Accounting for differences in estrogenic responses in rainbow trout (Oncorhynchus mykiss: Salmonidae) and roach (Rutilus rutilus: Cyprinidae) exposed to effluents from wastewater treatment works

Preparation of Immobilised 17β-Estradiol-Imprinted Nanoparticles onto Bacterial Cellulose Nanofibres to Use for the Removal of 17β-Estradiol from Wastewater

Estradiol, a phenolic steroid oestrogen, is one of the endocrine-disrupting chemicals (EDCs) found in natural and tap waters. The detection and removal of EDCs is attracting attention daily as they negatively affect animals' and humans' endocrine functions and physiological conditions. Therefore, developing a fast and practical method for the selective removal of EDCs from waters is essential. In this study, we prepared 17β-estradiol (E2)-imprinted HEMA-based nanoparticles onto bacterial cellulose nanofibres (E2-NP/BC-NFs) to use for the removal of E2 from wastewater. FT-IR and NMR confirmed the structure of the functional monomer. The composite system was characterised by BET, SEM, µCT, contact angle, and swelling tests. Additionally, the non-imprinted bacterial cellulose nanofibres (NIP/BC-NFs) were prepared to compare the results of E2-NP/BC-NFs. Adsorption of E2 from aqueous solutions was performed in batch mode and investigated via several parameters for optimisation conditions. The effect of pH studies was examined in the 4.0-8.0 range using acetate and phosphate buffers and a concentration of E2 of 0.5 mg/mL. The maximum E2 adsorption amount was 254 µg/g phosphate buffer at 45 °C. The experimental data show that the Langmuir is a relevant isotherm model for E2 adsorption. Additionally, the relevant kinetic model was the pseudo-second-order kinetic model. It was observed that the adsorption process reached equilibrium in less than 20 min. The E2 adsorption decreased with the increase in salt at varying salt concentrations. The selectivity studies were performed using cholesterol and stigmasterol as competing steroids. The results show that E2 is 46.0 times more selective than cholesterol and 21.0 times more selective than stigmasterol. According to the results, the relative selectivity coefficients for E2/cholesterol and E2/stigmasterol were 8.38 and 86.6 times greater for E2-NP/BC-NFs than for E2-NP/BC-NFs, respectively. The synthesised composite systems were repeated ten times to assess the reusability of E2-NP/BC-NFs.

Exposure to 17α-Ethinylestradiol Results in Differential Susceptibility of Largemouth Bass (Micropterus salmoides) to Bacterial Infection

Disease outbreaks, skin lesions, mortality events, and reproductive abnormalities have been observed in wild populations of centrarchids. The presence of estrogenic endocrine disrupting compounds (EEDCs) has been implicated as a potential causal factor for these effects. The effects of prior EEDC exposure on immune response were examined in juvenile largemouth bass (Micropterus salmoides) exposed to a potent synthetic estrogen (17α-ethinylestradiol, EE2) at a low (EE2_Low, 0.87 ng/L) or high (EE2_High, 9.08 ng/L) dose for 4 weeks, followed by transfer to clean water and injection with an LD₄₀ dose of the Gram-negative bacteria Edwardsiella piscicida. Unexpectedly, this prior exposure to EE2_High significantly increased survivorship at 10 d post-infection compared to solvent control or EE2_Low-exposed, infected fish. Both prior exposure and infection with E. piscicida led to significantly reduced hepatic glycogen levels, indicating a stress response resulting in depletion of energy stores. Additionally, pathway analysis for liver and spleen indicated differentially expressed genes associated with immunometabolic processes in the mock-injected EE2_High treatment that could underlie the observed protective effect and metabolic shift in EE2_High-infected fish. Our results demonstrate that exposure to a model EEDC alters metabolism and immune function in a fish species that is ecologically and economically important in North America.

Prevalence of reproductive drugs usage in humans and animals: A pilot study in Patiala city of India

Reproductive drugs that include contraceptive and fertility drugs are used to manage reproductive health in both humans and animals. Contraceptive drugs are mainly used by humans for reversible contraception whereas fertility drugs are mainly used in animals to increase milk production, poultry products and meat production. Usage of these drugs has increased manifold in the last decade. These drugs are excreted through body fluids (mainly urine and milk) that lead to contamination of surface water, milk and animal produce. Consumption of such contaminated products or water results in reproductive disorders and different types of cancers in humans. This questionnaire-based study was designed and conducted involving gynecologists, pharmacies, medical stores and veterinarians in Patiala city and its adjoining areas in India to evaluate the quantitative and qualitative aspects of use of these drugs. A total of 150 survey points were identified with random sampling method. Data was analyzed using appropriate statistical tools. The results showed that contraceptive drugs constitute 86% of reproductive drugs usage in humans. Further, steroidal contraceptives constitute a huge 94.7% share of contraceptive drugs, and of these combined oral contraceptives have 79.79% share among which a combination is ethinylestradiol and levonorgestrel is the most popular (20.92%). The consumption of COCs is higher than that of progestin only pills (Z = 3.39) as well as estrogen only pills (Z = 4.30). In contrast, usage of non-hormonal fertility drugs (89%) dominates over the hormonal class (11%) in humans. The most widely used non-hormonal fertility drug is clomiphene citrate (73.87%). In animals, the prescription rate of hormonal fertility drugs is higher (83%) than the non-hormonal one, where in the most widely prescribed drug is buserelin acetate. These findings are in consonance with the similar studies carried out in US, Europe and Canada which suggest that reproductive drugs usage pattern is more or less similar across the globe. A careful control to discourage indiscriminate use of such drugs is the need of hour to prevent damage of environment and ultimately to the health of living beings.

In vivo and in silico analyses of estrogenic potential of equine estrogens in medaka (Oryzias latipes)

Equine estrogens (EEs) are widely used in hormone replacement therapy pharmaceuticals for postmenopausal women. Previous studies have shown that EEs occur in the aquatic environment; however, the potential estrogenicity and risk of EEs in aquatic organisms, including fish, have yet to be studied in detail. Therefore, we evaluated the estrogenic potential of major EEs, namely equilin (Eq), 17α-dihydroequilin (17α-Eq), 17β-dihydroequilin (17β-Eq), equilenin (Eqn), 17α-dihydroequilenin (17α-Eqn), and 17β-dihydroequilenin (17β-Eqn), on medaka (Oryzias latipes) using in vivo and in silico assays. Quantitative real-time RT-PCR analyses revealed that expression levels of choriogenin L (ChgL) and choriogenin H (ChgH) in medaka embryos responded to various types and concentrations of EEs in a concentration-dependent manner, whereas transcription levels of vitellogenin 1 were not significantly affected by any of the EEs in the concentration range tested. The order of the in vivo estrogenic potencies of EEs was as follows: 17β-Eq > Eq > 17β-Eqn > Eqn > 17α-Eqn > 17α-Eq. Additionally, the 50% effective concentrations (EC₅₀) of 17β-Eq was lower than that of 17β-estradiol. We also investigated the interaction potential of EEs with medaka estrogen receptor (ER) subtypes in silico using a three-dimensional model of the ligand-binding domain (LBD) for each ER and docking simulations. All six EEs were found to interact with the LBDs of ERα, ERβ1, and ERβ2. The order of the in silico interaction potentials of EEs with each ER LBD was as follows: 17β-Eq > 17α-Eq > Eq > 17β-Eqn > 17α-Eqn > Eqn. Furthermore, we identified the key amino acids that interact with EEs in each ER LBD; our findings suggest that amino acids and/or their hydrogen bonding may be responsible for the ligand-specific interactions with each ER. This study is the first to comprehensively analyze the estrogenic potential of EEs in medaka both in vivo and in silico.

Organic contaminants in Ganga basin: from the Green Revolution to the emerging concerns of modern India

The Ganga basin includes some of the most densely populated areas in the world, in a region characterized by extremely high demographic and economic growth rates. Although anthropogenic pressure in this area is increasing, the pollution status of the Ganga is still poorly studied and understood. In the light of this, we have carried out a systematic literature review of the sources, levels and spatiotemporal distribution of organic pollutants in surface water and sediment of the Ganga basin, including for the first time emerging contaminants (ECs). We have identified 61 publications over the past thirty years, with data on a total of 271 organic compounds, including pesticides, industrial chemicals, and by-products, artificial sweeteners, pharmaceuticals, and personal care products (PPCPs).

