Methodology for profiling anti-androgen mixtures in river water using multiple passive samplers and bioassay-directed analyses

Identification and Prioritization of Environmental Organic Pollutants: From an Analytical and Toxicological Perspective

Exposure to environmental organic pollutants has triggered significant ecological impacts and adverse health outcomes, which have been received substantial and increasing attention. The contribution of unidentified chemical components is considered as the most significant knowledge gap in understanding the combined effects of pollutant mixtures. To address this issue, remarkable analytical breakthroughs have recently been made. In this review, the basic principles on recognition of environmental organic pollutants are overviewed. Complementary analytical methodologies (i.e., quantitative structure-activity relationship prediction, mass spectrometric nontarget screening, and effect-directed analysis) and experimental platforms are briefly described. The stages of technique development and/or essential parts of the analytical workflow for each of the methodologies are then reviewed. Finally, plausible technique paths and applications of the future nontarget screening methods, interdisciplinary techniques for achieving toxicant identification, and burgeoning strategies on risk assessment of chemical cocktails are discussed.

Bioanalytical and chemical characterization of organic micropollutant mixtures in long-term exposed passive samplers from the Joint Danube Survey 4: Setting a baseline for water quality monitoring

Monitoring methodologies reflecting the long-term quality and contamination of surface waters are needed to obtain a representative picture of pollution and identify risk drivers. This study sets a baseline for characterizing chemical pollution in the Danube River using an innovative approach, combining continuous three-months use of passive sampling technology with comprehensive chemical (747 chemicals) and bioanalytical (seven in vitro bioassays) assessment during the Joint Danube Survey (JDS4). This is one of the world's largest investigative surface-water monitoring efforts in the longest river in the European Union, which water after riverbank filtration is broadly used for drinking water production. Two types of passive samplers, silicone rubber (SR) sheets for hydrophobic compounds and AttractSPETM HLB disks for hydrophilic compounds, were deployed at nine sites for approximately 100 days. The Danube River pollution was dominated by industrial compounds in SR samplers and by industrial compounds together with pharmaceuticals and personal care products in HLB samplers. Comparison of the Estimated Environmental Concentrations with Predicted No-Effect Concentrations revealed that at the studied sites, at least one (SR) and 4-7 (HLB) compound(s) exceeded the risk quotient of 1. We also detected AhR-mediated activity, oxidative stress response, peroxisome proliferator-activated receptor gamma-mediated activity, estrogenic, androgenic, and anti-androgenic activities using in vitro bioassays. A significant portion of the AhR-mediated and estrogenic activities could be explained by detected analytes at several sites, while for the other bioassays and other sites, much of the activity remained unexplained. The effect-based trigger values for estrogenic and anti-androgenic activities were exceeded at some sites. The identified drivers of mixture in vitro effects deserve further attention in ecotoxicological and environmental pollution research. This novel approach using long-term passive sampling provides a representative benchmark of pollution and effect potentials of chemical mixtures for future water quality monitoring of the Danube River and other large water bodies.

Spatial and temporal variations in anti-androgenic activity and environmental risk in a small river

The biological effects of multiple compounds have been widely investigated in aquatic environments. However, investigations of spatial and temporal variations in biological effects are rarely performed because they are time-consuming and labor-intensive. In this study, the variability of the anti-androgen, receptor-mediated activity of surface water samples was observed over 3 years using in vitro bioassays. Large-volume water samples were collected at one site upstream (Wer site) and two sites downstream (Sil and Nien sites) of a wastewater treatment plant (WWTP) outfall in the Holtemme River. Anti-AR activity was persistently present in all surface water samples over the three years. Large spatial variations in anti-androgenic activity were observed, with the lowest activity at the Wer site (mean concentration of 9.5 ± 7.2 μg flutamide equivalents/L) and the highest activity at the Sil site (mean concentration of 31.1 ± 12.0 μg flutamide equivalents/L) directly influenced by WWTP effluents. On the temporal scale, no distinct trend for anti-AR activity was observed among the seasons in all three years. The anti-androgenic activity at the upstream Wer site showed a decreasing trend from 2014 to 2016, indicating improved water quality. A novel bioanalytical-equivalent-based risk assessment method considering the frequency of risk occurrence was developed and then utilized to assess the environmental risk of anti-androgenic activity in the Holtemme River. The results revealed that the highest risk was present at the Sil site, while the risk was considerably reduced at the Nien site. The risk at the upstream Wer site was the lowest.

Passive sampling and in vitro assays to monitor antiandrogens in a river affected by wastewater discharge

Pharmaceuticals and personal care products, antibiotics, estrogens, and antiandrogens are found widely in aquatic environments. Monitoring studies by sampling surface water and effluents of wastewater treatment plants (WWTPs) have been conducted recently to monitor antiandrogens, which, along with estrogens, cause endocrine disruption. However, few studies have investigated antiandrogenic activity (AA) combined with a chemical analyses of emerging antiandrogens. Therefore, we analyzed the presence and persistence of 12 types of antiandrogens, atrazine, and carbamazepine using grab sampling and polar organic chemical integrative sampler (POCIS) along a river affected by WWTP discharges. Water and sediment samples were collected from the WWTP effluent (WW), as well as upstream (US) and downstream (DS) of the WWTP. We detected only tebuconazole, triclosan, propiconazole, and fluconazole during the two sampling campaigns in 2016 and 2017. Grab sampling of the site WW detected tebuconazole (7-77 ng/L), propiconazole (5-47 ng/L), and fluconazole (6-45 ng/L). However, the concentrations in the river water were below the detection limits. Nevertheless, fluconazole and triclosan were detected by POCIS in the site WW (45.7 and 26.8 ng/L, respectively) and all river samples ranges of 0.3-9.3 and 2.4-3.7, respectively. This detection was attributed to the limit of quantification of POCIS being lower than that of grab sampling. Nilutamide and triclosan were detected in the river sediment, suggesting that their concentrations in the water column were at least partly attenuated through sediment sorption. We also observed AA by analyzing POCIS extracts with the yeast androgen screen assay. The highest AA was found in the site WW and it was still observable several kilometers downstream of the point of discharge despite decreasing. Therefore, the WWTP effluent was most likely contributor to the persistent AA in the river.

