Occurrence of Glucocorticoids, Mineralocorticoids, and Progestogens in Various Treated Wastewater, Rivers, and Streams

Eco-endocrinological dynamics: Unraveling dexamethasone's influence on the interrenal axis in juvenile carp Cyprinus carpio

This study delves into the eco-endocrinological dynamics concerning the impact of dexamethasone (DXE) on the interrenal axis in juvenile carp, Cyprinus carpio. Through a comprehensive analysis, we investigated the effects of DXE exposure on oxidative stress, biochemical biomarkers, gene expression, and bioaccumulation within the interrenal axis. Results revealed a concentration-dependent escalation of cellular oxidation biomarkers, including 1) hydroperoxides content (HPC), 2) lipid peroxidation level (LPX), and 3) protein carbonyl content (PCC), indicative of heightened oxidative stress. Concurrently, the activity of critical antioxidant enzymes, superoxide dismutase (SOD), and catalase (CAT), significantly increased, underscoring the organism's response to oxidative insult. Notable alterations were observed in biochemical biomarkers, particularly Gamma-glutamyl-transpeptidase (GGT) and alkaline phosphatase (ALP) activity, with GGT displaying a significant decrease with increasing DXE concentrations. Gene expression analysis revealed a significant upregulation of stress and inflammation response genes, as well as those associated with sensitivity to superoxide ion presence and calcium signaling, in response to DXE exposure. Furthermore, DXE demonstrated a concentration-dependent presence in interrenal tissue, with consistent bioconcentration factors observed across all concentrations tested. These findings shed light on the physiological and molecular responses of juvenile carp to DXE exposure, emphasizing the potential ecological implications of DXE contamination in aquatic environments. Understanding these dynamics is crucial for assessing the environmental impact of glucocorticoid pollutants and developing effective management strategies to mitigate their adverse effects on aquatic ecosystems.

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.

Screening androgen receptor agonists of fish species using machine learning and molecular model in NORMAN water-relevant list

Androgen receptor (AR) agonists have strong endocrine disrupting effects in fish. Most studies mainly investigate AR binding capacity using human AR in vitro. However, there is still few methods to rapidly predict AR agonists in aquatic organisms. This study aimed to screen AR agonists of fish species using machine learning and molecular models in water-relevant list from NORMAN, a network of reference laboratories for monitoring contaminants of emerging concern in the environment. In this study, machine learning approaches (e.g., Deep Forest (DF)), Random Forests and artificial neural networks) were applied to predict AR agonists. Zebrafish, fathead minnow, mosquitofish, medaka fish and grass carp are all important aquatic model organisms widely used to evaluate the toxicity of new pollutants, and the molecular models of ARs from these five fish species were constructed to further screen AR agonists using AlphaFold2. The DF method showed the best performances with 0.99 accuracy, 0.97 sensitivity and 1 precision. The Asn705, Gln711, Arg752, and Thr877 residues in human AR and the corresponding sites in ARs from the five fish species were responsible for agonist binding. Overall, 245 substances were predicted as suspect AR agonists in the five fish species, including, certain glucocorticoids, cholesterol metabolites, and cardiovascular drugs in the NORMAN list. Using machine learning and molecular modeling hybrid methods rapidly and accurately screened AR agonists in fish species, and helping evaluate their ecological risk in fish populations.

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.

Assessment for the data processing performance of non-target screening analysis based on high-resolution mass spectrometry

Non-target screening (NTS) based on high-resolution mass spectrometry (HRMS) is considered one of the most comprehensive approaches for the characterization of contaminants of emerging concern (CECs) in a complex sample. This study evaluated the performance of NTS in aquatic environments (including peak picking, database matching, product identification, semi-quantification, etc.) based on a self-developed data processing method using 38 glucocorticoids as testing compounds. Data-dependent acquisition (DDA) and data-independent acquisition (DIA) modes were used for obtaining the MS2 information for in-house or online database matching. Results indicate that DDA and DIA mode have their own advantages and can complement each other. The quantification method based on LC-HRMS has shown the potential to provide a fast and acceptable result for testing compounds. Finally, a matrix spike analysis was carried out on 66 CECs across different usage categories in wastewater, surface water, and seawater matrix samples, together with a case study performed for characterizing the whole contaminants in a Pearl River sample, to better illustrate the application potential of NTS workflow and the credibility of NTS outcomes. This study provides a foundation for novel applications of HRMS data by NTS workflow to identify and quantify CECs in complex systems.

Utilisation of molecularly imprinting technology for the detection of glucocorticoids for a point of care surface plasmon resonance (SPR) device

Herein, we describe the synthesis and characterisation of four synthetic recognition materials (nanoMIPs) selective for the glucocorticoid steroids - prednisolone, prednisone, dexamethasone, and cortisone. Using a solid-phase synthesis approach, these materials were then applied in the development of a surface plasmon resonance (SPR) sensor for the detection of these four targets in doped urine, to mimic the routine testing of agricultural waste for possible environmental exposure. The synthesised particles displayed a range of sizes between 104 and 160 nm. Affinity studies were performed, and these synthetic materials were shown to display nanomolar affinities (15.9-62.8 nM) towards their desired targets. Furthermore, we conducted cross-reactivity studies to assess the materials selectivity towards their desired target and the materials showed excellent selectivity when compared to the non-desired target, with selectivity factors calculated. Furthermore, through the use of 3D visualisation it can be seen that small changes between structures (such as a hydroxyl to ketone transformation) there is excellent selectivity between the compounds in the ranges of 100 fold plus. Using Surine™ doped samples the materials offered comparable nanomolar affinities (10.7-75.7 nM) towards their targets when compared to the standardised buffer preparation. Detection levels in urine for all compounds was in the nanomolar range. The developed sensor offers potential for these devices to be used in the prevention of these pharmaceutical compounds to enter the surrounding environment through agricultural waste through monitoring at source. Likewise, they can be used to monitor use in clinical samples.

Occurrence, distribution, and environmental risk of 61 glucocorticoids in surface water of the Yellow River Delta, China

Glucocorticoids (GCs), as important endocrine disrupting compounds and emerging contaminants, could have irreversible adverse effects on aquatic organisms even at ng/L levels. However, previous studies have only focused on the dissolved concentrations of GCs in the water, and limited data are available for their occurrences in the solid phase. In this study, the occurrence, distribution, and environmental risks of 61 natural and synthetic GCs in surface water of the Yellow River Delta (YRD) were simultaneously analyzed by investigating water, suspended particulate matter (SPM) and sediment samples at 64 sites in six major rivers in the wet season. Overall, 51 GCs were detected in all samples from different matrices, and their concentrations were in the range of not detected (ND)-274 ng/L in water, ND-42 ng/g dry weight (dw) in SPM and ND-9.98 ng/g dw in sediment. Natural GCs were the dominant compounds in all samples, followed by synthetic halogenated esters. High concentrations of GCs were observed in discharge outlet samples from livestock farming, aquaculture and industrial production, and the composition differences of GCs between human/animal sources and industrial sources could be used as indicators to identify pollution sources. Most GCs were distributed in the water phase, while compounds with higher log octanol/water partition coefficients (log Kow) tended to be adsorbed to SPM and sediment. The spatial distribution of GCs was primarily affected by anthropogenic activities and hydrodynamic conditions. Four synthetic compounds (budesonide [BD], fluocinolone acetonide [FOA], fluticasone propionate [FP], and clobetasol propionate [CBSP]) were identified as the main contributors to GC activity with a combined contribution of 57 %-95 %. Risk assessment using the risk quotient revealed that low to moderate risks are posed to aquatic organisms in surface water.