The most studied organic contaminants are pesticides, whereas knowledge of industrial compounds and PPCPs, among which some of the major ECs, is highly fragmentary. Most studies focus on the main channel of the Ganga, the Yamuna, the Gomti, and the deltaic region, while most of the Ganga's major tributaries, and the entire southern part of the catchment, have not been investigated. Hotspots of contamination coincide with major urban agglomerations, including Delhi, Kolkata, Kanpur, Varanasi, and Patna. Pesticides levels have decreased at most of the sites over recent decades, while potentially harmful concentrations of polychlorinated biphenyls (PCBs), organotin compounds (OTCs), and some PPCPs have been detected in the last ten years. Considering the limited geographical coverage of sampling and number of analyzed compounds, this review highlights the need for a more careful selection of locations, compounds and environmental matrices, prioritizing PPCPs and catchment-scale, source-to-sink studies.

Mummichog (Fundulus heteroclitus) are less sensitive to 17α-ethinylestradiol (EE2) than other common model teleosts: A comparative review of reproductive effects

The environmental estrogen 17α-ethinylestradiol (EE₂) will depress or completely inhibit egg production in many common model teleosts at low concentrations (≤0.5 ng/L; Runnalls et al., 2015). This inhibition is not seen in the estuarine killifish, or mummichog (Fundulus heteroclitus), even when exposed to 100 ng/L EE₂. This relative insensitivity to EE₂ exposure indicates species-specific mechanisms for compensating for exogenous estrogenic exposure. This review compares various reproductive responses elicited by EE₂ in mummichog to other common model teleosts, such as zebrafish (Danio rerio) and fathead minnow (Pimephales promelas), identifying key endpoints where mummichog differ from other studied fish. For example, EE₂ accumulates primarily in the liver/gall bladder of mummichog, which is different than zebrafish and fathead minnow in which accumulation is predominantly in the carcass. Despite causing species-specific differences in fecundity, EE₂ has been shown to consistently induce hepatic vitellogenin in males and cause feminization/sex reversal during gonadal differentiation in larval mummichog, similar to other species. In addition, while gonadal steroidogenesis and plasma steroid levels respond to exogenous EE_2, it is generally at higher concentrations than observed in other species. In mummichog, production of 17β-estradiol (E₂) by full grown ovarian follicles remains high; unlike other teleost models where E₂ synthesis decreases as 17α,20β-dihydroxy-4-prenen-3-on levels increase to induce oocyte maturation. New evidence in mummichog indicates some dissimilarity in gonadal steroidogenic gene expression responses compared to gene expression responses in zebrafish and fathead minnow exposed to EE₂. The role of ovarian physiology continues to warrant investigation regarding the tolerance of mummichog to exogenous EE₂ exposure. Here we present a comprehensive review, highlighting key biological differences in response to EE₂ exposure between mummichog and other commonly used model teleosts.

Responses in the crucian carp (Carassius auratus) exposed to environmentally relevant concentration of 17α-Ethinylestradiol based on metabolomics

17α-ethynylestradiol (EE2), a ubiquitous synthetic endocrine disrupting chemical, was the principal component of contraceptive drugs and one of common hormone medications. The detrimental impact of EE2 on the reproduction of organisms was widely recognized. However, the underlying mechanisms of physiological and metabolome effects of EE2 on freshwater fish are still unclear. This study investigated the toxic effects and related mechanisms of EE2 on freshwater fish crucian carp (Carassius auratus) based on metabolomics. Crucian carp were exposed to EE2 at environmentally relevant concentration for 9 days, 18 days, and 27 days, and the biological responses were explored through analysis of the physiological endpoints, steroid hormones, and metabolome. The physiological endpoints of crucian carp had no distinct change after EE2 exposure. However, metabolomics analysis probed significant deviation based on chemometrics, indicating that the metabolomics approach was more sensitive to the effects of EE2 at environmentally relevant concentration to freshwater fish than the traditional endpoints. The alterations of 24 metabolites in gonad and 16 metabolites in kidney were induced by treatment with EE2, respectively, which suggesting the perturbations in amino acid metabolism, lipid metabolism, energy metabolism, and oxidative stress. Moreover, EE2 exposure could induce the disruption of lipid metabolism and then broke the homeostasis of endogenous steroid hormones. Metabolomics provided a new strategy for the studies on contaminant exposure at a low dose in the short term and gave important information for the toxicology and mechanism of EE2.

Biomphalaria alexandrina: a model organism for assessing the endocrine disrupting effect of 17β-estradiol

A wide range of endocrine disruptor compounds are routinely discharged to the ecosystem. Water contaminated with these compounds has a potential effect on the reproductive physiology of aquatic organisms as well as humans. In the present study, we tested the effect of the steroid estrogen, 17β-estradiol, on Biomphalaria alexandrina, a snail species that is widely distributed in Egypt and that acts as an intermediate host for the human blood fluke, Schistosoma mansoni. The effects of exposure to 0.3 mg/L and 1 mg/L 17β-estradiol on fecundity (M_X) and reproductive rate (R₀) of B. alexandrina were recorded. In addition, levels of steroid sex hormones and antioxidants in the hemolymph and ovotestis (OT) of exposed snails were measured. Histopathological changes in the OT of B. alexandrina were also investigated. Exposure to 0.3 mg/L and 1 mg/L 17β-estradiol caused a significant increase in the number of egg masses per snail after 3 weeks and 1 week of exposure for the two tested concentrations compared with unexposed controls. An increase in the levels of progesterone hormone was recorded in the hemolymph of exposed snails in comparison with unexposed controls. Additionally, levels of the antioxidant enzyme glutathione (GSH) were increased in the hemolymph and OT tissues of snails after 2 and 4 weeks of exposure. Histopathological sections in the OT revealed an increase in the oocyte and a decrease in the sperm densities after 2 weeks and this effect was restored to normal conditions after 4 weeks of exposure to both tested concentrations. The current results indicate that B. alexandrina is sensitive to 17β-estradiol and can therefore be used as bioindicator and model organism for the assessment of water pollution with endocrine disruptor compounds.

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.

Examining the role of estrogenic activity and ocean temperature on declines of a coastal demersal flatfish population near the municipal wastewater outfall of Orange County, California, USA

Wastewater treatment plant effluent introduces a mixture of pollutants into marine environments; however, the impacts of chronic sublethal exposures on populations are often unclear. Presence of estrogenic agents in sediments and uptake of these compounds by demersal flatfishes has been reported at the Orange County Sanitation District (OCSD) wastewater outfall. Furthermore, estrogenic activity has been identified in male flatfish in the area, potentially contributing to observed population declines in the OCSD region. Rising ocean temperatures may further contribute to flatfish declines as relationships between temperature and abundance have been reported in the Southern California Bight. To investigate declines, sex ratios, condition factor, organ health indices, hormones, and vitellogenin were quantified in flatfish collected at OCSD outfall and reference sites. Additionally, historical temperature data was examined for trends with population abundances. Rather than being linked to estrogenic activity, results indicated that population declines were more correlated to increases in ocean temperature.

Indicators of exposure to estrogenic compounds at Great Lakes Areas of Concern: species and site comparisons

Adverse effects resulting from potential exposure of wild fishes to estrogenic endocrine disruptors were assessed at seven United States Great Lakes Areas of Concern using biomarkers ranging from organismal (gonadosomatic indices) to tissue/plasma (histology, plasma vitellogenin) and molecular (hepatic gene transcripts) levels. Biomonitoring was conducted on pelagic, top predator species, largemouth Micropterus salmoides and smallmouth M. dolomieu bass and benthic, omnivorous white sucker Catostomus commersonii. Seasonal (spring and fall) comparisons were conducted at select sites. Intersex (testicular oocytes), plasma vitellogenin, and hepatic vitellogenin transcripts were commonly observed in bass species. Testicular oocyte severity was positively, although weakly, correlated with plasma vitellogenin, hepatic transcripts of vitellogenin, estrogen receptor α, and estrogen receptor β2, while negatively correlated with androgen receptor β and phosphoenolpyruvate carboxykinase. No testicular oocytes were observed in white sucker; however, plasma vitellogenin and hepatic vitellogenin transcripts were commonly detected in the males. The results demonstrate the importance of utilizing multiple endpoints to assess exposure to estrogenic compounds as well as the importance of choosing sensitive species.