Monitoring of emerging contaminants of concern in the aquatic environment: a review of studies showing the application of effect-based measures

Water scarcity is increasingly a global cause of concern mainly due to widespread changes in climate conditions and increased consumptive water use driven by the exponential increase in population growth. In addition, increased pollution of fresh water sources due to rising production and consumption of pharmaceuticals and organic chemicals will further exacerbate this concern. Although surface water contamination by individual chemicals is often at very low concentration, pharmaceuticals for instance are designed to be efficacious at low concentrations, creating genuine concern for their presence in freshwater sources. Furthermore, the additive impact of multiple compounds may result in toxic or other biological effects that otherwise will not be induced by individual chemicals. Globally, different legislative frameworks have led to pre-emptive efforts which aim to ensure good water ecological status. Reports detailing the use and types of effect-based measures covering specific bioassay batteries that can identify specific mode of actions of chemical pollutants in the aquatic ecosystem to evaluate the real threat of pollutants to aquatic lives and ultimately human lives have recently emerged from monitoring networks such as the NORMAN network. In this review, we critically evaluate some studies within the last decade that have implemented effect-based monitoring of pharmaceuticals and organic chemicals in aquatic fauna, evaluating the occurrence of different chemical pollutants and the impact of these pollutants on aquatic fauna with special focus on pollutants that are contaminants of emerging concern (CEC) in urban wastewater. A critical discussion on studies that have used effect-based measures to assess biological impact of pharmaceutical/organic compound in the aquatic ecosystem and the endpoints measurements employed is presented. The application of effect-based monitoring of chemicals other than assessment of water quality status is also discussed.

Characterisation of (anti-)progestogenic and (anti-)androgenic activities in surface and wastewater using high resolution effectdirected analysis

The quality of surface waters is threatened by pollution with low concentrations of bioactive chemicals, among which those interfering with steroid hormone systems. Induced by reports of anti-progestogenic activity in surface waters, a two-year four-weekly survey of (anti-)progestogenic activity was performed at three surface water locations in the Netherlands that serve as abstraction points for the production of drinking water. As certain endogenous and synthetic progestogenic compounds are also potent (anti-)androgens, these activities were also investigated. Anti-progestogenic and anti-androgenic activities were detected in the majority of the monitoring samples, sometimes in concentrations exceeding effect-based trigger values, indicating the need for further research. To characterize the compounds responsible for the activities, a high resolution Effect-Directed Analysis (hr-EDA) panel was combined with PR and AR CALUX bioassays, performed in agonistic and antagonistic modes. The influent and effluent of a domestic wastewater treatment plant (WWTP) were included as effluent is a possible emission source of active compounds. As drivers for androgenic and progestogenic activities several native and synthetic steroid hormones were identified in the WWTP samples, namely androstenedione, testosterone, DHT, levonorgestrel and cyproterone acetate. The pesticides metolachlor and cyazofamid were identified as contributors to both the anti-progestogenic and anti-androgenic activities in surface water. In addition, epiconazole contributed to the anti-progestogenic activities in the rivers Rhine and Enclosed Meuse. This study showed the strength of hr-EDA for the identification of bioactive compounds in environmental samples and shed light on the drivers of (anti-)progestogenic and (anti-)androgenic activities in the aquatic environment.

Advancements in effect-based surface water quality assessment

Legally-prescribed chemical monitoring is unfit for determining the pollution status of surface waters, and there is a need for improved assessment methods that consider the aggregated risk of all bioavailable micropollutants present in the aquatic environment. Therefore, the present study aimed to advance effect-based water quality assessment by implementing methodological improvements and to gain insight into contamination source-specific bioanalytical responses. Passive sampling of non-polar and polar organic compounds and metals was applied at 14 surface water locations that were characterized by two major anthropogenic contamination sources, agriculture and wastewater treatment plant (WWTP) effluent, as well as reference locations with a low expected impact from micropollutants. Departing from the experience gained in previous studies, a battery of 20 in vivo and in vitro bioassays was composed and subsequently exposed to the passive sampler extracts. Next, the bioanalytical responses were divided by their respective effect-based trigger values to obtain effect-based risk quotients, which were summed per location. These cumulative ecotoxicological risks were lowest for reference locations (4.3-10.9), followed by agriculture locations (11.3-27.2) and the highest for WWTP locations (12.8-47.7), and were mainly driven by polar organic contaminants. The bioanalytical assessment of the joint risks of metals and (non-)polar organic compounds resulted in the successful identification of pollution source-specific ecotoxicological risk profiles: none of the bioassays were significantly associated with reference locations nor with multiple location types, while horticulture locations were significantly characterized by anti-AR and anti-PR activity and cytotoxicity, and WWTP sites by ERα activity and toxicity in the in vivo bioassays. It is concluded that the presently employed advanced effect-based methods can readily be applied in surface water quality assessment and that the integration of chemical- and effect-based monitoring approaches will foster future-proof water quality assessment strategies on the road to a non-toxic environment.

Factors Affecting Sampling Strategies for Design of an Effects-Directed Analysis for Endocrine-Active Chemicals

Effects-directed analysis (EDA) is an important tool for identifying unknown bioactive components in a complex mixture. Such an analysis of endocrine-active chemicals (EACs) from water sources has promising regulatory implications but also unique logistical challenges. We propose a conceptual EDA (framework) based on a critical review of EDA literature and concentrations of common EACs in waste and surface waters. Required water volumes for identification of EACs under this EDA framework were estimated based on bioassay performance (in vitro and in vivo bioassays), limits of quantification by mass spectrometry (MS), and EAC water concentrations. Sample volumes for EDA across the EACs showed high variation in the bioassay detectors, with genistein, bisphenol A, and androstenedione requiring very high sample volumes and ethinylestradiol and 17β-trenbolone requiring low sample volumes. Sample volume based on the MS detector was far less variable across the EACs. The EDA framework equation was rearranged to calculate detector "thresholds," and these thresholds were compared with the literature EAC water concentrations to evaluate the feasibility of the EDA framework. In the majority of instances, feasibility of the EDA was limited by the bioassay, not MS detection. Mixed model analysis showed that the volumes required for a successful EDA were affected by the potentially responsible EAC, detection methods, and the water source type, with detection method having the greatest effect on the EDA of estrogens and androgens. The EDA framework, equation, and model we present provide a valuable tool for designing a successful EDA. Environ Toxicol Chem 2020;39:1309-1324. © 2020 SETAC.