Chronic exposure to cortisone induces thyroid endocrine disruption and retinal dysfunction in adult female zebrafish (Danio rerio)

Cortisone has a large content in rivers because of its wide range of medical applications and elimination by organisms that naturally secrete it. As a steroid hormone, cortisone is recognized as a novel endocrine disruptor. Although ecotoxicological effects of the reproductive endocrine system have mainly been reported recently, thyroid endocrine in fish remains relatively less understood. Here, adult female zebrafish were exposed to cortisone at 0.0 (control), 3.2, 38.7, and 326.9 ng/L for 60 days. Evidence in this study came from fish behavior, hormone levels, gene expression, histological and morphological examinations. The results showed that THs (thyroid hormone) level disruption and pathohistological changes occurred in the thyroid gland, which may account for the gene expression changes in the hypothalamus-pituitary-thyroid gland axis. Specifically, more conversion of T4 (thyroxine) to T3 (triiodothyronine) led to an increased TSH (thyroid stimulating hormone) level in plasma. Severe thyroid tissue damage mainly occurred in the zebrafish exposed to 326.9 ng/L of cortisone. Meanwhile, consistent with the THs trend, the fish locomotion activity displayed more anxiety and excitement, the partial blockage of GABA (γ - aminobutyric acid) synthetic pathway genes might be the explanation of the underlying mechanism. Cortisone affected the gene expressions in the visual cycle and the circadian rhythm network also suggested interactions between thyroid endocrine disruption, retinal dysfunction, and abnormal behaviors of zebrafish. In summary, these findings suggest chronic exposure to cortisone induced various adverse effects in adult female zebrafish, which may help us better understand the risk of cortisone to fish in the wild.

Biotransformation of cyproterone acetate, drospirenone, and megestrol acetate in agricultural soils: Kinetics, microbial community dynamics, transformation products, and mechanisms

The occurrence of biologically active synthetic progestins in agricultural soils is of growing concern due to their potential to disrupt the endocrine function of aquatic fish in nearby surface waters. This study investigated the biotransformation outcomes of cyproterone acetate (CPA), drospirenone (DRO), and megestrol acetate (MGA) in four agricultural soils. The biotransformation data were fitted to a first-order decay model (R2 = 0.93-0.99), with half-lives and first-order decay coefficients ranging from 76.2-217 h and 9.10 × 10-3-3.20 × 10-3 (h-1), respectively. Abundant biotransformation products (TPs) were generated during incubation, with the number and yields varying across the four soils. 1,2-Dehydrogenation was the main transformation pathway of DRO in the four soils (yields of 32.3-214 %). Similarly, 1,2-dehydrogenation was the most relevant transformation pathway of MGA in the four soils (yields of 21.8-417 %). C3 reduction was the major transformation pathway of CPA in soils B, C, and D (yields of 114-245 %). Hydrogenation (yield of 133 %) and hydroxylation (yield of 21.0 %) were the second major transformation pathway of CPA in soil B and C, respectively. In particular, several TPs exhibited progestogenic and antimineralocorticoid activity, as well as genotoxicity. The high-throughput sequencing indicated that interactions between microorganisms and soil properties may affect biotransformation. Spearman correlation and bidirectional network correlation analysis further revealed that soil properties can directly interfere with the soil sorption capacity for the progestins, thus affecting biotransformation. In particular, soil properties can also limit or promote biotransformation and the formation of TPs (i.e., biotransformation pathways) by affecting the relative abundances of relevant microorganisms. The results of this study indicate that the ecotoxicity of synthetic progestins and related TPs can vary across soils and that the assessment of environmental risks associated with these compounds requires special consideration of both soil properties and microbial communities.

Tracing COVID-19 drugs in the environment: Are we focusing on the right environmental compartment?

The Coronavirus Disease 2019 (COVID-19) pandemic led to over 770 million confirmed cases, straining public healthcare systems and necessitating extensive and prolonged use of synthetic chemical drugs around the globe for medical treatment and symptom relief. Concerns have arisen regarding the massive release of active pharmaceutical ingredients (APIs) and their metabolites into the environment, particularly through domestic sewage. While discussions surrounding this issue have primarily centered on their discharge into aquatic environments, particularly through treated effluent from municipal wastewater treatment plants (WWTPs), one often overlooked aspect is the terrestrial environment as a significant receptor of pharmaceutical-laden waste. This occurs through the disposal of sewage sludge, for instance, by applying biosolids to land or non-compliant disposal of sewage sludge, in addition to the routine disposal of expired and unused medications in municipal solid wastes. In this article, we surveyed sixteen approved pharmaceuticals for treating COVID-19 and bacterial co-infections, along with their primary metabolites. For this, we delved into their physiochemical properties, ecological toxicities, environmental persistence, and fate within municipal WWTPs. Emphasis was given on lipophilic substances with log Kow >3.0, which are more likely to be found in sewage sludge at significant factions (25.2%-75.0%) of their inputs in raw sewage and subsequently enter the terrestrial environment through land application of biosolids, e.g., 43% in the United States and as high as 96% in Ireland or non-compliant practices of sewage sludge disposal in developing communities, such as open dumping and land application without prior anaerobic digestion. The available evidence underscores the importance of adequately treating and disposing of sewage sludge before its final disposal or land application in an epidemic or pandemic scenario, as mismanaged sewage sludge could be a significant vector for releasing pharmaceutical compounds and their metabolites into the terrestrial environment.

Transport of prednisolone, cortisone, and triamcinolone acetonide in agricultural soils: Sorption isotherms, transport dynamics, and field-scale simulation

The occurrence of glucocorticoids (GCs) in agricultural soils has raised concerns due to their high polarity, widespread biological effects in vertebrates, and their potential to disrupt vital processes such as glucose metabolism and immune function. This study investigated the sorption and transport dynamics of three GCs, namely cortisone (COR), prednisolone (PNL), and triamcinolone acetonide (TCA) in five soil-water systems (S1-S5 systems). The sorption data of the GCs were fitted to a linear sorption model (R2 = 0.95-0.99), with organic carbon (OC) normalized sorption coefficients ranging from 2.26 ± 0.02 to 3.36 ± 0.02. The sorption magnitudes (Kd) of the GCs exhibited a nearly linear correlation with their corresponding octanol-water partition coefficients (logKow) in the S1-S3 systems. However, some deviations from linearity were observed in the S4 and S5 systems. Furthermore, a strong correlation was observed between the Kd values of the GCs and the OC% of the soils. These data indicated that specific and hydrophobic partitioning interactions governed the sorption of GCs onto soils. The transport data of the GCs were fitted to a two-site nonequilibrium model using the CXTFIT program (R2 = 0.82-0.98). The retardation factor (R) for each GC exhibited a positive correlation with the OC% and clay contents of soils. Additionally, the relationships between the logR values and logKow values of the GCs deviated slightly from linear correlation in most columns. These results indicated that specific interactions in the columns were more pronounced compared to the batch systems. An initial field-scale simulation demonstrated that frequent precipitation can facilitate the dilution and vertical transport of the GCs through soil profiles. The transport potential of the GCs was affected by the properties and soils and GCs. Overall, these findings provide valuable insights into the transport potential and associated environmental risks of GCs in soil-water systems.

Endocrine disrupting chemicals in wastewater treatment plants in Kenya, East Africa: Concentrations, removal efficiency, mass loading rates and ecological impacts

This study investigated the levels, mass loadings, removal efficiency, and associated ecotoxicological risks of selected endocrine disrupting chemicals (EDCs), namely, dibutylphthalate (DBP), diethylhexylphthalate (DEHP), dimethylphthalate (DMP), linuron (LNR) and progesterone (PGT) in wastewater, sludge, and untreated dry biosolid (UDBS) samples from twelve wastewater treatment plants (WWTPs) in nine major towns in Kenya. Analysis was done using high-performance liquid chromatography coupled with triple quadrupole mass spectrometry (LC-MS/MS). All the wastewater influents had quantifiable levels of EDCs with DBP being the most abundant (37.49%) with a range of 4.33 ± 0.63 to 19.68 ± 1.24 μg L-1. DEHP was the most abundant in sludge and accounted for 48.2% ranging between 278.67 and 9243.49 ng g-1 dry weight (dw). In the UDBS samples, DEHP was also the most abundant (40%) of the total EDCs detected with levels ranging from 78.77 to 3938.54 ng g-1 dw. The average removal efficiency per pollutant was as follows: DMP (98.7%) > DEHP (91.7%) > PGT (83.4%) > DBP (77.9%) > LNR (72.2%) which can be attributed to sorption onto the biosolid, biological degradation, photolysis, and phytoremediation. The pH was negatively correlated to the EDC concentrations while total dissolved solids (TDS), chemical oxygen demand (COD), biochemical oxygen demand (BOD5), and electrical conductivity (EC) were positively correlated. The mass loadings were as high as 373.33 g day-1 of DBP in the treatment plants located in densely populated cities. DEHP and PGT had their Risk Quotients (RQs) > 1, posing a high risk to biota. DMP, DBP, and LNR posed medium risks as their RQ values were between 0.1 and 1. EDCs are therefore loaded to environmental compartments through either the effluent that loads these pollutants into the receiving aquatic ecosystem or through the UDBS, which are used as fertilizers in agricultural farmlands causing potential toxicological risks to aquatic and terrestrial life.

