Trace analysis of 61 natural and synthetic progestins in river water and sewage effluents by ultra-high performance liquid chromatography-tandem mass spectrometry

Human and fish differences in steroid receptors activation: A review

Steroid receptors (SRs) are transcription factors activated by steroid hormones (SHs) that belong to the nuclear receptors (NRs) superfamily. Several studies have shown that SRs are targets of endocrine disrupting chemicals (EDCs), widespread substances in the environment capable of interfering with the endogenous hormonal pathways and causing adverse health effects in living organisms and/or their progeny. Cell lines with SRs reporter gene are currently used for in vitro screening of large quantities of chemicals with suspected endocrine-disrupting activities. However, most of these cell lines express human SRs and therefore the toxicological data obtained are also extrapolated to non-mammalian species. In parallel, in vivo tests have recently been developed on fish species whose data are also extrapolated to mammalian species. As some species-specific differences in SRs activation by natural and synthetic chemicals have been recently reported, the aim of this review is to summarize those between human and fish SRs, as representatives of mammalian and non-mammalian toxicology, respectively. Overall, this literature study aims to improve inter-species extrapolation of toxicological data on EDCs and to understand which reporter gene cell lines expressing human SRs are relevant for the assessment of effects in fish and whether in vivo tests on fish can be properly used in the assessment of adverse effects on human health.

Establishment of a graphene quantum dot (GQD) based steroid binding assay for the nuclear progesterone receptor (pgr)

Previously, we established a homogeneous assay for membrane progesterone receptor alpha (mPRα) ligands by conjugating semiconductor nanoparticles known as graphene quantum dots (GQDs) to mPRα. When mixed with a progesterone-BSA-fluorescein isothiocyanate conjugate (P4-BSA-FITC), fluorescence occurred by fluorescence resonance energy transfer (FRET) but was reduced by the ligand-receptor binding activity. The established way showed ligand specificity as mPRα protein. In this study, we tried to establish the same way for nuclear progesterone receptor (Pgr). The ligand-binding domain (LBD) of zebrafish Pgr (zPgrLBD) was expressed as a fusion protein with glutathione S-transferase (GST) (GST-zPgrLBD). The recombinant protein was then purified and coupled with GQDs to produce GQD-conjugated GST-zPgrLBD (GQD-GST-zPgrLBD). When mixed with a P4-BSA-FITC and activated by 370 nm light, fluorescence at 520 nm appeared by FRET mechanism. Fluorescence at 520 nm was reduced by adding free progesterone to the reaction mixture. Reduction of fluorescence was induced by zPgr ligands but not by steroids or chemicals that do not interact with zPgr. The results showed the formation of a complex of GQD-GST-zPgrLBD and P4-BSA-FITC with ligand-receptor binding. The binding of the compounds was further confirmed by a radiolabeled steroid binding assay. A homogenous ligand-binding assay for nuclear progesterone receptor has been established.

High enrichment factors in chemical analysis of progestins and in bioassays: insights beyond trace levels

Concerns are growing about adverse effects of progestins on biota, even at ultra-trace concentrations. The enrichment factor (EF) from extraction of analytes in environmental samples that is needed for sample pre-concentration can affect not only performance of the analytical method but also the matrix effect. Therefore, the present study aimed to assess the influence of high sample EF on performance of the high-performance liquid chromatography with atmospheric pressure chemical ionization and photoionization coupled with high-resolution mass spectrometry (HPLC-APCI/APPI-HRMS) method for analysis of progestins in waste water treatment plant (WWTP) effluents and surface waters and analysis of (anti-)progestogenic activities measured by (anti-)PR-CALUX bioassays. The results showed that HPLC-APCI/APPI-HRMS coupled with solid-phase extraction and a high EF (33,333 Lwater/Lextract) enabled the detection of more compounds compared to samples with lower sample EF (10,000 Lwater/Lextract). The matrix effect did not increase proportionally compared to lower EFs (10,000 and 16,666 Lwater/Lextract), and lower limits of quantification were achieved in WWTP effluents and surface waters. The results of bioassays have shown that relative EF of 25 Lwater/Lbioassay appears high enough to detect progestogenic activity in treated waste water. Our study is one of the first to provide insights into sample pre-concentration in analysis of progestins and progestogenicity in aquatic environments.

A LC-MS/MS method for the simultaneous quantification of 17 opioids in biosolids

The solid product of wastewater treatment plants is commonly used as a fertiliser to increase sustainability and waste reuse. It has undergone extensive treatment to remove high nutrient loads, pathogens and heavy metals but the extensive matrix of household chemicals, pesticides and pharmaceuticals remains, untargeted by most treatment technologies. These compounds, particularly pharmaceuticals, have been detected in biosolids with there being evidence of uptake by plants. With the current opioid pandemic in North America and overprescription, a simple method is required for the extraction of opioids from a solid medium as to ascertain the concentrations the environment is exposed to. A sonication-liquid-liquid extracted method was developed where biosolids were suspended in water and extracted using ethyl acetate before analysis on LC MS/MS. Sodium and potassium chloride were compared along with acidic and alkaline conditions. The optimised method utilised NaCl at a pH of 12 and was validated for 17 opioids, achieving linearity >0.987, 86-113% matrix effect and 0.1-10 μg/kg limits of detection. Upon analysis of biosolids destined for agriculture, 14 opioids were detected across all samples in a concentration range of 1-289 μg/kg.

Chronic exposure to gestodene impairs reproductive system in adult female zebrafish (Daniarerio)

Gestodene (GES) is widely used in human therapy and animal husbandry and is frequently detected in aquatic environments. Although GES adversely affects aquatic organisms at trace levels, its effects on the reproductive biology of fish remain inconclusive. In this study, female zebrafish (Danio rerio) were exposed to environmentally relevant levels of GES for the evaluation of the effects of GES on the reproductive system by using endpoints including gene expression, plasma steroid concentrations, histological and morphological analyses, copulatory behavior, and reproductive output. Adult female zebrafish exposed to environmentally relevant concentrations of GES (4.0, 40.2, and 372.7 ng/L) for 60 d demonstrated stagnant ovarian oocyte development, evidenced by an increase in the percentage of perinuclear and atretic oocytes and a decrease in the percentage of late vitellogenic oocytes. GES-exposed females were less attractive to males and had lower copulatory intimacy than females in control. Consequently, spawning (44.3-49.2 %) and egg fertilization rates (27.9-32.0 %) were decreased. The decreased survival of fertilized eggs and hatching rates were accompanied by increased malformations. These negative effects were associated with abnormal transcriptional levels of gonadal steroid hormones, which were regulated by genes (Hsd17β3, Hsd11β2, Hsd20β, Cyp19a1a, and Cyp11b). Overall, our findings suggest that GES impairs the reproductive system of zebrafish, which may threaten population stability.