Reproductive drugs and environmental contamination: quantum, impact assessment and control strategies

Industrial and municipal solid wastes, noise, pesticides, fertilizers and vehicular emission are visible pollutants responsible for environmental contamination and ill-effects on health of all living systems. But, environmental contamination due to drugs or medicines used for different purposes in humans and animals goes unseen largely and can affect the health of living system severely. During the last few decades, the usage of drugs has increased drastically, resulting in increased drug load in soil and water. Contraceptive and fertility drugs are extensively and effectively used in humans as well as animals for different purposes. Usage of these reproductive drugs in humans is increased manifold to manage reproductive problems and/or for birth control with changing lifestyles. These drugs are excreted in urine and faeces as metabolite or conjugated forms, leading to contamination of water, milk and animal produce, which are consumed directly by humans as well as animals. These drugs are not eliminated even by water treatment plant. Consumption of such contaminated water, milk, meat and poultry products results in reproductive disorders such as fertility loss in men and increase risk of different types of cancers in humans. Therefore, assessment of impact of environmental contamination by these drugs on living system is of paramount importance. The purpose of this review article is to provide a comprehensive analysis of various research and review reports on different contraceptive and fertility drugs used in human and animals, their occurrence in the environment and their ill-effects on living systems. The approaches to control this invisible menace have also been proposed.

Occurrence and seasonal variation of equine estrogens, equilin and equilenin, in the river water of Japan: Implication with endocrine-disrupting potentials to Japanese medaka (Oryzias latipes)

In this study, we determined the concentration of equine estrogens, such as equilin (Eq) and equilenin (Eqn), in the river water collected from nine research stations in Hokkaido, Japan. The LC-MS/MS analysis revealed that Eq concentrations were 2.7 ± 6.7, 0.22 ± 0.12, and 1.2 ± 0.64 ng/L in Sep 2015, Feb 2016, and Jul 2016, respectively. Eqn had concentration levels similar to those of Eq. Comparison of the concentrations at nine research stations showed that seasonal variation was observed in the detected Eq and Eqn concentration levels. This study was the first to show the occurrences and seasonal variation of Eq and Eqn in the river water of Japan. We further investigated the reproductive and transgenerational effects of Eq in Japanese medaka (Oryzias latipes) exposed to 10, 100, and 1000 ng/L for 21 days and assessed the transcriptional profiles of the estrogen-responsive genes in the livers of both sexes. The reproduction assay demonstrated that 1000 ng/L of Eq adversely affected the reproduction (i.e. fecundity) in the F₀ generation and that the hatching of F₁ generation fertilized eggs was reduced in the 100 and 1000 ng/L treatment groups. Our qRT-PCR assay revealed that the mRNA expression levels of hepatic vitellogenin 1 and 2, choriogenin L and H, and estrogen receptor α were significantly up-regulated in males exposed to 100 and/or 1000 ng/L of Eq. In contrast, the transcriptional levels of several genes, such as pregnane X receptor and cytochrome P450 3A, were down-regulated in the livers of males after the 21-d exposure. These results suggest that Eq has endocrine-disrupting potential such as reproductive and transgenerational effects by the modulation of hepatic estrogen-responsive genes expression on medaka.

Effect-based trigger values for in vitro and in vivo bioassays performed on surface water extracts supporting the environmental quality standards (EQS) of the European Water Framework Directive

Effect-based methods including cell-based bioassays, reporter gene assays and whole-organism assays have been applied for decades in water quality monitoring and testing of enriched solid-phase extracts. There is no common EU-wide agreement on what level of bioassay response in water extracts is acceptable. At present, bioassay results are only benchmarked against each other but not against a consented measure of chemical water quality. The EU environmental quality standards (EQS) differentiate between acceptable and unacceptable surface water concentrations for individual chemicals but cannot capture the thousands of chemicals in water and their biological action as mixtures. We developed a method that reads across from existing EQS and includes additional mixture considerations with the goal that the derived effect-based trigger values (EBT) indicate acceptable risk for complex mixtures as they occur in surface water. Advantages and limitations of various approaches to read across from EQS are discussed and distilled to an algorithm that translates EQS into their corresponding bioanalytical equivalent concentrations (BEQ). The proposed EBT derivation method was applied to 48 in vitro bioassays with 32 of them having sufficient information to yield preliminary EBTs. To assess the practicability and robustness of the proposed approach, we compared the tentative EBTs with observed environmental effects. The proposed method only gives guidance on how to derive EBTs but does not propose final EBTs for implementation. The EBTs for some bioassays such as those for estrogenicity are already mature and could be implemented into regulation in the near future, while for others it will still take a few iterations until we can be confident of the power of the proposed EBTs to differentiate good from poor water quality with respect to chemical contamination.

Occurrence of intersex in wild freshwater fish in Slovenian rivers: a histological evaluation

The aim of this preliminary research was to establish if there are intersex occurrences in wild freshwater fish in Slovenian rivers and streams. In the first study we evaluated all fish species of both sexes obtained from the river Ljubljanica from its source to mouth. In the second study we focused on the rainbow trout (Oncorhynchus mykiss) and brown trout (Salmo trutta m. fario) males from 30 rivers and streams in different parts of Slovenia. The male gonads were histologically assessed for the presence of oocytes to determine the frequency and degree of intersex. Oocytes were found in the testicular tissue of a single grayling (Thymallus thymallus) and in the adipose tissue adjacent to the testis of a single common barbel (Barbus barbus), both from the Ljubljanica. Several cyst-like structures that resemble degenerated presumptive oocytes were also present in several trout testes. This preliminary report is the first of its kind in Slovenia. To gain a better insight into the intersex issue in Slovenia, we plan to regularly biomonitor freshwater pollution by histologically examining fish gonads and, if possible, by determining vitellogenin plasma levels in fish.

Pilot-scale UV/H2O2 advanced oxidation process for municipal reuse water: Assessing micropollutant degradation and estrogenic impacts on goldfish (Carassius auratus L.)

Low concentrations (ng/L-μg/L) of emerging micropollutant contaminants in municipal wastewater treatment plant effluents affect the possibility to reuse these waters. Many of those micropollutants elicit endocrine disrupting effects in aquatic organisms resulting in an alteration of the endocrine system. A potential candidate for tertiary municipal wastewater treatment of these micropollutants is ultraviolet (UV)/hydrogen peroxide (H2O2) as an advanced oxidation process (AOP) which was currently applied to treat the secondary effluent of the Gold Bar Wastewater Treatment Plant (GBWWTP) in Edmonton, AB, Canada. A new approach is presented to predict the fluence-based degradation rate constants (kf') of environmentally occurring micropollutants including carbamazepine [(0.87-1.39) × 10(-3) cm(2)/mJ] and 2,4-Dichlorophenoxyacetic acid (2,4-D) [(0.60-0.91) × 10(-3) cm(2)/mJ for 2,4-D] in a medium pressure (MP) UV/H2O2 system based on a previous bench-scale investigation. Rather than using removal rates, this approach can be used to estimate the performance of the MP UV/H2O2 process for degrading trace contaminants of concern found in municipal wastewater. In addition to the ability to track contaminant removal/degradation, evaluation of the MP UV/H2O2 process was also accomplished by identifying critical ecotoxicological endpoints (i.e., estrogenicity) of the treated wastewater. Using quantitative PCR, mRNA levels of estrogen-responsive (ER) genes ERα1, ERα2, ERβ1, ERβ2 and NPR as well as two aromatase encoding genes (CYP19a and CYP19b) in goldfish (Carassius auratus L.) were measured during exposure to the GBWWTP effluent before and after MP UV/H2O2 treatment (a fluence of 1000 mJ/cm(2) and 20 mg/L of H2O2) in spring, summer and fall. Elevated expression of estrogen-responsive genes in goldfish exposed to UV/H2O2 treated effluent (a 7-day exposure) suggested that the UV/H2O2 process may induce acute estrogenic disruption to goldfish principally because of the possible formation of various oxidation by-products. However, prolonged exposure of goldfish (60 days) in UV/H2O2 treated effluent showed a restoration trend of ER gene expressions, especially in the summer. Collectively, our findings provide valuable indications regarding the long-term in vivo assessment of the MP UV/H2O2 process for removing/degrading endocrine disrupting compounds detected in the municipal wastewater effluents.