Identifying bioaccessible suspect toxicants in sediment using adverse outcome pathway directed analysis

Chemical mixtures are a common occurrence in contaminated sediment and determining causal relationship between sediment contamination and adverse outcomes is challenging. The bioavailability and choice of bioassay endpoints played important roles in elucidating causality. As such, bioaccessibility-based XAD extraction and adverse outcome pathway (AOP) guided bioassays were incorporated into an effect-directed analysis to more effectively determine sediment causality. XAD extracts of sediments from urban waterways in Guangzhou, China were examined using cell viability bioassays with four human tumor cells from lung, liver, breast, and bone marrow. Pronounced effects to SH-SY5Y cells were noted, thus neurotoxicity was subsequently focused in the AOP-guided bioassays. Intracellular calcium influx, mitochondrial membrane potential inhibition, reactive oxygen species generation, and cell viability were utilized as evidence for neurotoxicity AOP-guided analysis. Suspect toxicants were identified in active fractions using GC-MS. Toxicity confirmation was performed by evaluating toxicity contributions of the candidates to the pathway. Cypermethrin, bisphenol A, galaxolide, tonalide, and versalide were found as the major stressors across key events of the studied pathway. Moreover, good correlations among key events validated the feasibility of method to predict in vivo response, suggesting that considering bioavailability and AOP improved environmental relevance for toxicant identification in a complex mixture.

Evaluation of a biological post-treatment after full-scale ozonation at a municipal wastewater treatment plant

To reduce the discharge of trace organic compounds into water bodies associated with potential toxic effects such as endocrine disruption, new advanced treatment methods are being investigated at several wastewater treatment plants (WWTPs). One of the most studied and already implemented technologies is ozonation. However, ozonation only partially oxidizes trace organic compounds (TrOC) and as a result, transformation products (TPs) with unknown properties can be formed. In order to minimise the risk of releasing unknown and potentially toxic TPs into surface water, it is recommended to install a biological post-treatment after ozonation. The aim of this study was to evaluate the efficiency of a moving bed reactor following ozonation in a full-scale plant. Different ozone dosages (z_spec. = 0.3, 0.5, 0.7 mg _O3/mg_DOC) were investigated. To assess the biological activity of the post-treatment, the assimilable organic carbon (AOC) was determined in addition to the formed biomass. Furthermore, selected TrOC were analysed in parallel to monitor the ozonation efficiency at different ozone doses. In addition, estrogenic, androgenic as well as corresponding antagonistic effects were investigated after each treatment step using the A-YES and A-YAS assay. A non-target screening was performed to evaluate a trend analysis of formed TPs as well as their removal by the post-treatment procedure. The results proved the successful design of the biological post-treatment reactor by a constant biofilm development and reduction of the AOC. Endocrine effects were removed below the limit of detection (LOD) of 10 pg EEQ/L already after ozonation for all applied ozone doses. Antagonistic effects were not significantly reduced during ozonation and subsequent biological post-treatment. For this reason, further research is needed to evaluate different post-treatment technologies. The trend analysis from non-target screening data showed a reduction of about 95% of the number of formed TPs by the biological post-treatment. Consequently, an assessment of the biological activity and the elimination capacity of a certain biological post-treatment technique is thus possible by applying the AOC in combination with a non-target screening.

Acute toxicity evolution during ozonation of mono-chlorophenols and initial identification of highly toxic intermediates

Acute toxicity changes during ozonation of 2-chlorophenol (2-CP), 3-chlorophenol (3-CP) and 4-chlorophenol (4-CP) under various conditions were studied using the luminescence inhibition test. Though the concentrations of mono-chlorophenols (CPs) and TOC decreased constantly, the acute toxicity evidently increased with reaction time until a maximum value was reached during ozonation of 2-CP at pH 3 to 7, 3-CP at pH 3 to 10, and 4-CP at pH 3 and 5. Principal component analysis (PCA) was applied to understand the relationships between acute toxicity and other physicochemical parameters. The intense interrelations between acute toxicity and SUVA280 were evident under all the pH conditions for 2-CP and 3-CP, and except at pH 12 for 4-CP, which implied that high-weight intermediates were formed and contributed to the increased toxicity. SUVA280 was a possible surrogate measure of acute toxicity during the ozonation of all three CPs. Profiling of acute toxicity in ozonated CPs was conducted using solid phase extraction with a series of different cartridges, high performance liquid chromatography (HPLC) fractionation and the luminescence inhibition bioassay. Considering the acute toxicity evolution under different conditions and profiles of acute toxicity in HPLC fractions, the highly toxic intermediates probably included same non-chlorine carboxylic acids though the three CPs had different substituent positions with higher polarity than their parent compounds. In this study, the acute toxicity evolution during ozonation of CPs and the forcing agents were thoroughly discussed. Therefore, ozonation is expected to be carefully operated and monitored, and toxicity tests should be used to evaluate whether effluent detoxification takes place.

Systematic Review of Toxicity Removal by Advanced Wastewater Treatment Technologies via Ozonation and Activated Carbon

Upgrading wastewater treatment plants (WWTPs) with advanced technologies is one key strategy to reduce micropollutant emissions. Given the complex chemical composition of wastewater, toxicity removal is an integral parameter to assess the performance of WWTPs. Thus, the goal of this systematic review is to evaluate how effectively ozonation and activated carbon remove in vitro and in vivo toxicity. Out of 2464 publications, we extracted 46 relevant studies conducted at 22 pilot or full-scale WWTPs. We performed a quantitative and qualitative evaluation of in vitro (100 assays) and in vivo data (20 species), respectively. Data is more abundant on ozonation (573 data points) than on an activated carbon treatment (162 data points), and certain in vitro end points (especially estrogenicity) and in vivo models (e.g., daphnids) dominate. The literature shows that while a conventional treatment effectively reduces toxicity, residual effects in the effluents may represent a risk to the receiving ecosystem on the basis of effect-based trigger values. In general, an upgrade to ozonation or activated carbon treatment will significantly increase toxicity removal with similar performance. Nevertheless, ozonation generates toxic transformation products that can be removed by a post-treatment. By assessing the growing body of effect-based studies, we identify sensitive and underrepresented end points and species and provide guidance for future research.