Assessment of occurrence, partitioning and ecological risk for 144 steroid hormones in Taihu Lake using UPLC-MS/MS with machine learning model

Steroid hormones (SHs) have attracted mounting attention due to their endocrine-disrupting effects on humans and aquatic organisms. However, the lack of analytical methods and toxicity data for a large number of SHs has limited the effective management of SH contamination in the water-sediment systems. In this study, we developed a highly sensitive analytical method for the simultaneous quantification of 144 SHs to investigate their occurrence, spatial distribution and partitioning in the water and sediment in Taihu Lake. The results showed that the total concentrations of SHs in water and sediment were 366.88-998.23 ng/L (mean: 612.84 ng/L) and 17.46-150.20 ng/g (mean: 63.41 ng/g), respectively. The spatial distribution of SHs in Taihu Lake might be simultaneously influenced by the pollution sources, lake hydrodynamics, and sediment properties. The sediment-water partitioning result implied that 28 SHs were in dynamic equilibrium at the water-water interface. In addition, 22 and 12 SHs tended to spread to water and settle into sediment, respectively. To assess the ecological risk of all SHs, a robust random forest model (R2 = 0.801) was developed to predict the acute toxicity of SHs for which toxicity data were not available from publications. Risk assessment showed that SHs posed a high ecological risk throughout Taihu Lake, with the highest risk in the northwestern areas. Estrone, 17β-estradiol and 17α-ethynylestradiol were the dominant risk contributors and were therefore recommended as the priority SHs in Taihu Lake. This work provided a valuable dataset for Taihu Lake, which would help to provide guidance and suggestions for future studies and be useful for the government to develop the mitigation and management measures.

Multi-criteria decision analysis: technique for order of preference by similarity to ideal solution for selecting greener analytical method in the determination of mifepristone in environmental water samples

This work proposes the use of multi-criteria decision analysis (MCDA) to select a more environmentally friendly analytical procedure. TOPSIS, which stands for Technique for Order of Preference by Similarity to Ideal Solution, is an example of a MCDA method that may be used to rank or select best alternative based on various criteria. Thirteen analytical procedures were used in this study as TOPSIS input choices for mifepristone determination in water samples. The input data, which consisted of these choices, was described using assessment criteria based on 12 principles of green analytical chemistry (GAC). Based on the objective mean weighting (MW), the weights for each criterion were assigned equally. The most preferred analytical method according to the ranking was solid phase extraction with micellar electrokinetic chromatography (SPE-MEKC), while solid phase extraction combined with ultra-high performance liquid chromatography tandem mass spectrometry (SPE-UHPLC-MS/MS) was ranked last. TOPSIS ranking results were also compared to the green metrics NEMI, Eco-Scale, GAPI, AGREE, and AGREEprep that were used to assess the greenness of thirteen analytical methods for mifepristone determination. The results demonstrated that only the AGREE metric tool correlated with TOPSIS; however, there was no correlation with other metric tools. The analysis results suggest that TOPSIS is a very useful tool for ranking or selecting the analytical procedure in terms of its greenness and that it can be easily integrated with other green metrics tools for method greenness assessment.

Novel biosensor for high-throughput detection of progesterone receptor-interacting endocrine disruptors

Progesterone receptor (PR)-interacting compounds in the environment are associated with serious health hazards. However, methods for their detection in environmental samples are cumbersome. We report a sensitive activity-based biosensor for rapid and reliable screening of progesterone receptor (PR)-interacting endocrine disrupting chemicals (EDCs). The biosensor is a cell line which expresses nuclear mCherry-NF1 and a green fluorescent protein (GFP)-tagged chimera of glucocorticoid receptor (GR) N terminus fused to the ligand binding domain (LBD) of PR (GFP-GR-PR). As this LBD is shared by the PRA and PRB, the biosensor reports on the activation of both PR isoforms. This GFP-GR-PR chimera is cytoplasmic in the absence of hormone and translocates rapidly to the nucleus in response to PR agonists or antagonists in concentration- and time-dependent manner. In live cells, presence of nuclear NF1 label eliminates cell fixation and nuclear staining resulting in efficient screening. The assay can be used in screens for novel PR ligands and PR-interacting contaminants in environmental samples. A limited screen of river water samples indicated a widespread, low-level contamination with PR-interacting contaminants in all tested samples.

Gestodene causes masculinization of the western mosquitofish (Gambusia affinis): Insights from ovary metabolomics

Gestodene (GES) is a common synthetic progesterone frequently detected in aquatic environments. Chronic exposure to GES can cause masculinization of a variety of fish; however, whether metabolism is closely related to the masculinization has yet to be explored. Hence, the ovary metabolome of adult female western mosquitofish (Gambusia affinis) after exposing to GES (0.0, 5.0, 50.0, and 500.0 ng/L) for 40 days was analyzed by using high-performance liquid chromatography ionization with quadrupole time-of-flight tandem mass spectrometry (HPLC-QTOF-MS). The results showed that GES increased the levels of cysteine, taurine, ophthalmic acid and cAMP while decreased methionine, these metabolites changes may owing to the oxidative stress of the ovaries; while taurcholic acid and uric acid were decreased along with induced oocyte apopotosis. Steroids hormone metabolism was also significantly affected, with progesterone and cortisol being the most affected. Enzyme-linked immunoassay results showed that estradiol levels were decreased while testosterone levels were increased with GES exposure. In addition, correlation analysis showed that the differential metabolites of some amino acids (e.g. leucine) were strongly correlated with the levels of steroids hormones secreted by the pituitary gland. The results of this study suggest that GES affects ovarian metabolism via the hypothalamus-pituitary-gonad and hypothalamic-pituitary-adrenal axes, impair antioxidant capacity, induce apoptosis in the ovary of G. affinis, and finally caused masculinization.

