Endocrine disruption due to estrogens derived from humans predicted to be low in the majority of U.S. surface waters

Spatiotemporal variations and risk assessment of estrogens in the water of the southern Bohai Sea: A comprehensive investigation spanning three years

The ubiquitous and adverse effects of estrogens have aroused global concerns. Natural and synthetic estrogens in 255 water samples from the southern Bohai Sea were analyzed over three years. Total estrogen concentrations were 11.0-268 ng/L in river water and 1.98-99.7 ng/L in seawater, with bisphenol A (BPA) and 17α-ethynylestradiol (EE2) being the predominant estrogens, respectively. Estrogen showed the highest concentrations in summer 2018, followed by spring 2021 and spring 2019, which was consistent with the higher estrogen flux from rivers during summer. Higher estrogen concentrations in 2021 than in 2019 were driven by the higher level of BPA, an additive used in personal protective equipment. Estrogen exhibited higher concentrations in the southern coast of the Yellow River Delta and the northeastern coast of Laizhou bay due to the riverine input and aquaculture. Estrogens could disturb the normal endocrine activities of organisms and edict high ecological risks (90th simulated RQT > 1.0) to aquatic organisms, especially to fish. EE2 was the main contributor of estrogenic potency and ecological risk, which requires special concern. This is the first comprehensive study of estrogen spatiotemporal variations and risks in the Bohai Sea, providing insights into the environmental behavior of estrogens in coastal regions.

Preparation and Adsorption Properties of Magnetic Molecularly Imprinted Polymers for Selective Recognition of 17β-Estradiol

In this paper, magnetic molecularly imprinted polymers (MMIPs) were fabricated on the surface of Fe3O4 by surface molecular imprinting technology, which can selectively adsorb 17β-estradiol (E2). The optimized experiments demonstrated that MMIPs possessed the best adsorption capacity when methanol was used as the solvent and MAA was used as the crosslinking agent, with a molar ratio of E2: MMA: EGDMA as 1:4:50. SEM, FTIR, and XRD were employed to investigate the morphologies of MMIPs and the results demonstrated that the MMIPs that can selectively adsorb E2 were successfully prepared on Fe3O4 particles. The adsorption experiments showed that 92.1% of E2 was adsorbed by the MMIPs, which is higher than the magnetic non-molecularly imprinted polymers (MNIPs). The Freundlich isotherm model was more suitable to describe the adsorption process of E2 by MMIPs. Meanwhile, MMIPs had a better recognition ability for E2 and its structural analogs such as estrone and estriol. The MMIPs still had good adsorption performance after methanol regeneration five times. The prepared MMIPs had the advantages of efficient adsorption ability and high reusability, so they can be applied for selective recognition and removal of E2.

Endocrine disruptors of sex hormone activities

Sex hormones, such as androgens, estrogens and progestins are naturally occurring compounds that tightly regulate endocrine systems in a variety of living organisms. Uncontrolled environmental exposure to these hormones or their biological and synthetic mimetics has been widely documented. Furthermore, water contaminants penetrate soil to affect flora, fauna and ultimately humans. Because endocrine systems evolved to respond to very small changes in hormone levels, the low levels found in the environment cannot be ignored. The combined actions of sex hormones with glucocorticoids and other nuclear receptors disruptors creates additional level of complexity including the newly described "dynamic assisted loading" mechanism. We reviewed the extensive literature pertaining to world-wide detection of these disruptors and created a detailed Table on the development and current status of methods used for their analysis.

Endocrine-disrupting chemicals in a typical urbanized bay of Yellow Sea, China: Distribution, risk assessment, and identification of priority pollutants

Endocrine-disrupting chemicals (EDCs) in water are receiving particular attention as they pose adverse effects on aquatic systems, even at trace concentrations. A comprehensive study was conducted on 14 EDCs (five estrogens and nine household and personal care products (HPCPs)) in the water of the urbanized Jiaozhou Bay in the Yellow Sea during summer and winter. Results showed that the total concentration of 14 EDCs ranged from 100 to 658 ng L^-1 and 56.7-212 ng L^-1 in the estuarine and bay water, respectively. The average total concentration of five estrogens in summer was significantly (p < 0.05) lower than that in winter due to the higher precipitation dilution and degradations during summer, whereas the average total concentration of nine HPCPs was significantly (p < 0.05) higher during the summer than that during the winter because of the higher usage and emissions during the summer. Estrogens and HPCPs were dominated by 17α-ethinylestradiol and p-hydroxybenzoic acid (PHBA), respectively. High PHBA concentrations may be related to the hydrolysis of parabens. The total concentrations of EDCs were higher in the eastern coastal seawater of the bay due to the strong influence of domestic and industrial wastewater discharge. Estrogens may interfere with the endocrine system of aquatic organisms in the bay because the total estradiol equivalent concentration exceeded 1 ng L^-1. 17α-ethinylestradiol was the main contributor to the estrogenic activity. The EDC mixtures posed high risks (RQ > 1) to mollusks, crustaceans, and fish, and low to moderate risks (RQ < 1) to algae. Fish was the most sensitive aquatic taxon to the EDC mixtures. Given the concentration and frequency of EDCs, the optimized risk quotient method revealed that 17α-ethinylestradiol, estrone, triclocarban, triclosan, and 17β-estradiol should be prioritized in ecological management because of their high risks (prioritization index of >1).

