Biological effects and bioaccumulation of steroidal and phenolic endocrine disrupting chemicals in high-back crucian carp exposed to wastewater treatment plant effluents

Free and conjugated forms of metabolites are indispensable components of steroids: The first evidence from an estuarine food web

Steroids have attracted particular attention as environmental contaminants because of their severe endocrine-disrupting effects. Previous studies have predominantly focused on parent steroids; however, the levels and proportions of the free and conjugated forms of their metabolites remain largely unclear, especially in food webs. Here, we first characterized the free and conjugated forms of parent steroids and their metabolites in 26 species in an estuarine food web. The steroids were dominated by their metabolites in water samples, whereas parent compounds were predominant in sediment samples. The total mean steroid concentrations in the biota samples that underwent non-enzymatic hydrolysis decreased in the following order: crabs (27 ng/g) > fish (5.9 ng/g) > snails (3.4 ng/g) > shrimps and sea cucumbers (1.2 ng/g); and those in the biota samples that underwent enzymatic hydrolysis decreased in the following order: crabs (57 ng/g) > snails (9.2 ng/g) > fish (7.9 ng/g) > shrimps and sea cucumbers (3.5 ng/g). The proportion of metabolites in the enzymatic hydrolysis biota samples was higher (38-79%) than that (2.9-65%) in non-enzymatic ones, indicating that the free and conjugated forms of metabolites in aquatic organisms were not negligible. Most synthetic steroids were either bioaccumulative or highly bioaccumulative. Importantly, in the invertebrate food web, 17α-methyltestosterone was biomagnified, while 17β-boldenone underwent trophic dilution. Although the estuarine water had a median ecological risk level, the health risks via aquatic product consumption were very low. This study provides novel insights into the composition and trophic transfer of steroids in an estuarine food web for the first time and highlights that free and conjugated metabolites should receive more attention, particularly in biota samples.

Bio-removal of emerging pollutants by advanced bioremediation techniques

This review highlights the relevance of bioremediation techniques for the removal of emerging pollutants (EPs). The EPs are chemical or biological pollutants that are not currently monitored or regulated by environmental authorities, but which can enter the environment and cause harmful effects to the environment and human health. In recent times, an ample range of EPs have been found in water bodies, where they can unbalance ecosystems and cause negative effects on non-target species. In addition, some EPs have shown high rates of bioaccumulation in aquatic species, thus affecting the safety and quality of seafood. The negative impacts of emerging pollutants, their wide distribution in the environment, their bioaccumulation rates, and their resistance to wastewater treatment plants processes have led to research on sustainable remediation. Remediation techniques have been recently directed to advanced biological remediation technologies. Such technologies have exhibited numerous advantages like in-situ remediation, low costs, eco-friendliness, high public acceptance, and so on. Thus, the present review has compiled the most recent studies on bioremediation techniques for water decontamination from emerging pollutants to extend the current knowledge on sustainable remediation technologies. Biological emerging contaminants, agrochemicals, endocrine-disrupting chemicals, and pharmaceutical and personal care products were considered for this review study, and their removal by bioremediation techniques involving plants, bacteria, microalgae, and fungi. Finally, further research opportunities are presented based on current challenges from an economic, biological, and operation perspective.

Systematic review of prenatal exposure to endocrine disrupting chemicals and autism spectrum disorder in offspring

LAY ABSTRACT

Autism spectrum disorders comprise a complex group with many subtypes of behaviorally defined neurodevelopmental abnormalities in two core areas: deficits in social communication and fixated, restricted, repetitive, or stereotyped behaviors and interests each with potential unique risk factors and characteristics. The underlying mechanisms and the possible causes of autism spectrum disorder remain elusive and while increased prevalence is undoubtable, it is unclear if it is a reflection of diagnostic improvement or emerging risk factors such as endocrine disrupting chemicals. Epidemiological studies, which are used to study the relation between endocrine disrupting chemicals and autism spectrum disorder, can have inherent methodological challenges that limit the quality and strength of their findings. The objective of this work is to systematically review the treatment of these challenges and assess the quality and strength of the findings in the currently available literature. The overall quality and strength were "moderate" and "limited," respectively. Risk of bias due to the exclusion of potential confounding factors and the lack of accuracy of exposure assessment methods were the most prevalent. The omnipresence of endocrine disrupting chemicals and the biological plausibility of the association between prenatal exposure and later development of autism spectrum disorder highlight the need to carry out well-designed epidemiological studies that overcome the methodological challenges observed in the currently available literature in order to be able to inform public policy to prevent exposure to these potentially harmful chemicals and aid in the establishment of predictor variables to facilitate early diagnosis of autism spectrum disorder and improve long-term outcomes.

Tris(1,3-dichloro-2-propyl)phosphate Reduces Growth Hormone Expression via Binding to Growth Hormone Releasing Hormone Receptors and Inhibits the Growth of Crucian Carp

Tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) has commonly been used as an additive flame retardant and frequently detected in the aquatic environment and in biological samples worldwide. Recently, it was found that exposure to TDCIPP inhibited the growth of zebrafish, but the relevant molecular mechanisms remained unclear. In this study, 5 day-old crucian carp (Carassius auratus) larvae were treated with 0.5, 5, or 50 μg/L TDCIPP for 90 days; the effect on growth was evaluated; and related molecular mechanisms were explored. Results demonstrated that 5 or 50 μg/L TDCIPP treatment significantly inhibited the growth of crucian carp and downregulated the expression of growth hormones (ghs), growth hormone receptor (ghr), and insulin-like growth factor 1 (igf1). Molecular docking, dual-luciferase reporter gene assay, and in vitro experiments demonstrated that TDCIPP could bind to the growth hormone releasing hormone receptor protein of crucian carp and disturb the stimulation of growth hormone releasing hormone to the expression of ghs, resulting in the decrease of the mRNA level of gh1 and gh2 in pituitary cells. Our findings provide new perceptions into the molecular mechanisms of developmental toxicity of TDCIPP in fish.

The Impact of Estrogen and Estrogen-Like Molecules in Neurogenesis and Neurodegeneration: Beneficial or Harmful?

Estrogens and estrogen-like molecules can modify the biology of several cell types. Estrogen receptors alpha (ERα) and beta (ERβ) belong to the so-called classical family of estrogen receptors, while the G protein-coupled estrogen receptor 1 (GPER-1) represents a non-classical estrogen receptor mainly located in the plasma membrane. As estrogen receptors are ubiquitously distributed, they can modulate cell proliferation, differentiation, and survival in several tissues and organs, including the central nervous system (CNS). Estrogens can exert neuroprotective roles by acting as anti-oxidants, promoting DNA repair, inducing the expression of growth factors, and modulating cerebral blood flow. Additionally, estrogen-dependent signaling pathways are involved in regulating the balance between proliferation and differentiation of neural stem/progenitor cells (NSPCs), thus influencing neurogenic processes. Since several estrogen-based therapies are used nowadays and estrogen-like molecules, including phytoestrogens and xenoestrogens, are omnipresent in our environment, estrogen-dependent changes in cell biology and tissue homeostasis have gained attention in human health and disease. This article provides a comprehensive literature review on the current knowledge of estrogen and estrogen-like molecules and their impact on cell survival and neurodegeneration, as well as their role in NSPCs proliferation/differentiation balance and neurogenesis.