Steroid metabolites as overlooked emerging contaminants: Insights from multimedia partitioning and source-sink simulation in an estuarine environment

Steroids have been attracting global attention given potential carcinogenic and endocrine-disrupting effects, yet the environmental status of steroids, especially their metabolites, in estuarine environment remain largely unexplored. This study investigated 31 steroids and metabolites in suspended particulate matter (SPM), water phase and sediments of the Pearl River Estuary (PRE) during the dry and wet seasons to elucidate their spatiotemporal patterning, partitioning behavior, and environmental fate. The results showed that natural steroids predominated in SPM and sediments while the metabolites predominated in water. The spatial distribution of steroids and metabolites varied seasonally, with hydrophobicity and environmental factors influencing phase partitioning in the estuary. Furthermore, a natural steroid, progesterone (P) could serve as a trustworthy chemical indicator to estimate the concentrations of steroids and metabolites in the PRE. Importantly, the mass budget of P was estimated using an improved multi-box mass balance model, revealing that outflow to the South China Sea was the primary sink of P in water (∼87%) and degradation was the primary sink of P in sediments (∼68%) of the PRE. Overall, this study offers insightful information about the distribution and environmental fate of steroids and metabolites in estuarine environment, with implications for future management strategies.

Experimental exploration of estrogenic effects of norethindrone and 17α-ethinylestradiol on zebrafish (Danio rerio) gonads

Synthetic progestins and xenoestrogens found in aquatic habitats are currently gaining attention on global scale. The current study aimed to investigate the time-and dose-dependent effects of synthetic progestin Norethindrone (NET; 100, 500 and 1000 ng/L) and estrogen 17α-ethinylestradiol (EE2; 100 ng/L) individually as well as in binary mixture (1000 ng/L NET + 100 ng/L EE2) on reproductive histology and transcriptional expression profile of genes in adult zebrafish. For this, 20 female (3.15 ± 0.18 cm & 0.33 ± 0.06 g) and 20 male zebrafish in each group (2.93 ± 0.13 cm & 0.29 ± 0.04 g) were exposed to drugs dissolved in water for 30 days in 12 L rectangular tanks. We found that both NET and EE2 exposure reduced the gonadosomatic index in females, while only EE2 exposure caused significant reduction in males (p ≤ 0.05). Interestingly, NET delayed oocyte maturation in females and accelerated spermatogenesis in males, while EE2 consistently suppressed sperm maturation throughout the experiment. Further, qRT-PCR results revealed differential expression pattern of the study genes (er-α, er-β1, er-β2, pgr, vegfaa and p53) in male and female zebrafish. Co-exposure indicated potential inconsistencies in steroidal function in mixtures rather than single exposures. Our findings imply that changes in gonadal histology after NET and EE2 exposure may result from unique regulation of steroid hormone receptors. Additionally, significantly reduced p53 levels (p ≤ 0.05) following co-exposure in both sexes may suggest an elevated risk of neoplastic transformations. Further research with mammalian models will help to explore the mechanisms behind differing effects of alone and co-exposures.

Effects of mifepristone, a model compound with anti-progestogenic activity, on the development of African clawed frog (Xenopus laevis)

The objective of this study was to assess the effects of a model substance with anti-progestogenic activity on development of African clawed frog (Xenopus laevis) from tadpole to juvenile stage. Mifepristone, a synthetic progesterone receptor-blocking steroid hormone used in medicine as an abortifacient, was chosen as a model compound with anti-progestogenic activity. In the experiment, African clawed frog tadpoles were exposed to mifepristone at three concentrations (2, 21, and 215 ng L-1). A control group was exposed to dimethyl sulfoxide (DMSO; 0.001 %). The experiment started when tadpoles reached stages 47-48 according to Nieuwkoop and Faber (NF; 1994) and continued until stage NF 66, when metamorphosis was complete. Exposure to mifepristone had no significant effect on the rate of tadpole development, occurrence of morphological anomalies, weight, body length, or sex ratio. Mortality was within an acceptable range of 0-3.6 % throughout the test and did not differ among the groups. Histopathological examination of the gonads and thyroid gland revealed no significant changes. Therefore, we can conclude that mifepristone had no negative effect on development of the African clawed frog up to juvenile stage. Nevertheless, at the highest tested mifepristone concentration (215 ng L-1), gene expression analysis revealed up-regulation of mRNA expression of nuclear progesterone receptor (npr), membrane progesterone receptor (mpr), estrogen receptor beta (esrβ), and luteinizing hormone (lh) in the brain-pituitary complex of exposed frogs at stage NF 66. Higher mRNA expression of npr was also found in frogs exposed to 22 ng L-1 mifepristone compared to the solvent control. These findings confirmed the anti-progestogenic activity of mifepristone in frogs because the up-regulation of progesterone receptors occurs if progesterone availability in the body is reduced. All the observed changes in combination may have negative consequences for reproduction and reproductive behavior later in life.

An effective tool for tracking steroids and their metabolites at the watershed level: Combining fugacity modeling and a chemical indicator

Steroids have attracted concern worldwide because of their potential carcinogenicity and severe adverse effects on aquatic organisms. However, the contamination status of various steroids, particularly their metabolites, at the watershed level remains unknown. This was the first study to employ field investigations to elucidate the spatiotemporal patterns, riverine fluxes, and mass inventories, and conduct a risk assessment of 22 steroids and their metabolites. This study also developed an effective tool for predicting the target steroids and their metabolites in a typical watershed based on the fugacity model combined with a chemical indicator. Thirteen steroids in the river water and seven steroids in sediments were identified with total concentrations of 1.0-76 ng/L and <LOQ-121 ng/g, respectively. In water, the levels of steroids were higher in the dry season, but the opposite trend was observed in sediments. Approximately 89 kg/a flux of steroids were transported from the river to the estuary. Mass inventories indicated that sediments acted as crucial sinks for steroids. Steroids in rivers might pose low to medium risks to aquatic organisms. Importantly, the fugacity model combined with a chemical indicator effectively simulated the steroid monitoring results within an order of magnitude at the watershed level, and various key sensitivity parameter settings provided reliable steroid concentration predictions under different circumstances. Our results should benefit environmental management and pollution control of steroids and their metabolites at the watershed level.