Hydrogen peroxide and persulfate activation using UVA-UVB radiation: Degradation of estrogenic compounds and application in sewage treatment plant waters

In the present work, the degradation of three estrogens (17β-estradiol (E2), estrone (E1) and 17α-ethinylestradiol (EE2)) was investigated under photoactivation of hydrogen peroxide and persulfate. Lab-scale irradiation experiments showed that both UVA and UVB radiations are able to photoactivate the oxidant precursors, although UVB is more efficient to generate radicals and therefore to degrade the targets. The efficiency of both oxidant precursors was investigated showing higher efficiency in the system with persulfate. The pseudo-first order degradation rate constants and the second order rate constants between the hydroxyl or the sulfate radicals and estrogens were measured. In order to evaluate the process efficiency in real treatment conditions, the degradation of the estrogens spiked into sewage treatment plant effluent was studied. Measurements of second order rate constants between the radical and the effluent organic matter by laser flash photolysis allowed to understand the involved quenching mechanisms. A Yeast Estrogen Screen (YES) assay was used to follow the decrease in estrogenic activity during the estrogen degradation. This assay permitted to ensure that the studied processes are not only able to degrade the estrogens but also to remove their estrogenic activity.

Occurrence and Fate of Steroid Estrogens in a Chinese Typical Concentrated Dairy Farm and Slurry Irrigated Soil

Animal husbandry is the second largest source of steroid estrogen (SE) pollutants in the environment, and it is significant to investigate the occurrence and fate of SEs discharged from concentrated animal feeding operations. In this research, with a Chinese typical concentrated dairy farm as the object, the concentrations of SEs (E1, 17α-E2, 17β-E2, E3, and E1-S3) in slurry, lagoon water, and slurry-irrigated soil samples in summer, autumn, and winter were determined. The total concentrations of SEs (mainly E1, 17α-E2, and 17β-E2) in slurry were very high in the range of 263.1-2475.08 ng·L^-1. In the lagoon water, the removal efficiencies of the aerobic tank could reach up to 89.53%, with significant fluctuation in different seasons. In the slurry-irrigated soil, the maximum concentrations of SEs in the topsoil and subsoil were 21.54 ng·g^-1 to 6.82 g·g^-1, respectively. Most of the SEs tended to transport downward and accumulate in the soil accompanied with the complex mutual conversion. Correlations and hierarchical clustering analysis showed a variety of intertransformation among SEs, and the concentrations of SEs were correlated with various physicochemical indexes, such as TN and NO₃^--N of the slurry, chemical oxygen demand of the lagoon water, and the heavy metals of soil. In addition, 17β-estradiol equivalency assessment and risk quotients indicated that the slurry irrigation and discharge of the lagoon water would cause potential estrogenic risks to the environment. Consequently, reasonable slurry irrigation and lagoon water discharge are essential to efficiently control SE pollution in the environment.

Polymer-based spherical activated carbon - ultrafiltration (UF-PBSAC) for the adsorption of steroid hormones from water: Material characteristics and process configuration

The European Union has proposed the value of 1 ng L^-1 as a drinking water quality standard for estradiol. With conventional technologies only partially removing estradiol, the investigation of novel alternatives is more than ever required. Tagliavini and Schäfer proposed that the use of a thin activated carbon layer combined with a membrane is worth considering. In this work, the process was further advanced through a systematic investigation of the role of activated carbon size, activation and surface chemistry on the removal of estradiol. The use of smaller carbon particles allows reaching the ambitious target value of 1 ng L^-1 in a millimetric layer. Further, adsorption kinetic enhancement by increasing the oxygen content on the carbon improves the removal from 96 to 99 % (for a layer of 2 mm) for OH-containing pollutants such as estradiol. High removal, together with low pressure and no by-product formation, are characteristics that make the UF-PBSAC a promising and competitive approach.

Estrogens in municipal wastewater and receiving waters in the Beijing-Tianjin-Hebei region, China: Occurrence and risk assessment of mixtures

The potentially high release of estrogens to surface waters due to high population density and local livestock production in the Beijing-Tianjin-Hebei region may pose adverse effects on reproductive systems of aquatic organisms. This study found that total measured concentrations of estrone (E1), 17β-estradiol (E2), estriol (E3), 17α-ethinylestradiol (EE2) and diethylstilbestrol (DES) were 468 ± 27 ng/L in treated wastewater and 219 ± 23 ng/L in river waters in this region. E2, E3 and EE2 were the predominant estrogens in river waters. The restriction of DES for human use should have been enforced, however concentrations of DES were relatively high compared to other studies. Haihe and Yongdingxin Rivers delivered approximately 1.8 tonnes of estrogens to the Bohai Bay annually. Concentrations of individual estrogens were significantly higher in river waters in the dry season, however, mass loadings were significantly higher in the wet season. The average E2-equivalent concentrations reached 1.2 ± 0.2 and 0.64 ± 0.08 μg-E2/L following long-term and short-term exposure estimates, respectively, in river waters with an EE2 contribution of over 90 %. This could give rise to high risks to fish. Estrogens in river waters largely derived from human excretion. Field studies on estrogenic effects on fish reproductive systems are required locally considering high estrogen contamination levels.