Study on the Release Potential of BPA and Steroid Estrogens in the Sediments of Erhai Lake, a Typical Plateau Lake of China

On-site sampling analysis and laboratory-scale experiments were conducted to study the pollution status and release potential of EDCs in Erhai Lake. We found that nitrogen and phosphorus pollution in Erhai Lake sediment were both at a high level, as well as EDCs pollution. The concentrations of BPA, E2α, E1, E2β, EE2, and E3 were 36.84 ng/g(DW), 13.04 ng/g(DW), 128.97 ng/g(DW), 52.57 ng/g(DW), 18.48 ng/g(DW) and 5.36 ng/g(DW), respectively. The concentrations of E2α, E1, E2β and EE2 in the bottom water were higher than the surface water due to the impact of sediment release. The results of the 20 days release test indicated that BPA release from the sediment had a greater correlation with the original concentration and the particle size of sediment, while the steroid EDCs had no obvious correlation with these two factors, probably due to the difference in hydrophobicity between them. Under hydraulic disturbance and aerobic conditions, the release process of EDCs was accompanied by a large amount of microbial degradation, and degradation amount > released amount. BPA was released quickly, 9.56% was released in 20 days, but only 3.37% of steroid EDCs released. In comparison, the release process of steroids was longer and posed a greater threat to aquatic ecology.

Multiple Xenosteroid Pollutants Biomarker Changes in Xultured Nile Tilapia Using Wastewater Effluents as Their Primary Water Source

Simple Summary

Estrogenic endocrine disruptive chemicals (E-EDCs) are important types of pollutants in fish farms worldwide and a globally concerned problem. In this study, Nile tilapia fish farms receiving wastewater effluents in Egypt were selected as highly, moderately polluted fish farms; besides, a putative control site was deemed low in contamination. Levels of E-EDCs (natural and synthetic steroids, and industrial phenolic compound/bisphenol A (BPA)) was recorded in farm water, and fish tissues at all sites under consideration, mainly, lower levels of testosterone, progesterone, zeranol, and 17β-estradiol were detected compared to the higher level of BPA. Moreover, the effects of these pollutants on fish biometric, reproductive genes, and hormonal biomarkers was evaluated along with the observed associated histopathological alterations. Our findings revealed the detection of some steroidal compounds with a higher level of the BPA. All analyzed biomarkers were reduced to a great extent in the highly polluted sites compared to others, and the histopathological alterations observed were supportive of other measurements. These observations warrant strict monitoring of aquatic pollution sources and the development of strategic plans to control aquaculture pollution.

Abstract

This study was undertaken to screen levels of xenosteroids (estrogenic endocrine disrupting chemicals/E-EDCs) in Nile tilapia (Oreochromis niloticus) fish farms subjected to water fill from the drain at three sites S1 (highly polluted), S2 (moderately polluted), and a putative reference site (RS). Biometric, hormonal, gene expression, and histopathological analysis were investigated. Testosterone, progesterone, and zeranol residues were detected at (0.12–3.44 µg/L) in water samples of different sites. Bisphenol-A (BPA) exhibited a very high concentration (6.5 µg/mL) in water samples from S1. Testosterone, 17β-estradiol residues were detected in fish tissues from all sites at (0.16–3.8 µg/Kg) and (1.05–5.01 µg/Kg), respectively. BPA residues were detected at a very high concentration in the liver and muscle of fish collected from S1 at higher levels of 25.9 and 48.07 µg/Kg, respectively. The detected E-EDCs, at different sites, particularly BPA, reduced the somatic and testicular growth among sites and oversampling time points. Meanwhile, hepatosomatic index (HSI) was significantly increased in S1 compared to S2. All analyzed genes estrogen receptor-type I (er-I, er-ɑ) and II (er-II, er-ß1), polypeptide 1a (cyp19a1), SRY-box containing gene 9 (sox9), and vitellogenin (vtg) and gonadotropin hormones (luteinizing hormone (LH), follicle-stimulating hormone (FSH)), testosterone, 17β-estradiol, and anti-Mullerian hormone (AMH) were significantly expressed at S1 compared to other sites. Histopathology was more evident in S1 than other sites. These findings warrant immediate strategies development to control aquatic pollution and maintain fish welfare and aquaculture sustainability.

Assessment of the potential ecological risk of residual endocrine-disrupting chemicals from wastewater treatment plants

Residual chemicals discharged from wastewater treatment plants (WWTPs) and subsequent ecological risk are important in production safety when reuse of the effluent water occurs. Thus, this work provides an investigation of the occurrence and removal of dissolved Endocrine-disrupting chemicals (EDCs) in 38 WWTPs in Guangdong Province, China. The results indicate that EDCs are widely distributed in the investigated WWTPs, while nonylphenols (NPs) are the predominant chemical among the target EDCs, accounting for >98% of the concentration in the influent and >97% of the concentration in the effluent. Moreover, 4 main types of wastewater treatment processes (oxidation ditch, A2/O, conventional activated sludge and microaeration oxidation ditch followed by A2/O) were found to be inefficient for removing dissolved EDCs, with a mean removal rate of approximately 25%. The potential environmental risk was predicted for residual EDCs. Specifically, 17α-ethynylestradiol (EE2) was considered to be the most hazardous chemical among the target EDCs, with a median risk quotient (RQ) of 8.94. In addition, β-estradiol (E2) and estrone (E1) have median RQs of 1.14 and 0.27, and NPs have median RQs of 0.61 (algae), 0.37 (inverberate) and 0.25 (fish), respectively.

Toxicity assessment of municipal sewage treatment plant effluent by an integrated biomarker response in the liver of crucian carp (Carassius auratus)

In this study, crucian carp (Carassius auratus) was exposed to the increasing concentrations of municipal sewage treatment plant effluent (MSTPE) for 15 days, and the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and acetylcholinesterase (AChE), together with the contents of malondialdehyde (MDA) and glutathione (GSH) in the liver of C. auratus were investigated. Moreover, the integrated biomarker response (IBR) approach was applied to assess the adverse effects of MSTPE in freshwater. The aim of the study was to provide an effective biological indicator for evaluating the toxicity effects and ecological risks of MSTPE in the freshwater environment quantitatively. Results showed that MSTPE could cause oxidative damage to the liver of C. auratus, which reflected through the increasing MDA content over the exposure period. MSTPE also led to the biochemical responses of antioxidant defense in C. auratus liver, such as the enhancement of SOD, CAT, and GPx activities, as well as the inhibition of AChE activity and GSH content. It was found that MDA, SOD, GPx, and GSH could be used as the biomarkers for reflecting the adverse effects of MSTPE in the receiving freshwater on the 12th day of exposure. A significant increase of IBR values was observed as the increasing concentration of MSTPE, and the IBR values presented a significant positive correlation (r = 0.891, P < 0.05) with the increasing concentrations of MSTPE, indicating that IBR approach is a promising tool for assessing the toxicity effects of MSTPE in environmental freshwater.