Validation of an isotope dilution mass spectrometry (IDMS) measurement procedure for the reliable quantification of steroid hormones in waters

Reliable data are compulsory to efficiently monitor pollutants in aquatic environments, particularly steroid hormones that can exert harmful effects at challenging analytical levels below the ng L^-1. An isotope dilution two-step solid-phase extraction followed by an ultra-performance liquid chromatography separation coupled to tandem mass spectrometry (UPLC-MS/MS) detection method was validated for the quantification of 21 steroid hormones (androgens, estrogens, glucocorticoids, and progestogens) in whole waters. To achieve a realistic and robust assessment of the performances of this method, the validation procedure was conducted using several water samples representative of its intended application. These samples were characterized in terms of concentration of ionic constituents, suspended particulate matter (SPM), and dissolved organic carbon contents (DOC). For estrogens that are part of the European Water Framework Directive Watchlist (17beta-estradiol and estrone), the performances met the European requirements (decision 2015/495/EU) in terms of limit of quantification (LQ) and measurement uncertainty. For 17alpha-ethinylestradiol, the challenging LQ of 0.035 ng L^-1 was reached. More generally, for 15 compounds out of 21, the accuracy, evaluated in intermediate precision conditions at concentrations ranging between 0.1 and 10 ng L^-1, was found to be within a 35% tolerance. The evaluation of the measurement uncertainty was realized following the Guide to the expression of Uncertainty in Measurement. Finally, a water monitoring survey demonstrated the suitability of the method and pointed out the contamination of Belgium rivers by five estrogens (17alpha-ethinylestradiol, estriol, 17alpha-estradiol, 17beta-estradiol, and estrone) and three glucocorticoids (betamethasone, cortisol, and cortisone) which have been up to now poorly documented in European rivers.

Environmental water extracts differentially activate zebrafish and human nuclear progesterone receptors

Many reports on anti-progestogenic activities in aquatic environments have been published in the past decade. These are monitored mainly by in vitro reporter gene bioassays based upon the human progesterone receptor (PR). However, results obtained by some human in vitro bioassays may not be relevant for aquatic animals, especially fish. The present work aimed to detect fish (anti-)PR activity in waste- and receiving surface waters. In parallel, human (anti-)PR activity was analysed to determine if there was any connection between human and fish (anti-)PR activities. Finally, (anti-)PR activities were linked to the occurrence of progestins in water samples. Human PR agonistic activity was detected in all wastewater and most receiving surface water samples. Nevertheless, zebrafish PR (zfPR) agonistic activity was found in only two influent wastewater samples (max. 117 ng/L 17α,20β-dihydroxy-4-pregnen-3-one [DHP] equivalents). Analysed synthetic progestins and progesterone accounted for 14 % to 161 % of detected human PR (hPR) agonistic activity in water samples. Progesterone also contributed significantly to zfPR agonistic activity (up to 10 %) in raw wastewater. The anti-hPR activity was detected also in most wastewater and some surface water samples, but synthetic progestins did not trigger anti-zfPR activity in excess of LOQ values. In addition, altrenogest, dienogest, and ulipristal acetate were tested for their potency to zfPR for the first time. The activity analyses of both pure substances and environmental samples showed that human and zebrafish progesterone receptors are differentially activated. Therefore, results based on human PR in vitro bioassays could not predict fish PR activities in the environment.

Thyroid endocrine disruption and neurotoxicity of gestodene in adult female mosquitofish (Gambusia affinis)

The frequent detection of progestins in various aquatic environments and their potential endocrine disruptive effects in fish have attracted increasing attention worldwide. However, data on their effects on thyroid function and neurotoxicity in fish are limited, and the underlying mechanisms remain unclear. Here, the effects of gestodene (GES, a common progestin) on the thyroid endocrine and nervous systems of mosquitofish (Gambusia affinis) were studied. Adult female fish were exposed to GES at environmentally relevant concentrations (4.4-378.7 ng/L) for 60 days. The results showed that exposure to 378.7 ng/L GES caused a significant decrease in fish growth compared with the control and a marked reduction in the total distance traveled (50.6%) and swimming velocity (40.1-61.9%). The triiodothyronine (T3) levels were significantly increased by GES in a dose-dependent manner, whereas those of tetraiodothyronine (T4) were significantly decreased only at the G500 concentration. The acetylcholinesterase (AChE) activity was decreased significantly in the 4.42 ng/L GES treatments, but increased significantly at 378.67 ng/L. In the brain, a strong increase in the transcriptional levels of bdnf, trh, and dio2 was observed in fish after the 378.7 ng/L treatment. In addition, chronic exposure to GES caused colloid depletion with a concentration-dependent manner in the thyroid, and angiectasis, congestion, and vacuolar necrosis in the brain. These findings provide a better understanding of the effects of GES and associated underlying mechanisms in G. affinis.

A sensitive, robust method for determining natural and synthetic hormones in surface and wastewaters by continuous solid-phase extraction-gas chromatography-mass spectrometry

Over recent decades, steroidal estrogens have become an emerging and very serious issue as they pose a serious threat to living organisms, soil, plants, and water resources in general. Estrogens have therefore been the subject of considerable scientific attention in order to develop new methodologies for its determination, being able of detecting them at very low concentrations. Those procedures minimize or eliminate the consumption of organic solvents and reagents that may be incompatible with the environment. In this respect, we developed a sensitive, selective method for the simultaneous determination of thirteen natural and synthetic hormones present at the nanogram-per-liter level in various types of water by using continuous solid-phase extraction in combination with gas chromatography and mass spectrometry (GC-MS). The target analytes were preferentially sorbed on an Oasis HLB sorbent column (80 mg) and eluted with acetone (600 µL) for derivatization with a mixture of 70 µL of N,O-bis(trimethylsilyl) trifluoroacetamide and trimethylchlorosilane and 35 µL of petroleum ether in a household microwave oven at 200 W for 4 min. Under optimum conditions, the ensuing method exhibited good linearity (r ≥ 0.998), good precision (RSD ≤ 7%), high recoveries (92-103%), and low detection limits (0.01-0.3 ng L-1). The method outperforms existing alternatives in robustness, sensitivity, throughput, flexibility-it allows both estrogens, progestogens, and androgens to be determined simultaneously-and compliance with the principles of Green Chemistry. It was successfully used to analyze various types of water samples (mineral, tap, well, pond, swimming pool, river, and waste) that were found to contain four estrogens (estrone, 17β-estradiol, 17α-ethinylestradiol, and hexestrol), two progestogens (testosterone, dihydrotestosterone), and one progestogen (progesterone) at concentrations ranging from 3.0 to 110 ng L-1.