Integrated Assessment of Wastewater Reuse, Exposure Risk, and Fish Endocrine Disruption in the Shenandoah River Watershed

Reuse of municipal and industrial wastewater treatment plant (WWTP) effluent is used to augment freshwater supplies globally. The Shenandoah River Watershed (U.S.A.) was selected to conduct on-site exposure experiments to assess endocrine disrupting characteristics of different source waters. This investigation integrates WWTP wastewater reuse modeling, hydrological and chemical characterization, and in vivo endocrine disruption bioassessment to assess contaminant sources, exposure pathways, and biological effects. The percentage of accumulated WWTP effluent in each river reach (ACCWW%) was used to predict environmental concentrations for consumer product chemicals (boron), pharmaceutical compounds (carbamazepine), and steroidal estrogens (estrone, 17-β-estradiol, estriol, and 17-α-ethinylestradiol). Fish endocrine disruption was evaluated using vitellogenin induction in adult male or larval fathead minnows. Water samples were analyzed for >500 inorganic and organic constituents to characterize the complex contaminant mixtures. Municipal ACCWW% at drinking water treatment plant surface water intakes ranged from <0.01 to 2.0% under mean-annual streamflow and up to 4.5% under mean-August streamflow. Measured and predicted environmental concentrations resulted in 17-β-estradiol equivalency quotients ranging from 0.002 to 5.0 ng L^-1 indicating low-to-moderate risk of fish endocrine disruption. Results from the fish exposure experiments showed low (0.5- to 3.2-fold) vitellogenin induction in adult males.

Occurrence, sorption, and transformation of free and conjugated natural steroid estrogens in the environment

Natural steroid estrogens (NSEs), including free estrogens (FEs) and conjugated estrogens (CEs), are of emerging concern globally among public and scientific community due to their recognized adverse effects on human and wildlife endocrine systems in recent years. In this review, the properties, occurrence, sorption process, and transformation pathways of NSEs are clarified in the environment. The work comprehensively summarizes the occurrence of both free and conjugated estrogens in different natural and built environments (e.g., river, WWTPs, CAFOs, soil, and sediment). The sorption process of NSEs can be impacted by organic compounds, colloids, composition of clay minerals, specific surface area (SSA), cation exchange capacity (CEC), and pH value. The degradation and transformation of free and conjugated estrogens in the environment primarily involves oxidation, reduction, deconjugation, and esterification reactions. Elaboration about the major, subordinate, and minor transformation pathways of both biotic and abiotic processes among NSEs is highlighted. The moiety types and binding sites also would affect deconjugation degree and preferential transformation pathways of CEs. Notably, some intermediate products of NSEs still remain estrogenic potency during transformation process; the elimination of total estrogenic activity needs to be addressed in further studies. The in-depth researches regarding the behavior of both free and conjugated estrogens are further required to tackle their contamination problem in the ecosystem. Graphical abstract ᅟ.

Downstream trends of in vitro bioassay responses in a wastewater effluent-dominated river

Surface waters are becoming increasingly influenced by wastewater effluents due to drought conditions, growing populations, and urbanization. These effluents contain mixtures of trace organic compounds (TOrCs), including bioactive constituents, which are not fully attenuated by conventional wastewater treatment systems. This study investigated the occurrence of glucocorticoid receptor (GR), aryl hydrocarbon receptor (AhR), and estrogen receptor (ER) activity, as well as the overall toxicity to bacteria (BLT-Screen), in the effluent of two wastewater reclamation facilities (WRF) and downstream of the Lower Santa Cruz River, Pima County, Arizona USA, which is dominated by the WRF effluents. The GR, AhR, and ER activities and toxicity to bacteria were determined by in vitro bioassays during four seasons. Bioassay results showed the highest activities at the wastewater outfalls, with activities decreasing downstream of the river. Biological equivalent concentrations ranged from 9 to 170 ng/L dexamethasone-equivalents (DexEQ), 0.1-0.8 ng/L 2,3,7,8-tetrachlorodibenzo-p-dioxin-equivalents (TCDDEQ), and <0.005-0.8 ng/L estradiol equivalents (EEQ) for GR-, AhR- and ER-mediated activity, respectively. This level of biological activity at times exceeded the relevant effects-based trigger value for environmental effects, indicating a potential risk to the receiving environment. Toxicity to bacteria was low at all sites, well below the trigger value of 1.0 TU_IC20, which represents an undiluted water sample causing 20% toxicity in the assay. The potential inducing glucocorticoid agonists were further analysed by liquid chromatography coupled to tandem mass spectrometry. Analytical results reveal triamcinolone acetonide as the most abundant glucocorticoid with concentrations up to 38 ng/L. Similar results for DexEQ concentrations calculated from both chemical and bioassay data indicate a successful mass balance for glucocorticoids. This mass balance illustrated lower DexEQ during summer months, which could be due to an increased attenuation from photodegradation.

Estimating the eco-toxicological risk of estrogens in China's rivers using a high-resolution contaminant fate model