Analytical and bioanalytical assessments of organic micropollutants in the Bosna River using a combination of passive sampling, bioassays and multi-residue analysis

Complex mixtures of contaminants from multiple sources, including agriculture, industry or wastewater enter aquatic environments and might pose hazards or risks to humans or wildlife. Targeted analyses of a few priority substances provide limited information about water quality. In this study, a combined chemical and effect screening of water quality in the River Bosna, in Bosnia and Herzegovina was carried out, with focus on occurrence and effects of contaminants of emerging concern. Chemicals in water were sampled at 10 sites along the Bosna River by use of passive sampling. The combination of semipermeable membrane devices (SPMDs) and polar organic chemical integrative samplers (POCIS) enabled sampling of a broad range of contaminants from hydrophobic (PAHs, PCBs, OCPs) to hydrophilic compounds (pesticides, pharmaceuticals and hormones), which were determined by use of GC-MS and LC-MS (MS). In vitro, cell-based bioassays were applied to assess (anti)androgenic, estrogenic and dioxin-like potencies of extracts of the samplers. Of a total of 168 targeted compounds, 107 were detected at least once. Cumulative pollutant concentrations decreased downstream from the city of Sarajevo, which was identified as the major source of organic pollutants in the area. Responses in all bioassays were observed for samples from all sites. In general, estrogenicity could be well explained by analysis of target estrogens, while the drivers of the other observed effects remained largely unknown. Profiling of hazard quotients identified two sites downstream of Sarajevo as hotspots of biological potency. Risk assessment of detected compounds revealed, that 7 compounds (diazinon, diclofenac, 17β-estradiol, estrone, benzo[k]fluoranthene, fluoranthene and benzo[k]fluoranthene) might pose risks to aquatic biota in the Bosna River. The study brings unique results of a complex water quality assessment in a region with an insufficient water treatment infrastructure.

Do progestins contribute to (anti-)androgenic activities in aquatic environments?

Unknown compounds with (anti-)androgenic activities enter the aquatic environment via municipal wastewater treatment plants (WWTPs). Progestins are well-known environmental contaminants capable of interfering with androgen receptor (AR) signaling pathway. The aim of the present study was to determine if 15 selected progestins have potential to contribute to (anti-)androgenic activities in municipal wastewaters and the respective recipient surface waters. AR-specific Chemically Activated LUciferase gene eXpression bioassay in agonistic (AR-CALUX) and antagonistic (anti-AR-CALUX) modes and liquid chromatography tandem atmospheric pressure chemical ionization/atmospheric photoionization with hybrid quadrupole/orbital trap mass spectrometry operated in high resolution product scan mode (LC-APCI/APPI-HRPS) methods were used to assess (anti-)androgenic activity and to detect the target compounds, respectively. The contribution of progestins to (anti-)androgenic activities was evaluated by means of a biologically and chemically derived toxicity equivalent approach. Androgenic (0.08-59 ng/L dihydrotestosterone equivalents - DHT EQs) and anti-androgenic (2.4-26 μg/L flutamide equivalents - FLU EQs) activities and progestins (0.19-75 ng/L) were detected in selected aquatic environments. Progestins displayed androgenic potencies (0.01-0.22 fold of dihydrotestosterone) and strong anti-androgenic potencies (9-62 fold of flutamide). Although they accounted to some extent for androgenic (0.3-29%) and anti-androgenic (4.6-27%) activities in influents, the progestins' contribution to (anti-)androgenic activities was negligible (≤2.1%) in effluents and surface waters. We also tested joint effect of equimolar mixtures of target compounds and the results indicate that compounds interact in an additive manner. Even if progestins possess relatively strong (anti-)androgenic activities, when considering their low concentrations (sub-ng/L to ng/L) it seems unlikely that they would be the drivers of (anti-)androgenic effects in Czech aquatic environments.

An integrative approach combining passive sampling, bioassays, and effect-directed analysis to assess the impact of wastewater effluent

Wastewater treatment plant (WWTP) effluents are major sources of endocrine-disrupting chemicals (EDCs) and other chemicals of toxicological concern for the aquatic environment. In the present study, we used an integrated strategy combining passive sampling (Chemcatcher®), developmental toxicity, and mechanism-based in vitro and in vivo bioassays to monitor the impacts of a WWTP on a river. In vitro screening revealed the WWTP effluent as a source of estrogen, glucocorticoid, and aryl hydrocarbon (AhR) receptor-mediated activities impacting the downstream river site where significant activities were also measured, albeit to a lesser extent than in the effluent. Effect-directed analysis of the effluent successfully identified the presence of potent estrogens (estrone, 17α-ethinylestradiol, and 17β-estradiol) and glucocorticoids (clobetasol propionate and fluticasone propionate) as the major contributors to the observed in vitro activities, even though other unidentified active chemicals were likely present. The impact of the WWTP was also assessed using zebrafish embryo assays, highlighting its ability to induce estrogenic response through up-regulation of the aromatase promoter-dependent reporter gene in the transgenic (cyp19a1b-green fluorescent protein [GFP]) zebrafish assay and to generate teratogenic effects at nonlethal concentrations in the zebrafish embryo toxicity test. The present study argues for the use of such an integrated approach, combining passive sampling, bioassays, and effect-directed analysis, to comprehensively identify endocrine active compounds and associated hazards of WTTP effluents. Environ Toxicol Chem 2018;37:2079-2088. © 2018 SETAC.