Short-term exposure to dexamethasone at environmentally relevant concentrations impairs embryonic development in Cyprinus carpio: Bioconcentration and alteration of oxidative stress-related gene expression patterns

In recent years and as a result of the Covid-19 pandemic, the consumption of dexamethasone (DXE) has increased. This favors that this corticosteroid is highly released in aquatic environments, generating deleterious effects in aquatic organisms. The information on the toxic effects of DXE in the environment is still limited. Thus, the objective of this work was to determine whether DXE at short-term exposure can cause alterations to embryonic development and alteration of oxidative stress-related gene expression patterns in Cyprinus carpio. For this purpose, common carp embryos (2 hpf) were exposed to realistic concentrations of DXE until 96 hpf. Alterations to embryonic development were evaluated at 12, 24, 48, 72 and 96 hpf. In addition, oxidative stress in carp embryos at 72 and 96 hpf was evaluated by cellular oxidation biomarkers (lipoperoxidation level, hydroperoxide and carbonyl protein content) and antioxidant enzymes activities (superoxide dismutase and catalase). Oxidative stress-related gene expression (sod, cat and gpx1) was also evaluated. Our results showed that DXE concentrations above 35 ng/L are capable of producing alterations to embryonic development in 50 % of the embryo population. Furthermore, DXE was able to induce alterations such as scoliosis, hypopigmentation, craniofacial malformations, pericardial edema and growth retardation, leading to the death of half of the population at 50 ng/L of DXE. Concerning oxidative stress, the results demonstrated that DXE induce oxidative damage on the embryos of C. carpio. In conclusion, DXE is capable of altering embryonic development and generating oxidative stress in common carp C. carpio.

Transcriptomic profiling of TLR-7-mediated immune-challenge in zebrafish embryos in the presence and absence of glucocorticoid-induced immunosuppression

Although numerous studies imply a correlation between chemical contamination and an impaired immunocompetence of wildlife populations, the assessment of immunomodulatory modes of action is currently not covered in the regulatory requirements for the approval of new substances. This is not least due to the complexity of the immune system and a lack of standardised methods and validated biomarkers. To tackle this issue, in this study, the transcriptomic profiles of zebrafish embryos were analysed in response to the immunosuppressive compound clobetasol propionate, a synthetic glucocorticoid, and/or the immunostimulatory compound imiquimod (IMQ), a TLR-7 agonist. Using IMQ, known for its potential to induce psoriasis-like effects in mice and human, this study additionally aimed at evaluating the usability of the zebrafish embryo model as an alternative and 3R conform system for the IMQ-induced psoriasis mouse model. Our study substantiates the suitability of previously proposed genes as possible biomarkers for immunotoxicity, such as socs3, nfkbia, anxa1c, fkbp5 and irg1l. Likewise, however, our findings indicate that these genes may be less suitable to distinguish a suppressive from stimulating fashion of action. In contrast, based on a differential regulation in opposite direction in response to both compounds, krt17, rtn4a, and1, smhyc1 and gmpr were identified as potential novel biomarkers with said power to differentiate. Observed IMQ-induced alterations in the expression of genes previously associated with the pathogenesis of psoriasis such as krt17, nfkbia, parp1, pparg, nfil3-6, per2, stat4, klf2, rtn4a, anxa1c and nr1d2 indicate the inducibility of psoriatic effects in the zebrafish embryo. Our work contributes to the establishment of an approach for a 3R-compliant investigation of immunotoxic mechanisms of action in aquatic vertebrates. The validated and newly identified biomarker candidates of specific immunotoxic effects can be used in future studies in the context of environmental hazard assessment of substances or also for human-relevant immunotoxicological questions.

Prednisolone Accelerates Embryonic Development of Zebrafish via Glucocorticoid Receptor Signaling at Low Concentrations

Synthetic glucocorticoids have been widely detected in aquatic ecosystems and may pose a toxicological risk to fish. In the present study, we described multiple end point responses of zebrafish to a commonly prescribed glucocorticoid, prednisolone (PREL), at concentrations between 0.001 and 9.26 μg/L. Of 23 end points monitored, 7 were affected significantly. Significant increases in the frequency of yolk extension formation, spontaneous contraction, heart rate, and ocular melanin density and significant decreases of ear-eye distance at PREL concentrations of 0.001 μg/L and above clearly pointed to the acceleration of embryonic development of zebrafish by PREL. Further confirmation came from the alterations in somite numbers, head-trunk angle, and yolk sac size, as well as outcomes obtained via RNA sequencing, in which signaling pathways involved in tissue/organ growth and development were highly enriched in embryos upon PREL exposure. In addition, the crucial role of glucocorticoid receptor (GR) for PREL-induced effects was confirmed by both, the coexposure to antagonist mifepristone (RU486) and GR-/- mutant zebrafish experiments. We further demonstrated similar accelerations of embryonic development of zebrafish upon exposure to 11 additional glucocorticoids, indicating generic adverse effect characteristics. Overall, our results revealed developmental alterations of PREL in fish embryos at low concentrations and thus provided novel insights into the understanding of the potential environmental risks of glucocorticoids.

Prioritizing pharmaceutically active compounds (PhACs) based on occurrence-persistency-mobility-toxicity (OPMT) criteria: an application to the Brazilian scenario

A study of Quantitative Structure Activity Relationship (QSAR) was performed to assess the possible adverse effects of 25 pharmaceuticals commonly found in the Brazilian water compartments and to establish a ranking of environmental concern. The occurrence (O), the persistence (P), the mobility (M), and the toxicity (T) of these compounds in the Brazilian drinking water reservoirs were evaluated. Moreover, to verify the predicted OPMT dataset outcomes, a quality index (QI) was also developed and applied. The main results showed that: (i) after in silico predictions through VEGA QSAR, 19 from 25 pharmaceuticals consumed in Brazil were classified as persistent; (ii) moreover, after in silico predictions through OPERA QSAR, 15 among those 19 compounds considered persistent, were also classified as mobile or very mobile. On the other hand, the results of toxicity indicate that only 9 pharmaceuticals were classified with the highest toxicity level. Ultimately, the QI of 7 from 25 pharmaceuticals were categorized as 'optimal'; 15 pharmaceuticals were categorized as 'good'; and only 3 pharmaceuticals were categorized as 'regular'. Therefore, based on the QI criteria used, it is possible to assume that this OPMT prediction dataset had a good reliability. Efforts to reduce emissions of OPMT-pharmaceuticals in Brazilian drinking water reservoirs are encouraged.

Baseline progestins characterization in surface waters of three main Portuguese estuaries

Synthetic progestins are micropollutants of special concern, due to their growing use in human and veterinary therapies and their risks to aquatic life. Currently, there is a lack of environmental information on these compounds, worldwide. The main objective of this work was to characterize the levels of the most consumed progestins in Portugal. For that, Ria de Aveiro, Tagus estuary and Ria Formosa were sampled in a temporal perspective to evaluate levels of drospirenone (DRO), desogestrel (DSG), gestodene (GST) and levonorgestrel (LNG). Drospirenone and desogestrel were the most abundant progestins. In the North of Portugal, DSG was the most abundant (Aveiro: 193.9 ng L-1 in summer), while DRO was more representative in the South (Tagus: 178.9 ng L-1; Formosa: 125.7 ng L-1) and also in summer. These spatial differences can be associated with the hydrodynamics of each estuarine system as well as the distinct population and tourist levels associated with each site.

A comparative study of human and zebrafish glucocorticoid receptor activities of natural and pharmaceutical steroids

Introduction

The action of environmental steroids on the human glucocorticoid receptor (hGR) has been pointed out with the risk to impair physiological immune and metabolic processes regulated by this nuclear receptor. However, there is still a lack of mechanistic information regarding their ability to interact with GR in aquatic species.

Methods

To investigate ligand activation differences between hGR and zebrafish GR (zfGR), we tested several natural and synthetic steroids using reporter cell lines expressing hGR or zfGR.