17β-estradiol at low concentrations attenuates the efficacy of tamoxifen in breast cancer therapy

Tamoxifen has been applied widely in the treatment of estrogen receptor (ER)-positive breast cancer. The impact of low concentrations of 17β-estradiol (E2) (a pervasive environmental pollutant) on its effectiveness was studied in vitro using an MCF-7 cell line. Cell proliferation, migration, invasion, and apoptosis were studied along with cell cycle progression, reactive oxygen species generation and mitochondrial membrane potentials repression. The signaling pathways involved were identified. Typical concentrations of E2 in the environment (10^-10 to 10^-8 M) were observed to promote cell growth and protect MCF-7 cells from tamoxifen's cytotoxicity. Cell migration, invasion, cell cycle progression and apoptosis all involved in reducing tamoxifen's cytotoxicity. E2 at environmental concentrations induced PI3K/Akt and MAPK/ERK signal transduction through the estrogen receptor pathways to affect cell proliferation. Taken together, the results explain how E2 in the environment may attenuate the efficacy of tamoxifen in ER-positive breast cancer therapy. They provide considerable support for E2's adverse effects on human health and cancer management.

Impact of Long-Term Exposure to 17α-Ethinylestradiol in the Live-Bearing Fish Heterandria formosa

17α-ethinylestradiol (EE2) is a potent synthetic estrogen that is routinely detected in aquatic ecosystems and exhibits estrogenic activity. Acute and chronic toxicity have been described for oviparous and ovoviviparous fish species; however, no information is available on the impacts of EE2 on viviparous, matrotrophic fish despite their ecological importance. The present study investigated the consequences of long-term EE2 exposure in the least killifish (Heterandria formosa). Effects on growth, time-to-sexual maturity, fecundity, and offspring survival were examined in an 8-month, life-cycle experiment. Starting as 0-6-day-old fish, least killifish were continuously exposed to EE2 at nominal concentrations of 0, 5, or 25 ng/L (measured concentrations averaged 0, 4.3, and 21.5 ng/L respectively). In the F0 generation, EE2-exposure did not affect survival but resulted in increased time-to-sexual maturity and a sex-dependent effect on size; female standard length was reduced while male standard length was increased. This caused the ordinarily larger females and smaller males to become more similar in size. Condition factor was reduced for both sexes. Fecundity was reduced by 50% and 75% at 5 and 25 ng/L EE2-exposure respectively. Continued EE2-exposure in the F1 generation resulted in significantly reduced survival. These results suggest that despite their matrotrophic development, these fish experience delayed development and reduced reproductive success from EE2-exposure and that effects appear to intensify in the second generation.

Uptake, Elimination, and Biotransformation Potential of a Progestagen (Cyproterone Acetate) in Tilapia Exposed at an Environmental Concentration

Although the distribution of progestagens in aquatic environments has been widely reported, details on their uptake, elimination, and biotransformation in fish have received little attention. This study investigated the uptake, elimination, and biotransformation potential of a progestagen, cyproterone acetate (CPTA), in Nile tilapia ( Oreochromis niloticus) exposed to an environmentally relevant concentration under semistatic regimes. CPTA in tilapia tissues followed a similar pattern, reaching a concentration plateau within 4 days of exposure, and dropping to below limits of quantitation within 4 days of elimination. The calculated steady-state bioconcentration factors suggest a low bioconcentration potential of CPTA in juvenile tilapia. Results of enzymatic hydrolysis treatments revealed that no conjugates of CPTA were present in tissues, but conjugated biotransformation products of CPTA were found in bile, liver, and muscle. Most CPTA entered tissues and then was biotransformed into seven different products by phase I and phase II metabolism. The concentrations of endogenous cortisol were significantly influenced by CPTA in plasma and liver during the uptake period. These findings suggest that biotransformation products of CPTA should be considered for the assessment of the bioconcentration potential and ecological effects of progestagens.

The effect of tertiary treated wastewater on fish growth and health: Laboratory-scale experiment with Poecilia reticulata (guppy)

Treated wastewater (TWW) constitutes a sustainable water resource and has been used for fish culture in some countries around the world, although there are no comprehensive data on the effect of TWW on fish growth and health in the context of aquaculture production. Our objectives were to examine how fish culture in TWW affected fish growth and fitness, as well as compliance with the international standards for safe consumption. Guppy (Poecilia reticulata) fingerlings were reared in 0%, 50% and 100% tertiary TWW (TTWW), from the age of five days, for a period of four months. In water analyses, 33 out of 67 tested organic micropollutants (OMPs) were detected in the TTWW samples at least once, at concentrations that are typically reported in domestic TTWW. Fish survival ranged between 77-80% and did not differ between treatment groups. Fish growth and mortality following challenge infection with Tetrahymena sp. (which ranged between 64-68%), were similar among treatment groups. Of tested immunological parameters, lysozyme and anti-protease was similar among treatments while complement activity was highest in the 50% TTWW-reared fish. No abnormalities were observed in the histopathological analysis. Levels of heavy metals, polychlorinated-biphenyls (PCBs) and organochlorines (OCs) in fish were below the detection limit and below the Food and Agriculture Organization of the United Nations (FAO) and the European Union EU maximal permitted levels in food fish. Results suggest that the yield of fish grown in TTWW is potentially similar to that in freshwater, and the produced fish comply with the standards of consumer safety. The results are in line with previous studies that examined the feasibility of TWW-fed aquaculture.

Toxic effects of single animal hormones and their mixtures on the growth of Chlorella vulgaris and Scenedesmus armatus

In their environments, aquatic organisms are simultaneously exposed to mixtures of several endocrine disrupting compounds, including hormones. However, most of the toxicity studies so far focused on effects of single contaminants. The available information on the potential toxicity of combined hormones on microalgae is extremely limited. For these reasons the aim of this study was to evaluate the individual and mixture effect of estrone (E1), ß-estradiol (E2), estriol (E3), 17-α-ethinylestradiol (EE2), progesterone (PRO), 5-pregnen-3β-ol-20-one (PRE), levonorgestrel (LG) and testosterone (TST) on Chlorella vulgaris and Scenedesmus armatus. Green algae cells were exposed to different concentrations (0.1-100 mg L^-1) of hormones for 14 days. Biomass in the form of dry weight and chlorophyll a was examined. The decreasing order of toxicity (based on EC₅₀, 14d) to Chlorella vulgaris and Scenedesmus armatus was: EE2>PRO > E2>PRE > TST > E3>LG > E1 and EE2>PRO > TST > E2>PRE > LG > E1>E3, respectively. Chlorella vulgaris was more sensitive to the effects of hormones than Scenedesmus armatus. Although mixed hormones were more toxic to green algae than single hormones, in the ecosystem mixtures can pose higher ecological risk than single pollutants. Therefore, data on the toxicology of both single and mixed hormones is very valuable for assessment of the possibility of adverse ecological effects caused by these pollutants. Furthermore, these results suggest that environmental exposure to hormone mixtures may cause toxicity levels different to the sum of those of the single hormones and provides a basic understanding of their toxic effect on algae.