In vitro assessment of sex steroids and related compounds in water and sediments - a critical review

Detection of endocrine disrupting compounds in water and sediment samples has gained much importance since the evidence of their effects was reported in aquatic ecosystems in the 1990s. The aim of this review is to highlight the advances made in the field of in vitro analysis for the detection of hormonally active compounds with estrogenic, androgenic and progestogenic effects in water and sediment samples. In vitro assays have been developed from yeast, mammalian and in a few cases from fish cells. These assays are based either on the hormone-mediated proliferation of sensitive cell lines or on the hormone-mediated expression of reporter genes. In vitro assays in combination with various sample enrichment methods have been used with limits of detection as low as 0.0027 ng L^-1 in water, and 0.0026 ng g^-1 in sediments for estrogenicity, 0.1 ng L^-1 in water, and 0.5 ng g^-1 in sediments for androgenicity, and 5 ng L^-1 in water for progestogenicity expressed as equivalent concentrations of standard reference compounds of 17β-estradiol, dihydrotestosterone and progesterone, respectively. The experimental results and limits of quantification, however, are influenced by the methods of sample collection, preparation, and individual laboratory practices.

Identification of Unknown Antiandrogenic Compounds in Surface Waters by Effect-Directed Analysis (EDA) Using a Parallel Fractionation Approach

Among all the nuclear-receptor mediated endocrine disruptive effects, antiandrogenicity is frequently observed in aquatic environments and may pose a risk to aquatic organisms. Linking these effects to responsible chemicals is challenging and a great share of antiandrogenic activity detected in the environment has not been explained yet. To identify drivers of this effect at a hot spot of antiandrogenicity in the German river Holtemme, we applied effect-directed analysis (EDA) including a parallel fractionation approach, a downscaled luciferase reporter gene cell-based anti-AR-CALUX assay and LC-HRMS/MS nontarget screening. We identified and confirmed the highly potent antiandrogen 4-methyl-7-diethylaminocoumarin (C47) and two derivatives in the active fractions. The relative potency of C47 to the reference compound flutamide was over 5.2, whereas the derivatives were less potent. C47 was detected at a concentration of 13.7 μg/L, equal to 71.4 μg flutamide equivalents per liter (FEq/L) in the nonconcentrated water extract that was posing an antiandrogenic activity equal to 45.5 (±13.7 SD) FEq/L. Thus, C47 was quantitatively confirmed as the major cause of the measured effect in vitro. Finally, the antiandrogenic activity of C47 and one derivate was confirmed in vivo in spiggin-gfp Medaka. An endocrine disrupting effect of C47 was observed already at the concentration equal to the concentration in the nonconcentrated water extract, underlining the high risk posed by this compound to the aquatic ecosystem. This is of some concern since C47 is used in a number of consumer products indicating environmental as well as human exposure.

Improving the accuracy of effect-directed analysis: the role of bioavailability

Aquatic ecosystems have been suffering from contamination by multiple stressors. Traditional chemical-based risk assessment usually fails to explain the toxicity contributions from contaminants that are not regularly monitored or that have an unknown identity. Diagnosing the causes of noted adverse outcomes in the environment is of great importance in ecological risk assessment and in this regard effect-directed analysis (EDA) has been designed to fulfill this purpose. The EDA approach is now increasingly used in aquatic risk assessment owing to its specialty in achieving effect-directed nontarget analysis; however, a lack of environmental relevance makes conventional EDA less favorable. In particular, ignoring the bioavailability in EDA may cause a biased and even erroneous identification of causative toxicants in a mixture. Taking bioavailability into consideration is therefore of great importance to improve the accuracy of EDA diagnosis. The present article reviews the current status and applications of EDA practices that incorporate bioavailability. The use of biological samples is the most obvious way to include bioavailability into EDA applications, but its development is limited due to the small sample size and lack of evidence for metabolizable compounds. Bioavailability/bioaccessibility-based extraction (bioaccessibility-directed and partitioning-based extraction) and passive-dosing techniques are recommended to be used to integrate bioavailability into EDA diagnosis in abiotic samples. Lastly, the future perspectives of expanding and standardizing the use of biological samples and bioavailability-based techniques in EDA are discussed.

Removal of novel antiandrogens identified in biological effluents of domestic wastewater by activated carbon

Environmental antiandrogenic (AA) contaminants in effluents from wastewater treatment plants have the potential for negative impacts on wildlife and human health. The aim of our study was to identify chemical contaminants with likely AA activity in the biological effluents and evaluate the removal of these antiandrogens (AAs) during advanced treatment comprising adsorption onto granular activated carbon (GAC). In this study, profiling of AA contaminants in biological effluents and tertiary effluents was conducted using effect-directed analysis (EDA) including high performance liquid chromatography (HPLC) fractionation, a recombinant yeast screen containing androgen receptor (YAS), in combination with mass spectrometry analyses. Analysis of a wastewater secondary effluent from a membrane bioreactor revealed complex profiles of AA activity comprising 14 HPLC fractions and simpler profiles of GAC effluents with only 2 to 4 moderately polar HPLC fractions depending on GAC treatment conditions. Gas chromatography-mass spectrometry and ultra-high performance liquid chromatography-nanospray mass spectrometry analyses of AA fractions in the secondary effluent resulted in detection of over 10 chemical contaminants, which showed inhibition of YAS activity and were potential AAs. The putative AAs included biocides, food additives, flame retardants, pharmaceuticals and industrial contaminants. To our knowledge, it is the first time that the AA properties of N-ethyl-2-isopropyl-5-methylcyclohexanecarboxamide (WS3), cetirizine, and oxcarbazepine are reported. The EDA used in this study was proven to be a powerful tool to identify novel chemical structures with AA activity in the complex aquatic environment. The adsorption process to GAC of all the identified antiandrogens, except WS3 and triclosan, fit well with the pseudo-second order kinetics models. Adsorption to GAC could further remove most of the AAs identified in the biological effluents with high efficiencies.