The contamination of freshwater systems arises in many river basins due to industrialization and population growth, posing risks to ecosystems and human health. Despite these concerns, the fate and potential impact of many emerging pollutants are currently unknown, especially when the compounds are released into surface waters from populations distributed across large spatial scales. In order to address this shortcoming, a spatially-explicit contaminant fate model was developed as an extension of the global, vector-based river routing model HydroROUT. HydroROUT operates at very high spatial resolution (∼500 m), simulates river and stream chemical transport with in-stream removal, and contains links to a set of lakes and reservoirs, which act as a partial sink during the transport. The chemical fate model was applied to China and includes a consumption and release module based on county-level population demographics, considers point-source contributions from 2547 wastewater treatment plants, and accumulates contributions of rural and urban populations not connected to sewage treatment plants. As a case study, the sources and fates of the estrogens estrone (E₁), 17β-estradiol (E₂), estriol (E₃), as well as the synthetic estrogenic steroid hormone 17α-ethinylestradiol (EE₂) were modelled in Chinese surface water bodies. Preliminary validation of the results showed predictions to be within the ranges of concentrations reported in literature, with exception of EE₂. The total estrogenic mass in the entire river and lake system amounted to 370 tonnes of estrogens, with about 1.3 tonnes per year discharged to the ocean, neighboring countries or to inland sinks. Under a selected baseline scenario, eco-toxicological risk-i.e., contaminant concentrations in excess of the predicted no effect concentration (PNEC)-is found in 23.6% of all analyzed rivers of China with an average flow > 0.1 m³/s. Out of these, about 4% of rivers showed a high level of risk of 10 times or more above PNEC. Medium-to-large rivers are disproportionally affected; for example, 23.6%, 37.3%, 29.0% and 21.6% of river length are at risk in rivers of 1-10, 10-100, 100-1,000, and 1,000-10,000 m³/s of discharge, respectively, whereas no risk was predicted in the largest rivers (i.e., >10,000 m³/s) of China. Wastewater treatment plants process 22.5% of the total hormone load and thus play an important role in water quality control by reducing the risk in substantial portions of the river network, which would otherwise show elevated risk. Releases from untreated population dominate by far the overall contribution to risk.

Analysis of the biodegradation of synthetic testosterone and 17α-ethynylestradiol using the edible mushroom Lentinula edodes

The mycelium of Lentinula edodes produces enzymes which may degrade xenobiotics including steroid hormones. The aim of the study was to determine whether the mycelium from in vitro cultures of L. edodes are able to degrade endocrine disruptors such as testosterone and 17α-ethynylestradiol. To prove the possibility of xenobiotics degradation, cultures of L. edodes were cultivated in an Oddoux liquid medium with the addition of synthetic 17α-ethynylestradiol and synthetic testosterone. The endocrine disruptors were extracted from the mycelium and determined qualitatively by RP-HPLC. The degradation products of testosterone and 17α-ethynylestradiol were identified using a UPLC/MS/MS analysis. Undegraded testosterone was determined at the amount of 2.97 mg/g dry weight but only in one of the L. edodes extracts from in vitro cultures supplemented with 50 mg of this compound. In turn, 17α-ethynylestradiol was not determined in any samples. Additionally in all extracts, mushroom sterols (ergosterol peroxide and ergosterol) were determined. Their total amounts were significantly lower in samples containing the abovementioned steroids than in extracts from mycelium L. edodes without the addition of steroid hormones. The results demonstrated that the mycelium of L. edodes can be used in the biodegradation process of a water environment contaminated with endocrine disruptors.

Environmental impact of estrogens on human, animal and plant life: A critical review

BACKGROUND

Since the inception of global industrialization, steroidal estrogens have become an emerging and serious concern. Worldwide, steroid estrogens including estrone, estradiol and estriol, pose serious threats to soil, plants, water resources and humans. Indeed, estrogens have gained notable attention in recent years, due to their rapidly increasing concentrations in soil and water all over the world. Concern has been expressed regarding the entry of estrogens into the human food chain which in turn relates to how plants take up and metabolism estrogens.

OBJECTIVES

In this review we explore the environmental fate of estrogens highlighting their release through effluent sources, their uptake, partitioning and physiological effects in the ecological system. We draw attention to the potential risk of intensive modern agriculture and waste disposal systems on estrogen release and their effects on human health. We also highlight their uptake and metabolism in plants.

METHODS

We use MEDLINE and other search data bases for estrogens in the environment from 2005 to the present, with the majority of our sources spanning the past five years. Published acceptable daily intake of estrogens (μg/L) and predicted no effect concentrations (μg/L) are listed from published sources and used as thresholds to discuss reported levels of estrogens in the aquatic and terrestrial environments. Global levels of estrogens from river sources and from Waste Water Treatment Facilities have been mapped, together with transport pathways of estrogens in plants.

RESULTS

Estrogens at polluting levels have been detected at sites close to waste water treatment facilities and in groundwater at various sites globally. Estrogens at pollutant levels have been linked with breast cancer in women and prostate cancer in men. Estrogens also perturb fish physiology and can affect reproductive development in both domestic and wild animals. Treatment of plants with steroid estrogen hormones or their precursors can affect root and shoot development, flowering and germination. However, estrogens can ameliorate the effects of other environmental stresses on the plant.

CONCLUSIONS

There is published evidence to establish a causal relationship between estrogens in the environment and breast cancer. However, there are serious gaps in our knowledge about estrogen levels in the environment and a call is required for a world wide effort to provide more data on many more samples sites. Of the data available, the synthetic estrogen, ethinyl estradiol, is more persistent in the environment than natural estrogens and may be a greater cause for environmental concern. Finally, we believe that there is an urgent requirement for inter-disciplinary studies of estrogens in order to better understand their ecological and environmental impact.

Emerging contaminants in the environment: Risk-based analysis for better management

Emerging contaminants (ECs) are chemicals of a synthetic origin or deriving from a natural source that has recently been discovered and for which environmental or public health risks are yet to be established. This is due to limited available information on their interaction and toxicological impacts on receptors. Several types of ECs exist such as antibiotics, pesticides, pharmaceuticals, personal care products, effluents, certain naturally occurring contaminants and more recently nanomaterials. ECs may derive from a known source, for example released directly to the aquatic environment from direct discharges such as those from wastewater treatment plants. Although in most instances the direct source cannot be identified, ECs have been detected in virtually every country's natural environment and as a consequence they represent a global problem. There is very limited information on the fate and transport of ECs in the environment and their toxicological impact. This lack of information can be attributed to limited financial resources and the lack of analytical techniques for detecting their effects on ecosystems and human health on their own or as mixture. We do not know how ECs interact with each other or various contaminants. This paper presents an overview of existing knowledge on ECs, their fate and transport and a risk-based analysis for ECs management and complementary strategies.