Results and discussion

Almost all the glucocorticoids tested (dexamethasone, cortisol, bimedrazol, medrol, cortivazol and fluticasone) are agonists of the two receptors with similar potencies. The dissociated glucocorticoids, RU24782 and RU24858 are agonists of both zfGR and hGR but with a better potency for the latter. On the other hand, the synthetic glucocorticoid forbimenol and the mineralocorticoid aldosterone are agonist on hGR but antagonist on zfGR. The other steroids tested, androgens and progestins, are all antagonists of both GRs with equal or lower potency on zfGR than on hGR. Surprisingly, the lower efficacy and potency on zfGR of aldosterone, forbimenol and the dissociated glucocorticoids is not related to their affinity for the receptors which would suggest that it could be related to less efficacious recruitment of coactivators by zfGR compared to hGR.

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.

A robust multi-residue method for the monitoring of 25 endocrine disruptors at ultra-trace levels in surface waters by SPE-LC-MS/MS

Estrogenic endocrine disruptors are one of the biggest ecotoxicological threats in water that pose a significant ecological burden and health-risk for humans due to their high biological activity and proven additive effects. Therefore, we have developed and validated the most comprehensive and ultra-sensitive analytical method published to date, for reliable quantification of 25 high-risk endocrine disruptors at their ecologically relevant concentrations: naturally excreted hormones (estradiol, estrone, estriol, testosterone, corticosterone, and progesterone), synthetic hormones used for contraception and menopausal symptoms (ethinylestradiol, drospirenone, chlormadinone acetate, norgestrel, gestodene, tibolone, norethindrone, dienogest, and cyproterone) and bisphenols (BPS, BPA, BPF, BPE, BPAF, BPB, BPC, and BPZ). It is based on a solid-phase extraction of water samples, followed by a robust dansyl chloride derivatization with detection by liquid chromatography-tandem mass spectrometry with a single sample preparation and two analytical methods using the same analytical column and mobile phases. The achieved limits of quantitation are in the sub-ng L^-1 range, and detection limits as low as 0.02 ng L^-1, meeting the newest proposal for environmental quality standards (EQS) by the EU water framework directive for estradiol and ethinylestradiol. The method was extensively validated and applied to seven representative Slovenian water samples, where we detected 21 out of 25 analytes; 13 were quantified in at least one sample. Estrone and progesterone were quantified in all samples, reaching levels up to 50 ng L^-1; ethinylestradiol was higher than the current EQS (0.035 ng L^-1) in three samples, and estradiol was above its EQS (0.4 ng L^-1) in one sample, proving the method's applicability and the necessity for monitoring these pollutants.

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.

Suspended particulate matter-associated environmental corticosteroids in the Pearl River, China: Occurrence, distribution, and partitioning

Suspended particulate matter (SPM) plays an important role in the geochemical behavior and fate of organic micropollutants in aquatic environments. However, the presence of trace emerging endocrine disruptors such as environmental corticosteroids (ECs) in SPM is less well understood. This study focused on the occurrence, distribution, and partitioning of SPM-associated ECs in the Pearl River system, China. Ubiquitous particulate ECs were found in the surface water of the rivers at average concentrations (dry weight) between 0.46 ng/g (flumethasone) and 8.83 ng/g (clobetasone butyrate). The total EC (∑ECs) concentrations of the 24 selected target compounds varied from <1.03 ng/g to 62.3 ng/g, with an average and median of 17.6 ng/g and 13.7 ng/g, respectively. Higher SPM-bound EC levels were commonly observed in winter (dry season), and spatially, their relatively high contamination in urban tributary networks decreased while flowing to mainstreams and then gradually attenuated from upstream to the estuary. Despite the approximately 90 % mass distribution of ∑ECs in the aqueous phase, approximately 50 % of their effect burden was derived from the suspended particulate fractions. For the first time, in situ SPM-water partitioning coefficients (K_p) and their organic carbon-normalized ones (K_oc) of ECs were determined in surface waters, and a field-derived preliminary linear equation was proposed to estimate K_oc for ECs using basic physicochemical parameters n-octanol/water partitioning coefficient (K_ow), which is of importance with regard to the assessment of transport, fate, and risk of these emerging hazardous chemicals. Furthermore, the significant logK_oc-logK_ow relationship for ECs reveals that nonspecific hydrophobic partitioning is a major association mechanism between SPM and ECs. Moreover, hydrogen bonding is suggested to be a prevailing specific binding mechanism and provides more contribution to nonhydrophobic interactions between ECs and particulate organic matter than environmental estrogens.

Reproductive endocrine disruption and gonadal intersex induction in male Japanese medaka chronically exposed to betamethasone at environmentally relevant levels

The broad utilization of betamethasone in medical treatments may pose a significant ecotoxicological risk to aquatic organisms, yet its potential reproductive toxicity remains unclear. The present study examined the impacts of environmental exposure on male reproduction using Japanese medaka (Oryzias latipes). After 110 days of betamethasone exposure at environmentally relevant concentrations (0, 20 and 200 ng/L), LH/FSH synthesis and release in the pituitary was inhibited, and the production of sex hormones and their signaling pathways in the gonads of male medaka were greatly influenced. This synthetic glucocorticoid restrained testosterone (T) synthesis and gave rise to a significant increase in E₂/T and E₂/11-KT ratios. Furthermore, chronic betamethasone exposure (20 and 200 ng/L) led to the suppression of androgen receptor (AR) signaling and enhancement of estrogen receptors (ERs) signaling. An increase in hepatic vitellogenin contents was also detected, and testicular oocytes were observed in both 20 and 200 ng/L betamethasone-treated groups. It showed that 20 and 200 ng/L betamethasone could induce male feminization and even intersex, triggering abnormal spermatogenesis in medaka males. With its adverse effects on male fertility, betamethasone could potentially influence the fishery productivity and population dynamics in aquatic ecosystems.

Estrogenic, androgenic, and glucocorticoid activities and major causative compounds in river waters from three Asian countries

Estrogen, androgen, and glucocorticoid receptors (ER, AR, and GR) agonist activities in river water samples from Chennai and Bangalore (India), Jakarta (Indonesia), and Hanoi (Vietnam) were evaluated using a panel of chemical-activated luciferase gene expression (CALUX) assays and were detected mainly in the dissolved phase. The ER agonist activity levels were 0.011-55 ng estradiol (E2)-equivalent/l, higher than the proposed effect-based trigger (EBT) value of 0.5 ng/l in most of the samples. The AR agonist activity levels were < 2.1-110 ng dihydrotestosterone (DHT)-equivalent/l, and all levels above the limit of quantification exceeded the EBT value of 3.4 ng/l. GR agonist activities were detected in only Bangalore and Hanoi samples at dexamethasone (Dex)-equivalent levels of < 16-150 ng/l and exceeded the EBT value of 100 ng/l in only two Bangalore samples. Major compounds contributing to the ER, AR, and GR agonist activities were identified for water samples from Bangalore and Hanoi, which had substantially higher activities in all assays, by using a combination of fractionation, CALUX measurement, and non-target and target chemical analysis. The results for pooled samples showed that the major ER agonists were the endogenous estrogens E2 and estriol, and the major GR agonists were the synthetic glucocorticoids Dex and clobetasol propionate. The only AR agonist identified in major androgenic water extract fractions was DHT, but several unidentified compounds with the same molecular formulae as endogenous androgens were also found.

Three-dimensional hydroxylated covalent organic frameworks for solid phase extraction of glucocorticoids in environmental water samples

It is challenging to achieve the highly sensitive detection of glucocorticoids at ultratrace levels because of the abundant hydrophilic groups in their molecules and the complexity of environmental water sample matrices. Here, a highly crystalline three-dimensional hydroxylated covalent organic frameworks (denoted by COF-301) with tetra(4-anilyl)methane (TAM) and 2,5-dihydroxyterephthalaldehyde (DHTA) as building units was constructed and proposed as adsorbent for solid phase extraction (SPE) of glucocorticoids. Theoretical studies were conducted to elucidate the potential adsorption mechanism of glucocorticoids on the COF-301. The COF-301 based SPE combined with liquid chromatography-tandem mass spectrometry provides a promising approach for the preconcentration and determination of glucocorticoids residue in water samples. Good linearity with a correlation coefficient exceeding 0.9988, low limits of detection ranging from 0.024 to 0.075 ng L^-1 and relative standard deviations below 6.68% were achieved. The proposed method was successfully applied to analyze glucocorticoids residue in actual water samples, demonstrating the prospects of this method for the determination of trace glucocorticoids.

