Natural and synthetic endocrine disrupting compounds (EDCs) in water, sediment and biota of a coastal lagoon

Thresholds and interactive effects of BPA-gradient and temperature on life history traits of Daphnia magna

Bisphenol A (BPA), a synthetic organic compound widely used in the production of plastics, is recognized as an emerging contaminant because of its toxicity and the potential risks associated with bioaccumulation in organisms. Despite potential environmental hazards, there is a lack of studies examining BPA toxicity mechanisms and its potential impact on various trophic levels, with even fewer exploring whether global stressors such as temperature can affect the toxicity of BPA in organisms. Our aim was to assess the combined impact of BPA and varying temperature regimes on life-history traits in Daphnia magna. Our results revealed a significant impact of BPA on the growth, reproduction, and accumulated moulting of D. magna, with adverse effects primarily associated with the assimilation of BPA in algae rather than the BPA present in the medium, pointing to a trophic transfer mechanism. The interactive effect between BPA and temperature demonstrated a slight stimulatory effect of low BPA level on D. magna growth rate under warming constant conditions, but an inhibitory under warming fluctuating temperatures. Additionally, a BPA threshold was identified, below which growth became temperature-dependent. This study emphasizes the crucial role of considering temperature in predicting how toxins may affect Daphnia within aquatic food webs.

Contaminants of emerging concern in water and sediment of the Venice Lagoon, Italy

This study investigates for the first time the contamination of water and sediment of the Venice Lagoon by twenty Contaminants of Emerging Concern (CECs): three hormones, six pharmaceutical compounds (diclofenac and five antibiotics, three of which are macrolides), nine pesticides (methiocarb, oxadiazon, metaflumizone, triallate, and five neonicotinoids), one antioxidant (BHT), and one UV filter (EHMC). Water and sediment samples were collected in seven sites in four seasons, with the aim of investigating the occurrence, distribution, and possible emission sources of the selected CECs in the studied transitional environment. The most frequently detected contaminants in water were neonicotinoid insecticides (with a frequency of quantification of single contaminants ranging from 73% to 92%), and EHMC (detected in the 77% of samples), followed by BHT (42%), diclofenac (39%), and clarithromycin (35%). In sediment the highest quantification frequencies were those of BHT (54%), estrogens (ranging from 35% to 65%), and azithromycin (46%). Although this baseline study does not highlight seasonal or spatial trends, results suggested that two of the major emission sources of CECs in the Venice Lagoon could be tributary rivers from its drainage basin and treated wastewater, due to the limited removal rates of some CECs in WWTPs. These preliminary results call for further investigations to better map priority emission sources and improve the understanding of CECs environmental behavior, with the final aim of drawing up a site-specific Watch List of CECs for the Venice Lagoon and support the design of more comprehensive monitoring plans in the future.

Emerging and legacy contaminants on the Brazilian southern coast (Santa Catarina): A multi-biomarker approach in oysters Crassostrea gasar (Adanson, 1757)

Coastal environments, such as those in the Santa Catarina State (SC, Brazil), are considered the primary receptors of anthropogenic pollutants. In this study, our objective was to evaluate the levels of emerging contaminants (ECs) and persistent organic pollutants (POPs) in indigenous Crassostrea gasar oysters from different regions of SC coast in the summer season (March 2022). Field collections were conducted in the São Francisco do Sul, Itajaí, Florianópolis and Laguna coastal zones. We analyzed the bioaccumulation levels of 75 compounds, including antibiotics (AB), endocrine disruptors (ED), non-steroidal anti-inflammatory drugs (NSAIDs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and pesticides. Furthermore, we assessed biomarker responses related to biotransformation, antioxidant defense, heat shock protection and oxidative damage in oysters' gills. Prevalence of ECs was observed in the central and southern regions, while the highest concentrations of POPs were detected in the central-northern regions of SC. Oysters exhibited an induction in biotransformation systems (cyp2au1 and cyp356a1, sult and GST activity) and antioxidant enzymes activities (SOD, CAT and GPx). Higher susceptibility to lipid peroxidation was observed in the animals from Florianópolis compared to other regions. Correlation analyses indicated possible associations between contaminants and environmental variables in the biomarker responses, serving as a warning related to climate change. Our results highlight the influence of anthropogenic activities on SC, serving as baseline of ECs and POPs levels in the coastal areas of Santa Catarina, indicating more critical zones for extensive monitoring, aiming to conserve coastal regions.

Nonylphenol and its derivatives: Environmental distribution, treatment strategy, management and future perspectives

In recent years, emerging pollutants, including nonylphenol (NP) and nonylphenol ethoxylate (NPE), have become a prominent topic. These substances are also classified as persistent organic pollutants. NP significantly affects the hormone secretion of organisms and exhibits neurotoxicity, which can affect the human hippocampus. Therefore, various countries are paying increased attention to NP regulation. NPEs are precursors of NPs and are widely used in the manufacture of various detergents and lubricants. NPEs can easily decompose into NPs, which possess strong biological and environmental toxicity. This review primarily addresses the distribution, toxicity mechanisms and performance, degradation technologies, management policies, and green alternative reagents of NPs and NPEs. Traditional treatment measures have been unable to completely remove NP from wastewater. With the progressively tightening management and regulatory policies, identifying proficient and convenient treatment methods and a sustainable substitute reagent with comparable product effectiveness is crucial.

Parabens, Triclosan and Bisphenol A in Surface Waters and Sediments of Baiyang Lake, China: Occurrence, Distribution, and Potential Risk Assessment

The extensive use of the parabens triclosan (TCS) and bisphenol A (BPA) has potential adverse effects on human health and aquatic organisms. However, their monitoring information in freshwater lakes is still limited. This study simultaneously summarized the concentrations, spatial distribution characteristics, and correlations of four types of parabens, TCS, and BPA in the surface water and sediment of Baiyang Lake. Finally, the potential risks of target pollutants were evaluated from two aspects: human health risks and ecological risks. The average contaminations of target compounds in surface water and sediment-BPA, TCS, and ∑4 parabens-was 33.1, 26.1, 0.7 ng/L and 24.5, 32.5, 2.5 ng/g, respectively. The total concentration of target compounds at the inlet of the upstream Fu River and Baigouyin River is significantly higher than that near Hunan and the outlet. In addition, Spearman's correlation analysis showed a significant positive correlation between compounds. The health hazards of target compounds in surface water were all within safe limits. However, the risk quotient results indicate that in some locations in surface water, TCS poses a high risk to algae and a moderate risk to invertebrates and fish, and appropriate attention should be paid to these areas.