Contamination and ecological risks of steroid metabolites require more attention in the environment: Evidence from the fishing ports

Due to strong endocrine disrupting effects, steroids in the environment have attracted substantial attention, with studies mostly focusing on the parent steroids. Here, we conducted the first investigation on the contamination profiles, possible sources, mass inventories, and ecological risks of 27 steroids and their metabolites in 15 typical fishing ports in Southeast China. Twelve steroids were detectable in the sediment samples with the total mean concentrations of 4.6-35 ng/g. High proportions of steroid metabolites were measured in the sediments and five metabolites were newly observed. Untreated municipal sewage and aquaculture wastes constitute the possible steroid sources in the studied fishing ports. The total inventories of steroids in fishing ports ranged from 2.1-16 mg/m², with their metabolites being important contributors. The ecological risk analysis indicated high risks across all sampling sites mainly due to the contributions of parent steroids. Furthermore, our results found that progesterone is an acceptable chemical indicator for various steroids in sediments. This study provides the first evidence of steroid metabolites in the marine environment, calling for more studies in environmental behavior and ecotoxicology of steroid metabolites.

Overcoming matrix effects in quantitative liquid chromatography-mass spectrometry analysis of steroid hormones in surface waters

RATIONALE

Accurate and reliable measurements are mandatory in the field of environmental monitoring. Matrix effects are often depicted as the Achilles' heel of liquid chromatography-mass spectrometry analysis since they may be prejudicial for analytical performances such as detection capability and accuracy, if not documented or compensated. Here a methodology for the evaluation and compensation of matrix effects is described.

METHODS

Natural and synthetic representative water samples were used for the evaluation of matrix effects with the post-extraction addition technique. Samples were analysed using ultra-performance liquid chromatography separation coupled to tandem mass spectrometry and electrospray ionization. Isotopic dilution was investigated as a way to allow compensation of signal alteration and therefore satisfactory quantification. When this approach was not possible, a methodology was conducted for choosing the most appropriate internal standard.

RESULTS

The matrix effects were dependent on both matrix composition and nature of analyte. They ranged from total signal suppression to signal enhancement of +27% but were independent of compound concentration. The correction of matrix effects by internal standards was satisfactory, particularly for compounds benefiting from isotope dilution leading to acceptable quantification performances.

CONCLUSIONS

Even if no exhaustive or agreed criteria exist for the final interpretation of matrix effects, this study highlights the interest in isotope dilution for reducing their inherent prejudicial effects in quantification and the need to conduct this type of study for representative matrices. Moreover, a methodological approach is proposed for choosing the most appropriate available internal standard when isotope dilution is not possible.

The interactive effects of ethinylestradiol and progesterone on transcriptional expression of genes along the hypothalamus-pituitary-thyroid axis in embryonic zebrafish (Danio rerio)

Progestins and estrogens are widespread in various aquatic environments and their potential endocrine disruption effects to aquatic organisms have drawn growing concern. However, their combined effects in aquatic organisms remain elusive. The aim of the present study was to assess the effects of the binary mixtures of gestodene (GES) and 17α-ethinylestradiol (EE2) on the hypothalamic-pituitary-thyroid (HPT) axis of zebrafish (Danio rerio) using the eleuthero-embryos. Embryos were exposed to GES and EE2 alone or in combination at concentrations ranging from 41 to 5329 ng L^-1 (nominal ones from 50 to 5000 ng L^-1) for 48 h, 96 h and 144 h post fertilization (hpf). The results showed that the transcripts of the genes along the HPT axis displayed pronounced alterations. There was no clear pattern in the change of the transcripts of these genes over time and with concentrations. However, in general, the transcripts of the genes were inversely affected by EE2 (increase 0.5 to 4.2-folds) and GES (inhibition 0.4 to 4.9-folds), and their mixtures showed interactive effects in embryonic zebrafish. In addition, physiological data (mortality, malformation, body length and heart rate etc.) denoted higher toxicity of the two chemicals in combination than alone based on the developmental toxicity and neurotoxicity (locomotor behavior). These results indicated that the interactive effects of these two chemicals might be different between at the transcriptional level and at the whole organismal level. In summary, GES and EE2 affect the HPT axis (related genes expression and thyroid hormones (THs) levels) and exhibit developmental toxicity and neurotoxicity.

Progestogen-induced alterations and their ecological relevance in different embryonic and adult behaviours of an invertebrate model species, the great pond snail (Lymnaea stagnalis)

The presence of oral contraceptives (basically applying estrogens and/or progestogens) poses a challenge to animals living in aquatic ecosystems and reflects a rapidly growing concern worldwide. However, there is still a lack in knowledge about the behavioural effects induced by progestogens on the non-target species including molluscs. In the present study, environmental progestogen concentrations were summarised. Knowing this data, we exposed a well-established invertebrate model species, the great pond snail (Lymnaea stagnalis) to relevant equi-concentrations (1, 10, 100, and 500 ng L-1) of mixtures of four progestogens (progesterone, drospirenone, gestodene, levonorgestrel) for 21 days. Significant alterations were observed in the embryonic development time, heart rate, feeding, and gliding activities of the embryos as well as in the feeding and locomotion activity of the adult specimens. All of the mixtures accelerated the embryonic development time and the gliding activity. Furthermore, the 10, 100, and 500 ng L-1 mixtures increased the heart rate and feeding activity of the embryos. The 10, 100, and 500 ng L-1 mixtures affected the feeding activity as well as the 1, 10, and 100 ng L-1 mixtures influenced the locomotion of the adult specimens. The differences of these adult behaviours showed a biphasic response to the progestogen exposure; however, they changed approximately in the opposite way. In case of feeding activity, this dose-response phenomenon can be identified as a hormesis response. Based on the authors' best knowledge, this is the first study to investigate the non-reproductive effects of progestogens occurring also in the environment on molluscan species. Our findings contribute to the global understanding of the effects of human progestogens, as these potential disruptors can influence the behavioural activities of non-target aquatic species. Future research should aim to understand the potential mechanisms (e.g., receptors, signal pathways) of progestogens induced behavioural alterations.