No evidence of exposure to environmental estrogens in two feral fish species sampled from the Yarra River, Australia: A comparison with Northern Hemisphere studies

Environmental estrogens originate from a variety of sources including sewage treatment plant (STP) effluents and adverse physiological effects (endocrine disruption) have been observed in several fish species sampled downstream of STP discharges. In this study we examined common carp (Cyprinus carpio) and roach (Rutilis rutilis) for signs of exposure to environmental estrogens in the iconic Yarra River, Melbourne, Australia. The Yarra River flows through the city of Melbourne and more than 2 million people live within the catchment. Two STPs discharge water into the Yarra River within the middle reaches, and the areas immediately downstream of these discharge locations were the focus of this study. Carp and roach were chosen as test species since both have been utilised extensively for endocrine disruption research throughout Europe, North America and Asia, and data from various international studies was used for comparison with the results of the present study. Neither species showed evidence of exposure to environmental estrogens, with no elevation of plasma vitellogenin levels in males and no incidence of intersex gonads. Most physiological endpoints in both species from this study were within ranges reported in carp and roach from reference sites in other studies, however some degenerative histological changes in both male and female gonads were observed. Surface water samples showed no estrogenic activity (measured by the yeast-estrogen screen, YES), but did display strong anti-estrogenic and weak androgenic activity (measured by the yeast-androgen screen, YAS). Whilst the results show no evidence of impacts from environmental estrogens in the Yarra River, the presence of both anti-estrogenic and androgenic activity in water samples, as well as some gonadal changes in carp is concerning and indicates that our focus needs to broaden, in order to look for biological impacts in resident fauna that might be due to environmental pollutants other than environmental estrogens.

Derivation of water quality guidelines for priority pharmaceuticals

Pharmaceuticals can enter freshwater and affect aquatic ecosystem health. Although toxicity tests have been carried out for the commonly used pharmaceuticals, evidence-based water quality guidelines have not been derived. High-reliability water quality guideline values have been derived for 4 pharmaceuticals-carbamazepine, diclofenac, fluoxetine, and propranolol-in freshwaters using a Burr type III distribution applied to species sensitivity distributions of chronic toxicity data. Data were quality-assured and had to meet acceptability criteria for "chronic" no-observed-effect concentrations or concentrations affecting 10% of species, endpoints of population relevance (namely, effect endpoints based on development, growth, reproduction, and survival). Biomarker response data (e.g., biochemical, histological, or molecular responses) were excluded from the derivation because they are typically not directly relevant to wildlife population-related impacts. The derived guideline values for 95% species protection were 9.2 μg/L, 770 μg/L, 1.6 μg/L, and 14 μg/L for carbamazepine, diclofenac, fluoxetine, and propranolol, respectively. These values are significantly higher than the unknown reliability values derived for the European Commission, Switzerland, or Germany that are based on the application of assessment factors to the most sensitive experimental endpoint (which may include biochemical, histological, or molecular biomarker responses) of a limited data set. The guideline values derived in the present study were not exceeded in recent data for Australian rivers and streams receiving pharmaceutical-containing effluents from wastewater-treatment plants. Environ Toxicol Chem 2016;35:1815-1824. © 2015 SETAC.

Comparison of the sensitivity of four native Canadian fish species to 17-α ethinylestradiol, using an in vitro liver explant assay

Exposure to environmental estrogens and other endocrine-active chemicals can impact reproduction of freshwater fishes. While extensive data exists regarding the effect of estrogens on standard laboratory species, little is known about the sensitivity of freshwater fishes native to North America to these compounds. Current testing strategies for the toxicological assessment of contaminants still rely heavily on studies with live animals, which poses increasing concerns from an economical and ethical perspective. Therefore, the aim of the present study was to investigate the sensitivity of four native species, namely, northern pike (Esox lucius), walleye (Sander vitreus), white sucker (Catostomus commersoni), and juvenile white sturgeon (Acipenser transmontanus), to an environmental estrogen, 17α-ethinylestradiol (EE2), using an in vitro tissue explant approach. Transcript abundances of vitellogenin (VTG) as well as the estrogen receptors (ER) α and β were used as the measuring endpoints as they represent well established biomarkers previously used to assess exposure to estrogens. Transcript abundance of VTG was upregulated in a concentration-dependent manner in each species. Liver explants of male walleye were found to have the greatest sensitivity to EE2, with a lowest observable effect concentration of 300 ng/L (1.0 nM) for VTG transcript abundance, with juvenile white sturgeon having the greatest magnitude of VTG transcript upregulation in exposed tissue (15-fold relative to control). Exposure of liver explants to EE2 resulted in no alteration in transcript abundance of ERβ, whereas upregulation of ERα was observed in northern pike only. Based on in vitro expression of VTG, the species tested were among the species with greatest sensitivity to environmental estrogens tested to date.

Effects of Exposure to WwTW Effluents over Two Generations on Sexual Development and Breeding in Roach Rutilus rutilus

Exposure to environmental estrogens in wastewater treatment works (WwTW) effluents induces feminized responses in male fish, including the development of eggs in male testes. However, the impacts on the offspring of exposed fish are not well understood. In this study, we examined whether roach (Rutilus rutilus) from mothers that had been exposed to an undiluted WwTW effluent from early life to sexual maturity had altered susceptibility to gonadal feminization and an impaired capacity to reproduce. For males from both WwTW effluent exposed mothers and dilution water exposed mothers, effluent exposure for up to 3 years and 9 months induced feminized male gonads, although the intersex condition was relatively mild. There was no difference in the severity of gonadal feminization in roach derived from either WwTW effluent exposed or dilution water exposed mothers. Furthermore, a breeding study revealed that roach with effluent-exposed mothers reproduced with an equal success as roach with mothers exposed to clean water. Roach exposed to the effluent for 3 years in this study were able to reproduce successfully. Our findings provide no evidence for impacts of WwTW effluent exposure on reproduction or gonadal disruption in roach down the female germ line and add to existing evidence that male roach with a mild intersex condition are able to breed competitively.

Evaluation of Estrogenic Activity of Wastewater: Comparison Among In Vitro ERα Reporter Gene Assay, In Vivo Vitellogenin Induction, and Chemical Analysis

The in vitro estrogen receptor (ER) reporter gene assay has long been used to measure estrogenic activity in wastewater. In a previous study, we demonstrated that the assay represents net estrogenic activity in the balance between estrogenic and antiestrogenic activities in wastewater. However, it remained unclear whether the net estrogenic activity measured by the in vitro ERα reporter gene assay can predict the in vivo estrogenic effect of wastewater. To determine this, we measured the following: estrogenic and antiestrogenic activities of wastewater and reclaimed water by the in vitro ERα reporter gene assay, expression of vitellogenin-1 (vtg1) and choriogenin-H (chgH) in male medaka (Oryzias latipes) by quantitative real-time PCR, and estrone, 17β-estradiol, estriol, and 17α-ethynylestradiol concentrations chemically to predict estrogenic activity. The net estrogenic activity measured by the in vitro medaka ERα reporter gene assay predicted the in vivo vtg1/chgH expression in male medaka more accurately than the concentrations of estrogens. These results also mean that in vivo vtg1/chgH expression in male medaka is determined by the balance between estrogenic and antiestrogenic activities. The in vitro medaka ERα reporter gene assay also predicted in vivo vtg1/chgH expression on male medaka better than the human ERα reporter gene assay.