Isolation and characterization of an estrogen-degrading Pseudomonas putida strain SJTE-1

In this report, Pseudomonas putida SJTE1 isolated from an enrichment culture of sludge was confirmed to degrade natural estrogens (17β-estradiol, estrone, estriol), estrogenic chemicals (naphthalene and phenanthrene) and testosterone. The strain completely degraded 1 mg/L 17β-estradiol in 24 h and transformed it into estrone; 90% and 75% of 50 mg/L and 100 mg/L 17β-estradiol were utilized in 7 days, respectively. The transformation efficiency of this strain against natural estrogens was much higher than that against other estrogenic chemicals. Organic carbon sources, lipopolysaccharide and surfactants could enhance the degradation efficiency of strain SJTE-1 against 17β-estradiol. The adsorption of 17β-estradiol onto the biomass was the premise for transmembrane and cellular utilization of this chemical. This work has the potential to bioremediate the environmental estrogens.

Steroidal and phenolic endocrine disrupting chemicals (EDCs) in surface water of Bahe River, China: Distribution, bioaccumulation, risk assessment and estrogenic effect on Hemiculter leucisculus

This study investigated selected steroidal and phenolic endocrine disrupting compounds (EDCs) in the surface water of the Bahe River (China) using gas chromatography mass spectrometry (GC-MS). Their effect on the wild sharpbelly Hemiculter leucisculus was investigated. The concentrations of 4-t-octylphenol, nonylphenol, bisphenol-A, estrone, 17 β-estradiol, 17 α-Ethinylestradiol, and estriol were up to 126.0, 634.8, 1573.1, 55.9, 23.9, 31.5, and 5.2 ng L^-1 in the surface water, and up to 26.4, 103.5, 146.9, 14.2, 9.3, 13.8, and 1.3 ng g^-1 in the fish muscle tissue, respectively. High estrogen equivalent levels and hazard quotients were found in the middle and lower reaches of the river, and the pollution in these regions caused enhanced growth conditions, inhibition of gonad growth, and suppression of spermatogenesis in H. leucisculus. The up-regulation of Vitellogenin mRNA expression in male fish, collected from relatively heavily EDCs contaminated areas, indicates a potential estrogenic effect. The differential expression profiles of genes related to steroidogenesis at all sampling sites suggests that these endpoints may play an important role for the pollution monitoring of estrogenic EDCs in the Bahe River.

Enhanced degradation of phenol in floating treatment wetlands by plant-bacterial synergism

Phenol is a commonly found organic pollutant in industrial wastewaters. Its ecotoxicological significance is well known and, therefore, the compound is often required to be removed prior to discharge. In this study, plant-bacterial synergism was established in floating treatment wetlands (FTWs) in an attempt to maximize the removal of phenol from contaminated water. A common wetland plant, Typha domingensis, was vegetated on a floating mat and augmented with three phenol-degrading bacterial strains, Acinetobacter lwofii ACRH76, Bacillus cereus LORH97, and Pseudomonas sp. LCRH90, to develop FTWs for the remediation of water contaminated with phenol. All of the strains are known to have phenol-reducing properties, and grow well in FTWs. Results showed that T. domingensis was able to remove a small amount of phenol from the contaminated water; however, bacterial augmentation enhanced the removal potential significantly, i.e., 0.146 g/m²/day vs. 0.166 g/m²/day, respectively. Plant biomass also increased in the presence of bacterial consortia; and inoculated bacteria displayed successful colonization/survival in the rhizosphere, root interior and shoot interior of the plant. Similarly, highest reduction in chemical oxygen demand (COD), biochemical oxygen demand (BOD₅), and total organic carbon (TOC) was achieved by the combined application of plants and bacteria. The study demonstrates that the plant-bacterial synergism in a FTW may be a more effective approach for the remediation of phenol-contaminated water.

Evaluation of total phenol pollution in water of San Martin Canal from Santiago del Estero, Argentina

Santiago del Estero is a province located in northwestern Argentina. The Dulce River is used for irrigation through a vast network of channels and ditches, including the San Martin Canal (SMC), which crosses the capital city of Santiago del Estero. This canal's water is used for drinking, as well as recreational use for the general population. However, this river has been seriously polluted for several decades. The present study focuses on the identification and the quantification of the water pollution levels of total phenols in the SMC according to the seasonal periods. Water samples from various areas of the canal in different months of the year, extending from December to September, were collected for analysis. Additionally, the concentration of total dissolved solids (TDS), chlorides, sulphates, nitrites and organic matter, as well as water hardness and alkalinity, were analysed in order to conduct a more complete study of the contamination of this area. The results showed a worrying total phenol concentration that exceeded the limit set by Argentine legislation for drinking water, as well as water for recreational use (5 μg/L). The total phenol (TP) concentration was directly determined by a molecular absorption spectroscopy method based on a new flow injection analysis system (FIA). Under the selected experimental conditions, the detection and quantification limits were 0.0490 and 0.1633 μg/mL, respectively. The developed method provides a number of improvements related to the speed of analysis, the restricted consumption of the reagents and sample volumes and the unnecessary sample treatment that contribute to environmentally friendly analytical chemistry. The results showed that TP make a significant contribution in the SMC pollution, especially during the months of April (400 ± 110 μg/L) and September (240 ± 20 μg/L). A high sulphate concentration that was higher than the limit allowed by the legislation was also found.

Phragmites australis - a helophytic grass - can establish successful partnership with phenol-degrading bacteria in a floating treatment wetland

Helophytic plants contribute significantly in phytoremediation of a variety of pollutants due to their physiological or biochemical mechanisms. Phenol, which is reported to have negative/deleterious effects on plant metabolism at concentrations higher than 500 mg/L, remains hard to be removed from the environmental compartments using conventional phytoremediation procedures. The present study aims to investigate the feasibility of using P. australis (a helophytic grass) in combination with three bacterial strains namely Acinetobacter lwofii ACRH76, Bacillus cereus LORH97, and Pseudomonas sp. LCRH90, in a floating treatment wetland (FTW) for the removal of phenol from contaminated water. The strains were screened based on their phenol degrading and plant growth promoting activities. We found that inoculated bacteria were able to colonize in the roots and shoots of P. australis, suggesting their potential role in the successful removal of phenol from the contaminated water. Pseudomonas sp. LCRH90 dominated the bacterial community structure followed by A. lowfii ACRH76 and B. cereus LORH97. The removal rate was significantly high when compared with the individual partners, i.e., plants and bacteria separately. The plant biomass, which was drastically reduced in the presence of phenol, recovered significantly with the inoculation of bacterial consortia. Likewise, highest reduction in chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total organic carbon (TOC) is achieved when both plants and bacteria were employed. The study, therefore, suggests that P. australis in combination with efficient bacteria can be a suitable choice to FTWs for phenol-degradation in water.