Occurrence, sources and environmental risk assessment of organic micropollutants in coastal sediments from the Atacama Region (Chile)

Nowadays, there is still a scientific knowledge gap regarding occurrence and distribution of organic contaminants in remote areas. In this study, we have monitored for the first time the presence of a wide range of persistent and emerging organic pollutants in the Atacama Desert coastal region (Chile), a key area in the Humboldt Current System. Nonylphenols (NPs), polycyclic aromatic hydrocarbons (PAHs), pesticides, UV filters, synthetic fragrances, and organophosphate flame retardants (OPFRs) were determined in sediments along the >500 km length Atacama coastline. NPs, well-known endocrine disruptors, were the predominant pollutants in the area (up to 333.5 ng g-1 dw). We identified inputs of different classes of contaminants from anthropogenic activities such as mining, agriculture, direct effluent discharges, harbors, energy plants, recreational activities, and tourism occurring along the coastline. Environmental risk assessment through calculation of hazard quotients (HQs) showed a high ecological risk level for NPs in the three provinces of Atacama (HQ >1). In the case of PAHs, (pyrene, benz(a)anthracene, chrysene, acenaphthene, naphthalene and benzo(a)pyrene) HQ >1 was showed in Copiapó province. Furthermore, estradiol equivalent concentrations (EEQ) were determined to estimate estrogenicity of the environmental sediment samples. The maximum EEQ value was for NPs in H1 (Carrizal Bajo wetland), province of Huasco, where the highest concentration of NPs was found. The sampling point H1 is a particular location because it is the exit of a wetland and a tourist point used as a beach. The potential risks of anthropogenic chemical substances impacting remote regions such as the one studied here highlight the need of expand monitoring efforts worldwide for a better assessment of the global pollution status.

Bisphenol A contamination in aquatic environments: a review of sources, environmental concerns, and microbial remediation

The production of polycarbonate, a high-performance transparent plastic, employs bisphenol A, which is a prominent endocrine-disrupting compound. Polycarbonates are frequently used in the manufacturing of food, bottles, storage containers for newborns, and beverage packaging materials. Global production of BPA in 2022 was estimated to be in the region of 10 million tonnes. About 65-70% of all bisphenol A is used to make polycarbonate plastics. Bisphenol A leaches from improperly disposed plastic items and enters the environment through wastewater from plastic-producing industries, contaminating, sediments, surface water, and ground water. The concentration BPA in industrial and domestic wastewater ranges from 16 to 1465 ng/L while in surface water it has been detected 170-3113 ng/L. Wastewater treatment can be highly effective at removing BPA, giving reductions of 91-98%. Regardless, the remaining 2-9% of BPA will continue through to the environment, with low levels of BPA commonly observed in surface water and sediment in the USA and Europe. The health effects of BPA have been the subject of prolonged public and scientific debate, with PubMed listing more than 17,000 scientific papers as of 2023. Bisphenol A poses environmental and health hazards in aquatic systems, affecting ecosystems and human health. While several studies have revealed its presence in aqueous streams, environmentally sound technologies should be explored for its removal from the contaminated environment. Concern is mostly related to its estrogen-like activity, although it can interact with other receptor systems as an endocrine-disrupting chemical. Present review article encompasses the updated information on sources, environmental concerns, and sustainable remediation techniques for bisphenol A removal from aquatic ecosystems, discussing gaps, constraints, and future research requirements.

Single and multispecies microalgae toxicological tests assessing the impact of several BPA analogues used by industry

BPA is a hazard for human and environmental health and recently BPA was added to the Candidate List of substances of very high concern by European Chemical Agency (ECHA). In accordance with this proposal, the authorities have encouraged the replacement of BPA by BPA analogues; however, little is known about the impact of these compounds on the environment. Due to this situation five BPA analogues (BPS, BPAP, BPAF, BPFL and BPC) were chosen in order to study their effects on marine primary producers. Three marine microalgae species (Phaeodactylum tricornutum, Tetraselmis suecica and Nannochloropsis gaditana) were selected for single and multispecies tests concerning the ecotoxicological effects of these BPA analogues. Microalgae were exposed to BPs over 72 h at different dosages (5, 20, 40, 80, 150 and 300 μM). Responses such as: growth, ROS production, cell complexity, cell size, autofluorescence of chlorophyll a, effective quantum yield of PSII and pigment concentrations were assessed at 24, 48 and 72 h. The results revealed that BPS and BPA showed lower toxicity to microalgae in comparison with BPFL > BPAF > BPAP and >BPC for the endpoints studied. N. gaditana was the least sensitive microalgae in comparison to P. tricornutum and T. suecica. However, a different trend was found in the multispecies tests where T. suecica dominated the microalgae community in relation to N. gaditana and P. tricornutum. The results of this work revealed for first time that present day BPA analogues are a threat and not a safe substitute for BPA in terms of the marine phytoplanktonic community. Therefore, the results of their impact on aquatic organisms should be shared.

Fate of five bisphenol derivatives in Chlamydomonas mexicana: Toxicity, removal, biotransformation and microalgal metabolism

Bisphenols (BPs) are recognized as emerging contaminants because of their estrogenic properties and frequent occurrence in environmental matrices. Here, we evaluated the toxic effects of five common BPs on freshwater microalga Chlamydomonas mexicana and removal of the BPs by the alga. Bisphenols -AF (BPAF), -B (BPB), and -Z (BPZ) (96 h, EC50 1.78-12.09 mg·L-1) exhibited higher toxicity to C. mexicana compared to bisphenol -S (BPS) and -F (BPF) (96 h, EC50 30.53-85.48 mg·L-1). In contrast, the mixture of BPs exhibited acute toxicity (96 h, EC50 8.07 mg·L-1). After 14 days, C. mexicana had effectively removed 61%, 99%, 55%, 87%, and 89% of BPS, BPF, BPAF, BPB, and BPZ, respectively, at 1 mg L-1. The biotransformed products of all five BPs were analyzed using UHPLC QTOF, and their toxicity was predicted. All biotransformed products were observed to be less toxic than the parent compounds. The fatty acid composition of C. mexicana after exposure to the BP mixture was predominantly palmitic acid (34.14%), followed by oleic acid (18.9%), and γ-linolenic acid (10.79%). The results provide crucial information on the ecotoxicity of these five BPs and their removal by C. mexicana; the resulting biomass is a potential feedstock for producing biodiesel.

Environmental occurrence and ecotoxicity of aquaculture-derived plastic leachates

Plastic products such as fishing nets and foam buoys have been widely used in aquaculture. To enhance the desirable characteristics of the final equipment, plastic gear for aquaculture is mixed with a wide range of additives. Recent studies have shown that additives could be leached out to the environment with a long-term use of aquaculture plastics, forming aquaculture-derived plastic leachates. It should be emphasized that some leachates such as phthalic acid esters (PAEs) and organophosphate esters (OPEs) are endocrine disruptors, which could increase the exposure risk of aquatic products and subsequently display potential threats to human health via food chain. However, systematic studies on the release, occurrence, bioaccumulation, and toxic effects of aquaculture-derived plastic leachates are missing, overlooking their potential sources and ecotoxicological risks in aquatic environments. We have reviewed and compared the concentrations of major plastic leachates in the water environment and organisms of global aquaculture and non-farmed areas, confirming that aquaculture leachate is an important source of contaminants in the environment. Moreover, the toxic effects of aquaculture-derived plastic additives and the related mechanisms are summarized with fish as a representative, revealing their potential health risk. In addition, we proposed current challenges and future research needs, which provides scientific guidance for the use and management of plastic products in aquaculture industries.