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.

Evaluation of the persistence of transformation products from ozonation of trace organic compounds - a critical review

Ozonation is an efficient treatment system to reduce the concentration of trace organic compounds (TrOCs) from technical aquatic systems such as drinking water, wastewater and industrial water, etc. Although it is well established that ozonation generally improves the removal of organic matter in biological post-treatment, little is known about the biodegradability of individual transformation products resulting from ozonation of TrOCs. This publication provides a qualified assessment of the persistence of ozone-induced transformation products based on a review of published product studies and an evaluation of the biodegradability of transformation products with the biodegradability probability program (BIOWIN) and the University of Minnesota Pathway Prediction System (UM-PPS). The oxidation of TrOCs containing the four major ozone-reactive sites (olefins, amines, aromatics and sulfur-containing compounds) follows well described reaction pathways leading to characteristic transformation products. Assessment of biodegradability revealed a high sensitivity to the formed products and hence the ozone-reactive site present in the target compound. Based on BIOWIN, efficient removal can be expected for products from cleavage of olefin groups and aromatic rings. In contrast, estimations and literature indicate that hydroxylamines and N-oxides, the major products from ozonation of secondary and tertiary amines are not necessarily better removed in biological post-treatment. According to UM-PPS, degradation of these products might even occur via reformation of the corresponding amine. Some product studies with sulfide-containing TrOCs showed a stoichiometric formation of sulfoxides from oxygen transfer reactions. However, conclusions on the fate of transformation products in biological post-treatment cannot be drawn based on BIOWIN and UM-PPS.

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.

Assessment of the sensitivity of three North American fish species to disruptors of steroidogenesis using in vitro tissue explants

There is concern regarding exposure of aquatic organisms to chemicals that interfere with the endocrine system. One critical mechanism of endocrine disruption is impairment of steroidogenesis that can lead to altered hormone levels, altered or delayed sexual development, and ultimately reproductive failure. With the current large gap in knowledge and a high degree of uncertainty regarding the sensitivity of fishes native to northern ecosystems to endocrine disrupting chemicals (EDCs), the aim of this study was to develop an in vitro gonadal explant assay enabling the assessment of EDCs on sex-steroid production in wild fish species native to North America. Northern pike (Esox lucius), walleye (Sander vitreus), and white sucker (Catostomus commeroni) were sampled from a reference location in Lake Diefenbaker, Saskatchewan, Canada, at spawn and multiple post-spawn time points. Gonads were excised and immediately exposed for 24h to a model inducer (forskolin) or inhibitor (prochloraz) of steroidogenesis in L-15 supplemented media. Furthermore, seasonal profiles of plasma 11-ketotestosterone (11-KT) and 17-β estradiol (E2) concentrations were characterized. Enzyme-linked immunosorbent assays were used to quantify hormone concentrations in plasma and media. The seasonal profile of plasma hormones was significantly correlated with basal in vitro hormone production. Gonad tissue exposed to forskolin showed a concentration-dependent increase in E2 and a general increase in 11-KT. Gonad tissue exposed to prochloraz resulted in a decrease of concentrations of 11-KT and E2. These results illustrated that gonadal tissue is undergoing steroidogenesis in an in vitro setting that is comparable to in vivo hormone profiles, and which is responsive to chemical exposure in a concentration-dependent manner. The seasonal time point during which gonad explants were excised and exposed had an impact on the potency and magnitude of responses, resulting in a seasonal effect on sensitivity. Male and female white sucker showed greatest sensitivity to forskolin, while male and female walleye showed greatest sensitivity to prochloraz. Also, gonad explants from these species were found to have greater sensitivity than responses previously reported for in vitro explants of other fish species such as the fathead minnow (Pimephales promelas), and stable cell lines currently used as screening applications to detect chemicals that might disrupt the endocrine system. Therefore, current approaches that use stable cell lines or tissue explants from standardized small bodied laboratory species might not be protective of some wild fish species. Future research is required that investigates whether this in vitro gonadal explant assay is predictive of in vivo effects in wild species of fishes.

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.

Impact of environmental estrogens on Yfish considering the diversity of estrogen signaling

Research on endocrine disruption in fish has been dominated by studies on estrogen-active compounds which act as mimics of the natural estrogen, 17β-estradiol (E2), and generally exert their biological actions by binding to and activation of estrogen receptors (ERs). Estrogens play central roles in reproductive physiology and regulate (female) sexual differentiation. In line with this, most adverse effects reported for fish exposed to environmental estrogens relate to sexual differentiation and reproduction. E2, however, utilizes a variety of signaling mechanisms, has multifaceted functions and targets, and therefore the toxicological and ecological effects of environmental estrogens in fish will extend beyond those associated with the reproduction. This review first describes the diversity of estrogen receptor signaling in fish, including both genomic and non-genomic mechanisms, and receptor crosstalk. It then considers the range of non-reproductive physiological processes in fish that are known to be responsive to estrogens, including sensory systems, the brain, the immune system, growth, specifically through the growth hormone/insulin-like growth factor system, and osmoregulation. The diversity in estrogen responses between fish species is then addressed, framed within evolutionary and ecological contexts, and we make assessments on their relevance for toxicological sensitivity as well as ecological vulnerability. The diversity of estrogen actions raises questions whether current risk assessment strategies, which focus on reproductive endpoints, and a few model fish species only, are protective of the wider potential health effects of estrogens. Available - although limited - evidence nevertheless suggests that quantitative environmental threshold concentrations for environmental protection derived from reproductive tests with model fish species are protective for non-reproductive effects as well. The diversity of actions of estrogens across divergent physiological systems, however, may lead to and underestimation of impacts on fish populations as their effects are generally considered on one functional process only and this may underrepresent the impact on the different physiological processes collectively.

Effect of microwave hydrolysis on transformation of steroidal hormones during anaerobic digestion of municipal sludge cake

Fate and removal of 16 steroidal (estrogenic, androgenic and progestogenic) hormones were studied during advanced anaerobic digestion of sludge cake using microwave (MW) pretreatment. Effect of pretreatment temperature (80, 120, 160 °C), operating temperature (mesophilic at 35 ± 2 °C, thermophilic at 55 ± 2 °C) and sludge retention time (SRT: 20, 10, 5 days) were studied employing eight lab-scale semi-continuously fed digesters. To determine the potential effect of MW hydrolysis, hormones were quantified in total (sorbed + soluble) and supernatant (soluble) phases of the digester influent and effluent streams. Seven of 16 hormones were above the method reporting limit (RL) in one or more of the samples. Hormone concentrations in total phase of un-pretreated (control) and pretreated digester feeds ranged in <157-2491 ng/L and <157-749 ng/L, respectively. The three studied factors were found to be statistically significant (95% confidence level) in removal of one or more hormones from soluble and/or total phase. MW hydrolysis of the influent resulted in both release (from sludge matrix) and attenuation of hormones in the soluble phase. Accumulation of estrone (E1) as well as progesterone (Pr) and androstenedione (Ad) in most of the digesters indicated possible microbial transformations among the hormones. Compared to controls, all pretreated digesters had lower total hormone concentrations in their influent streams. At 20 days SRT, highest total removal (E1+E2+Ad +Pr) was observed for the thermophilic control digester (56%), followed by pretreated mesophilic digesters at 120 °C and 160 °C with around 48% efficiency. In terms of conventional performance parameters, relative (to control) improvements of MW pretreated digesters at a 5-d SRT ranged in 98-163% and 57-121%, for volatile solids removal and methane production, respectively.