Three classes of steroids in typical freshwater aquaculture farms: Comparison to marine aquaculture farms

This study provides a comprehensive analysis of the occurrence of androgens, glucocorticoids and progestogens in typical freshwater aquaculture farms in comparison with marine aquaculture farms. The results showed that more steroids were detected in the marine aquaculture farms. For all aquatic products, the total concentrations of steroids in fish muscle were 22-2000ng/g, which were much higher than those detected in crabs, shrimps or mollusks (0.5-8.1ng/g). Based on the hazard index of the selected steroids, most water samples were in the low or medium risks. Some banned steroids were identified in the freshwater shrimps and all marine products, indicating that there may be certain health risks by the consumption of these aquatic products in the studied aquaculture farms. Furthermore, the total contributions of steroids in China were estimated to be 2300kg/y and 1200kg/y from freshwater fish culture and shrimp-crab culture, respectively.

Steroid bioaccumulation profiles in typical freshwater aquaculture environments of South China and their human health risks via fish consumption

More attention was previously paid to adverse effects of steroids on aquatic organisms and their ecological risks to the aquatic environment. So far, little information has been reported on the bioaccumulative characteristics of different classes of steroids in cultured fish tissues. The present study for the first time provided a comprehensive analysis of the occurrence, bioaccumulation, and global consumers' health risks via fish consumption of androgens, glucocorticoids and progestanges in typical freshwater cultured farms in South China. The numbers and total concentrations of steroids detected in the tissues of five common species of the cultured fish were in the order of plasma > bile > liver > muscle and plasma > bile, muscle > liver, respectively. The field bioaccumulation factors for the detected synthetic steroids ranged from 450 to 97,000 in bile, 450 to 65,000 in plasma, 2900 to 16,000 in liver, and 42 to 2600 in muscle of fish, respectively. This data suggests that steroids are bioaccumulative in fish tissues. Mostly important, 4-androstene-3,17-dione (AED) and cortisone (CRN) were found to be reliable chemical indicators to predict the levels of steroids in plasma and muscle of the inter-species cultured fish, respectively. Furthermore, the maximum hazard quotients (HQs) of testosterone and progesterone were 5.8 × 10^-4 and 9.9 × 10^-5, suggesting that human health risks were negligible via ingestion of the steroids-contaminated fish.

Distribution and bioaccumulation of endocrine disrupting chemicals in water, sediment and fishes in a shallow Chinese freshwater lake: Implications for ecological and human health risks

The occurrence, distribution and bioaccumulation of six endocrine disrupting compounds (EDCs) were investigated in water, sediment and biota samples from Luoma Lake, a shallow Chinese freshwater lake. Total concentrations of ∑phenolic EDCs were much higher than ∑estrogens EDCs in both waters and sediments. There were not obvious differences on the concentrations of target compounds [except nonylphenol (NP)] in upstream, lake and downstream locations, these may be suggested that they were mainly affected by non-point discharges in this area. However, the high concentration of NP in water may be associated with the discharge of rural domestic wastewater without thorough treatment. Furthermore, concentrations of NP were about 2-3 order magnitude higher than those of OP in both water and sediment compartments. Relatively higher bioaccumulation factors (BAF) were obtained for DES and EE2. Ecological risk assessment revealed greater risk of NP in surface water, which may pose a serious threat to aquatic ecosystems. The estrogen equivalent concentration (EEQ) of male were higher than those in female, and occurred in the order of city >rural-urban>countryside.

Nonmonotonic responses to low doses of xenoestrogens: A review

Xenoestrogens (XEs) mimic or block the synthesis, metabolism and transport of normal endogenous hormones, disturbing normal endocrine function. The available data on the nonmonotonic estrogenic effects of low doses of many XEs are reviewed, covering in vitro, in vivo and epidemiological studies. The observed nonmonotonic patterns of the dose-response curves are discussed, along with possible underlying mechanisms. This review is intended to provide guidance for harm predication and to suggest prevention measures.

Deep eutectic solvent-based liquid phase microextraction for the determination of pharmaceuticals and personal care products in fish oil

The analytical method of PPCPs in fish oil was first developed based on the green solvent DES.

Characterization, specificity and sensibility of produced anti-Rhamdia quelen vitellogenin in Brazilian fish species

Endocrine-disrupting chemicals (EDCs) are widespread used and can interfere on hormone regulation with adverse consequences for both biota and human. Vitellogenin (vtg) is a yolk precursor protein synthesized by the liver in response to estrogen. In order to characterize the vtg of tropical fish Rhamdia quelen and establish a molecular biomarker, adult male individuals were exposed to 17-β-estradiol (E₂) for vtg induction and anti-R. quelen vtg polyclonal antibodies production. Vitellogenic female fish were used as positive control group. E₂-induced vtg was characterized as a glycolipophosphoprotein of high molecular mass with peptide mass fingerprint very similar in E₂-exposed male and vitellogenic female fish. A polyclonal serum containing anti-R. quelen vtg antibodies was produced and showed high specificity and sensibility to detect the vtg of three fish species: R. quelen, Piaractus mesopotamicus and Prochilodus lineatus. Wildlife and laboratory studies reported that EDCs released into the environment may alter the levels of plasma vtg in male fish, making this protein a valuable biomarker of xenoestrogens exposure. Then, we propose the use of anti-R. quelen vtg as a tool for biomonitoring studies and water quality assessment in Brazil and South American countries where the three fish species occur.

Dissolved organic matter as a terminal electron acceptor in the microbial oxidation of steroid estrogen

Steroid estrogen in natural waters may be biodegraded by quinone-reducing bacteria, dissolved organic matter (DOM) may serve as a terminal electron acceptor in this process. The influence of temperature, pH, dissolved oxygen and light illumination on the reduction efficiency of anthraquinone-2-disulfonate (AQS) was investigated using 17β-estradiol (E2) as the target species. The optimum reduction conditions were found to be in the dark under anaerobic conditions at pH 8.0 and 30 °C. Quinone-reducing bacteria can use the quinone structure of DOM components as a terminal electron acceptor coupling with microbial growth to promote biodegradation. Compared with other DOM models, AQS best stimulated E2 biodegradation and the mediating effect was improved as the AQS concentration increased from 0 to 0.5 mM. However, further increase had an inhibiting effect. Natural DOM containing lake humic acid (LHA) and lake fulvic acid (LFA) had a very important accelerating effect on the degradation of E2, the action mechanism of which was consistent with that defined using DOM models. The natural DOM contained more aromatic compounds, demonstrating their greater electron-accepting capacity and generally more effective support for microorganism growth and E2 oxidation than Aldrich humic acid (HA). These results provide a more comprehensive understanding of microbial degradation of steroid estrogens in anaerobic environments and confirm DOM as an important terminal electron acceptor in pollutant transformation.