Occurrence, bioconcentration, and human health risks of pharmaceuticals in biota in the Sea of Marmara, Türkiye

The presence, bioconcentration, and health risk via seafood consumption of 11 pharmaceutical compounds belonging to different therapeutic groups (anti-inflammatory, antiepileptic, lipid regulators, and hormones) were investigated in the muscle tissues of fish and the meat of shrimp in the Sea of Marmara. Six biota species (Merlangius merlangus, Trachurus meditterraneus, Serranus hepatus, Pomatomus saltatrix, Parapenaeus longirostris, Spratus sprattus) were collected from the five stations in October and April 2019. Ultrasonic extraction method followed by solid phase extraction was used for extraction of pharmaceutical compounds from biota samples and then analyzed using high-performance liquid chromatography. Of the 11 compounds, 10 were detected in biota species. Ibuprofen was the most frequently detected pharmaceutical in the biota tissues at high concentrations (<3.0-1225 ng/g, dw). The other widely detected compounds were fenoprofen (<3.6-323 ng/g, dw), gemfibrozil (<3.2-480 ng/g, dw), 17α-ethynylestradiol (<2.0-462 ng/g, dw), and carbamazepine (<7.6-222 ng/g, dw). The bioconcentration factors of the selected pharmaceuticals calculated in various aquatic organisms ranged from 9 to 2324 L/kg. The estimated daily intakes of anti-inflammatories, antiepileptics, lipid regulators, and hormones via seafood consumption were 0.37-568, 1.1-324, 8.5-197, 3-340 ng/kg bw. Day, respectively. Based on hazard quotients, estrone, 17β-estradiol, and 17α-ethynylestradiol may pose a health risk to humans through the consumption of this seafood.

Effects of 17α-ethinylestradiol on the neuroendocrine gonadotropic system and behavior of European sea bass larvae (Dicentrarchus labrax)

The widespread use of 17α-ethinylestradiol (EE2), and other estrogenic endocrine disruptors, results in a continuous release of estrogenic compounds into aquatic environments. Xenoestrogens may interfere with the neuroendocrine system of aquatic organisms and may produce various adverse effects. The aim of the present study was to expose European sea bass larvae (Dicentrarchus labrax) to EE2 (0.5 and 50 nM) for 8 d and determine the expression levels of brain aromatase (cyp19a1b), gonadotropin-releasing hormones (gnrh1, gnrh2, gnrh3), kisspeptins (kiss1, kiss2) and estrogen receptors (esr1, esr2a, esr2b, gpera, gperb). Growth and behavior of larvae as evidenced by locomotor activity and anxiety-like behaviors were measured 8 d after EE2 treatment and a depuration period of 20 d. Exposure to 0.5 nM EE2 induced a significant increase in cyp19a1b expression levels, while upregulation of gnrh2, kiss1, and cyp19a1b expression was noted after 8 d at 50 nM EE2. Standard length at the end of the exposure phase was significantly lower in larvae exposed to 50 nM EE2 than in control; however, this effect was no longer observed after the depuration phase. The upregulation of gnrh2, kiss1, and cyp19a1b expression levels was found in conjunction with elevation in locomotor activity and anxiety-like behaviors in larvae. Behavioral alterations were still detected at the end of the depuration phase. Evidence indicates that the long-lasting effects of EE2 on behavior might impact normal development and subsequent fitness of exposed fish.

Transcriptome analysis of changes in M. aeruginosa growth and microcystin production under low concentrations of ethinyl estradiol

Ethinyl estradiol (EE2) is a synthetic environmental estrogen with considerable estrogenic activity. It has been found to consequently pose a significant threat to the aquatic ecosystem. Harmful algal blooms are a major aquatic ecological issue. However, the relationship between EE2 and cyanobacterial bloom is mainly unknown. In this study, the physiological and molecular responses of Microcystis aeruginosa to EE2 exposure were investigated. A low level of EE2 (0.02 μg/L) significantly enhanced the growth of algal cells (P < 0.05), whereas higher concentrations of EE2 (0.2-200 μg/L) inhibited it. EE2 at doses ranging from 0.02 to 200 μg/L promoted the production of microcystins (MCs), with genes mcyABD playing a key role in the regulation of MC synthesis. The alterations of chlorophyll-a, carotenoid, and phycocyanin contents caused by EE2 showed the same trend as cell growth. At the molecular level, 200 μg/L EE2 significantly down-regulated genes in photosynthetic pigment synthesis, light harvesting, electron transfer, NADPH, and ATP generation. High concentrations of EE2 caused oxidative damage to algal cells on the 4th d. After 12d exposure, although there was no significant change in superoxide dismutase (SOD) content and no damage observed in membrane lipids, genes related to SOD and glutathione were changed. In addition, due to the down-regulation of pckA, PK, gltA, nrtA, pstS, etc., carbon fixation, glycolysis, TCA cycle, nitrogen and phosphorus metabolism were hindered by EE2 (200 μg/L). Gene fabG in fatty acid biosynthesis was significantly up-regulated, promoting energy storage in cells. These findings provide important clues to elucidate the effects and mechanisms of cyanobacterial blooms triggered by EE2 and help to effectively prevent and control cyanobacterial blooms.

Direct Production of Bio-Recalcitrant Carboxyl-Rich Alicyclic Molecules Evidenced in a Bacterium-Induced Steroid Degradation Experiment

Carboxyl-rich alicyclic molecules (CRAM) are highly unsaturated compounds extensively distributed throughout aquatic environments and sediments. This molecular group is widely referred to as a major proxy of recalcitrant organic materials, but its direct biosynthesis remains unclear. Steroids are a typical anthropogenic contaminant and have been previously suggested to be precursors of CRAM; however, experimental evidence to support this hypothesis is lacking. Here, a steroid-degrading bacterium, Comamonas testosteroni ATCC 11996, was incubated in a liquid medium supplemented with testosterone (a typical steroid) as the sole carbon source for 90 days. Testosterone-induced metabolites (TIM) were extracted for molecular characterization and to examine the bioavailability during an additional 90-day incubation after inoculation with a natural coastal microbial assemblage. The results showed that 1,775 molecular formulas (MFs) were assigned to TIM using ultrahigh-resolution mass spectrometry, with 66.99% categorized as CRAM-like constituents. A large fraction of TIM was respired or transformed during the additional 90-day seawater incubation; nevertheless, 638 MFs of the TIM persisted or increased during incubation. Among the 638 MFs, 394 were commonly assigned in natural deep seawater samples (depths of 500 to 2,000 m) from the South China Sea. Compared to the catabolites of the well-established testosterone degradation pathway, we compiled a list of bio-refractory MFs and potential chemical structures, some of which shared structural homology with CRAM. These results demonstrated direct microbial production of bio-refractory CRAM from steroid hormones and indicated that some of the biogenic CRAM resisted microbial decomposition, potentially contributing to the aquatic refractory dissolved organic matter (DOM) pool. IMPORTANCE CRAM are an operationally defined DOM group comprising a complex mixture of carboxylated and fused alicyclic structures. This DOM group is majorly characterized as refractory DOM in the marine environment. However, the origins of the complex CRAM remain unclear. In this study, we demonstrated that testosterone (a typical steroid) could be transformed into bio-refractory CRAM by a single bacterial strain and observed that some of the CRAM highly resisted microbial degradation. Through molecular comparison and screening, potential chemical structures of steroid-induced CRAM were suggested. This study established the biological connection between steroids and bio-refractory CRAM, and it provides a novel perspective explaining the fate of terrestrial contaminants in aquatic environments.