Deriving bio-equivalents from in vitro bioassays: assessment of existing uncertainties and strategies to improve accuracy and reporting

Bio-equivalents (e.g., 17β-estradiol or dioxin equivalents) are commonly employed to quantify the in vitro effects of complex human or environmental samples. However, there is no generally accepted data analysis strategy for estimating and reporting bio-equivalents. Therefore, the aims of the present study are to 1) identify common mathematical models for the derivation of bio-equivalents from the literature, 2) assess the ability of those models to correctly predict bio-equivalents, and 3) propose measures to reduce uncertainty in their calculation and reporting. We compiled a database of 234 publications that report bio-equivalents. From the database, we extracted 3 data analysis strategies commonly used to estimate bio-equivalents. These models are based on linear or nonlinear interpolation, and the comparison of effect concentrations (ECX ). To assess their accuracy, we employed simulated data sets in different scenarios. The results indicate that all models lead to a considerable misestimation of bio-equivalents if certain mathematical assumptions (e.g., goodness of fit, parallelism of dose-response curves) are violated. However, nonlinear interpolation is most suitable to predict bio-equivalents from single-point estimates. Regardless of the model, subsequent linear extrapolation of bio-equivalents generates additional inaccuracy if the prerequisite of parallel dose-response curves is not met. When all these factors are taken into consideration, it becomes clear that data analysis introduces considerable uncertainty in the derived bio-equivalents. To improve accuracy and transparency of bio-equivalents, we propose a novel data analysis strategy and a checklist for reporting Minimum Information about Bio-equivalent ESTimates (MIBEST).

Fate of estrogenic hormones in wastewater and sludge treatment: A review of properties and analytical detection techniques in sludge matrix

Estrogenic hormones (estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethinylestradiol (EE2)) are the major contributor to the total estrogenicity in waterways. Presence of these compounds in biosolids is also causing concern in terms of their use as soil amendment. In comparison with wastewater treatment, removal of estrogenic compounds in sewage sludge has received less attention. This paper presents a literature review regarding the source and occurrence of these pollutants in our environment. The removal pathways of estrogenic compounds in engineered systems, such as full-scale wastewater treatment plants (WWTPs), are also discussed. Review of the fate studies revealed that activated sludge system with nutrient removal shows very high (>90%) removal of estrogenic hormones in most of the cases. Although, aerobic digestion showed better attenuation of estrogenic compounds, anaerobic digestion increased the overall estrogenicity of biosolids. Finally, this paper highlights the challenges involved in analytical determination of these compounds in sewage sludge matrix.

The xenometabolome and novel contaminant markers in fish exposed to a wastewater treatment works effluent

Organisms exposed to wastewater treatment works (WwTW) effluents accumulate complex mixtures of xenobiotics but there is a scarcity of information on the nature and impacts of these chemical mixtures. We applied metabolomics techniques as a novel approach to identify xenobiotics and their metabolites (the xenometabolome) that bioconcentrate in fish exposed to a WwTW effluent. Exposed juvenile rainbow trout (Oncorhynchus mykiss) accumulated surfactants, naphthols, chlorinated xylenols, and phenoxyphenols, chlorophenes, resin acids, mefenamic acid, oxybenzone, and steroidal alkaloids in the bile or plasma, and there were perturbations in the plasma concentrations of bile acids and lipids. Exposure of adult roach (Rutilus rutilus) to 50% or 100% concentrations of the same effluent resulted in dose-dependent increases in plasma concentrations of xenometabolites as well as cyprinol sulfate and taurocholic acid, lysophospholipids, and a decrease in sphingosine levels (a key component of cell membrane lipids). Our findings reveal the highly complex nature of xenobiotics accumulating in effluent-exposed fish, and the great potential of metabolomics for both identifying plasma marker (bio)chemicals for monitoring exposure to wastewater effluents, and for targeting studies on potential consequent impacts on fish health.

Determination of pharmaceutical residues in fish bile by solid-phase microextraction couple with liquid chromatography-tandem mass spectrometry (LC/MS/MS)

The present study investigates possible uptake and bioconcentration of different classes of pharmaceuticals residues (organic contaminants) in fish bile using a simplified analytical methodology based on solid phase microextration (SPME). The use of solid phase microextraction (SPME), as a simple analytical tool, to screen for target pharmaceuticals in fish bile samples was validated in rainbow trout (Oncorhynchus mykiss) following short-term laboratory exposures to carbamazepine and fluoxetine. While fish bioconcentrated both fluoxetine and carbamazepine from exposure water, fluoxetine accumulated to a greater degree in bile than carbamazepine. Good agreement was obtained for both analytes in bile samples between SPME and traditional liquid (solvent) extraction approaches (R(2) > 0.99). The field application of SPME sampling was further demonstrated in fathead minnow (Pimephales promelas), a small-bodied fish caged upstream and downstream of a local wastewater treatment plant where fluoxetine, atorvastatin, and sertraline were detected in fish bile at the downstream location. SPME is a promising analytical tool for investigating the bioconcentration of trace contaminants in fish bile, facilitating detection of trace environmental contaminants otherwise undetectable due to low concentrations in the environment and biological tissues as well as the complexity of the sample matrices.

Effects of ethinylestradiol and of an environmentally relevant mixture of xenoestrogens on steroidogenic gene expression and specific transcription factors in zebrafish

In natural environments fish are exposed to endocrine disrupting compounds (EDCs) present at low concentrations and with different modes of actions. Here, adult zebrafish of both sexes were exposed for 21 days to an estrogenic mixture (Mix) of eleven EDCs previously quantified in Douro River estuary (Portugal) and to 100 ng/L 17α-ethinylestradiol (EE2) as positive control. Vitellogenin mRNA and HSI in males confirmed both exposure regimes as physiologically active. Potential candidates for estrogenic disturbance of steroidogenesis were identified (StAR, 17β-HSD1, cyp19a1), but Mix only affected cyp19a1 in females. Significant differences in the response of FSHβ, cypa19a2, 20β-HSD were observed between EE2 and Mix. Mtf-1 and tfap2c transcription factor binding sites were discovered in the putative promoter regions and corresponding transcription factors were found to be differentially expressed in response to Mix and EE2. The results suggest that "non-classical effects" of estrogenic EDC in fish are mediated via transcription factors.

Comparative responsiveness to natural and synthetic estrogens of fish species commonly used in the laboratory and field monitoring

Exposure to estrogenic chemicals discharged into the aquatic environment has been shown to induce feminization in wild freshwater fish and although fish species have been reported to differ in their susceptibility for these effects, empirical studies that directly address this hypothesis are lacking. In this study, in vitro ERα activation assays were applied in a range of fish species used widely in chemical testing (including, zebrafish, fathead minnow, medaka) and/or as environmental monitoring species (including, roach, stickleback, carp) to assess their comparative responsiveness to natural (estrone, estradiol, estriol) and synthetic (17α-ethinylestradiol (EE2), diethylstilbestrol (DES)) estrogens. In vivo exposures to EE2 via the water (nominal 2 and 10 ng/L for 7 days) were also conducted for seven fish species to compare their responsiveness for hepatic vitellogenin (VTG) mRNA induction (an ER mediated response). Of the fish species tested, zebrafish ERα was found to be the most responsive and carp and stickleback ERα the least responsive to natural steroid estrogens. This was also the case for exposure to EE2 with an ERα-mediated response sensitivity order of zebrafish > medaka > roach > fathead minnow > carp > stickleback. For VTG mRNA induction in vivo, the order of species responsiveness was: rainbow trout (not tested in the ERα activation assays) > zebrafish > fathead minnow > medaka > roach > stickleback > carp. Overall, the responses to steroid estrogens in vitro via ERα compared well with those seen in vivo (VTG induction for exposure to EE2) showing in vitro screening of chemicals using fish ERα-mediated responses indicative of estrogenic responses (VTG induction) in vivo.