Steroid hormones in the aquatic environment

Steroid hormones are extremely important natural hormones in all vertebrates. They control a wide range of physiological processes, including osmoregulation, sexual maturity, reproduction and stress responses. In addition, many synthetic steroid hormones are in widespread and general use, both as human and veterinary pharmaceuticals. Recent advances in environmental analytical chemistry have enabled concentrations of steroid hormones in rivers to be determined. Many different steroid hormones, both natural and synthetic, including transformation products, have been identified and quantified, demonstrating that they are widespread aquatic contaminants. Laboratory ecotoxicology experiments, mainly conducted with fish, but also amphibians, have shown that some steroid hormones, both natural and synthetic, can adversely affect reproduction when present in the water at extremely low concentrations: even sub-ng/L. Recent research has demonstrated that mixtures of different steroid hormones can inhibit reproduction even when each individual hormone is present at a concentration below which it would not invoke a measurable effect on its own. Limited field studies have supported the conclusions of the laboratory studies that steroid hormones may be environmental pollutants of significant concern. Further research is required to identify the main sources of steroid hormones entering the aquatic environment, better describe the complex mixtures of steroid hormones now known to be ubiquitously present, and determine the impacts of environmentally-realistic mixtures of steroid hormones on aquatic vertebrates, especially fish. Only once that research is completed can a robust aquatic risk assessment of steroid hormones be concluded.

Summary of reference chemicals evaluated by the fish short-term reproduction assay, OECD TG229, using Japanese Medaka, Oryzias latipes

Under the Organisation for Economic Co-operation and Development (OECD), the Ministry of the Environment of Japan (MOE) added Japanese medaka (Oryzias latipes) to the test guideline fish short-term reproduction assay (FSTRA) developed by the United States Environmental Protection Agency (US EPA) using fathead minnow (Pimephales promelas). The FSTRA was designed to detect endocrine disrupting effects of chemicals interacting with the hypothalamic-pituitary-gonadal axis (HPG axis) such as agonists or antagonists on the estrogen receptor (Esr) and/or the androgen receptor (AR) and steroidogenesis inhibitors. We conducted the FSTRA with Japanese medaka, in accordance with OECD test guideline number 229 (TG229), for 16 chemicals including four Esr agonists, two Esr antagonists, three AR agonists, two AR antagonists, two steroidogenesis inhibitors, two progesterone receptor agonists, and a negative substance, and evaluated the usability and the validity of the FSTRA (TG229) protocol. In addition, in vitro reporter gene assays (RGAs) using Esr1 and ARβ of Japanese medaka were performed for the 16 chemicals, to support the interpretation of the in vivo effects observed in the FSTRA. In the present study, all the test chemicals, except an antiandrogenic chemical and a weak Esr agonist, significantly reduced the reproductive status of the test fish, that is, fecundity or fertility, at concentrations where no overt toxicity was observed. Moreover, vitellogenin (VTG) induction in males and formation of secondary sex characteristics (SSC), papillary processes on the anal fin, in females was sensitive endpoints to Esr and AR agonistic effects, respectively, and might be indicators of the effect concentrations in long-term exposure. Overall, it is suggested that the in vivo FSTRA supported by in vitro RGA data can adequately detect effects on the test fish, O. latipes, and probably identify the mode of action (MOA) of the chemicals tested.

Norethindrone causes cellular and hepatic injury in zebrafish by compromising the metabolic processes associated with antioxidant defence: Insights from metabolomics

Progestins, such as norethindrone (NET), have been increasingly detected in aquatic environments due to their extensive use for medical applications. While NET is notorious for its endocrine disrupting effects, it has been recently shown to cause cellular damage, suggesting its potential impacts on the body defence of organisms. Hence, we examined the histological features and antioxidant defence of zebrafish (Danio rerio) after exposing to NET (50 ng/L and 500 ng/L) for 72 days, followed by analysing its metabolome to explore whether NET disturbs the metabolic processes responsible for antioxidant defence. While acute mortality was not triggered, we found that antioxidant defence was substantially weakened by NET at 500 ng/L (i.e. reduced SOD and GSH levels) and hence liver injury was inflicted (i.e. elevated ALT and MDA levels), as manifested by vacuolization of liver tissues and reduced number of normal cells in the liver. Metabolomic analysis showed that the metabolic processes responsible for antioxidant defence were disrupted by NET (e.g. upregulation of nervonyl carnitine and chenodeoxycholic acid 3-sulfate; downregulation of homolanthionine and acevaltrate) and these changes can undermine antioxidant defence by suppressing Nrf2-ARE and NF-κB pathways that contribute to the synthesis of SOD and GSH. This study demonstrates how NET can compromise the body defence of aquatic organisms via metabolic disruption, suggesting that the impacts of progestins on their fitness are more detrimental than previously thought.

Development and implementation of an analytical procedure for the quantification of natural and synthetic steroid hormones in whole surface waters

Natural and synthetic steroid hormones are chronically released into aquatic spheres. Whereas knowledge on their combined mode of action and the cocktail effect are needed, only few multi-class methods address the challenge of their trace quantification in surface waters. The current study describes a sensitive multi-residue analytical strategy aiming to quantify 23 steroid hormones belonging to androgens, estrogens, glucocorticoids and progestogens in whole surface waters. The procedure relies on a two-step solid-phase extraction followed by an ultra-performance liquid chromatography separation coupled to tandem mass spectrometry detection (UPLC-MS/MS). Isotope dilution was implemented when possible in order to ensure the reliability of the measurement. The procedure was optimized toward the reliable quantification of the 23 target compounds at the predicted no-effect concentrations when existing or below the ng L^-1 level. Satisfactory absolute global recoveries ≥ 77% were obtained for almost all compounds (21 out of 23) in intermediate precision conditions. Measurement errors were comprised between -27% and +17% for the great majority of compounds (21 out of 23) with standard deviations < 20% in intermediate precision conditions. Despite signal suppression was observed in water samples, satisfactory limits of quantification were achieved, ranging from 0.035 ng L^-1 for 17alpha-ethinylestradiol to 1 ng L^-1 for 6beta-hydroxycortisol and 6beta-hydroxydexamethasone. Abiotic stability was demonstrated for the great majority of target compounds (22 out of 23) in reference water samples stored at 4 ± 3 °C during 48 h, driving our sampling strategy. To demonstrate its fitness for purpose, the procedure was implemented in a preliminary monitoring survey of Belgian surface waters. As a result, 6 out of 23 target compounds were detected or quantified, showing a contamination by some estrogens and glucocorticoids at levels ranging from 0.1 to 0.9 ng L^-1.