Concentrations of levonorgestrel and ethinylestradiol in wastewater effluents: Is the progestin also cause for concern?

Synthetic hormones have been widely reported in treated sewage effluents, and consequently receiving aquatic environments. Ethinylestradiol (EE2) is a potent synthetic estrogen commonly used in conjunction with levonorgestrel in oral contraceptive pills. Both EE2 and levonorgestrel have been identified in the aquatic environment, but although there is a significant amount of literature on EE2, there is much less information on levonorgestrel. Using Australian prescription data as well as excretion and predicted wastewater removal rates, the concentrations of EE2 and levonorgestrel in Australian wastewater were calculated at 0.1 ng/L to 0.5 ng/L and 0.2 ng/L to 0.6 ng/L, respectively. Both compounds were analyzed in treated wastewater and surface water grab samples from 3 Southeast Queensland, Australia sites. The predicted no-effect concentration (PNEC) for EE2 of 0.1 ng/L was exceeded at most sites, with EE2 concentrations up to 2 ng/L in treated effluent, albeit quickly diluted to 0.1 ng/L to 0.2 ng/L in the receiving environment. A provisional PNEC for levonorgestrel of 0.1 ng/L derived in the present study was slightly lower than predicted effluent concentrations of 0.2 ng/L to 0.6 ng/L, indicating a potential risk of endocrine-related effects in exposed aquatic species. The detection limit for levonorgestrel in the present study was 2.5 ng/L, and all samples were below detection limit. The present study's results suggest that improvements in analytical capabilities for levonorgestrel are warranted to more accurately quantify the risk of this compound in the receiving environment. Environ Toxicol Chem 2016;35:1378-1385. © 2015 SETAC.

Risk of endocrine disruption to fish in the Yellow River catchment in China assessed using a spatially explicit model

The global water availability assessment (GWAVA) model, incorporating regional water abstractions and reservoir information, was used to model the human-sourced steroid estrogens estrone (E1) and estradiol (E2) in the Yellow River catchment (China). The river flows in the main stem were calibrated using gauged flows. Following a review of Chinese data on estrogen discharge from a range of sewage treatment plants, low, median, and high discharge rates were identified and used as best, expected, and worst-case scenarios, respectively. For any given location, the temporal variation of modeled estrogen levels was summarized using the mean and upper 90th percentile, which is where the model predicts 90% of values would be below this concentration. The predicted means and 90th percentiles for E1 were comparable to previous E1 measurements reported in the river. For the whole catchment, only 19% (mean value) of the river system by length was predicted to exceed 1 ng/L E2 equivalents (EEQs) using expected estrogen sewage discharge. Only 3% of the network by length was predicted to exceed the dangerously high 10 ng/L EEQ when considering 90th percentile concentrations. The highest exposures were in the Fen and Wei tributaries. Endocrine disruption risk from estrogens was predicted to be minimal in the main stem. Only in the worst-case discharge scenario and 90th percentile predicted concentrations were the most downstream river reaches of the main stem predicted to be at risk. Reservoirs appeared to be helpful in reducing estrogen concentrations thanks to longer water residence facilitating biodegradation.

Wastewater compounds in urban shallow groundwater wells correspond to exfiltration probabilities of nearby sewers

Wastewater compounds are frequently detected in urban shallow groundwater. Sources include sewage or reclaimed wastewater, but origins are often unknown. In a prior study, wastewater compounds were quantified in waters sampled from shallow groundwater wells in a small coastal California city. Here, we resampled those wells and expanded sample analyses to include sewage- or reclaimed water-specific indicators, i.e. pharmaceutical and personal care product chemicals or disinfection byproducts. Also, we developed a geographic information system (GIS)-based model of sanitary sewer exfiltration probability--combining a published pipe failure model accounting for sewer pipe size, age, materials of construction, with interpolated depths to groundwater--to determine if sewer system attributes relate to wastewater compounds in urban shallow groundwater. Across the wells, groundwater samples contained varying wastewater compounds, including acesulfame, sucralose, bisphenol A, 4-tert-octylphenol, estrone and perfluorobutanesulfonic acid (PFBS). Fecal indicator bacterial concentrations and toxicological bioactivities were less than known benchmarks. However, the reclaimed water in this study was positive for all bioactivity tested. Excluding one well intruded by seawater, the similarity of groundwater to sewage, based on multiple indicators, increased with increasing sanitary sewer exfiltration probability (modeled from infrastructure within ca. 300 m of each well). In the absence of direct exfiltration or defect measurements, sewer exfiltration probabilities modeled from the collection system's physical data can indicate potential locations where urban shallow groundwater is contaminated by sewage.