Fate of progesterone and norgestrel in anaerobic/anoxic/oxic (A/A/O) process: Insights from biotransformation and mass flow

Progesterone (P4) and norgestrel (NGT) are two steroid progestogens that can pose adverse effects on aquatic organisms at ng/L levels. Despite increasing concern on their occurrence and removal in wastewater, their fate in the wastewater treatment process has not been well documented. This study identified the transformation products (TPs) of P4 and NGT in anaerobic/anoxic/oxic (A/A/O) process. Potential functional genes involved in biotransformation of P4 and NGT were explored. The elimination or formation behavior of P4, NGT and convinced TPs along various units of A/A/O process was revealed through the mass flow. Results showed that 12 and 13 TPs were identified in the P4 and NGT groups respectively, wherein 10 identical TPs and C-19 structures transformation pathways were observed in both groups. Six genes were found that may be involved in dehydrogenation and isomerization reactions in the pathways. Mass flow indicated that P4 and NGT were mainly eliminated in anaerobic and anoxic units, while convinced TPs mainly formed in anaerobic and anoxic units and were then eliminated in aerobic unit. Further, the ecological risks of the effluent should not be ignored as residual compounds including P4 or NGT and their TPs in the effluent still posed adverse effects on zebrafish transcript levels.

Endocrine disrupting chemicals entering European rivers: Occurrence and adverse mixture effects in treated wastewater

In the present study on endocrine disrupting chemicals (EDCs) in treated wastewater, we used chemical and effect-based tools to analyse 56 wastewater treatment plant (WWTP) effluents from 15 European countries. The main objectives were (i) to compare three different receptor-based estrogenicity assays (ERα-GeneBLAzer, p-YES, ERα-CALUX®), and (ii) to investigate a combined approach of chemical target analysis and receptor-based testing for estrogenicity, glucocorticogenic activity, androgenicity and progestagenic activity (ERα-, GR-, AR- and PR-GeneBLAzer assays, respectively) in treated wastewater. A total of 56 steroids and phenols were detected at concentrations ranging from 25 pg/L (estriol, E3) up to 2.4 μg/L (cortisone). WWTP effluents, which passed an advanced treatment via ozonation or via activated carbon, were found to be less contaminated, in terms of lower or no detection of steroids and phenols, as well as hormone receptor-mediated effects. This result was confirmed by the effect screening, including the three ERα-bioassays. In the GeneBLAzer assays, ERα-activity was detected in 82 %, and GR-activity in 73 % of the samples, while AR- and PR-activity were only measured in 14 % and 21 % of the samples, respectively. 17β-estradiol was confirmed as the estrogen dominating the observed estrogenic mixture effect and triamcinolone acetonide was the dominant driver of glucocorticogenic activity. The comparison of bioanalytical equivalent concentrations (BEQ) predicted from the detected concentrations and the relative effect potency (BEQ_chem) with measured BEQ (BEQ_bio) demonstrated good correlations of chemical target analysis and receptor-based testing results with deviations mostly within a factor of 10. Bioassay-specific effect-based trigger values (EBTs) from the literature, but also newly calculated EBTs based on previously proposed derivation options, were applied and allowed a preliminary assessment of the water quality of the tested WWTP effluent samples. Overall, this study demonstrates the high potential of linking chemical with effect-based analysis in water quality assessment with regard to EDC contamination.

Sand and sand-GAC filtration technologies in removing PPCPs: A review

Concerns have been raised about the risks that pharmaceuticals and personal care products (PPCPs) in aquatic environments posed to humans and the environment. In recent years, sand filtration has been used to potentially remove these emerging contaminants from water. However, there has been no review of the effectiveness of this technology to date. This paper presents a brief introduction of sand filtration types, reviews the current progress in PPCPs removal through sand filtration, and discusses the mechanisms behind this process and the combination of granular activated carbon (GAC) and sand as an enhanced sand-GAC filtration technology. Sand filtration achieves a reasonable but highly variable degree of PPCPs removal. Biodegradation and adsorption are the two main mechanisms of PPCPs removal, in particular the biodegradation since adsorption capacity of sand is relatively low. Other processes, such as bio-sorption and indirect adsorption, may also contribute to PPCPs removal. To compensate for the inadequate PPCPs removal through sand filtration, porous GAC has been combined with sand to develop sand-GAC filtration technologies. Serial, dual, and sandwich filters have been investigated, and significant removal enhancement has been observed, due to the strengthened adsorption capacity, suggesting the applicability of these variants. Future research focus, such as investigating the influence of different operational conditions on sand filter performance, obtaining a deeper understanding of the various removal mechanisms, and investigating of long-term performance of the filter used for PPCPs removal, are suggested.

Evaluation and Application of a Novel Diffusive Gradients in Thin-Films Technique for In Situ Monitoring of Glucocorticoids in Natural Waters

The potential environmental risks of glucocorticoids (GCs) have attracted attention in the past few decades. In this study, a novel diffusive gradients in thin-films (DGT) device and analytical technique based on the second generation of polar enhanced phase (PEP-2), PEP-2-DGT, were developed for sampling and quantifying natural and synthetic GCs in aquatic systems. The capacity of PEP-2 gels for accumulating all target compounds was >600 μg per disc, sufficient for long-term passive sampling of selected GCs, even in wastewaters. Systematic tests were carried out to verify the application of DGT in natural waters and wastewaters. The performance of PEP-2-DGT devices was independent (C_DGT/C_soln was in the acceptable range of 0.9-1.1) of a wide range of environmental conditions: ionic strength (0.001-0.5 mol L^-1), dissolved organic matter (0-20 mg L^-1), and pH (3.06-9.02). It was tested for various diffusive layer thicknesses (0.565-2.065 mm) and different deployment times (10-168 h). Diffusion coefficients (D) of selected GCs through an agarose-based diffusive gel were determined for the first time (3.80-4.85 × 10^-6 cm^-2 s ^-1 at 25 °C). Linear correlations between D and log K_ow were established for three groups of target GCs (R² = 0.96-0.99). This could enable prediction of D values for other GCs with similar structures in the future, which will help for rapid screening and emergency monitoring. Concentrations and distribution patterns of analytes obtained by PEP-2-DGT devices in five rivers after 7- and 14-day deployments were in accordance with those measured from grab samples, with total GC concentrations ranging from 7 to 27 ng L^-1 at all sampling sites, confirming the reliability and robustness of the DGT devices for monitoring GCs in natural waters. The development of the new DGT technique will help improve understanding of the behavior and fate of these compounds in the aquatic environments.

Enhancing fluoroglucocorticoid defluorination using defluorinated functional strain Acinetobacter. pittii C3 via humic acid-mediated biotransformation

Defluorination is a key factor in reducing biologically accumulated carcinogenic and teratogenic toxicity of fluoroglucocorticoids (FGCs). To enhance defluorination efficiency, a highly efficient defluorination-degrading strain Acinetobacter. pittii C3 was isolated, and the promotion mechanism through humic acid (HA)-mediated biotransformation was investigated. Optimal biodegradation conditions for Acinetobacter sp. pittii C3 were pH of 7.0, temperature of 25 ℃, and HA content of 5.5 mg/L, according to response surface methodology analysis. The attenuation rate constant and maximum defluorination percentage of triamcinolone acetonide (TA) in HA-mediated biotransformation system (HA-C3) were 3.99 × 10^-2 and 96%, respectively, which were 2.22 and 1.24 times higher than those in the unitary C3 biodegradation system (U-C3), respectively. The major defluorination pathways included elimination, hydrolysis, and hydrogenation, with contributions of 24.5%, 32.4%, and 43.1%, respectively. The bio-reductive hydrodefluorination rate was enhanced by 1.89 times that of HA-mediated, while the other two defluorination pathways exhibited insignificant changes. HA, as the congeries of negatively charged microbes and hydrophobic TA, accelerates the electron transfer rate between Acinetobacter. pittii C3 and TA through the quinone groups. Furthermore, the mutual conversion between the functional groups of hydroxyl oxidation and ketone reduction of HA provided electron donors for TA reductive defluorination and hydrogenation and electron acceptors for TA oxidation. This study provides an effective strategy for FGC-enhanced detoxification using natural HA.