Evaluation of estrogenic activity in the Pearl River by using effect-directed analysis

This study investigated estrogenic activity of water, sediment, and fish bile of the Pearl River in southern China by effect-directed analysis based on in vitro yeast screen assay and chemical analysis. Results showed higher estradiol equivalents (EEQ) for surface water in dry season than in wet season. Simple risk assessment suggested that high estrogenic risk would be expected in Shima River and Danshui River receiving discharge of effluents from cities in the region. Fractionation and effect-directed analysis showed that estrogenic activity mainly occurred in relatively polar fractions of surface water. Seven target estrogenic compounds (bisphenol A, 4-nonylphenol, 4-tert-octylphenol, 17α-ethynyl estradiol, estrone, diethylstilbestrol, and 17β-estradiol) only accounted for part of the measured estrogenic activity, with the rest contributions from other potential estrogenic chemicals such as phenols. Findings from this study suggest that fish in the river could be affected by those estrogenic chemicals. Proper measures should be taken to reduce the estrogenic activity in wastewaters before they are discharged into the riverine system in order to protect aquatic organisms.

Bisphenol A in Edible Part of Seafood

Bisphenol A (BPA) is a man-made compound, mainly used as a monomer to produce polycarbonate (PC), epoxy resins, non-polymer additives to other plastics, which have many food related applications, such as food storage containers, tableware and internal coating of cans, as well as non-food applications such as electronic equipment, construction materials and medical devices. BPA exposure can occur when the residual monomer migrates into packaged food and beverages. Moreover, due to the ubiquitous presence of this compound, the general population can be exposed to environmental sources such as water, air and soil. Many studies have investigated the potential health hazards associated with BPA, which can elicit toxic and cancerogenic effects on humans. According to the European Food Safety Authority opinion, diet is considered to be the main source of exposure, especially canned food; moreover, among non-canned food, meat and fish products have the highest levels of BPA contamination. This review focuses on BPA contamination in seafood, analysing worldwide literature (from January 2010 to October 2015) on BPA contamination of edible parts. The authors try to identify differences between canned and non-canned seafood in literature, and gaps in the state of art. The data evaluated underline that all concentrations for both canned and non-canned seafood were below the specific migration limit set by the European Community Directive for BPA in food. Moreover, the canned seafood is more contaminated than the non-canned one.

Effects of pH and dissolved oxygen on the photodegradation of 17α-ethynylestradiol in dissolved humic acid solution

To probe the mechanisms responsible for pH and dissolved oxygen (DO) affecting the photodegradation of 17α-ethynylestradiol (EE2) in dissolved humic acid (HA) solution, EE2 aqueous solutions with pH values ranging from 3.0 to 11.0 and different DO conditions were irradiated by using a 300 W mercury lamp equipped with 290 nm light cutoff filters. In 5.0 mg L(-1) HA solutions (pH 8.0), EE2 was degraded at a rate of 0.0739 h(-1) which was about 4-fold faster than that in Milli-Q water. The degradation of EE2 was mainly caused by the oxidation of photogenerated reactive species (RS), and the contribution of direct photodegradation to EE2 degradation was always lower than 27%. Both the direct and indirect photodegradation of EE2 were closely dependent on the EE2 initial concentration, pH value and DO concentration. The photodegradation rate of EE2 decreased with increased initial concentration of EE2 due to the limitation of photon flux. With pH and DO increasing, the degradation rate of EE2 increased significantly due to the increase in the yields of excited EE2 and RS. Among the photogenerated RS, HO˙ and (3)HA* were determined to be the key contributors, and their global contribution to EE2 photodegradation was about 50%. Although HA could generate more (1)O2 than HO˙, the contribution of (1)O2 to EE2 degradation was lower than 13% due to its low reactivity towards EE2. This study could enlarge our knowledge on the photochemical behaviors of steroid estrogens in natural sunlit waters.

Occurrence, bioaccumulation, and trophic magnification of pharmaceutically active compounds in Taihu Lake, China

The occurrence, bioaccumulation, and trophic magnification of pharmaceutically active compounds, (PhACs) including antibiotics (roxithromycin and erythromycin), non-steroidal anti-inflammatory drugs (ibuprofen and diclofenac), a non-selective β-adrenoceptor blocker (propranolol), an antiepileptic drug (carbamazepine), and steroid estrogens (17β-estradiol and 17α-ethynylestradiol), were investigated in Taihu Lake, China. All eight PhACs were widely detected in surface water and sediment samples with maximal concentrations in the range of 8.74-118 ng L(-1) and 0.78-42.5 ng g(-1) dry weight (dw), respectively. The investigated organisms in the natural freshwater food web in Taihu Lake included phytoplankton, zooplankton, zoobenthos, and fish, and the maximal concentrations of target compounds in these biota samples ranged from 0.65 to 132 ng g(-1) dw. Bioaccumulation factors (BAFs) for all target PhACs were lower than 1000 L kg(-1), suggesting their low bioaccumulation potential in aquatic organisms from Taihu Lake. Trophic magnification factors (TMFs) were estimated at 1.11 for roxithromycin, 0.31 for propranolol, and 1.06 for diclofenac, indicating none of these PhACs underwent trophic magnification in this freshwater food web.

Why endocrine disrupting chemicals (EDCs) challenge traditional risk assessment and how to respond

Endocrine disrupting compounds (EDCs) are a diverse group of "chemicals of emerging concern" which have attracted much interest from the research community since the 1990s. Today there is still no definitive risk assessment tool for EDCs. While some decision making organizations have attempted to design methodology guidelines to evaluate the potential risk from this broadly defined group of constituents, risk assessors still face many uncertainties and unknowns. Until a risk assessment paradigm is designed specifically for EDCs and is vetted by the field, traditional risk assessment tools may be used with caution to evaluate EDCs. In doing so, each issue of contention should be addressed with transparency in order to leverage available information and technology without sacrificing integrity or accuracy. The challenges that EDCs pose to traditional risk assessment are described in this article to assist in this process.

Effects and bioaccumulation of 17β-estradiol and 17α-ethynylestradiol following long-term exposure in crucian carp

Bioaccumulation and effects of 17β-estradiol (E2) and 17α-ethynylestradiol (EE2) were assessed by crucian carp (Carassius auratus) following single and binary mixture exposures in flow-through exposure system for 16 months. In comparison with water control (DWC) and solvent control (SC), a significant reduction in body weight, body length and gonadosomatic index (GSI), and increase in hepatosomatic index (HSI) and plasma vitellogenin (VTG) levels were observed, in a time- and concentration-dependent manner. Bioconcentration factors (BCFs) of E2 and EE2 in fish muscle ranged from 3.2 to 40 and from 64 to 123, respectively. Crucian carp were found to be more sensitive to EE2 than E2. The bioaccumulation and toxicological effects in binary mixture exposed fish (mixture of E2 and EE2) were more significant than exposure of individual compound. Crucian carp is sensitive to E2 and EE2 in long-term laboratory exposure experiments and can be used as a potential model species for investigating the toxicity of hormones.