Occurrence, distribution, and ecological risk assessment of pharmaceuticals and personal care products in the surface water of the middle and lower reaches of the Yellow River (Henan section)

Pharmaceuticals and personal care products (PPCPs) are commonly seen emerging organic contaminants in aquatic environments. The transects for the occurrence and distribution of 24 PPCPs along the middle and lower reaches of the Yellow River (Henan section) were investigated in this study. All 24 targeted compounds were detected in surface water, with concentrations in the range from not detected (ND) to 527.4 ng/L. Among these PPCPs, caffeine is found to have the highest concentration and its detection frequency is 100%. The total PPCP concentration ranged from 136 ng/L to 916 ng/L (median, 319.5 ng/L). Spatial analysis showed that the pollution level of PPCPs in the trunk stream was lower than that in most tributaries in the middle and lower reaches of the Yellow River (Henan section). The ecotoxicological risk assessment indicated that norfloxacin, azithromycin, estrone, and triclosan posed high risks to aquatic organisms (RQ > 1), roxithromycin and oxytetracycline imposed moderate risks (0.1 ≤ RQ < 1), and the tributary Jindi River had the highest mixed risk (MRQ = 222).

Evaluating chemicals of emerging concern in the Ganga River at the two major cities Prayagraj and Varanasi through validated analytical approaches

Evaluating environmental water quality means to assess and protect the environment against unfriendly impacts from various organic impurities emerging from industrial emissions and those released during harvesting. Potential risks related with release of polycyclic aromatic hydrocarbons (PAHs), pesticides and pharmaceuticals (PhAcs), and personal care products (PCPs) into the environment have turned into an increasingly serious issue in ecological safety. Monitoring helps in control of chemicals and ecological status compliance to safeguard specific water uses, for example, drinking water abstraction. A longitudinal review was carried out for 55 different persistent organic pollutants (POPs) for the Ganga River which passes through the urban areas of Prayagraj and Varanasi, India, through validated analytical approaches and measurement uncertainty (MU) estimation to assess their potential use for routine analysis. Furthermore, environmental risk assessment (ERA) carried out in the present study has revealed risk quotient (RQ) higher than 1 in a portion of the aquatic bodies. Using a conservative RQ strategy, POPs were assessed for having extensive risks under acute and chronic exposure, proposing that there is currently critical ecological risk identified with these compounds present in the Ganga River. In general, these outcomes demonstrate a significant contribution for focusing on measures and feasible techniques to minimize the unfavorable effects of contaminants on the aquatic environment.

Micro(nano)plastics and plastic additives effects in marine annelids: A literature review

Plastic debris are dispersed in the marine environment and are consequently available to many organisms of different trophic levels, including sediment-dwelling organisms such as polychaetae. Plastic degradation generates micro (MPs) and nanoplastics (NPs) and as well as releases bounded plastic additives, increasing the ecotoxicological risk for marine organisms. Therefore, this review summarizes current knowledge on the accumulation and effects of MPs and NPs and plastic additives in polychaetes, derived from laboratory and field evidences. Thirty-six papers (from January 2011 to September 2021) were selected and analysed: about 80% of the selected works were published since 2016, confirming the emerging role of this topic in environmental sciences. The majority of the analysed manuscripts (68%) were carried out in the laboratory under controlled conditions. These studies showed that polychaetes accumulate and are responsive to this contaminant class, displaying behavioural, physiological, biochemical and immunological alterations. The polychaetes Hediste diversicolor and Arenicola marina were the most frequent used species to study MPs, NPs and plastic additive effects. The consideration of field studies revealed that MP accumulation was dependent on the plastic type present in the sediments and on the feeding strategy of the species. Polychaetes are known to play an important role in coastal and estuarine food webs and exposure to MPs, NPs and plastic additives may impair their behavioural, physiological, biochemical and immunological responses. Thus, the estimated global increase of these contaminants in the marine environment could affect the health of these benthic organisms, with consequences at population and ecosystem levels.

Environmental contamination status with common ingredients of household and personal care products exhibiting endocrine-disrupting potential

The continuous use of household and personal care products (HPCPs) produces an immense amount of chemicals, such as parabens, bisphenols, benzophenones and alkylphenol ethoxylates, which are of great concern due to their well-known endocrine-disrupting properties. These chemicals easily enter the environment through man-made activities, thus contaminating the biota, including soil, water, plants and animals. Thus, on top of the direct exposure on account of their presence in HPCPs, humans are also susceptible to secondary indirect exposure attributed to the ubiquitous environmental contamination. The aim of this review was therefore to examine the sources and occurrence of these noteworthy contaminants (i.e. parabens, bisphenols, benzophenones, alkylphenol ethoxylates), to summarise the available research on their environmental presence and to highlight their bioaccumulation potential. The most notable environmental contaminants appear to be MeP and PrP among parabens, BPA and BPS among bisphenols, BP-3 among benzophenones and NP among alkylphenols. Their maximum detected concentrations in the environment are mostly in the range of ng/L, while in human tissues, their maximum concentrations achieved μg/L due to bioaccumulation, with BP-3 and nonylphenol showing the highest potential to bioaccumulate. Finally, of another great concern is the fact that even the unapproved parabens and benzophenones have been detected in the environment.

Continuous 17α-ethinylestradiol exposure impairs the sperm quality of marine medaka (Oryzias melastigma)

17α-ethinylestradiol (EE2) is an anthropogenic estrogen that is widely used for hormone therapy and oral contraceptives. It was reported that EE2 exposure induced reproductive impairments through processes affecting reproduction behavior and inducing ovotestis. However, the effects of continuous EE2 exposure on the reproductive performance remain largely unknown. In this study, adult marine medaka fish (Oryzias melastigma) were exposed to EE2 (85 ng/L) for one (F₀) and two (F₁) generations. Our results indicate that continuous EE2 exposure reduced fecundity and sperm motility. The testicular transcriptome, followed by bioinformatic analysis revealed the dysregulation of pathways related to steroidogenesis, sperm motility, and reproductive system development. Collectively, our findings indicate that continuous EE2 exposure directly affected sperm quality via the alteration of steroidogenesis and dysregulation of reproductive system development. The identified key factors including DNM1, PINK1, PDE7B, and SLC12A7 can serve as biomarkers to assess EE2-reduced sperm motility.

Removal of emerging organic micropollutants via modified-reverse osmosis/nanofiltration membranes: A review

Hazardous micropollutants (MPs) such as pharmaceutically active compounds (PhACs), pesticides and personal care products (PCPs) have emerged as a critical concern nowadays for acquiring clean and safe water resources. In the last few decades, innumerable water treatment methods involving biodegradation, adsorption and advanced oxidation process have been utilized for the removal of MPs. Of these methods, membrane technology has proven to be a promising technique for the removal of MPs due to its sustainability, high efficiency and cost-effectiveness. Herein, the aim of this article is to provide a comprehensive review regarding the MPs rejection mechanisms of reverse osmosis (RO) and nanofiltration (NF) membranes after incorporation of nanomaterials and also surface modification atop the PA layer. Size exclusion, adsorption and electrostatic charge interaction mechanisms play important roles in governing the MP removal rate. In addition, this review also discusses the state-of-the-art research on the surface modification of thin film composite (TFC) membrane and nanomaterials-incorporated thin film nanocomposite (TFN) membrane in enhancing MPs removal performance. It is hoped that this review can provide insights in modifying the physicochemical properties of NF and RO membranes to achieve better performance in water treatment process, particularly for the removal of emerging hazardous substances.