Distribution of selected antiandrogens and pharmaceuticals in a highly impacted watershed

Endocrine disruption and high occurrences of intersex have been observed in wild fish associated with municipal wastewater treatment plant (WWTP) effluents in urbanized reaches of rivers around the globe. These reproductive effects have often been attributed to the presence of estrogen receptor agonists in effluents. However, recent studies have isolated a number of androgen receptor antagonists (antiandrogens) that may also contribute to the endocrine disruption observed at sites that are influenced by WWTP outfalls. This study aimed to characterize the spatial and temporal distribution of antiandrogenic personal care products (triclosan, chlorophene, dichlorophene, oxybenzone, 1-naphthol, and 2-naphthol), along with a herbicide (atrazine) and representative pharmaceuticals (carbamazepine, ibuprofen, naproxen, and venlafaxine) in the Grand River watershed in southern Ontario. Surface water sampling of 30 sites associated with six municipal WWTP outfalls was conducted during a summer low flow. Monthly samples were also collected immediately upstream and downstream of a major WWTP from August to November 2012. Atrazine was consistently found in all surface water sampling locations. Many of the target pharmaceuticals and triclosan were detected in WWTP effluents, especially those that did not nitrify. Under low flow conditions, the concentrations of triclosan and several pharmaceuticals increased directly downstream of the WWTPs then decreased rapidly with distance downstream. Chlorophene was either found at trace levels or below detection limits in the effluents while dichlorophene, oxybenzone, 1-naphthol, and 2-naphthol were not detected in any samples. Chlorophene was detected in surface water during the low flow summer period and once during the monthly sampling from August to November. However, the primary source of chlorophene did not appear to be associated with WWTP effluent. This study documents the spatial and temporal occurrence of several antiandrogens and pharmaceuticals in a highly impacted Canadian watershed. It supports previous observations that there is a diversity of contaminants in wastewater effluents and other sources that have the potential to alter endocrine function in wild fish.

An assessment of endocrine activity in Australian rivers using chemical and in vitro analyses

Studies on endocrine disruption in Australia have mainly focused on wastewater effluents. Limited knowledge exists regarding the relative contribution of different potential sources of endocrine active compounds (EACs) to the aquatic environment (e.g., pesticide run-off, animal farming operations, urban stormwater, industrial inputs). In this study, 73 river sites across mainland Australia were sampled quarterly for 1 year. Concentrations of 14 known EACs including natural and synthetic hormones and industrial compounds were quantified by chemical analysis. EACs were detected in 88 % of samples (250 of 285) with limits of quantification (LOQ) ranging from 0.05 to 20 ng/l. Bisphenol A (BPA; LOQ = 20 ng/l) was the most frequently detected EAC (66 %) and its predicted no-effect concentration (PNEC) was exceeded 24 times. The most common hormone was estrone, detected in 28 % of samples (LOQ = 1 ng/l), and the PNEC was also exceeded 24 times. 17α-Ethinylestradiol (LOQ = 0.05 ng/l) was detected in 10 % of samples at concentrations ranging from 0.05 to 0.17 ng/l. It was detected in many samples with no wastewater influence, and the PNEC was exceeded 13 times. In parallel to the chemical analysis, endocrine activity was assessed using a battery of CALUX bioassays. Estrogenic activity was detected in 19 % (53 of 285) of samples (LOQ = 0.1 ng/l 17β-estradiol equivalent; EEQ). Seven samples exhibited estrogenic activity (1-6.5 ng/l EEQ) greater than the PNEC for 17β-estradiol. Anti-progestagenic activity was detected in 16 % of samples (LOQ = 8 ng/l mifepristone equivalents; MifEQ), but the causative compounds are unknown. With several compounds and endocrine activity exceeding PNEC values, there is potential risk to the Australian freshwater ecosystems.

Quantitative cross-species extrapolation between humans and fish: the case of the anti-depressant fluoxetine

Fish are an important model for the pharmacological and toxicological characterization of human pharmaceuticals in drug discovery, drug safety assessment and environmental toxicology. However, do fish respond to pharmaceuticals as humans do? To address this question, we provide a novel quantitative cross-species extrapolation approach (qCSE) based on the hypothesis that similar plasma concentrations of pharmaceuticals cause comparable target-mediated effects in both humans and fish at similar level of biological organization (Read-Across Hypothesis). To validate this hypothesis, the behavioural effects of the anti-depressant drug fluoxetine on the fish model fathead minnow (Pimephales promelas) were used as test case. Fish were exposed for 28 days to a range of measured water concentrations of fluoxetine (0.1, 1.0, 8.0, 16, 32, 64 µg/L) to produce plasma concentrations below, equal and above the range of Human Therapeutic Plasma Concentrations (H_TPCs). Fluoxetine and its metabolite, norfluoxetine, were quantified in the plasma of individual fish and linked to behavioural anxiety-related endpoints. The minimum drug plasma concentrations that elicited anxiolytic responses in fish were above the upper value of the H_TPC range, whereas no effects were observed at plasma concentrations below the H_TPCs. In vivo metabolism of fluoxetine in humans and fish was similar, and displayed bi-phasic concentration-dependent kinetics driven by the auto-inhibitory dynamics and saturation of the enzymes that convert fluoxetine into norfluoxetine. The sensitivity of fish to fluoxetine was not so dissimilar from that of patients affected by general anxiety disorders. These results represent the first direct evidence of measured internal dose response effect of a pharmaceutical in fish, hence validating the Read-Across hypothesis applied to fluoxetine. Overall, this study demonstrates that the qCSE approach, anchored to internal drug concentrations, is a powerful tool to guide the assessment of the sensitivity of fish to pharmaceuticals, and strengthens the translational power of the cross-species extrapolation.