Toxicity of the pharmaceuticals finasteride and melengestrol acetate to benthic invertebrates

The toxicity of endocrinologically active pharmaceuticals finasteride (FIN) and melengestrol acetate (MGA) was assessed in freshwater mussels, including acute (48 h) aqueous tests with glochidia from Lampsilis siliquoidea, sub-chronic (14 days) sediment tests with gravid female Lampsilis fasciola, and chronic (28 days) sediment tests with juvenile L. siliquoidea, and in chronic (42 days) sediment tests with the amphipod Hyalella azteca and the mayfly Hexagenia spp. Finasteride was not toxic in acute aqueous tests with L. siliquoidea glochidia (up to 23 mg/L), whereas significant toxicity to survival and burial ability was detected in chronic sediment tests with juvenile L. siliquoidea (chronic value (ChV, the geometric mean of LOEC and NOEC) = 58 mg/kg (1 mg/L)). Amphipods (survival, growth, reproduction, and sex ratio) and mayflies (growth) were similarly sensitive (ChV = 58 mg/kg (1 mg/L)). Melengestrol acetate was acutely toxic to L. siliquoidea glochidia at 4 mg/L in aqueous tests; in sediment tests, mayflies were the most sensitive species, with significant growth effects observed at 37 mg/kg (0.25 mg/L) (ChV = 21 mg/kg (0.1 mg/L)). Exposure to sublethal concentrations of FIN and MGA had no effect on the (luring and filtering) behaviour of gravid L. fasciola, or the viability of their brooding glochidia. Based on the limited number of measured environmental concentrations of both chemicals, and their projected concentrations, no direct effects are expected by these compounds individually on the invertebrates tested. However, organisms are exposed to contaminant mixtures in the aquatic environment, and thus, the effects of FIN and MGA as components of these mixtures require further investigation.

Microbial degradation of steroid sex hormones: implications for environmental and ecological studies

Steroid hormones modulate development, reproduction and communication in eukaryotes. The widespread occurrence and persistence of steroid hormones have attracted public attention due to their endocrine-disrupting effects on both wildlife and human beings. Bacteria are responsible for mineralizing steroids from the biosphere. Aerobic degradation of steroid hormones relies on O2 as a co-substrate of oxygenases to activate and to cleave the recalcitrant steroidal core ring. To date, two oxygen-dependent degradation pathways - the 9,10-seco pathway for androgens and the 4,5-seco pathways for oestrogens - have been characterized. Under anaerobic conditions, denitrifying bacteria adopt the 2,3-seco pathway to degrade different steroid structures. Recent meta-omics revealed that microorganisms able to degrade steroids are highly diverse and ubiquitous in different ecosystems. This review also summarizes culture-independent approaches using the characteristic metabolites and catabolic genes to monitor steroid biodegradation in various ecosystems.

Aerobic Biodegradation of Four Groups of Steroid Hormones in Activated Sludge

Steroid hormones in the environment have obtained considerable attention, as they can be harmful to aquatic organisms at very low concentrations. An analytical method was developed for simultaneously monitoring four estrogens, seven androgens, seven progestogens, and eleven glucocorticoids in a single water sample using liquid chromatography-electrospray tandem mass spectrometry. Laboratory studies were then performed to investigate the aerobic biodegradation of 29 steroids belonging to the four groups. The degradation of target steroids followed first-order reaction kinetics, and the degradation half-life (t1/2) of estrogens, androgens, progestogens and glucocorticoids was 1.2–8.7 h, 0.3–1.3 h, 1.4–7.7 h, and 1.4–23.1 h, respectively. Most of the esterified glucocorticoids were more persistent than the parent compounds, but the t1/2 for halogenated glucocorticoids was longer than that of their esterified compounds. In addition, C-21 ester glucocorticoids were more prone to decomposition than C-17 esters. Hydrolysis did not significantly affect the decomposition of esterified steroids.

Effect-Directed Analysis of Progestogens and Glucocorticoids at Trace Concentrations in River Water

Effect-based monitoring is increasingly applied to detect and-in conjunction with chemical analysis-to identify endocrine-disrupting compounds (EDCs) in the environment. Although this approach of effect-directed analysis has been successfully demonstrated for estrogenicity and androgenicity, data on progestogens and glucocorticoids driving endocrine disruption are quite limited. We investigated progestogenic and glucocorticoid activities in Danube River water receiving untreated wastewater from Novi Sad, Serbia. After a 2-step fractionation, all fractions were tested with reporter gene bioassays for agonistic and antagonistic hormonal responses at progestogenic and glucocorticoid hormone receptors as well as with target and nontarget analytical screening of active fractions by liquid chromatography-high-resolution mass spectrometry. Due to masking by cytotoxic mixture components, the effects could not be detected in the raw water extract but were unraveled only after fractionation. Target chemical screening of the fraction that was active in the progesterone receptor (PR) assay revealed that progesterone and megestrol acetate were predominant drivers of PR-mediated activity along with medroxyprogesterone, dihydrotestosterone, androsterone, and epiandrosterone. Hydrocortisone was detected at sub-ng/L concentration in the active fraction in the glucocorticoid receptor (GR) assay but could not explain a significant fraction of the observed GR activity. The present study indicates that effect-based monitoring is a powerful tool to detect EDCs in the aquatic environment but that fractionation may be required to avoid masking effects of mixture components. Future effect-directed analysis studies are required to better understand the occurrence of EDCs and masking compounds in different lipophilicity windows, to finally reduce fractionation requirements for monitoring to a smart clean-up. Environ Toxicol Chem 2019;39:189-199. © 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC.