Removal of micropollutants by UASB reactor and post-treatment by Fenton and photo-Fenton: Matrix effect and toxicity responses

Literature is scarce on the performance of Fenton-based processes as post-treatment of municipal wastewater treated by upflow anaerobic sludge blanket (UASB) reactor. This study aims to perform Fenton and photo-Fenton from UASB influent and effluent matrices to remove micropollutants (MPs) models: atrazine (ATZ), rifampicin (RIF), and 17α-ethynylestradiol (EE2). A UASB reactor at bench-scale (14 L) was operated with these MPs, and the AOPs experiments at bench-scale were performed on a conventional photochemical reactor (1 L). A high-pressure vapor mercury lamp was used for photo-Fenton process (UVA-Vis) as a radiation source. Microcrustacean Daphnia magna (acute toxicity) and seeds of Lactuca sativa (phytotoxicity) were indicator organisms for toxicity monitoring. The UASB reactor showed stability removing 90% of the mean chemical oxygen demand, and removal efficiencies for ATZ, RIF, and EE2 were 16.5%, 45.9%, and 15.7%, respectively. A matrix effect was noted regarding the application of both Fenton and photo-Fenton in UASB influent and effluent to remove MPs and toxicity responses. The pesticide ATZ was the most recalcitrant compound, yet the processes carried out from UASB effluent achieved removal >99.99%. The post-treatment of the UASB reactor by photo-Fenton removed acute toxicity in D. magna for all treatment times. However, only the photo-Fenton conducted for 90 min did not result in a phytotoxic effect in L. sativa.

Novel hyphenation of DGT in-situ passive sampling with YES assay to ascertain the potency of emerging endocrine disruptors in water systems in New Zealand

This study represents the first attempt to investigate selected estrogenic compounds that include 17α-ethynylestradiol (EE2), 17β-estradiol (E2) bisphenol A (BPA), and bisphenol AF (BPAF) along the drinkable water, from river-to-tap, and wastewater, from effluent-to-treated wastewater, treatment processes of the Hamilton City Council and the monitoring of the freshwater, from source-to-outfall, of the Waikato River in New Zealand. This was accomplished by the adoption of a novel combination of diffusive gradients in thin films (DGTs) in-situ passive sampling coupled with high-performance liquid chromatography/mass spectrometry analysis (HPLC/MS) and the Yeast Estrogen Screen (YES). Estradiol equivalency quantities, integrated in time, were evaluated theoretically (cEEQ) by DGT-HPLC/MS and experimentally (EEQ) by DGT-YES assay. cEEQ and EEQ highlighted that primary treatments are not suitable for estrogens and bisphenolic plastics removal both at drinkable and wastewater treatment plants in Hamilton where they worsen the water quality in terms of estrogenicity making these pollutants more available in the water phase. All downstream sites monitored along the Waikato River showed higher cEEQ and EEQ, moreover the Waikato River water quality showed a moderate worsening moving from Taupo (source) to Tuakau (outfall). The most polluted sites were downstream of Hamilton city and Huntly township wastewater treatment plants that serve the main conurbations in the area. cEEQ and EEQ generally showed good agreement at low concentrations but differed substantially at more polluted sites where cEEQ consistently underestimated estrogenic potency, possibly due to DGT accumulation of estrogenic compounds not quantified by HPLC/MS.

Effect of 17β-Estradiol on Growth and Biosynthesis of Microalgae Scenedesmus quadricauda (CPCC-158) and Duckweed Lemna minor (CPCC-490) Grown in Three Different Media

As fish farm wastewaters have detectable levels of fish hormones, such as 17β-estradiol (E2), an understanding of the influence of fish steroids on algal (Scenedesmus quadricauda) and duckweed (Lemna minor) physiology is relevant to the potential use of fishery wastewaters for microalgae and plant biomass production. The study was conducted using three types of media: Bold Basal Medium (BBM), natural fishery wastewater (FWW), and reconstituted fishery wastewater (RFWW) with the nutrient composition adjusted to mimic FWW. During the experiment, the media were aerated and changes in the pH and conductivity of the water were closely monitored. E2 promoted the growth of S. quadricauda and L. minor, with significant accumulation of high-value biomolecules at very low steroid concentrations. However, clear differences in growth performance were observed in both test cultures, S. quadricauda and L. minor, grown in different media, and the most effective hormone concentrations were evidently different for the algae and the plant.

Effects of 17α-Ethinylestradiol (EE2) exposure during early life development on the gonadotropic axis ontogenesis of the European sea bass, Dicentrarchus labrax

Exposure of young organisms to oestrogenic endocrine disrupting chemicals (EDCs) can elicit adverse effects, particularly on the reproductive function. In fish, as in other vertebrates, reproduction is controlled by the neuroendocrine gonadotropic axis, whose components are mainly regulated by sex steroids and may then be targets for EDCs. In the present study, we investigated the effects of a xenoestrogen exposure on the ontogenesis of the gonadotropic axis in European sea bass. After exposure of hatching larvae for 8 days to 17α-ethinylestradiol (EE2) (0.5 nM and 50 nM), gene expression for kisspeptins (kiss1, kiss2), gonadotropin-releasing hormones (gnrh1, gnrh2, gnrh3), gonadotropin beta subunits (lhβ and fshβ) and brain type aromatase (cyp19a1b) were measured using quantitative real-time PCR. Our results demonstrate that EE2 strongly stimulated the expression of brain type aromatase (cyp19a1b) in sea bass larvae. In addition, EE2 exposure also affected the mRNA levels of kiss1, gnrh1 and gnrh3 by inducing a downregulation of these genes during the early developmental stages, while no effect was seen in gnrh2, lhβ and fshβ. These results reinforce the idea that the larval development is a sensitive critical period in regard to endocrine disruption and that the gonadotropic axis in the developing sea bass is sensitive to xenoestrogen exposure.

Waves of follicle development, growth and degeneration in adult ovary of zebrafish (Danio rerio) on chronic exposure to environmental estrogens in laboratory

Patterns of quantitative production of follicles, their growth, and degeneration in the adult ovary of zebrafish (Danio rerio) in response to long-term (80 days) exposure to environmental estrogens (EE) in the laboratory, were studied. Experimentally naive female D. rerio procured from fish farm were acclimated to the laboratory (natural temperature, 26 ± 1° C, photoperiod, 11.30 L:12.30 D) for two weeks and divided into 10 groups. Each group (n = 20) was housed in a separate glass aquarium containing 10 L of conditioned water (physico-chemical parameters maintained within the permissible range prescribed for zebrafish) along with either 5 ng or 10 ng/L of 17α-ethynylestradiol (EE₂) or diethylstilbestrol (DES) or bisphenol A (BPA) or estradiol 17-β (positive control) or water with no chemical (negative control). All experimental fish were fed twice daily on commercial pellets (ad libitum) supplemented with Artemia nauplius, the exposure was semi-static and chemical residues in media samples were determined by ultra-performance liquid chromatography (UPLC). Exposure of fish to estrogens increased (p < 0.05) (i) body mass and gonadosomatic indices (GSI) in E₂, EE₂ and DES groups (ii) previtellogenic and vitellogenic follicles in E₂ and EE₂ groups (iii) atretic follicles (AF) in DES and BPA groups compared to controls and (iv) decrease in total oocyte volumes (V = 4/3. π. r³) compared to those of E₂ group. These results suggest that the chronic exposure of fish to EE (at environmentally relevant concentrations) has a profound influence on ovarian follicular dynamics and the effects of individual EE are discrete on the ovary.