Using passive sampling and zebrafish to identify developmental toxicants in complex mixtures

Using effects-directed analysis, we investigated associations previously observed between polycyclic aromatic hydrocarbons (PAHs) and embryotoxicity in field-deployed low-density polyethylene (LDPE). We conducted effects-directed analysis using a zebrafish embryo assay and iterative fractionation of extracts of LDPE that were deployed in the Portland Harbor superfund megasite, Oregon (USA). Whole extracts induced toxicity including mortality, edema, and notochord distortion at 20% effect concentration (EC20) values of approximately 100, 100, and 10 mg LDPE/mL, respectively. Through fractionation, we determined that PAHs at concentrations similar to previous research did not contribute markedly to toxicity. We also eliminated pesticides, phthalates, musks, and other substances identified in toxic fractions by testing surrogate mixtures. We identified free fatty acids as lethal components of LDPE extracts and confirmed their toxicity with authentic standards. We found chromatographic evidence that dithiocarbamates are responsible for notochord and other sublethal effects, although exact matches were not obtained. Fatty acids and dithiocarbamates were previously unrecorded components of LDPE extracts and likely contribute to the toxicity of the whole mixture. The present study demonstrates the success of effects-directed analysis in nontargeted hazard identification using the zebrafish embryo test as a self-contained battery of bioassays that allows identification of multiple chemicals with different modes of action. This is the first effects-directed analysis to combine LDPE and zebrafish, approaches that are widely applicable to identifying developmental hazards in the bioavailable fraction of hydrophobic organic compounds. Environ Toxicol Chem 2017;36:2290-2298. © 2017 SETAC.

Use of low density polyethylene membranes for assessment of genotoxicity of PAHs in the Seine River

The genotoxicity of river water dissolved contaminants is usually estimated after grab sampling of river water. Water contamination can now be obtained with passive samplers that allow a time-integrated sampling of contaminants. Since it was verified that low density polyethylene membranes (LDPE) accumulate labile hydrophobic compounds, their use was proposed as a passive sampler. This study was designed to test the applicability of passive sampling for combined chemical and genotoxicity measurements. The LDPE extracts were tested with the umu test (TA1535/pSK1002 ± S9) and the Ames assay (TA98, TA100 and YG1041 ± S9). We describe here this new protocol and its application in two field studies on four sites of the Seine River. Field LDPE extracts were negative with the YG1041 and TA100 and weakly positive with the TA98 + S9 and Umu test. Concentrations of labile mutagenic PAHs were higher upstream of Paris than downstream of Paris. Improvement of the method is needed to determine the genotoxicity of low concentrations of labile dissolved organic contaminants.

Downscaling procedures reduce chemical use in androgen receptor reporter gene assay

Bioactivity screening studies often face sample amount limitation with respect to the need for reliable, reproducible and quantitative results. Therefore approaches that minimize sample use are needed. Low-volume exposure and chemical dilution procedures were applied in an androgen receptor reporter gene human cell line assay to evaluate environmental contaminants and androgen receptor modulators, which were the agonist 5α-dihydrotestosterone (DHT); and the antagonists flutamide, bisphenol A, 1-hydroxypyrene and triclosan. Cells were exposed in around 1/3 of the medium volume recommended by the protocol (70μL/well). Further, chemical losses during pipetting steps were minimized by applying a low-volume method for compound dilution in medium (250μL for triplicate wells) inside microvolume glass inserts. Simultaneously, compounds were evaluated following conventional procedures (200μL/well, dilution in 24-well plates) for comparison of results. Low-volume exposure tests produced DHT EC50 (3.4-3.7×10(-10)M) and flutamide IC50 (2.2-3.3×10(-7)M) values very similar to those from regular assays (3.1-4.2×10(-10) and 2.1-3.3×10(-7)M respectively) and previous studies. Also, results were within assay acceptance criteria, supporting the relevance of the downscaling setup for agonistic and antagonistic tests. The low-volume exposure was also successful in determining IC50 values for 1-hydroxypyrene (2.1-2.8×10(-6)M), bisphenol A (2.6-3.3×10(-6)M), and triclosan (1.2-1.9×10(-6)M) in agreement with values obtained through high-volume exposure (2.3-2.8, 2.5-3.4 and 1.0-1.3×10(-6)M respectively). Finally, experiments following both low-volume dosing and exposure produced flutamide and triclosan IC50 values similar to those from regular tests. The low-volume experimental procedures provide a simple and effective solution for studies that need to minimize bioassay sample use while maintaining method reliability. The downscaling methods can be applied for the evaluation of samples, fractions or chemicals which require minimal losses during the steps of pipetting, transference to medium and exposure in bioassays.

Advancing Biological Wastewater Treatment: Extended Anaerobic Conditions Enhance the Removal of Endocrine and Dioxin-like Activities

Conventional activated sludge treatment of wastewater does not completely remove micropollutants. Here, extending anaerobic conditions may enhance biodegradation. To explore this, we combined iron-reducing or substrate-limiting and aerobic pilot-scale reactors directly at a wastewater treatment plant. To assess the removal of endocrine disrupting chemicals (EDCs) as group of micropollutants that adversely affects wildlife, we applied a bioanalytical approach. We used in vitro bioassays covering seven receptor-mediated mechanisms of action, including (anti)androgenicity, (anti)estrogenicity, retinoid-like, and dioxin-like activity. Untreated wastewater induced antiandrogenic, estrogenic, antiestrogenic, and retinoid-like activity. Full-scale as well as reactor-scale activated sludge treatment effectively removes the observed effects. Nevertheless, high antiandrogenic and minor dioxin-like and estrogenic effects persisted in the treated effluent that may still be environmentally relevant. The anaerobic post-treatment under substrate-limiting conditions resulted in an additional removal of endocrine activities by 17-40%. The anaerobic pre-treatment under iron-reducing conditions significantly enhanced the removal of the residual effects by 40-75%. In conclusion, this study demonstrates that a further optimization of biological wastewater treatment is possible. Here, implementing iron-reducing anaerobic conditions preceding aerobic treatment appears promising to improve the removal of receptor-mediated toxicity.

Assessment of estrogenic and androgenic activity in PM10 air samples from an urban, industrial and rural area in Flanders (Belgium) using the CALUX bioassay

BACKGROUND

Endocrine disrupting chemicals represent a broad class of compounds, are widespread in the environment and can pose severe health effects.

OBJECTIVES

The objective of this study was to investigate and compare the overall estrogen and androgen activating potential of PM10 air samples at an urban, rural and industrial location in Flanders, using a human in vitro cell bioassay.