A landscape-based reconnaissance survey of estrogenic activity in streams of the upper Potomac, upper James, and Shenandoah Rivers, USA

Endocrine-disrupting compounds (EDCs) are becoming of increasing concern in waterways of the USA and worldwide. What remains poorly understood, however, is how prevalent these emerging contaminants are in the environment and what methods are best able to determine landscape sources of EDCs. We describe the development of a spatially structured sampling design and a reconnaissance survey of estrogenic activity along gradients of land use within sub-watersheds. We present this example as a useful approach for state and federal agencies with an interest in identifying locations potentially impacted by EDCs that warrant more intensive, focused research. Our study confirms the importance of agricultural activities on levels of a measured estrogenic equivalent (E2Eq) and also highlights the importance of other potential sources of E2Eq in areas where intensive agriculture is not the dominant land use. Through application of readily available geographic information system (GIS) data, coupled with spatial statistical analysis, we demonstrate the correlation of specific land use types to levels of estrogenic activity across a large area in a consistent and unbiased manner.

Europe-wide survey of estrogenicity in wastewater treatment plant effluents: the need for the effect-based monitoring

A pan-European monitoring campaign of the wastewater treatment plant (WWTP) effluents was conducted to obtain a concise picture on a broad range of pollutants including estrogenic compounds. Snapshot samples from 75 WWTP effluents were collected and analysed for concentrations of 150 polar organic and 20 inorganic compounds as well as estrogenicity using the MVLN reporter gene assay. The effect-based assessment determined estrogenicity in 27 of 75 samples tested with the concentrations ranging from 0.53 to 17.9 ng/L of 17-beta-estradiol equivalents (EEQ). Approximately one third of municipal WWTP effluents contained EEQ greater than 0.5 ng/L EEQ, which confirmed the importance of cities as the major contamination source. Beside municipal WWTPs, some treated industrial wastewaters also exhibited detectable EEQ, indicating the importance to investigate phytoestrogens released from plant processing factories. No steroid estrogens were detected in any of the samples by instrumental methods above their limits of quantification of 10 ng/L, and none of the other analysed classes of chemicals showed correlation with detected EEQs. The study demonstrates the need of effect-based monitoring to assess certain classes of contaminants such as estrogens, which are known to occur at low concentrations being of serious toxicological concern for aquatic biota.

Contraceptive options and their associated estrogenic environmental loads: relationships and trade-offs

This work explores the relationships between a user's choice of a given contraceptive option and the load of steroidal estrogens that can be associated with that choice. Family planning data for the USA served as a basis for the analysis. The results showed that collectively the use of contraception in the USA conservatively averts the release of approximately 4.8 tonnes of estradiol equivalents to the environment. 35% of the estrogenic load released over the course of all experienced pregnancies events and 34% the estrogenic load represented by all resultant legacies are a result of contraception failure and the non-use of contraception. A scenario analysis conducted to explore the impacts of discontinuing the use of ethinylestradiol-based oral contraceptives revealed that this would not only result in a 1.7-fold increase in the estrogenic loading of the users, but the users would also be expected to experience undesired family planning outcomes at a rate that is 3.3 times higher. Additional scenario analyses in which ethinylestradiol-based oral contraceptive users were modeled as having switched entirely to the use of male condoms, diaphragms or copper IUDs suggested that whether a higher or lower estrogenic load can be associated with the switching population depends on the typical failure rates of the options adopted following discontinuation. And, finally, it was estimated that, in the USA, at most 13% of the annual estrogenic load can be averted by fully meeting the contraceptive needs of the population. Therefore, while the issue of estrogen impacts on the environment cannot be addressed solely by meeting the population's contraceptive needs, a significant fraction of the estrogenic mass released to environment can be averted by improving the level with which their contraceptive needs are met.

Ethinyl estradiol and other human pharmaceutical estrogens in the aquatic environment: a review of recent risk assessment data

Interest in pharmaceuticals in the environment has increased substantially in recent years. Several studies in particular have assessed human and ecological risks from human pharmaceutical estrogens, such as 17α-ethinyl estradiol (EE2). Regulatory action also has increased, with the USA and other countries developing rules to address estrogens and other pharmaceuticals in the environment. Accordingly, the Center for Drug Evaluation and Research at the US Food and Drug Administration has conducted a review and analysis of current data on the long-term ecological exposure and effects of EE2 and other estrogens. The results indicate that mean-flow long-term predicted environmental concentrations (PECs) of EE2 in approximately 99% or more of US surface water segments downstream of wastewater treatment plants are lower than a predicted no-effect concentration (PNEC) for aquatic chronic toxicity of 0.1 ng/L. Exceedances are expected to be primarily in localized, effluent-dominated water segments. The median mean-flow PEC is more than two orders of magnitude lower than this PNEC. Similar results exist for other pharmaceutical estrogens. Data also suggest that the contribution of EE2 more broadly to total estrogenic load in the environment from all sources (including other human pharmaceutical estrogens, endogenous estrogens, natural environmental estrogens, and industrial chemicals), while highly uncertain and variable, appears to be relatively low overall. Additional data and a more comprehensive approach for data collection and analysis for estrogenic substances in the environment, especially in effluent-dominated water segments in sensitive environments, would more fully characterize the risks.

What level of estrogenic activity determined by in vitro assays in municipal waste waters can be considered as safe?