How temperature rise will influence the toxic impacts of 17 α-ethinylestradiol in Mytilus galloprovincialis?

Pharmaceutical drugs are Contaminants of Emerging Concern (CECs) and are continuously discharged into the environment. As a result of human and veterinary use, these substances are reaching aquatic coastal systems, with limited information regarding the toxic effects of these compounds towards inhabiting organisms. Among CECs are pharmaceuticals like 17 α-ethinylestradiol (EE2), which is a synthetic hormone with high estrogenic potency. EE2 has been increasingly found in different aquatic systems but few studies addressed its potential toxicity to marine wildlife, in particular to bivalves. Therefore, the aim of the present study was to evaluate the influence of temperature (17 °C-control and 21 °C) on the potential effects of EE2 on the mussel Mytilus galloprovincialis. For this purpose, mussels were exposed to different concentrations of EE2 (5.0; 25.0; 125.0 and 625 ng/L), resembling low to highly polluted sites. Mussels exposed to each concentration were maintained under two temperatures, 17 and 21 °C, which represent actual and predicted warming conditions, respectively. After 28 days, oxidative stress status, metabolism related parameters, neurotoxicity and histopathological alterations were measured. The results obtained clearly showed an interactive effect of increased temperature and EE2, with limited antioxidant and biotransformation capacity when both stressors were acting together, leading to higher cellular damage. The combination of both stressors also enhanced mussels' metabolic capacity and neurotoxic effects. Nevertheless, loss of redox balance was confirmed by the strong decrease of the ratio between reduce glutathione (GSH) and oxidized glutathione (GSSG) in contaminated mussels, regardless the temperature. Histopathological indexes in contaminated mussels were significantly different from the control group, indicating impacts in gills and digestive glands of mussels due to EE2, with higher values observed at 21 °C. Overall, this study demonstrates that of EE2 represents a threat to mussels and predicted warming conditions will enhance the impacts, which in a near future might result in impairments at the population and community levels.

Estrogen Receptors Mediated Negative Effects of Estrogens and Xenoestrogens in Teleost Fishes-Review

Estrogen receptors (ERs) play a key role in many biochemical and physiological processes, that are involved in maintaining organism homeostasis. At the most basic level, they can be divided into nuclear estrogen receptors and membrane estrogen receptors that imply their effect in two ways: slower genomic, and faster non-genomic. In these ways, estrogens and xenoestrogens can negatively affect animal health and welfare. Most of the available literature focuses on human and mammalian physiology, and clearly, we can observe a need for further research focusing on complex mutual interactions between different estrogens and xenoestrogens in aquatic animals, primarily fishes. Understanding the mechanisms of action of estrogenic compounds on the ERs in fishes and their negative consequences, may improve efforts in environmental protection of these animals and their environment and benefit society in return. In this review, we have summarized the ER-mediated effects of xenoestrogens and estrogens on teleost fishes metabolism, their carcinogenic potential, immune, circulatory, and reproductive systems.

Presence of pharmaceuticals and their metabolites in wild-living aquatic organisms - Current state of knowledge

In the last decades an increasing number of studies has been published concerning contamination of aquatic ecosystems with pharmaceuticals. Yet, the distribution of these chemical compounds in aquatic environments raises many questions and uncertainties. Data on the presence of selected pharmaceuticals in the same water bodies varies significantly between different studies. Therefore, since early 1990 s, wild organisms have been used in research on environmental contamination with pharmaceuticals. Indeed, pharmaceutical levels measured in biological matrices may better reflect their overall presence in the aquatic environments as such levels include not only direct exposure of a given organisms to a specific pollutant but also processes such as bioaccumulation and biomagnification. In the present paper, data concerning occurrence of pharmaceuticals in aquatic biota was reviewed. So far, pharmaceuticals have been studied mainly in fish and molluscs, with only a few papers available on crustaceans and macroalgae. The most commonly found pharmaceuticals both in freshwater and marine organisms are antibiotics, antidepressants and NSAIDS while there is no information about the presence of anticancer drugs in aquatic organisms. Furthermore, only single studies were conducted in Africa and Australia. Hence, systematization of up-to-date knowledge, the main aim of this review, is needed for further research targeting.

Polystyrene microplastics increase estrogenic effects of 17α-ethynylestradiol on male marine medaka (Oryzias melastigma)

Microplastics (MPs) and endocrine disrupting chemicals are ubiquitous pollutants in marine environments, but their combined ecological risk is unclear. This study exposed male marine medaka (Oryzias melastigma) to 10 ng/L 17α-ethynylestradiol (EE₂) alone or EE₂ plus 2, 20, and 200 μg/L polystyrene MPs for 28 days to investigate the impacts of MPs on the reproductive disruption of EE₂. The results showed that 10 ng/L EE₂ alone did not affect biometric parameters, while co-exposure to EE₂ and 20, 200 μg/L MPs suppressed the growth and decreased gonadosomatic and hepatosomatic indices. Compared to EE₂ alone, EE₂ plus MPs exposure significantly increased plasma 17β-estradiol (E₂) levels in a dose-dependent manner, and co-exposure to EE₂ and 20, 200 μg/L MPs significantly increased the ratios of E₂/testosterone (T). Moreover, EE₂ plus MPs exposure elevated the transcription levels of estrogen biomarker genes vitellogenin and choriogenin, and estrogen receptor (ERα and ERβ). Morphological analysis also showed that co-exposure to EE₂ and MPs induced more severe damage to the testes and livers, indicating that MPs increased the toxicity of EE₂. The actual EE₂ concentrations in the solution increased with the exposure concentrations of MPs, suggesting that MPs changed the fate and behavior of EE₂ in the seawater. These findings demonstrate that MPs could increase the estrogenic effects of EE₂ on marine fish, suggesting that the combined health risk of MPs and endocrine disrupting chemicals on marine organisms should be paid great attention.

Studies on a widely-recognized snail model species (Lymnaea stagnalis) provide further evidence that vertebrate steroids do not have a hormonal role in the reproduction of mollusks

Experiments were carried out to determine whether, as with other mollusks that have been studied, the snail, Lymnaea stagnalis, can absorb, esterify and store vertebrate steroids that are present in the water. We also carried out experiments to determine whether neural tissues of the snail could be immunohistochemically stained with an antibody to human aromatase (a key enzyme that catalyzes the conversion of testosterone [T] to 17β-estradiol [E₂]); and, if so, to determine the significance of such staining. Previous studies on other mollusks have reported such staining and have proposed this as decisive evidence that mollusks have the same steroid synthesis pathway as vertebrates. We found that snails absorb, esterify and retain esterified T, E₂, progesterone and ethinyl-estradiol (albeit with an absorption rate about four times slower, on a weight basis, than the mussel, Mytilus edulis). We also found that not only anti-human aromatase, but also anti-human nuclear progesterone receptor (nPR) and anti-human gonadotropin-releasing hormone antibodies immunohistochemically stained snail neural cells. However, further experiments, involving gel electrophoretic separation, followed by immunostaining, of proteins extracted from the neural tissue, found at least two positively-stained bands for each antibody, none of which had masses matching the human proteins to which the antibodies had been raised. The anti-aromatase antibody even stained the 140 kDA ladder protein used as a molecular weight marker on the gels. Mass spectrometric analysis of the bands did not find any peptide sequences that corresponded to the human proteins. Our findings confirm that the presence of vertebrate-like sex steroids in molluscan tissues is not necessarily evidence of endogenous origin. The results also show that immunohistochemical studies using antibodies against human proteins are grossly non-specific and likely to have little or no value in studying steroid synthesis or activity in mollusks. Our conclusions are consistent with the fact that genes for aromatase and nPR have not been found in the genome of the snail or of any other mollusk. Our overarching conclusion, from this and our previous studies, is that the endocrinology of mollusks is not the same as that of humans or any other vertebrates and that continuing to carry out physiological and ecotoxicological studies on mollusks on the basis of this false assumption, is an unconscionable waste of resources.