Spironolactone affects cardiovascular and craniofacial development in zebrafish embryos (Danio rerio)

Spironolactone, a potassium-sparing diuretic and aldosterone antagonist, is a mineralocorticoid hormone commonly prescribed to patients suffering from heart failure, hirsutism, dermatological afflictions, and hypertension. Interestingly, relatively little work has been done on the development of vertebrate embryos after exposure to this compound. Here, we treat zebrafish embryos with spironolactone at 10^-6 M, 10^-7 M, or 10^-8 M, and observe them after three to seven days of exposure. While no effect was observed in mortality, we did detect differences in cardiovascular development at 3 dpf and craniofacial development at 5 dpf. At 10^-6 M, smaller atria, ventricles, and blood vessels were observed. The highest concentrations also caused a longer ceratohyal/Meckel's distance, longer palatoquadrate, and smaller angles between the palatoquadrate and both the ceratohyal and Meckel's. Further research of spironolactone's effects on embryonic development could lead to a better understanding of the compound resulting in improved public and environmental health.

Synthetic Progestins in Waste and Surface Waters: Concentrations, Impacts and Ecological Risk

Synthetic progestins (PGs) are a large family of hormones used in continuously growing amounts in human and animal contraception and medicinal therapies. Because wastewater treatment plants (WWTPs) are unable to eradicate PGs after excretion, they are discharged into aquatic systems, where they can also be regenerated from conjugated PG metabolites. This review summarises the concentrations of 12 PGs in waters from 2015 to 2021. The selected PGs were considered of particular interest due to their wide use, activity, and hormonal derivation (from testosterone, progesterone, and spirolactone). We concluded that PGs had been analysed in WWTPs influents and effluents and, to a lesser extent, in other matrices, including surface waters, where their concentrations range from ng/L to a few µg/L. Because of their high affinity for cell hormone receptors, PGs are endocrine disruptor compounds that may alter the reproductive fitness and development of biota. This review focused on their biological effects in fish, which are the most used aquatic model organisms to qualify the impacts of PGs, highlighting the risks that environmental concentrations pose to their health, fecundity, and fertility. It is concluded that PGs research should be expanded because of the still limited data on their environmental concentrations and effects.

Occurrence and removal of progestogens from wastewater treatment plants in China: Spatiotemporal variation and process comparison

This study investigated the overall occurrence and spatiotemporal variation of 19 progestogens in 608 samples collected from 17 wastewater treatment plants (WWTPs) distributed across China during four seasons. The aqueous removal efficiencies of progestogens were calculated and the efficacies of process segments, secondary and advanced processes, and process units in the removal of progestogens were explored. The results indicated that progestogens were widely detected in investigating WWTPs, with the progesterone, dydrogesterone, dienogest, ethisterone, and norethindrone were always dominant in the influent, secondary effluent, final effluent, and excess sludge. Seasonally, the influent exhibited more variability than the other matrices, that 10 progestogens concentrations varied significantly during the four seasons. Spatially, the influent concentrations of progestogens were generally higher in northern WWTPs than that in southern WWTPs during spring and summer. Eight progestogens were stably removed by the WWTPs across seasons, and most progestogens varied considerably in removal in different WWTPs. The conventional process segment was the dominant contributor to progestogen removal. The anaerobic-anoxic-oxic process and a combined process consisting of densadeg and cloth media filter and ultraviolet disinfection showed the highest removal of progestogens among various secondary and advanced treatment processes, respectively. Mass balance analysis showed that most progestogens were effectively eliminated in the aerobic unit, with biodegradation being the primary removal pathway. This study presents the first picture of the spatiotemporal dynamics of the distribution of progestogens in WWTPs of China and provides valuable information for better understanding of the occurrence and removal of progestogens in WWTPs.

[Simultaneous determination of 24 corticosteroids in sediments based on ultrasonic extraction, solid-phase extraction, liquid chromatography, and tandem mass spectrometry]

Corticosteroids (CSs) are widely used to treat various inflammatory and immune diseases in humans and animals, such as arthritis and lupus. Thus far, CSs have been frequently detected in diverse pollution sources, such as in the influent and effluent of traditional wastewater treatment plants, livestock farms, and aquaculture. Owing to incomplete removal or limited treatment, CSs can enter the water environment and eventually be adsorbed in the sediment. Due to hydrodynamic effects, CSs can re-enter the surface water through the resuspension of sediments, and pose a hazard to the ecosystem and human health via the enrichment of aquatic organisms and transmission through the food chain. Therefore, trace analysis of CSs in sediments is significant for exploring their prevalence and behavior in multiple environments. However, existing research mainly focuses on the determination of glucocorticoids in water samples, and studies on the systematic quantitative analysis of CSs in environmental solid samples with more complex matrices are scarce. Moreover, majority of previous investigations focused on a limited number of glucocorticoids, making it important to widen the range of target compounds to be studied, including mineralocorticoids. In this study, the main factors which could influence the accuracy and sensitivity in the determination of 24 target CSs were systematically optimized in the sample pretreatment and instrument analysis. A novel method based on ultrasonic extraction coupled with solid phase extraction (SPE) for sample pretreatment was developed for the simultaneous determination of the 24 CSs in sediments using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The sediment sample was ground to homogenize the particle sizes after freeze-drying. The analytes from 2.0 g of the sample were ultrasonicated and extracted with methanol-acetone (1∶1, v/v). After concentrating and diluting each extract, SPE was performed. The water sample was extracted and purified using hydrophile-lipophile balance (HLB) cartridges, following which the extract was further purified with LC-NH2 cartridges. The extracts were concentrated using a rotary evaporator, dried under a gentle stream of nitrogen, and re-dissolved in methanol for instrumental analysis. Chromatographic separation was conducted on an Agilent ZORBAX Eclipse Plus C8 column (100 mm×2.1 mm, 1.8 μm), with a column flow rate of 0.3 mL/min and a gradient of mobile phases A (water with 0.1% acetic acid) and B (acetonitrile). The column temperature was set to 30 ℃ and the injection volume was fixed at 5 μL. Electrospray ionization MS in the dynamic multiple reaction monitoring (DMRM) and selected ion monitoring (SIM) modes were performed in the positive mode for the qualitative and quantitative analysis of the target compounds. Quantitation of the target compounds was carried out using the internal standard method. The effects of different extraction solvents, purification conditions, and MS conditions on the recoveries of the target compounds were investigated. The limits of detection (LODs) (S/N≥3) and limits of quantification (LOQs) (S/N≥10) of all 24 compounds were in the ranges of 0.14-1.25 μg/kg and 0.26-2.26 μg/kg, respectively. The correlation coefficients of linear calibration curves were higher than 0.995 in the range of 1.0-100 μg/L. The recoveries of the 24 CSs at 5, 20, and 50 μg/kg spiked levels ranged from 64.9% to 125.1% with relative standard deviations of 0.4%-12.6% (n=5). The developed method was applied to analyze the CSs in three sediment samples from the rivers of the Pearl River Delta. In all, 11 target compounds were detected in these samples, with contents in the range of 1.25-29.38 μg/kg. The characteristic of this method is efficient, sensitive, reliable, and suitable for the trace determination of varieties of natural and synthesized CSs in environmental sediments.