METHODS

PM10 samples were collected on glass fiber filters every six days between April 2013 and January 2014 using a high-volume sampler. Extraction was executed with a hexane/acetone mixture before analysis using a recombinant estrogen- or androgen responsive human carcinoma cell line. Results were expressed as bioanalytical equivalents (BEQs) per cubic meter of air.

RESULTS

High fluctuations in estrogenic activity were observed during the entire sampling period, with median BEQs of 32.1, 35.9 and 31.1 fg E2-Eq m(-)³ in the industrial, urban and rural background area, respectively. Estrogenic activity was measured in 70% of the samples, while no androgenic activity was observed in any of the samples. The estrogenic activity in the industrial area was positively correlated with the airborne concentration of the sum of the non-carcinogenic PAHs pyrene and fluoranthene (rho=0.48; p<0.01) and the sum of the carcinogenic PAHs (rho=0.36; p=0.05).

CONCLUSIONS

This study showed that no androgenic activity was present in PM10 and that although the median estrogenic activity was rather low and comparable in the three locations, high fluctuations in estrogenic response exist over time. While atmospheric PAHs contributed to the observed estrogenic response, especially in the industrial area, the chemicals responsible for the majority of estrogenic activity remain to be identified.

Strategies for Transferring Mixtures of Organic Contaminants from Aquatic Environments into Bioassays

Mixtures of organic contaminants are ubiquitous in the environment. Depending on their persistence and physicochemical properties, individual chemicals that make up the mixture partition and distribute within the environment and might then jointly elicit toxicological effects. For the assessment and monitoring of such mixtures, a variety of cell-based in vitro and low-complexity in vivo bioassays based on algae, daphnids or fish embryos are available. A very important and sometimes unrecognized challenge is how to combine sampling, extraction and dosing to transfer the mixtures from the environment into bioassays, while conserving (or re-establishing) their chemical composition at adjustable levels for concentration-effect assessment. This article outlines various strategies for quantifiable transfer from environmental samples including water, sediment, and biota into bioassays using total extraction or polymer-based passive sampling combined with either solvent spiking or passive dosing.

Polyurethane foam (PUF) passive samplers for monitoring phenanthrene in stormwater

Pollution from highway stormwater runoff has been an increasing area of concern. Many structural Best Management Practices (BMPs) have been implemented for stormwater treatment and management. One challenge for these BMPs is to sample stormwater and monitor BMP performance. The main objective of this study was to evaluate the feasibility of using polyurethane foam (PUF) passive samplers (PSs) for sampling phenanthrene (PHE) in highway stormwater runoff and BMPs. Tests were conducted using batch reactors, glass-tube columns, and laboratory-scale BMPs (bioretention cells). Results indicate that sorption for PHE by PUF is mainly linearly relative to time, and the high sorption capacity allows the PUF passive sampler to monitor stormwater events for months or years. The PUF passive samplers could be embedded in BMPs for monitoring influent and effluent PHE concentrations. Models developed to link the results of batch and column tests proved to be useful for determining removal or sorption parameters and performance of the PUF-PSs. The predicted removal efficiencies of BMPs were close to the real values obtained from the control columns with errors ranging between -8.46 and 1.52%. This research showed that it is possible to use PUF passive samplers for sampling stormwater and monitoring the performance of stormwater BMPs, which warrants the field-scale feasibility studies in the future.

Endocrine-Disrupting Chemicals and Oil and Natural Gas Operations: Potential Environmental Contamination and Recommendations to Assess Complex Environmental Mixtures

BACKGROUND

Hydraulic fracturing technologies, developed over the last 65 years, have only recently been combined with horizontal drilling to unlock oil and gas reserves previously deemed inaccessible. Although these technologies have dramatically increased domestic oil and natural gas production, they have also raised concerns for the potential contamination of local water supplies with the approximately 1,000 chemicals that are used throughout the process, including many known or suspected endocrine-disrupting chemicals.

OBJECTIVES

We discuss the need for an endocrine component to health assessments for drilling-dense regions in the context of hormonal and antihormonal activities for chemicals used.

METHODS

We discuss the literature on a) surface and groundwater contamination by oil and gas extraction operations, and b) potential human exposure, particularly in the context of the total hormonal and antihormonal activities present in surface and groundwater from natural and anthropogenic sources; we also discuss initial analytical results and critical knowledge gaps.

DISCUSSION

In light of the potential for environmental release of oil and gas chemicals that can disrupt hormone receptor systems, we recommend methods for assessing complex hormonally active environmental mixtures.

CONCLUSIONS

We describe a need for an endocrine-centric component for overall health assessments and provide information supporting the idea that using such a component will help explain reported adverse health trends as well as help develop recommendations for environmental impact assessments and monitoring programs.

Effect-directed analysis supporting monitoring of aquatic environments--An in-depth overview

Aquatic environments are often contaminated with complex mixtures of chemicals that may pose a risk to ecosystems and human health. This contamination cannot be addressed with target analysis alone but tools are required to reduce this complexity and identify those chemicals that might cause adverse effects. Effect-directed analysis (EDA) is designed to meet this challenge and faces increasing interest in water and sediment quality monitoring. Thus, the present paper summarizes current experience with the EDA approach and the tools required, and provides practical advice on their application. The paper highlights the need for proper problem formulation and gives general advice for study design. As the EDA approach is directed by toxicity, basic principles for the selection of bioassays are given as well as a comprehensive compilation of appropriate assays, including their strengths and weaknesses. A specific focus is given to strategies for sampling, extraction and bioassay dosing since they strongly impact prioritization of toxicants in EDA. Reduction of sample complexity mainly relies on fractionation procedures, which are discussed in this paper, including quality assurance and quality control. Automated combinations of fractionation, biotesting and chemical analysis using so-called hyphenated tools can enhance the throughput and might reduce the risk of artifacts in laboratory work. The key to determining the chemical structures causing effects is analytical toxicant identification. The latest approaches, tools, software and databases for target-, suspect and non-target screening as well as unknown identification are discussed together with analytical and toxicological confirmation approaches. A better understanding of optimal use and combination of EDA tools will help to design efficient and successful toxicant identification studies in the context of quality monitoring in multiply stressed environments.