Occurrence and mass balance of sixty-two progestins in a municipal sewage treatment plant

Progestins (PGs) are a group of steroid hormones known to have endocrine-disrupting effects. These compounds can enter the aquatic environment via the discharge of treated or untreated wastewater and the disposal of sludge from sewage treatment plants (STPs); thus, their removal in STPs are of great importance. The present study simultaneously investigated the occurrences and fates of 62 PGs in a municipal STP in Beijing, China. Progesterone (P) and its metabolites were found to be the predominant compounds, with total dissolved concentrations of 1866 ng/L in the influent. About 11 P metabolites were newly detected, accounting for 25-55% and 75-91% of the total concentrations in wastewater and sludge, respectively. For the other three groups of PGs derived from different parent compounds, P derivatives were first detected in the STP with the highest concentration in the wastewater and sludge, followed by 19-nortestosterone (NT) derivatives and 17α-hydroxyprogesterone (17α-OHP) derivatives. The removal efficiencies in the dissolved phase of wastewater were relatively high for P and its metabolites (95-99%) and P derivatives (91-99%). And the relative persistence of NT (68-99%) and 17α-OHP derivatives (79-99%) was observed during the wastewater treatment processes. Mass balance analysis showed that the lost mass proportions were as high as 41-99%, the mass fractions in sludge were in the range of 0-55%, and 0.24-25% of the initial mass loadings was present in the effluent. These results indicated that biodegradation was the major removal mechanism of PGs in the STP.

Progesterone affects sex differentiation and alters transcriptional of genes along circadian rhythm signaling and hypothalamic-pituitary-gonadal axes in juvenile Yellow River Carp (Cyprinus carpio var.)

Progesterone (P4) is a biologically active steroid hormone that is involved in the regulation of oocyte growth and maturation, as well as development of the endometrium and implantation in the uterus of humans. It can also stimulate oocyte maturation in female fish, as well as spermatogenesis and sperm motility in male fish. Thus, P4 has been extensively used in human and animal husbandry as a typical progestin. However, P4 remaining in the water environment will pose a potential hazard to aquatic organisms. For example, it can interfere with sex differentiation and reproduction in aquatic vertebrates such as fish. Therefore, we investigated the effects of prolonged progesterone exposure on the expression of genes related to circadian rhythm signaling and the hypothalamic-pituitary-gonadal (HPG) axes in Yellow River Carp, which may have a potential impact on their sex differentiation. Our results suggested that P4 exposure altered the expression of genes related to circadian rhythm signaling, which can lead to disorders in the endocrine system and regulate the HPG axes-related activities. Furthermore, the expression of genes related to the HPG axes was also altered, which might affect gonadal development and the reproductive systems of Yellow River Carp. In addition, these changes may provide a plausible mechanism for the observed shifts in their sex ratio toward females.

Spatiotemporal evolvement and factors influencing natural and synthetic EDCs and the microbial community at different groundwater depths in the Chaobai watershed: A long-term field study on a river receiving reclaimed water

In this long-term field study, to restore a dried river ecosystem, reclaimed water was used as a supplementary water source. The main aim of this study was to investigate the accumulation and migration potential of EDCs in groundwater during long-term utilization of reclaimed water and the changes in microbial community during the removal of EDCs. A long-term field study was conducted in order to ascertain the temporal and spatial distribution of four selected endocrine-disrupting chemicals (EDCs) in an underground aquifer in the Chaobai watershed, where reclaimed water is the primary water source. Anew, the microbial community structure at different groundwater depths, along with related environmental factors were also determined. Based on the results obtained from this long-term study, it was found that the EDCs in the surface water of the Chaobai river have entered a depth of 80 m in the groundwater aquifers, within a distance of 360 m from the river. The vertical profiles of the concentrations of bisphenol A (BPA), 4-nonylphenol (NP), estrone (E1), and estriol (E3) decreased significantly from the surface to different groundwater depths with first-order attenuation rates of 0.0416, 0.0343, 0.0498, and 0.0173 m^-1. The aquifer depth, water temperature, conductivity, and coexisting anions correlated well with the distribution of EDCs in groundwater.

Dydrogesterone affects the transcription of genes in GnRH and steroidogenesis pathways and increases the frequency of atretic follicles in zebrafish (Danio rerio)

Dydrogesterone (DDG) is a synthetic progestin broadly used in human and veterinary medicine and has been widely detected in aquatic environments. However, its potential effects on aquatic organisms are little documented. Here we investigate the short-term effects of DDG on the transcriptional and histological responses in adult zebrafish (Danio rerio). Adult zebrafish were exposed to 32.0, 305 and 2490 ng L^-1 of DDG for 14 days. Real time quantitative PCR analysis showed that DDG significantly increased transcripts of most genes involved in the gonadotropin-releasing hormone (GnRH) pathway in the brain of female. In contrast, apparent down-regulation of these gene transcriptions was observed in the brain of males. The transcription of cyp19a1a in the ovary had a 2.3 fold increase at 2490 ng L^-1 of DDG and the transcription of hsd17b2 at 305 and 2490 ng L^-1 in the testis was enhanced by approximately 2.0 fold and 2.4 fold, respectively. Histopathological analysis revealed exposure to 2490 ng L^-1 DDG significantly increased the percentage of atretic follicles in the ovary. The results of this study suggest that DDG has potential endocrine disrupting effects and affects the ovarian development in zebrafish.

Determination of Progestin Residues in Fish by UPLC-Q-TOF/MS Coupled with QuEChERS

A novel method was developed for simultaneous determination of 10 progestin residues in fish by ultra-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) combined with a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method. The homogenized samples were dispersed by water, extracted with acetonitrile, and then purified by QuEChERS reagent. The concentrated analytes were detected by UPLC-Q-TOF/MS. High linearities (R ² > 0.995) and recoveries (85.71-117.08%) at three spiked levels (5, 10, and 20 ng/g) and low relative standard deviation values (<8.83%, n = 7) and limits of detection (0.23-0.66 ng/g) were obtained. This method is simple, rapid, reliable, sensitive, and efficient and can be used for monitoring of progestin residues in fish. This method provides a strong guarantee to deal with food emergencies for the laboratory, provides technical support for the screening and quantitative detection of progesterone in fish, and provides technical support for the food safety of aquatic products.

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.