Enhanced bio-reductive degradation of fluoroglucocorticoids in the groundwater fluctuation zone by external electron donors: Performance, microbial community, and functional genes

This study evaluated the effectiveness of external electron donors on the bio-reductive degradation enhancement of fluoroglucocorticoids (FGCs) in the groundwater fluctuation zone during the wet season when reverse upward fluctuation of the groundwater table occurs and the dry season after the groundwater table declines. The results showed that the external electron donors, provided by the addition of nano zero-valent iron-modified biochar (nZVI@BC), inhibited the migration and enhanced the reductive defluorination of triamcinolone acetonide (TA), a representative FGC. The accumulation rate constant with temporal fluctuation depth and the attenuation rate constant with vertical fluctuation depth were -2.55 × 10^-3 and 4.20 × 10^-2, respectively, in the groundwater of the natural groundwater fluctuation zone (N-FZ). In contrast, the accumulation and attenuation rate constants were, respectively, 35.6% and 2.64 times higher in the groundwater fluctuation zone amended with nZVI@BC (nZVI@BC-FZ) as compared with those observed in the N-FZ. Furthermore, the decay rate constant of the TA residue in the dry season was 0.843 × 10^-2 μg/d in N-FZ and was 2.19 times higher in nZVI@BC-FZ. This enhancement effect, caused by the addition of external electrons, was positively correlated with the evolution of the microbial community and the expression of functional genes. The microbes evolved into functional genera with reductive dehalogenation (Xylophilus and Hydrogenophaga) and iron-oxidizing (Lysobacter, Pseudoxanthomonas, and Sphingomonas) abilities in the nZVI@BC-FZ system, which increased dehalogenation and iron oxide genes by a 4-5 order of magnitude. The utilization proportion of external electrons for TA metabolism was 50.04%, of which 30.82%, 10.26%, and 8.96% were utilized for defluorination, hydrogenation, and ring-opening, respectively. This study provides an effective method to reduce pollutant diffusion and enhance the bio-reductive degradation caused by groundwater table fluctuation.

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.

Probabilistic framework for assessing ecological risk of Contaminants of Emerging Concern: Application to a Canadian lake system

Contaminants of Emerging Concern (CECs) in natural water pose risks to ecosystems. The concentration of CECs varies spatially and temporally, and their estimated ecotoxicities differ widely by toxicological studies. This study extensively reviewed literature on ecological risk assessment and proposed a probabilistic framework for assessing ecological risk and its uncertainties (aleatory and epistemic). The framework integrated Adverse Outcome Pathway in risk assessment and was applied to a Canadian lake system for seven CECs: salicylic acid, acetaminophen, caffeine, carbamazepine, ibuprofen, drospirenone, and sulfamethoxazole. Altogether 264 water samples were collected and analyzed from 15 sites May 2016 to September 2017. Phytoplankton, zooplankton, and fish were also sampled and analyzed. The results show ecological risk estimates (Risk Quotient, RQ) varied considerably indicating a range of uncertainty. Based on the conservative estimate, the central tendency estimate of the ecological risk of mixture compounds was medium (RQ = 0.6) including drospirenone. However, the reasonably maximum estimate of the risk was high (RQ = 1.4) for mixture compounds including drospirenone. The high risk is primarily due to drospirenone as its individual risk was high (RQ = 1.1) to fish. The specific site and time of high drospirenone exposure was identified for implementing control measures. Classification of ecotoxicity values based on environmental parameters such as climate and water quality, can reduce uncertainty in the risk estimate.

Effectiveness of chelating agent-assisted Fenton-like processes on remediation of glucocorticoid-contaminated soil using chemical and biological assessment: performance comparison of CaO2 and H2O2

Glucocorticoids (GCs) have drawn great concern due to widespread contamination in the environment and application in treating COVID-19. Most studies on GC removal mainly focused on aquatic environment, while GC behaviors in soil were less mentioned. In this study, degradation of three selected GCs in soil has been investigated using citric acid (CA)-modified Fenton-like processes (H₂O₂/Fe(III)/CA and CaO₂/Fe(III)/CA treatments). The results showed that GCs in soil can be removed by modified Fenton-like processes (removal efficiency gt; 70% for 24 h). CaO₂/Fe(III)/CA was more efficient than H₂O₂/Fe(III)/CA at low oxidant dosage (< 0.28-0.69 mmol/g) for long treatment time (> 4 h). Besides the chemical assessment with GC removal, effects of Fenton-like processes were also evaluated by biological assessments with bacteria and plants. CaO₂/Fe(III)/CA was less harmful to the richness and diversity of microorganisms in soil compared to H₂O₂/Fe(III)/CA. Weaker phytotoxic effects were observed on GC-contaminated soil treated by CaO₂/Fe(III)/CA than H₂O₂/Fe(III)/CA. This study, therefore, recommends CaO₂-based treatments to remediate GC-contaminated soils.

Effects-based monitoring of bioactive compounds associated with municipal wastewater treatment plant effluent discharge to the South Platte River, Colorado, USA

Previous studies have detected numerous organic contaminants and in vitro bioactivities in surface water from the South Platte River near Denver, Colorado, USA. To evaluate the temporal and spatial distribution of selected contaminants of emerging concern, water samples were collected throughout 2018 and 2019 at 11 sites within the S. Platte River and surrounding tributaries with varying proximities to a major wastewater treatment plant (WWTP). Water samples were analyzed for pharmaceuticals, pesticides, steroid hormones, and wastewater indicators and screened for in vitro biological activities. Multiplexed, in vitro assays that simultaneously screen for agonistic activity against 24 human nuclear receptors detected estrogen receptor (ER), peroxisome proliferator activated receptor-gamma (PPARγ), and glucocorticoid receptor (GR) bioactivities in water samples near the WWTP outflow. Targeted in vitro bioassays assessing ER, GR, and PPARγ agonism corroborated bioactivities for ER (up to 55 ± 9.7 ng/L 17β-estradiol equivalents) and GR (up to 156 ± 28 ng/L dexamethasone equivalents), while PPARγ activity was not confirmed. To evaluate the potential in vivo significance of the bioactive contaminants, sexually-mature fathead minnows were caged at six locations upstream and downstream of the WWTP for 5 days after which targeted gene expression analyses were performed. Significant up-regulation of male hepatic vitellogenin was observed at sites with corresponding in vitro ER activity. No site-related differences in GR-related transcript abundance were detected in female adipose or male livers, suggesting observed environmental concentrations of GR-active contaminants do not induce a detectable in vivo response. In line with the lack of detectable targeted in vitro PPARɣ activity, there were no significant effects on PPARɣ-related gene expression. Although the chemicals responsible for GR and PPAR-mediated bioactivities are unknown, results from the present study provide insights into the significance (or lack thereof) of these bioactivities relative to short-term in situ fish exposures.

Occurrence of Pharmaceuticals and Endocrine Disrupting Compounds in Brazilian Water and the Risks They May Represent to Human Health

The risks of pharmaceuticals and endocrine disrupting compounds (P&EDC) to the environment and human health are a current topic of interest. Hundreds of P&EDC may reach the environment, hence, there is a need to rank the level of concern of human exposure to these compounds. Thus, this work aimed at setting a priority list of P&EDC in Brazil, by studying their occurrence in raw and drinking water, calculating health guideline values (GV), and estimating the risks of population exposure to water intake. Data on the Brazilian pharmaceutical market as well as published data of the monitoring of Brazilian natural and drinking water have been collected by means of an exhaustive literature review. Furthermore, many foreign data were also collected to enable a comparison of the values found in Brazilian studies. A list of 55 P&EDC that have the potential to be found in Brazilian water is proposed, and for 41 of these a risk assessment was performed by estimating their margin of exposure (ME), by considering their occurrence in drinking water, and guideline values estimated from reported acceptable daily intake (ADI) data. For seven compounds the risk was deemed high (three estrogens and four anti-inflammatories), whereas for another seven compounds, it was regarded as an 'alert' situation. Although such risk analysis is conservative, since it has been calculated based on the highest reported P&EDC concentration in drinking water, it highlights the need to enhance their monitoring in Brazil to strengthen the database and support decision makers. An analysis of the occurrence of antimicrobial resistance agents (antibiotics, resistant bacteria, and resistance genes) in surface waters was also carried out and confirmed that such agents are present in water sources throughout Brazil, which deserves the attention of policy makers and health agents to prevent dissemination of antimicrobial resistance through water use.

Occurrence, Fate, Effects, and Risks of Dexamethasone: Ecological Implications Post-COVID-19

The recent outbreak of respiratory syndrome-coronavirus-2 (SARS-CoV-2), which causes coronavirus disease (COVID-19), has led to the widespread use of therapeutics, including dexamethasone (DEXA). DEXA, a synthetic glucocorticoid, is among the widely administered drugs used to treat hospitalized COVID-19 patients. The global COVID-19 surge in infections, consequent increasing hospitalizations, and other DEXA applications have raised concerns on eminent adverse ecological implications to aquatic ecosystems. Here, we aim to summarize published studies on DEXA occurrence, fate, and effects on organisms in natural and engineered systems as, pre-COVID, the drug has been identified as an emerging environmental contaminant. The results demonstrated a significant reduction of DEXA in wastewater treatment plants, with a small portion, including its transformation products (TPs), being released into downstream waters. Fish and crustaceans are the most susceptible species to DEXA exposure in the parts-per-billion range, suggesting potential deleterious ecological effects. However, there are data deficits on the implications of DEXA to marine and estuarine systems and wildlife. To improve DEXA management, toxicological outcomes of DEXA and formed TPs should entail long-term studies from whole organisms to molecular effects in actual environmental matrices and at realistic exposure concentrations. This can aid in striking a fine balance of saving human lives and protecting ecological integrity.