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.

Steroids in marine aquaculture farms surrounding Hailing Island, South China: occurrence, bioconcentration, and human dietary exposure

The occurrence, bioconcentration, and human dietary exposure via seafood consumption of 24 steroids were investigated by rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) in six typical marine aquaculture farms surrounding Hailing Island, South China. Ten, 9, 10, 15 of 24 steroids were detected at concentrations ranging from <0.1 (testosterone) to 40 ng/L (prednisolone), from 0.1 (4-androstene-3,17-dione) to 2.4 ng/g (progesterone), from 0.3 ng/g (testosterone) to 21.4 ng/g (epi-androsterone), and from <0.1 (testosterone) to 560 ng/g (cortisol) (wet weight) in the water, sediment, feed and biota samples, respectively. Synthetic steroids (androsta-1,4-diene-3,17-dione, 17α-boldenone, 17β-boldenone, 17β-trenbolone, prednisolone, norgestrel) were detected in the feed samples, clearly demonstrating the illegal use of steroids in the feed. The field bioconcentration factors (BCFs) of steroids calculated in different aquatic organisms ranged from 93.8 to 4000. The estimated daily intakes (EDIs) of androgens, glucocorticoids, and progestagens via consumption of seafood (i.e., shrimps, crabs, mollusks, and fish) for different age groups were in the range of 33.4-134, 2061-8566, and 40.4-155 ng/d for children (2-5 years), youth (6-18 years), and adults (>18 years), respectively. Even though no significant risk from dietary exposure arises from individual steroid, elevated risk to humans can result from the occurrence of multiple steroids in the seafood raised in the aquaculture farms, especially for the sensitive populations, such as pregnant women and children.

Occurrence, removal, and fate of progestogens, androgens, estrogens, and phenols in six sewage treatment plants around Dianchi Lake in China

The occurrence and behavior of endocrine disrupting chemicals (EDCs) in sewage treatment plants (STPs), especially estrogens and phenols, have been closely concerned in previous studies. However, the systematical researches about progestogens and androgens were scarce in STPs adopting different treatment technologies. This work investigated the occurrence, removal, and fate of one progestogen, three androgens, four estrogens, and six phenols in six STPs around Dianchi Lake in China, where the influents, effluents of primary treatment, secondary treatment, and advanced treatment, as well as excess sludge samples, were analyzed. All of the above EDCs were detected out in influents of the six STPs. Bisphenol A, nonylphenol-mono-ethoxylate, and nonylphenol-diethoxylate were the dominant EDCs detected in those influent samples with the concentrations that varied from 637.6 to 1,684.0 ng/L, 633.8 to 1,540.0 ng/L, and 648.7 to 2,246.0 ng/L, respectively; E1 and dihydrotestosterone were the major steroids with the mean concentration of 126.8 and 277.4 ng/L. For effluents and sludges, phenols showed higher concentration (366.8-1,233.0 ng/L and 1,478.1-6,948.9 ng/g dry weight (dw)) and detection rate (100 %). The total removal rates were more than 80 % for most compounds in wastewater treatment processes, and high removal efficiency (86-100 %) was found for androgens and progestogens compared with estrogens (75-92 %) and phenols (62-85 %). The secondary treatment processes play significant roles on degrading EDCs, whereas the primary sedimentation has little effects. The treatment capacity of anoxic-anaerobic-anoxic membrane bioreactor and anaerobic/anoxic/oxic technologies was superior to the conventional oxidation ditch in the degradation of EDCs. The advanced treatment process, two units of filter (D-type or V-type), and ultraviolet disinfection were adopted and presented effective to remove these compounds. According to fate analysis, it was obvious that biological degradation was the main pathway on the removal of EDCs in STPs compared with adsorption. Risk quotients were calculated to assess ecological risks of those EDCs. Risk quotients of 54 and 61 % were more than 1 in effluents and sludges, respectively, showing potential hazard of effluents and sludges to the environment.

Occurrence of 17α-ethynylestradiol (EE2) in the environment and effect on exposed biota: a review

17α-ethynylestradiol (EE2) is a synthetic hormone, which is a derivative of the natural hormone, estradiol (E2). EE2 is an orally bio-active estrogen, and is one of the most commonly used medications for humans as well as livestock and aquaculture activity. EE2 has become a widespread problem in the environment due to its high resistance to the process of degradation and its tendency to (i) absorb organic matter, (ii) accumulate in sediment and (iii) concentrate in biota. Numerous studies have reported the ability of EE2 to alter sex determination, delay sexual maturity, and decrease the secondary sexual characteristics of exposed organisms even at a low concentration (ng/L) by mimicking its natural analogue, 17β-estradiol (E2). Thus, the aim of this review is to provide an overview of the science regarding EE2, the concentration levels in the environment (water, sediment and biota) and summarize the effects of this compound on exposed biota at various concentrations, stage life, sex, and species. The challenges in respect of EE2 include the extension of the limited database on the EE2 pollution profile in the environment, its fate and transport mechanism, as well as the exposure level of EE2 for better prediction and definition revision of EE2 toxicity end points, notably for the purpose of environmental risk assessment.

Rational modification of estrogen receptor by combination of computational and experimental analysis

In this manuscript, we modulate the binding properties of estrogen receptor protein by rationally modifying the amino acid composition of its ligand binding domain. By combining sequence alignment and structural analysis of known estrogen receptor-ligand complexes with computational analysis, we were able to predict estrogen receptor mutants with altered binding properties. These predictions were experimentally confirmed by producing single point variants with up to an order of magnitude increased binding affinity towards some estrogen disrupting chemicals and reaching an half maximal inhibitory concentration (IC50) value of 2 nM for the 17α-ethinylestradiol ligand. Due to increased affinity and stability, utilizing such mutated estrogen receptor instead of the wild type as bio-recognition element would be beneficial in an assay or biosensor.

Distribution and bioconcentration of endocrine disrupting chemicals in surface water and fish bile of the Pearl River Delta, South China

The distribution and bioconcentration of endocrine disrupting chemicals (EDCs) in water, algae, and wild carp bile of the Pearl River Delta (PRD), South China were investigated. 4-tert octylphenol (OP), 4-nonylphenol (NP), and bisphenol A (BPA) (unit, ng L(-1)) in water were in the ranges of 1-14, 117-865, and 4-377, those (ng g(-1) dry weight) in algae were in the ranges of 2-13, 53-282, and 16-94, and those (ng g(-1)) in carp bile were in the ranges of 14-39, 950-4648, 70-1020, respectively. Estrone (E1) and 17α-ethinylestradiol (EE2) in water ranged from <LOQ to 1.58 ng L(-1) and from <LOQ to 3.43 ng L(-1), respectively. In bile and algae, E1 ranged from nd to 30 ng g(-1), but EE2 was not detected. The E2 activity equivalents (EEQs) ranged from 1.20 to 10.97 ng g(-1) in carp bile and from 0.07 to 8.06 ng L(-1) in water. The EEQs in carp bile were significantly related to those in water, illustrating that occurrence of EDCs in carp bile can reflect that in ambient water in the PRD region. The bioconcentration factors (BCF, L kg(-1)) of OP, NP, BPA, and E1 in algae were in the ranges of 482-7251, 131-740, 2846-12979, and undetectable, respectively, and those in carp bile were in the ranges of 1500-12960, 1648-11137, 3583-14178, and 13208-39623, respectively. The phenolic EDCs can be accumulated by wild carp bile and algae in the investigated aquatic ecosystems, which is also affected by the degree of the eutrophication. This study for the first time reported EDCs in carp bile and algae collected from the PRD, China.