Evaluation and characterization of anti-estrogenic and anti-androgenic activities in soil samples along the Second Songhua River, China

In the present study, re-combined estrogen receptor (ER) and androgen receptor (AR) gene yeast assays combined with a novel approach based on Monte Carlo simulation were used for evaluation and characterization of soil samples collected from Jilin along the Second Songhua River to assess their antagonist/agonist properties for ER and AR. The results showed that estrogenic activity only occurred in the soil samples collected in the agriculture area, but most soil samples showed anti-estrogenic activities, and the bioassay-derived 4-hydroxytamoxifen equivalents ranged from N.D. to 23.51 μg/g. Hydrophilic substance fractions were determined as potential contributors associated with anti-estrogenic activity in these soil samples. Moreover, none of the soil samples exhibited AR agonistic potency, whereas 54% of the soil samples exhibited AR antagonistic potency. The flutamide equivalents varied between N.D. and 178.05 μg/g. Based on Monte Carlo simulation-related mass balance analysis, the AR antagonistic activities were significantly correlated with the media polar and polar fractions. All of these results support that this novel calculation method can be adopted effectively to quantify and characterize the ER/AR agonists and antagonists of the soil samples, and these data could help provide useful information for future management and remediation efforts.

Toxic Identification and Evaluation of Androgen Receptor Antagonistic Activities in Acid-Treated Liver Extracts of High-Trophic Level Wild Animals from Japan

Sulfuric acid-treated liver extracts of representative high-trophic level Japanese animals were analyzed by toxic identification and evaluation (TIE) with chemically activated luciferase expression (CALUX) and chemical analysis to elucidate androgen receptor (AR) antagonistic activities and potential contributions of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). The activities were detected in striped dolphins (n = 5), Stejneger's beaked whales (n = 6), golden eagle (n = 1), and Steller's sea eagle (n = 1) with CALUX-flutamide equivalents (FluEQs) as follow: 38 (20-52), 47 (21-96), 5.0, and 80 μg FluEQ/g-lipid, respectively. The AR antagonism was detected in limited number of specimens at lower levels for finless porpoise, raccoon dog, and common cormorant. Theoretical activities (Theo-FluEQs) were calculated using the concentration of OCPs and PCBs and their IC25-based relative potency (REP) values. These total contribution to CALUX-FluEQ was 126%, 84%, 53%, 55%, and 44% for striped dolphin, Steller's sea eagle, Stejneger's beaked whale, finless porpoise, and golden eagle, respectively, and the main contributor was p,p'-DDE. However, most of the activities for raccoon dog (7.6%) and common cormorant (17%) could not be explained by OCPs and PCBs. This suggests other unknown compounds could function as AR antagonists in these terrestrial species.

Characterization of Missouri surface waters near point sources of pollution reveals potential novel atmospheric route of exposure for bisphenol A and wastewater hormonal activity pattern

Surface water contamination by chemical pollutants increasingly threatens water quality around the world. Among the many contaminants found in surface water, there is growing concern regarding endocrine disrupting chemicals, based on their ability to interfere with some aspect of hormone action in exposed organisms, including humans. This study assessed water quality at several sites across Missouri (near wastewater treatment plants and airborne release sites of bisphenol A) based on hormone receptor activation potencies and chemical concentrations present in the surface water. We hypothesized that bisphenol A and ethinylestradiol would be greater in water near permitted airborne release sites and wastewater treatment plant inputs, respectively, and that these two compounds would be responsible for the majority of activities in receptor-based assays conducted with water collected near these sites. Concentrations of bisphenol A and ethinylestradiol were compared to observed receptor activities using authentic standards to assess contribution to total activities, and quantitation of a comprehensive set of wastewater compounds was performed to better characterize each site. Bisphenol A concentrations were found to be elevated in surface water near permitted airborne release sites, raising questions that airborne releases of BPA may influence nearby surface water contamination and may represent a previously underestimated source to the environment and potential for human exposure. Estrogen and androgen receptor activities of surface water samples were predictive of wastewater input, although the lower sensitivity of the ethinylestradiol ELISA relative to the very high sensitivity of the bioassay approaches did not allow a direct comparison. Wastewater-influenced sites also had elevated anti-estrogenic and anti-androgenic equivalence, while sites without wastewater discharges exhibited no antagonist activities.

Comparative evaluation of adsorption kinetics of diclofenac and isoproturon by activated carbon

Adsorption mechanism of diclofenac and isoproturon onto activated carbon has been proposed using Langmuir and Freundlich isotherms. Adsorption capacity and optimum adsorption isotherms were predicted by nonlinear regression method. Different kinetic equations, pseudo-first-order, pseudo-second-order, intraparticle diffusion model and Bangham kinetic model, were applied to study the adsorption kinetics of emerging contaminants on activated carbon in two aqueous matrices.

In vitro bioassays to screen for endocrine active pharmaceuticals in surface and waste waters

In the context of the European Water Framework Directive (WFD) it is fully recognized that pharmaceuticals can represent a relevant issue for the achievement of the good chemical and ecological status of European surface water bodies. The recent European Directive on the review of priority substances in surface water bodies has included three pharmaceuticals of widespread use (diclofenac, 17α-ethinylestradiol (EE2), 17β-estradiol (E2)) in the European monitoring list, the so-called watch list. Endocrine active pharmaceuticals such as EE2 and E2 (also occurring as natural hormone) can cause adverse effects on aquatic ecosystems at very low levels. However, monitoring of these pharmaceuticals within the watch list mechanism of the WFD and national monitoring programs can be difficult because of detection problems of most routine analytical methods. With proposed annual average Environmental Quality Standards (AA-EQS) of 0.035 ng/L and 0.4 ng/L, respectively, the estrogenic pharmaceutical EE2 and the natural hormone E2 are among those substances. Sensitive in vitro bioassays could reduce the current detection problems by measuring the estrogenic activity of environmental samples. In a short review article the application of this approach to screen and assess the risks of endocrine active pharmaceuticals with a focus on estrogenic pharmaceuticals in environmental waters is discussed.