Two CYP3A-like genes in the marine mussel Mytilus edulis: mRNA expression modulation following short-term exposure to endocrine disruptors

Members of the vertebrate CYP3A subfamily are involved in the metabolism of steroids and a wide range of xenobiotics. In this study two CYP3A-like mRNAs have been isolated from the mussel (Mytilus edulis), and their seasonal expression profile and modulation by estrogens examined. Sexual dimorphism of CYP3A-like mRNA expression was not observed in mussel gonads of individuals collected throughout a year. Nevertheless, natural variation in gonadal CYP3A-like mRNA expression was observed, with highest levels of CYP3A isoform1 and lowest levels of CYP3A isoform2 mRNA during the maturation and spawning season. Exposure to a 10% sewage treatment works extract did not result in any significant changes in mRNA expression of CYP3A-like. In contrast, exposure to E2 (200 ng/L) and TBT (100 ng/L) significantly down-regulated the expression of CYP3A-like isoform1 but not CYP3A-like isoform2 suggesting differential regulation.

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

Endocrine disrupting chemicals (EDCs) found in wastewater treatment plant (WWTP) effluents have been shown to cause adverse effects, but the uptake of EDCs from effluents (measured in fish muscle) are not known. In this study, the biological effects and bioaccumulation of steroidal and phenolic EDCs were assessed in high-back crucian carp (Carassius auratus) exposed to WWTP effluents for 141 days. Compared with fish controls caged in Dianchi Lake, a significant reduction in gonadosomatic index (GSI) and increase in hepatosomatic index (HSI) and plasma vitellogenin (VTG) levels were observed in effluent-exposed fish. The concentrations of steroids and phenols in effluent-exposed fish showed time-dependent increase during the exposure. In addition, bioconcentration factors (BCFs) for steroids and phenols were between 17 and 59 on day 141. The results confirm that steroids and phenols bioconcentrate in fish muscle and this accumulation may account for the biological effects associated with exposures to WWTP effluents.

Development of enzyme-linked immunosorbent assays for plasma vitellogenin in Chinese rare minnow (Gobiocypris rarus)

Due to the wide occurrence of endocrine disrupting chemicals in the environment, it is much of importance to develop high throughput screening method for the analysis of this kind of pollutants. Using anion-exchange membrane chromatography, vitellogenin (VTG) from the plasma of 17β-estradiol (E(2)) treated Chinese rare minnow was rapidly purified within 15 min. Both polyclonal antibody (PcAb) and monoclonal antibody (McAb) against rare minnow VTG (R-VTG) were prepared in rabbit and Balb/c mice, respectively. The competitive enzyme-linked immunosorbent assays (ELISA) based on either PcAb or McAb were developed to identify and quantify R-VTG in the plasma, and these two methods showed similar characteristics. The detection limits of both assays were lower than 3 ng mL(-1) with the working ranges covering three magnitudes. The recovery efficiencies of PcAb and McAb based ELISA were 104.2% and 102.6%, respectively; and the intra-assay and inter-assay of these two assays were 6.2% and 9.2%, 8.6% and 12.8%, respectively. These results indicated that the described competitive ELISA methods were sensitive and valuable tools for quantifying vitellogenin in rare minnow plasma. These methods were then applied to measure R-VTG concentrations in plasma of male fish exposed to a series of E(2) concentrations. When E(2) levels were less than 10 ng L(-1), R-VTG levels in plasma were comparable to that in solvent control, while R-VTG levels significantly increased 15-folds and 350-folds, respectively when E(2) exposure concentrations were controlled at 10 and 50 ng L(-1). The high sensitivity of Chinese rare minnow to E(2) was demonstrated, making it a valuable model species to study environmental estrogens.

Occurrence and fate of bulk organic matter and pharmaceutically active compounds in managed aquifer recharge: a review

Managed aquifer recharge (MAR) is a natural water treatment process that induces surface water to flow in response to a hydraulic gradient through soil/sediment and into a vertical or horizontal well. It is a relatively cost-effective, robust and sustainable technology. Detailed characteristics of bulk organic matter and the occurrence and fate of pharmaceutically active compounds (PhACs) during MAR processes such as bank filtration (BF) and artificial recharge (AR) were reviewed. Understanding the fate of bulk organic matter during BF and AR is an essential step in determining pre- and/or post-treatment requirements. Analysis of organic matter characteristics using a suite of analytical tools suggests that there is a preferential removal of non-humic substances during MAR. Different classes of PhACs were found to behave differently during BF and AR. Antibiotics, non-steroidal anti-inflammatory drugs (NSAIDs), beta blockers, and steroid hormones generally exhibited good removal efficiencies, especially for compounds having hydrophobic-neutral characteristics. However, anticonvulsants showed a persistent behavior during soil passage. There were also some redox-dependent PhACs. For example, X-ray contrast agents measured, as adsorbable organic iodine (AOI), and sulfamethoxazole (an antibiotic) degraded more favorably under anoxic conditions compared to oxic conditions. Phenazone-type pharmaceuticals (NSAIDs) exhibited better removal under oxic conditions. The redox transition from oxic to anoxic conditions during soil passage can enhance the removal of PhACs that are sensitive to redox conditions. In general, BF and AR can be included in a multi-barrier treatment system for the removal of PhACs.

Sorption and degradation of wastewater-associated non-steroidal anti-inflammatory drugs and antibiotics in soils

Presence of pharmaceuticals at trace levels in recycled water is an emerging issue impacting the beneficial reuse of treated wastewater, including practices such as irrigation and groundwater recharge in arid and semi-arid regions. To assess the environmental risks of irrigation with recycled water containing such micropollutants, in this study we evaluated sorption and degradation of five pharmaceuticals that are antibiotic and anti-inflammatory drugs in two soils collected from arid regions. Naproxen and trimethoprim showed moderate to strong sorption, while the sorption of diclofenac, ibuprofen and sulfamethoxazole was negligible in both soils. Under aerobic conditions, the studied compounds were susceptible to microbial degradation with half-lives varying from 4.8 to 69.3d. Apart from sulfamethoxazole, the other compounds were relatively persistent under anaerobic conditions as indicated by a negligible loss over 84d of incubation or half-lives >50d. The degradation of the selected pharmaceuticals was influenced by microbial activities, oxygen status in the soil, soil type and compound characteristics. The poor sorption and relative persistence of diclofenac and ibuprofen under anaerobic conditions suggest that the two chemicals may pose a high leaching risk when using recycled for irrigation or groundwater replenishment.

Investigation of the estrogenic risk to feral male brown trout (Salmo trutta) in the Shannon International River Basin District of Ireland

The estrogenic potential of sewage treatment effluents and their receiving waters in the Shannon International River Basin District (SIRBD) of Ireland was investigated. An integrated approach, combining biological and chemical methods, was conducted to assess 11 rivers adjacent to sewage treatment plants (STPs) and their possible interference with the endocrine system of feral brown trout (Salmo trutta). Hepatosomatic index, gonadosomatic index, condition factor, histological (intersexuality) and endocrine (vitellogenin induction) parameters were assessed in a sample size of 10 at each location. The estrogenic burden was determined using an in vitro recombinant yeast assay containing the human estrogen receptor (YES assay). In addition, endocrine disrupting chemicals (EDCs) were quantitatively identified through a selection of pre-concentration techniques combined with chromatographic analysis at or near the selected locations. Chemical analysis of representative site samples identified phthalates and an alkylphenol in water and sediments in μg/L and mg/kg concentrations, respectively. There were no significant difference in somatic indices or the condition factor between upstream control and downstream test sites, and there was no evidence of reproductive alterations or the presence of intersex in studied male brown trout. However, raised vitellogenin (vtg) levels were detected in the blood plasma samples of male brown trout at 8 of the 11 sites. Significant levels were reported at 3 of the positive sites (p ≤ 0.05). In one particular location, vtg induction was observed in 100% of the male brown trout sampled downstream. These findings were supported by the YES assay, where estrogenic activity was detected in the same upstream and downstream sites giving 17β-estradiol equivalency factor (EEF) values of up to 2.67 ng/L. This study represents an integrated assessment approach, confirming the presence of estrogens in rivers of the SIRBD of Ireland, thus suggesting a cause-effect relationship to prolonged EDC-exposure in fish.