Sensitivity of the vitellogenin assay to diagnose exposure of fathead minnows to 17α-ethynylestradiol

Vitellogenin is frequently used as a biomarker of exposure to environmental estrogens due to its specificity and sensitivity. Appropriate incorporation of this biomarker into environmental monitoring and assessment necessitates evaluation of its critical performance parameters. In this study, we characterize the sensitivity of both vitellogenin gene (vtg) mRNA transcripts in liver and protein (VTG) in plasma over a range of concentrations and exposure durations. Male fathead minnows were exposed to 17α-ethynylestradiol (EE2) in a flow-through system for 2, 4 and 7 days at multiple EE2 concentrations in order to provide information regarding the sensitivity of each of these biomarkers to diagnose exposure to this representative estrogen. Measurements of the expression of the vitellogenin gene and protein both reliably detected exposures to EE2 at concentrations of 5ng/l and higher at all time points. Vtg mRNA and plasma VTG appear to have similar sensitivities, though the lower variability in VTG in control fish may make it more sensitive to small changes in expression compared to vtg. For lower concentrations, sensitivity may be improved by increasing exposure duration. A sample size of ∼12 fish was sufficient in many cases to produce a statistically significant increase in vitellogenin. Larger sample sizes may provide more sensitivity at low concentrations, but detecting exposure to estrogens in the lower range of environmentally relevant concentrations may need larger sample sizes. These data will assist in designing experiments that have sufficient statistical power necessary to determine if fish have been exposed to estrogens.

Biological response of high-back crucian carp (Carassius auratus) during different life stages to wastewater treatment plant effluent

This study presents the adverse effects of endocrine disrupting chemicals (EDCs) in effluent of wastewater treatment plants (WwTPs) on fish health. A study of chronic exposure to WwTPs effluent for 10 months was undertaken in high-back crucian carp (Carassius auratus) during different life stages, covering early-life-stage (ELS), prespawning period, and postspawning period. Condition factor (CF), gonadosomatic index (GSI), hepatosomatic index (HSI), and plasma vitellogenin (VTG) levels were employed as indicators to assess biological effects of effluent on this gynogenesis species. Meanwhile, some high-back crucian carp were caged in Demonstration Base of Biological Purification for Filter-feeding Fish (hereinafter, Demonstration Base), as WwTPs effluent exposure controls. In the meantime, a depuration study was carried out to determine whether or not the estrogenic effects caused by effluent exposure could be reduced after moving fish into EDCs-free water. CF, HSI, GSI, and plasma Vtg levels of high-back crucian carp caged in Demonstration Base were generally in accordance with seasonal change. Effluent exposure inhibited gonadal growth, reducing GSI in ELS while increasing it around spawning, sharpened liver burdens, increasing HSI, and induced abnormal Vtg expression in juvenile high-back crucian carp, augmenting Vtg concentrations in plasma. Around spawning period, Vtg in high-back crucian carp were mainly induced by endogenous estrogens, and EDCs in effluent had less influence on them. Staying in EDCs-free water for 30 days made high-back crucian carp recover from effects of previous effluent exposure, relieving inhibition of gonadal development and hypertrophy of liver as well as reducing Vtg induced by EDCs in effluent. The results revealed that high-back crucian carp in ELS are more sensitive to WwTPs effluent exposure. Additionally, the depuration study showed a clearance of the estrogenic effects caused by effluent.

Pharmaceuticals and personal care products (PPCPs): a review on environmental contamination in China

Pharmaceuticals and personal care products (PPCPs) which contain diverse organic groups, such as antibiotics, hormones, antimicrobial agents, synthetic musks, etc., have raised significant concerns in recently years for their persistent input and potential threat to ecological environment and human health. China is a large country with high production and consumption of PPCPs for its economic development and population growth in recent years. This may result in PPCP contamination in different environmental media of China. This review summarizes the current contamination status of different environment media, including sewage, surface water, sludge, sediments, soil, and wild animals, in China by PPCPs. The human body burden and adverse effects derived from PPCPs are also evaluated. Based on this review, it has been concluded that more contamination information of aquatic environment and wildlife as well as human body burden of PPCPs in different areas of China is urgent. Studies about their environmental behavior and control technologies need to be conducted, and acute and chronic toxicities of different PPCP groups should be investigated for assessing their potential ecological and health risks.

Occurrence, removal and bioaccumulation of steroid estrogens in Dianchi Lake catchment, China

The occurrence, removal and bioaccumulation of steroid estrogens such as the natural estrone (E1), 17β-estradiol (E2) and estriol (E3), as well as the synthetic 17α-ethynylestradiol (EE2) were investigated in Dianchi Lake catchment, China. The results show that traditional secondary treatment processes in eight sewage treatment plants (STPs) of Kunming were not efficient enough to completely remove steroid estrogens, but ultraviolet (UV) photodegradation in advanced treatment displayed more effectively for the removal of the residual compounds. The amount of total steroid estrogens (∑SEs) discharged to Dianchi Lake catchment by the eight STPs was 35.8g/day, in which STP-3 was the dominant source, accounting for 50.8%. Because of the pollution input from treated and untreated sewages, estrogens were widely detected in surface water and sediment samples collected from 21 inflow rivers of Dianchi Lake, 10 National Surface Water Quality Monitoring Sites of the lake itself and its unique outflow river, with the mean concentration of ∑SEs in the range of 5.3-798.2ng/L (water) and 3.7-202.4ng/g (dry weight, sediment), 1.5-39.2ng/L (water) and 2.7-20.9ng/g (sediment), and 4.2ng/L (water) and 6.6ng/g (sediment), respectively. Due to the continuous input of estrogens to Dianchi Lake from STPs and inflow rivers, present estrogen levels in various tissues of wild fish species sampled from the lake (2013) were higher than the values detected in the previous years (2009 and 2010). The bioaccumulation of steroid estrogens in wild fish species from different sampling sites was in the order of STP-5>Dianchi Lake (2013)>Dianchi Lake (2010)≈Dianchi Lake (2009)≫field control>laboratory control, which is mainly affected by exposure concentrations. By employing risk quotient (RQ), it is found that eco-toxicological risk of steroid estrogens in Dianchi Lake catchment was in a sequence of 22 rivers>effluents of eight STPs>Dianchi Lake (2013)>Dianchi Lake (2010), and high RQs were found in EE2, which should be controlled preferentially in this catchment.