In vitro assays are broadly used tools to evaluate the estrogenic activity in Waste Water Treatment Plant (WWTP) effluents and their receiving rivers. Since potencies of individual estrogens to induce in vitro and in vivo responses can differ it is not possible to directly evaluate risks based on in vitro measures of estrogenic activity. Estrone, 17beta-estradiol, 17alfa-ethinylestradiol and to some extent, estriol have been shown to be responsible for the majority of in vitro estrogenic activity of municipal WWTP effluents. Therefore, in the present study safe concentrations of Estrogenic Equivalents (EEQs-SSE) in municipal WWTP effluents were derived based on simplified assumption that the steroid estrogens are responsible for all estrogenicity determined with particular in vitro assays. EEQs-SSEs were derived using the bioassay and testing protocol-specific in vitro potencies of steroid estrogens, in vivo predicted no effect concentration (PNECs) of these compounds, and their relative contributions to the overall estrogenicity detected in municipal WWTP effluents. EEQs-SSEs for 15 individual bioassays varied from 0.1 to 0.4ng EEQ/L. The EEQs-SSEs are supposed to be increased by use of location-specific dilution factors of WWTP effluents entering receiving rivers. They are applicable to municipal wastewater and rivers close to their discharges, but not to industrial waste waters.

Most oxidative stress response in water samples comes from unknown chemicals: the need for effect-based water quality trigger values

The induction of adaptive stress response pathways is an early and sensitive indicator of the presence of chemical and non-chemical stressors in cells. An important stress response is the Nrf-2 mediated oxidative stress response pathway where electrophilic chemicals or chemicals that cause the formation of reactive oxygen species initiate the production of antioxidants and metabolic detoxification enzymes. The AREc32 cell line is sensitive to chemicals inducing oxidative stress and has been previously applied for water quality monitoring of organic micropollutants and disinfection byproducts. Here we propose an algorithm for the derivation of effect-based water quality trigger values for this end point that is based on the combined effects of mixtures of regulated chemicals. Mixture experiments agreed with predictions by the mixture toxicity concept of concentration addition. The responses in the AREc32 and the concentrations of 269 individual chemicals were quantified in nine environmental samples, ranging from treated effluent, recycled water, stormwater to drinking water. The effects of the detected chemicals could explain less than 0.1% of the observed induction of the oxidative stress response in the sample, affirming the need to use effect-based trigger values that account for all chemicals present.

Modeling of steroid estrogen contamination in UK and South Australian rivers predicts modest increases in concentrations in the future

The prediction of risks posed by pharmaceuticals and personal care products in the aquatic environment now and in the future is one of the top 20 research questions regarding these contaminants following growing concern for their biological effects on fish and other animals. To this end it is important that areas experiencing the greatest risk are identified, particularly in countries experiencing water stress, where dilution of pollutants entering river networks is more limited. This study is the first to use hydrological models to estimate concentrations of pharmaceutical and natural steroid estrogens in a water stressed catchment in South Australia alongside a UK catchment and to forecast their concentrations in 2050 based on demographic and climate change predictions. The results show that despite their differing climates and demographics, modeled concentrations of steroid estrogens in effluents from Australian sewage treatment works and a receiving river were predicted (simulated) to be similar to those observed in the UK and Europe, exceeding the combined estradiol equivalent's predicted no effect concentration for feminization in wild fish. Furthermore, by 2050 a moderate increase in estrogenic contamination and the potential risk to wildlife was predicted with up to a 2-fold rise in concentrations.

Comparing predicted estrogen concentrations with measurements in US waters

The range of exposure rates to the steroidal estrogens estrone (E1), beta-estradiol (E2), estriol (E3), and ethinyl estradiol (EE2) in the aquatic environment was investigated by modeling estrogen introduction via municipal wastewater from sewage plants across the US. Model predictions were compared to published measured concentrations. Predictions were congruent with most of the measurements, but a few measurements of E2 and EE2 exceed those that would be expected from the model, despite very conservative model assumptions of no degradation or in-stream dilution. Although some extreme measurements for EE2 may reflect analytical artifacts, remaining data suggest concentrations of E2 and EE2 may reach twice the 99th percentile predicted from the model. The model and bulk of the measurement data both suggest that cumulative exposure rates to humans are consistently low relative to effect levels, but also suggest that fish exposures to E1, E2, and EE2 sometimes substantially exceed chronic no-effect levels.

Predicted-no-effect concentrations for the steroid estrogens estrone, 17β-estradiol, estriol, and 17α-ethinylestradiol

The authors derive predicted-no-effect concentrations (PNECs) for the steroid estrogens (estrone [E1], 17β-estradiol [E2], estriol [E3], and 17α-ethinylestradiol [EE2]) appropriate for use in risk assessment of aquatic organisms. In a previous study, they developed a PNEC of 0.35 ng/L for EE2 from a species sensitivity distribution (SSD) based on all available chronic aquatic toxicity data. The present study updates that PNEC using recently published data to derive a PNEC of 0.1 ng/L for EE2. For E2, fish were the most sensitive taxa, and chronic reproductive effects were the most sensitive endpoint. Using the SSD methodology, we derived a PNEC of 2 ng/L for E2. Insufficient data were available to construct an SSD for E1 or E3. Therefore, the authors used in vivo vitellogenin (VTG) induction studies to determine the relative potency of the steroid estrogens to induce VTG. Based on the relative differences between in vivo VTG induction, they derive PNECs of 6 and 60 ng/L for E1 and E3, respectively. Thus, for long-term exposures to steroid estrogens in surface water (i.e., >60 d), the PNECs are 6, 2, 60, and 0.1 ng/L for E1, E2, E3, and EE2, respectively. Higher PNECs are recommended for short-term (i.e., a few days or weeks) exposures.