Molecular cloning of vitellogenin gene and mRNA expression by 17alpha-ethinylestradiol from slender bitterling

Indigenous aquatic population such as fish could be used as a successful test species for evaluating the ecological effects in aquatic environment. In the present study, vitellogenin (Vtg) from slender bitterling (Acheilognathus yamatsutae), an indigenous aquatic species in Korea, was cloned and sequenced to determine if the Vtg gene possesses an important characteristic so as to act as a sensitive biomarker for estrogenic endocrine disrupting chemicals (EEDCs). The sbVtg cDNA is 5010 bp in length, containing a 4653 bp open reading frame, which encodes 1550 amino acid residues. The sbVtg cDNA was divided into lipovitellin heavy chain (LvH), phosvitin (Pv), lipovitellin light chain (LvL) as well as a beta'-component (beta'-c) domain, and belongs to VtgAo2. SbVtg has conserved important sequences for Vtg functions such as signal peptide, VtgR-binding region, and disulfide bond formation, all of which are consistent with those of other teleosts. In addition, the male slender bitterling aqueous exposed to 17 alpha-ethinylestradiol (EE2, 12.5, 25, and 50 ng/L) produced a statistically significant and concentration-dependent increase in hepatic Vtg mRNA expression, which showed a similar pattern to biliary estrogenic activity, measured by ERE-reporter gene assay. Thus, this study clearly indicates that the induction of Vtg in slender bitterling might be a suitable biomarker in toxicological research of EEDCs.

PCB and PBDE levels in wild common carp (Cyprinus carpio) from eastern Lake Erie

Male common carp (Cyprinus carpio) from eastern Lake Erie, which is greatly effected by urbanization, agriculture, and industry, were analyzed for PCB and PBDE concentrations in plasma, muscle, and liver to evaluate exposure to these chemicals through habitat interactions. Additional male carp from two nearby relatively clean lakes (Bear Lake and Hemlock Lake, NY) were also sampled as controls. While PCBs were detected in muscle, liver, and plasma of Lake Erie carp, the largest concentrations were found in muscle, which also had the most number of congeners. The dominant congeners were PCB 138 and PCB 153. Concentrations of PCB 153 in the muscle were correlated with fish length, total weight, and age. Therefore, larger (and generally older) carp had the highest concentrations of PCB 153. In contrast, PBDEs were found only in muscle with the predominant congener being PBDE 47. The total PCB concentrations in muscle of male carp from eastern Lake Erie (ranging from nd to 15,000 ng g(-1) lipid) were 100-fold higher than the total PBDE observed (1.5-100 ng g(-1) lipid), indicating a higher level of contamination of PCBs in Lake Erie. The high PCB levels in carp points to PCB resistance to metabolic degradation.

In vitro and immunological assessment of the estrogenic activity and concentrations of 17beta-estradiol, estrone, and ethinyl estradiol in treated effluent from 45 wastewater treatment plants in Victoria, Australia

The project was conducted between May 2006 and September 2007, and involved the collection of effluent samples from 45 wastewater treatment plants (WWTPs). The 45 WWTPs included 16 lagoon-based plants and 29 with activated sludge-based processes. Permission was obtained from all the relevant water authorities to collect samples of final effluent at point of discharge to the environment, whether that was to a creek, a river, the ocean, or the land. Samples were collected on two occasions, namely, in August 2006 (winter) and late February-early March 2007 (summer), and subjected to a number of biological and chemical analyses, including toxicity tests, measurement of hormonal (estrogenic) activity using yeast-based bioassays, and measurement of specific hormonal concentrations using enzyme-linked immunosorbent assays (ELISAs). Almost all of the effluents examined showed estrogenic activity: in winter, no activity to 73 ng/l 17beta-estradiol equivalents (EEQ); and in summer, no activity to 20 ng/l EEQ. On the whole, the levels of estrogenic activity observed were comparable with the range recently reported in Australia and New Zealand using human estrogen receptor-based assays ("not detected" to approximately 10 ng/l EEQ). The low/no bioassay response was confirmed by the chemical assessment of estradiol, estrone, and ethinyl estradiol concentrations by ELISA, which returned concentrations of these compounds for the most part below 10 ng/l.

Endocrine disruption in wild populations of chub (Leuciscus cephalus) in contaminated French streams

The aim of this study was to assess endocrine disruptive effects in wild population of fish in five French rivers selected to represent different pollution contexts at two seasons (summer and fall). For that purpose, a panel of biometrical parameters (length, weight, and gonado-somatic index: GSI) and biochemical (ethoxyresorufin-O-deethylase: EROD, vitellogenin: VTG, and brain aromatase) and histological biomarkers (gonads histology) were used in chub (Leuciscus cephalus), a common cyprinid fish species. In fish from the reference site, EROD activity and VTG levels were low at the two seasons. Brain aromatase activities (AAs) were similar to other species and increased with increasing GSI and gonad maturation. Among the four contaminated sites, the Jalle d'Eysines River was the most impacted site. At this site, fish were exposed to estrogenic substances as demonstrated by the VTG induction in males and the arrest of development of the gonads that led to lower brain AA compared to fish from the reference site. In fish from other contaminated sites, EROD activity was induced as compared to fish from the reference site and some males had elevated concentrations of VTG. Moreover, the presence of aromatase-inhibiting compounds was demonstrated in the sediments of three contaminated sites, even if the precise nature of contaminants is not known. This study provides new data concerning endocrine disruption in wild fish populations inhabiting French rivers and demonstrates that measurements of in vivo and in vitro aromatase could be used as biomarkers of endocrine disruption in field studies.

Influence of alkalinity and salinity on the sonochemical degradation of estrogen hormones in aqueous solution

Ultrasound assisted degradation of estrogen hormones was examined in a batch reactor using a 2 kW (20 kHz) sonication unit. The degradation of estrogens follow a pseudo first order rate kinetics, and the order of degradation is 17alpha-dihydroequilin > equilin >17alpha-ethinyl estradiol >17alpha-estradiol >17beta-estradiol > estrone > estriol. Effect of solution alkalinity and salinity on the sonochemical degradation of estrogen hormones is examined. At alkalinity concentration of 10 mM, no adverse effect on the degradation rate constants of estradiols (17alpha-estradiol, 17beta-estradiol, and 17alpha-ethinyl estradiol) was observed, whereas equilin compounds showed a decrease in their degradation rate constants. Significant inhibitory effects were observed for all the compounds at high alkalinity concentration of 120 mM and which could be due to the scavenging of OH(*) radicals in the bulk solution. The presence of salinity (0.17 M) enhanced the estrogen degradation except for the equilin compounds. Simultaneous presence of high alkalinity (120 mM) and salinity (0.17 M) also increased the degradation of estrogen hormones than the case when only alkalinity (120 mM) was present, indicating the diffusion of analytes to the cavity interface where most of the degradation occurs under these conditions. A mechanistic approach was used to model the degradation behavior of estrogen hormones under different solution alkalinity and salinity conditions.

Profiles and some initial identifications of (anti)androgenic compounds in fish exposed to wastewater treatment works effluents

Exposure of fish to wastewater treatment works (WwTWs) effluents can result in reproductive anomalies consistent with exposure to estrogenic compounds. However, UK WwTWs effluents also contain compounds with androgen receptor activities which may contribute to reproductive dysfunction in fish. A toxicity identification and evaluation (TIE) approach was used to profile (anti)androgenic compounds in bile of fish exposed to two WwTWs effluents. Extracts of bile from exposed fish and effluent were fractionated by liquid chromatography and tested for (anti)androgenic activity using a yeast androgen receptor transcription screen (YAS). A number of bile fractions contained (anti)androgenic activity unique to the effluent-exposed fish. Some of these fractions contained di(chloromethyl)anthracene or dichlorophene, and these contaminants showed antagonistic activity in the YAS when tested as pure compounds. No androgenic activity was detected in the effluents, but TIE analysis of bile revealed a number of androgenic fractions which contained testosterone metabolites that were unique to effluent-exposed fish. This is the first work reported on the nature of some of the (anti)androgenic compounds that bioaccumulate in fish from WwTWs effluents and indicates that other contaminants, besides estrogenic substances, need to be considered for their potential to contribute to the disruption of reproductive system of fish in UK waters.