17α-Ethinylestradiol (EE2): concentrations in the environment and methods for wastewater treatment – an update

17α-Ethinylestradiol (EE2) is a frequently used drug and an endocrine disruptive substance. Adverse effects on biota have been reported when they are exposed to this substance in the environment. The last review on EE2 in the environment was published in 2014. Since then, well above 70 studies on EE2 and related substances have been published. The aim of this review was therefore to bring together recent data with earlier ones. The topics emphasized were observable trends of environmental levels of EE2 and methods to reduce EE2 levels in wastewater, before it can enter the environment. This should give an overview of the recent knowledge and developments regarding these environmental aspects of EE2. In the studies discussed, EE2 levels in surface waters were well detectable in many countries, both above and below the predicted no effect concentration (PNEC) of 0.035 ng L⁻¹, although analytical methods used for the quantification often are unsatisfactory regarding their limit of detection. To support the degradation of EE2 prior to entry into the environment, appropriate treatment methods could help to control the emissions of EE2. Several methods for the reduction of EE2 levels of up to 100% removal efficiency were reported recently and are of chemical, biological, adsorptive or ion-exchange nature. Depending on the required properties like initial EE2 concentration or treatment duration, several promising methods are available.

17α-Ethinylestradiol (EE2) is a frequently used drug and an endocrine disruptive substance.

Effects of chronic exposure to environmental levels of tributyltin on the lined seahorse (Hippocampus erectus) liver: Analysis of bioaccumulation, antioxidant defense, and immune gene expression

Tributyltin (TBT), an organotin compound frequently detected in the coastal environments, poses a threat to aquatic organisms. The lined seahorse (Hippocampus erectus) is a vulnerable species found in nearshore water habitats. The mechanisms by which this fish responds to TBT exposure are not yet fully understood. Histological, biochemical, and transcriptional analyses were conducted, and the results showed that 60 days of exposure to 50 and 500 ng/L TBT caused significant tin accumulation and liver damage to seahorses. Antioxidant defenses and immune responses to TBT exposure in the livers of seahorses were further investigated. The enzymatic activity of superoxide dismutase and malondialdehyde content increased, while catalase activity decreased. Transcriptomic analysis revealed that a series of genes involved in the antioxidant defense system were highly induced to protect the hepatic cells from oxidative damage. TBT exposure also resulted in the induction of genes associated with immune and inflammatory processes, representing a stress response to combat the adverse environmental conditions in the exposed seahorses. Furthermore, seahorses showed an increased health risk, according to the elevation of the expression of genes with tumor-promoting effects, when exposed to TBT. These findings contribute to our understanding of the adverse effects of TBT exposure on seahorses, and their potential defense mechanisms.

Occurrence, spatial distribution and risk assessment of high concern endocrine-disrupting chemicals in Jiangsu Province, China

Endocrine-disrupting chemicals (EDCs) have attracted much concern because of the environmental and health risks they pose. Here we used liquid chromatography coupled with quadrupole-Orbitrap high-resolution mass spectrometry to quantify 10 types of EDCs at 118 sampling sites in Jiangsu Province, China, and then evaluated their respective environmental risk using a conservative risk quotient method. The results show that, in surface water, the targeted nonylphenol (NP), 4-tert-octylphenol (4-t-OP), and (2-ethylhexyl)phthalate (DEHP) were ranked highest, having mean concentrations above 300 ng/L. In comparison, both 4-t-OP and DEHP were also ranked highest, with mean concentrations above 100 ng/g, in the sediment samples. Moreover, the ∑₁₀EDCs concentration in the Huai River Basin was similar to that in the Yangtze River Basin. Notably, Huai'an city had the maximum mean concentration for EDCs in the Huai River Basin, followed by Xuzhou city and Suqian city, while Yangzhou city ranked highest in the Yangtze River Basin. Furthermore, the corresponding risk distribution revealed that (1) NP, bisphenol A (BPA), and 4-t-OP are of medium to high risk in 70%, 100% and 95% of the surface water samples, and likewise in 45%, 88% and 100% of the sediment samples, respectively; the maximum RQ value for NP in surface water samples reached 74.9; (2) DEHP belongs to the high-risk category in all samples (100%), whose maximum RQ reached 54.7. To our best knowledge, this is the first study to report on the occurrence, spatial distribution, and risk assessment of EDCs of high concern in Jiangsu Province, China.

In silico prediction of nuclear receptor binding to polychlorinated dibenzofurans and its implication on endocrine disruption in humans and wildlife

Polychlorinated dibenzofurans (PCDFs) are known to cause endocrine disruption in humans and wildlife but the mechanisms underlying this disruption have not been adequately investigated. In this paper, the susceptibility of the endocrine system to disruption by PCDF congeners via nuclear receptor binding was studied using molecular docking simulation. Findings revealed that some PCDF congeners exhibit high probabilities of binding to androgen receptor in its agonistic and antagonistic conformations. In depth molecular docking analysis of the receptor-ligand complexes formed by PCDFs with androgen receptor in its agonistic and antagonistic conformations showed that, these complexes were stabilized by electrostatic, van der Waals, pi-effect and hydrophobic interactions. It was also observed that PCDF molecules mimic the modes of interaction observed in androgen-testosterone and androgen-bicalutamide complexes, utilizing between 65 and 83% of the amino acid residues used by the co-crystallized ligands for binding. This computational study suggests that some PCDF congeners may act as agonists and antagonists of androgen receptor in humans and wildlife via inapproprate binding to the receptor.

A Review on Environmental Contaminants-Related Fertility Threat in Male Fishes: Effects and Possible Mechanisms of Action Learned from Wildlife and Laboratory Studies

Increasing global rates of diminished fertility in males has been suggested to be associated with exposure to environmental contaminants (ECs). The aquatic environments are the final repository of ECs. As the reproductive system is conserved in vertebrates, studies on the effects of ECs on fertility endpoints in fishes provide us with valuable information to establish biomarkers in risk assessment of ECs, and to understand the ECs-related fertility threat. The aim of the present review was to evaluate associations between ECs and fertility determinants to better understand ECs-related male fertility threat in male fishes. Wildlife studies show that the reproductive system has been affected in fishes sampled from the polluted aquatic environment. The laboratory studies show the potency of ECs including natural and synthetic hormones, alkylphenols, bisphenols, plasticizers, pesticides, pharmaceutical, alkylating, and organotin agents to affect fertility determinants, resulting in diminished fertility at environmentally relevant concentrations. Both wildlife and laboratory studies reveal that ECs adverse effects on male fertility are associated with a decrease in sperm production, damage to sperm morphology, alternations in sperm genome, and decrease in sperm motility kinetics. The efficiency of ECs to affect sperm quality and male fertility highly depends on the concentration of the contaminants and the duration of exposure. Our review highlights that the number of contaminants examined over fertility tests are much lower than the number of contaminants detected in our environment. The ECs effects on fertility are largely unknown when fishes are exposed to the contaminants at early developmental stages. The review suggests the urgent need to examine ECs effects on male fertility when a fish is exposed at different developmental stages in a single or combination protocol. The ECs effects on the sperm genome are largely unknown to understand ECs-related inheritance of reproductive disorders transmitted to the progeny. To elucidate modes of action of ECs on sperm motility, it is needed to study functional morphology of the motility apparatus and to investigate ECs-disrupted motility signaling.