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.

Biotransformation of Current-Use Progestin Dienogest and Drospirenone in Laboratory-Scale Activated Sludge Systems Forms High-Yield Products with Altered Endocrine Activity

Dienogest (DIE) and drospirenone (DRO) are two fourth-generation synthetic progestins widely used as oral contraceptives. Despite their increasing detection in wastewaters and surface waters, their fate during biological wastewater treatment is unclear. Here, we investigated DIE and DRO biotransformation with representative activated sludge batch incubations and identified relevant transformation products (TPs) using high-resolution mass spectrometry. DIE exhibited slow biotransformation (16-30 h half-life) and proceeded through a quantitative aromatic dehydrogenation to form TP 309 (molar yields of ∼55%), an aromatic TP ∼30% estrogenic as 17β-estradiol. DRO experienced more rapid biotransformation (<0.5 h half-life), and 1,2-dehydrogenation formed the major TP 364 (molar yields of ∼40%), an antimineralocorticoid drug candidate named as spirorenone. Lactone ring hydrolysis was another important biotransformation pathway for DRO (molar yields of ∼20%) and generated pharmacologically inactive TP 384. Other minor pathways for DIE and DRO included hydroxylation, methoxylation, and 3-keto and C4(5) double-bond hydrogenation; distinct bioactivities are plausible for such TPs, including antigestagenic activity, antigonadotropic activity, and pregnancy inhibition effects. Thus, biotransformation products of DIE and DRO during wastewater treatment should be considered in environmental assessments of synthetic progestins, especially certain TPs such as the estrogenic TP 309 of DIE and the antimineralocorticoid spirorenone (TP 364) of DRO.

Developmental aspects of the hypothalamic-pituitary network related to reproduction in teleost fish

The hypothalamic-pituitary-gonadal axis is the main system that regulates reproduction in vertebrates through a complex network that involves different neuropeptides, neurotransmitters, and pituitary hormones. Considering that this axis is established early on life, the main goal of the present work is to gather information on its development and the actions of its components during early life stages. This review focuses on fish because their neuroanatomical characteristics make them excellent models to study neuroendocrine systems. The following points are discussed: i) developmental functions of the neuroendocrine components of this network, and ii) developmental disruptions that may impact adult reproduction. The importance of the components of this network and their susceptibility to external/internal signals that can alter their specific early functions and/or even the establishment of the reproductive axis, indicate that more studies are necessary to understand this complex and dynamic network.

A critical review on the distribution and ecological risk assessment of steroid hormones in the environment in China

During past two decades, steroid hormones have raised significant public concerns due to their potential adverse effects on the hormonal functions of aquatic organisms and humans. Considering China being a big producer and consumer of steroid hormones, we summarize the current contamination status of steroid hormones in different environmental compartments in China, and preliminarily assess the associated risks to ecological systems. The results show that steroid hormones are ubiquitously present in Chinese surface waters where estrogens are the most studied steroids compared with androgens, progestogens and glucocorticoids. Estrone (E1), 17β-estradiol (17β-E2) and estriol (E3) are generally the dominant steroid estrogens in Chinese surface waters, whereas for the other steroids, androsterone (ADR), epi-androsterone (EADR), progesterone (PGT), cortisol (CRL) and cortisone (CRN) have relatively large contributions. Meanwhile, the investigations for the other environmental media such as particles, sediments, soils and groundwater have been limited, as well as for steroid conjugates and metabolites. The median risk quotients of most steroid hormones in surface waters and sediments are lower than 1, indicating low to moderate risks to local organisms. This review provides a full picture of steroid distribution and ecological risks in China, which may be useful for future monitoring and risk assessment. More studies may focus on the analysis of steroid conjugates, metabolites, solid phase fractions, analytical method development and acute/chronic toxicities in different matrices to pursue a more precise and holistic risk assessment.

A critical review on environmental presence of pharmaceutical drugs tested for the covid-19 treatment

On March 11, 2020, the World Health Organization (WHO) declared COVID-19 a pandemic. The outbreak caused a worldwide impact, becoming a health threat to the general population and its professionals. To date, there are no specific antiviral treatments or vaccines for the COVID-19 infection, however, some drugs are being clinically tested. The use of these drugs on large scale raises great concern about their imminent environmental risk, since the elimination of these compounds by feces and urine associated with the inefficiency of sewage treatment plants in their removal can result in their persistence in the environment, putting in risk the health of humans and of other species. Thus, the goal of this work was to conduct a review of other studies that evaluated the presence of the drugs chloroquine, hydroxychloroquine, azithromycin, ivermectin, dexamethasone, remdesivir, favipiravir and some HIV antivirals in the environment. The research indicated the presence of these drugs in the environment in different regions, with concentration data that could serve as a basis for further comparative studies following the pandemic.

Novel polar AhR-active chemicals detected in sediments of an industrial area using effect-directed analysis based on in vitro bioassays with full-scan high resolution mass spectrometric screening

Studies investigating aryl hydrocarbon receptor (AhR)-active compounds in the environment typically focus on non- and mid-polar substances, such as PAHs; while, information on polar AhR agonists remains limited. Here, we identified polar AhR agonists in sediments collected from the inland creeks of an industrialized area (Lake Sihwa, Korea) using effect-directed analysis combined with full-scan screening analysis (FSA; using LC-QTOFMS). Strong AhR-mediated potencies were observed for the polar and latter fractions of RP-HPLC (F3.5-F3.8) from sediment organic extracts in the H4IIE-luc in vitro bioassays. FSA was performed on the corresponding fractions. Twenty-eight tentative AhR agonists were chosen using a five-step process. Toxicological confirmation using bioassay revealed that canrenone, rutaecarpine, ciprofloxacin, mepanipyrim, genistein, protopine, hydrocortisone, and medroxyprogesterone were significantly active. The relative potencies of these AhR-active compounds compared to that of benzo[a]pyrene ranged from 0.00002 to 2.0. Potency balance analysis showed that polar AhR agonists explained, on average, ~6% of total AhR-mediated potencies in samples. Some novel polar AhR agonists also exhibited endocrine-disrupting potentials capable of binding to estrogen and glucocorticoid receptors, as identified by QSAR modeling. In conclusion, the focused studies on distributions, sources, fate, and ecotoxicological effects of novel polar AhR agonists in the environment are necessary.

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.

TiO2-Photocatalyzed Water Depollution, a Strong, yet Selective Depollution Method: New Evidence from the Solar Light Induced Degradation of Glucocorticoids in Freshwaters

The photodegradation of the most prescribed glucocorticoids (GCs) was studied under relevant environmental conditions in the presence of suspended TiO2. The considered drugs included cortisone (CORT), hydrocortisone (HCORT), betamethasone (BETA), dexamethasone (DEXA), prednisone (PRED), prednisolone (PREDLO), and triamcinolone (TRIAM). The experiments were carried out at concentrations (50 µg L−1) close to the real ones in freshwater samples (tap and river) under simulated and natural sunlight, and their decomposition took place very efficiently under natural sunlight. The reactions were monitored by high-pressure liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). According to a pseudo-first-order decay, all drugs underwent degradation within 15 min, following different paths with respect to the direct photolysis. The observed kinetic constants, slightly lower in river than in tap water, varied from 0.29 to 0.61 min−1 with modest differences among GCs in the same matrix. Among main matrix macro-constituents, humic acids (HAs) were the most interfering species involved in GCs degradation. The photogenerated primary products were identified by HPLC-ESI-MS/MS, allowing to elucidate the general photochemical path of GCs. Finally, a comparison with literature data obtained using different advanced oxidation processes (AOPs) highlights the treatment efficiency with TiO2/solar light for removing such persistent aquatic contaminants.