr and Cu were controlled by mixed anthropogenic and natural sources, and Mg, Fe and Al had natural origins from weathered rocks and crustal materials. Cluster analysis (CA) was used to classify the 53 sample points into three groups of water pollution, high pollution, moderate pollution, and low pollution, reflecting influences from tributaries, power plants and vehicle exhaust, and agricultural activities, respectively. The results of the water quality index (WQI) indicate that water in the Huaihe River is heavily polluted by trace elements, so approximately 96% of the water in the Huaihe River is unsuitable for drinking. A health risk assessment using the hazard quotient and index (HQ/HI) recommended by the USEPA suggests that Co, Cd and Pb in the river could cause non-carcinogenic harm to human health.
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•Zn, Cd and Pb were identified as the dominant pollutants in the water body.•Approximately 96% of the waters in the Huaihe River were unsuitable for drinking.•Co, Cd and Pb in the river could pose potential non-carcinogenic effects on human health.
Concentrations of hexabromocyclododecanes (HBCDs), polybrominated diphenyl ethers (PBDEs), and three novel flame retardants, namely 2-ethylhexyl 2,3,4,5-tetrabromobenzoate (TBB), ...bis-(2-ethylhexyl)-tetrabromophthalate (TBPH), and hexachlorocyclopentadienyldibromocyclooctane (HCDBCO), were determined in blubber samples of Indo−Pacific humpback dolphins (Sousa chinensis) and finless porpoises (Neophocaena phocaenoides). The levels of HBCDs and PBDEs in cetacean samples ranged from 4.1 to 519 and 103 to 51,100 ng/g lw, respectively. A significant increasing trend of ΣHBCDs was observed in dolphin samples from 1997 to 2007 with an estimated annual rate of 5%, whereas no significant temporal trends of ΣPBDEs appeared over the sampling period. This pattern may be attributed to the increasing usage of HBCDs following the restriction/voluntary withdrawal of the production and use of PBDE commercial mixtures in several countries. HCDBCO was not found in the blubber samples. This is the first report of the presence of TBB and TBPH, two new flame retardants that have previously been identified in house dust from the U.S., in marine mammals; concentrations of these compounds in dolphins and porpoises ranged from the instrumental detection limit (IDL) (<0.04) to 70 and IDL (<0.04) to 3859 ng/g lw, respectively. Levels of TBPH were comparable to ΣHBCDs in porpoise samples. The presence of these novel flame retardants in top-trophic-level marine organisms raises concern about their release into the environment and indicates the need for further monitoring of these compounds in other environmental matrices.
Summary
Background : Population‐based data on gastro‐oesophageal reflux disease in Chinese are lacking. The prevalence, clinical spectrum and health care‐seeking behaviour of subjects with ...gastro‐oesophageal reflux disease were studied.
Methods : Ethnic Chinese (3605) were invited to participate in a telephone survey using a validated gastro‐oesophageal reflux disease questionnaire and the Hospital Anxiety and Depression Scale.
Results : A total of 2209 subjects (58% female; mean age, 40.3 years) completed the interview. The annual, monthly and weekly prevalence rates of gastro‐oesophageal reflux disease were 29.8%, 8.9% and 2.5%, respectively. Gastro‐oesophageal reflux disease symptoms were associated with non‐cardiac chest pain odds ratio (OR), 2.3; 95% confidence interval (95% CI), 1.7–3.1, dyspepsia (OR, 1.9; 95% CI, 1.4–2.5), globus (OR, 1.8; 95% CI, 1.2–2.7), acid feeling in the stomach (OR, 5.8; 95% CI, 4.5–7.5) and the use of non‐steroidal anti‐inflammatory drugs (OR, 2.3; 95% CI, 1.5–3.6), but not with dysphagia, bronchitis, asthma, hoarseness and pneumonia. Patients with gastro‐oesophageal reflux disease had a significantly higher anxiety and depression score and required more days off work when compared with subjects without. The frequency of heartburn (P = 0.032), female gender (P < 0.001), degree of depression (P = 0.004) and social morbidity (P < 0.001) were independent factors associated with health care‐seeking behaviour.
Conclusion : The prevalence of gastro‐oesophageal reflux disease was lower than that in Western populations, but carried a significant socio‐economic burden in the studied Chinese population. The frequency of heartburn, female gender and psychosocial factors were associated with health care utilization in gastro‐oesophageal reflux disease.
To determine how environmental pollutants induce dysbiosis of the gut microbiota, we exposed adult zebrafish to model pollutants with varied modes of action (atrazine, estradiol, polychlorinated ...biphenyl PCB126, and PCB153) for 7 days. Subsequently, metagenomic sequencing of the intestines was performed to compare the gut microbiomes among the groups. We observed clear compound- and sex-specific responses to xenobiotic stress. Principal component analysis revealed involvement of the aryl hydrocarbon receptor (AhR) and, to a lesser extent, the estrogen receptor (ER) in the dysregulation of the intestinal microbiota. The model pollutants differentially impaired intestinal and hepatic physiological activities, as indicated by assessments of gut motility, epithelial permeability, inflammation, and oxidative stress. Correlation analysis showed that abnormal Aeromonas reproduction, especially in the PCB126 groups, was significantly positively associated with oxidative damage. Aeromonas closely interacted with Mannheimia and Blastococcus to regulate intestinal permeability. In summary, we demonstrated that ER and AhR signaling regulated the dynamics of the gut microbiota. Our findings provide new mechanistic insight into the complex interactions between the host metabolism and gut microbiota, which may contribute to the grouped assessment of environmental pollutants in future.
Organic UV filters are common ingredients of personal care products (PCPs), but little is known about their distribution in and potential impacts to the marine environment. This study reports the ...occurrence and risk assessment of twelve widely used organic UV filters in surface water collected in eight cities in four countries (China, the United States, Japan, and Thailand) and the North American Arctic. The number of compounds detected, Hong Kong (12), Tokyo (9), Bangkok (9), New York (8), Los Angeles (8), Arctic (6), Shantou (5) and Chaozhou (5), generally increased with population density. Median concentrations of all detectable UV filters were <250 ng/L. The presence of these compounds in the Arctic is likely due to a combination of inadequate wastewater treatment and long-range oceanic transport. Principal component analysis (PCA) and two-way analysis of variance (ANOVA) were conducted to explore spatiotemporal patterns and difference in organic UV filter levels in Hong Kong. In general, spatial patterns varied with sampling month and all compounds showed higher concentrations in the wet season except benzophenone-4 (BP-4). Probabilistic risk assessment showed that 4-methylbenzylidene camphor (4-MBC) posed greater risk to algae, while benzophenone-3 (BP-3) and ethylhexyl methoxycinnamate (EHMC) were more likely to pose a risk to fishes and also posed high risk of bleaching in hard corals in aquatic recreational areas in Hong Kong. This study is the first to report the occurrence of organic UV filters in the Arctic and provides a wider assessment of their potential negative impacts in the marine environment.
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•The occurrence of 12 organic UV filters in marine surface water was investigated.•They were widespread, with higher concentrations observed in the wet season.•Incomplete WWTP removal and recreational activities are their main sources.•Their occurrence in the Arctic is likely due to oceanic transport.•UV filters could pose high risks to marine organisms at different trophic levels.