Transient effect of bisphenol A (BPA) and di-(2-ethylhexyl) phthalate (DEHP) on the cosmopolitan marine diatom Chaetoceros decipiens-lorenzianus

Incubation under controlled laboratory conditions were performed to assess the toxic effects of two plastic derived chemicals, bisphenol A (BPA) and di-(2-ethylhexyl) phthalate (DEHP), on the growth, photosynthetic efficiency and photosynthetic activity of the cosmopolitan diatom Chaetoceros decipiens-lorenzianus. Non-axenic diatom cells were exposed to concentrations of BPA and DEHP (separately and in mixture), mimicking concentrations observed in contaminated marine ecosystems, for seven days. Upon short-term exposure (i.e., during the first 48 h), BPA and DEHP induced a slight but significant stimulation of biomass and photosynthetic activity relative to the control, whereas, no significant impact was observed on the photosynthetic efficiency. Nevertheless, this pattern was transient. The stimulation was followed by a return to control conditions for all treatments at the end of incubation. These results showed that the cosmopolitan diatom Chaetoceros was not impacted by representative in situ concentrations of plastic derivatives, thus confirming its ability to thrive in coastal anthropogenic environments.

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.

Bisphenols' occurrence in bivalves as sentinel of environmental contamination

Bisphenols are massively used in several manufacture processes such that bisphenol A (BPA) is ubiquitous in environment worldwide. After the implementation of regulations about BPA use, manufacturers have moved their production toward alternative substances structurally similar to it. Unfortunately, BPA analogues, given their structural similarity, exert also similar adverse effects. This review aims to investigate the occurrence of bisphenols (BPs) in bivalve molluscs. In this way, valuable information on the amount of BPs released into the environment in different areas are given. The current research indicates that BPA presence in bivalve molluscs has been investigated in Asia (Indian Ocean and Pacific Ocean), Europe (Mediterranean Sea, Baltic Sea and Atlantic Ocean) and America (Lake Mead, Nevada) with the highest amount of studies reported in bivalves harvested in Asian Coasts. BPA analogues are frequently detected in several matrices and their levels will continuously increase in the environment. Nevertheless, there is a current lack of studies analysing BPs other than BPA in bivalves. Further investigations should be conducted in this direction, in order to assess environmental distribution and the hazard for animals and human health given that seafood consumption could be an important pathway of bisphenols intake.

A review of 17α-ethynylestradiol (EE2) in surface water across 32 countries: Sources, concentrations, and potential estrogenic effects

17α-ethynylestradiol (EE2) is a synthetic estrogen with very strong estrogenic potency. Due to its wide usage in human and livestock as well as its high recalcitration to biodegradation, it was ubiquitous in different environment. This review summarized EE2 concentration levels in surface waters among 32 countries across seven continents. EE2 concentrations varied greatly in different surface waters, which ranged from not detected to 17,112 ng/L. The top 10 countries ranked in the order of high to low average EE2 concentration in surface water, were Vietnam, Cambodia, China, Laos, Brazil, Argentina, Kuwait, Thailand, Indonesia and Portugal, with the respective mean concentrations of 27.7, 22.1, 21.5, 21.1, 13.6, 9.6, 9.5, 8.8, 7.6 and 6.6 ng/L. Generally speaking, the EE2 concentration levels in surface waters in developing countries were much higher than those in developed countries. EE2 in effluent of municipal wastewater treatment plant (WWTP) was the dominant source to most countries, which suggested that improving the EE2 removal performance of municipal WWTP is the key to mitigate EE2 contamination to surface water body. Livestock, hospital, pharmacy factory and aquaculture wastewaters were also the important sources, but further work should be performed to elucidate their contribution. Evaluation based on estrogenic effects, the EE2-derived estrogen equivalence in surface waters ranged from 0 to 33 ng E2/L, among which about 65% of surface waters among 32 countries were at risk or high risk, indicating global serious EE2 contamination. MAIN FINDING: EE2 concentration in surface waters across 32 countries were summarized, along which its potential estrogenic effects were evaluated.

Behavioral and reproductive effects in Poecilia vivipara males from a tropical estuary affected by estrogenic contaminants

Contamination of aquatic habitats by endocrine disruptor chemicals is a major concern globally. This study evaluated histochemical, behavioral, and reproductive effects on adult male Poecilia vivipara sampled from Capibaribe River Estuarine System (CRES), compared to laboratory control males after breeding with virgin control females. CRES is contaminated by a mixture of estrogenic contaminants estrone, 17β-estradiol, estriol, 17α-Ethinylestradiol, bisphenol A and caffeine in concentrations averaging 13.9; 4.2; 19.5; 8.6; 27 and 23.2 ng L^-1, respectively. Estrogenic risk in 17β-estradiol-equivalent-concentrations is above probable no effect concentrations. Males sampled from CRES indicated liver phosphoprotein induction, decreased number of contacts and copulation attempts when paired with control females, slower swimming speed and lower female impregnation success rates, compared to control males. A reduction of 62% in fecundity was observed in control females paired with field sampled males compared with control males. Our results highlight hazards posed to fish reproduction by estrogenic micropollutants.

Evaluation of the oestrogenic potential of oestrone and bisphenol-A on the reproduction of Astyanax bimaculatus males after subacute exposure

In the last decades, oestrogenic compounds have often been reported in environmentally relevant concentrations in aquatic environments around the world. Most laboratory studies of oestrogens try to understand the effects of a single contaminant, but in natural environments, the effects may be quite different due to interactions with other compounds. The present study aimed to compare the action of oestrone (E1) and bisphenol-A (BPA), acting singularly and in combination, on the spermatogenesis of Astyanax bimaculatus. After exposure to 100 ng/L of E1, BPA and a mixture of the two for 15 days, our results showed that E1 and the E1 + BPA mixture significantly altered the number of spermatogenic cells. BPA presented high cytotoxicity when compared to other treatments. Analysis of the two oestrogenic compounds suggests that the E1 + BPA mixture has no additive or synergistic effects. Together, the results of the present study indicate that endocrine-disrupting chemicals (EDCs) analysed alone may behave differently than when administered with other substances.

Bioaccumulation of phenolic endocrine disruptors in the clam Rangia cuneata: Storage in shells and influence of size and sex

This study aimed to investigate the sequestration of phenolic endocrine disrupting compounds (EDCs) such as bisphenol A (BPA), 4-t-octylphenol (4-t-OP), and 4-nonylphenol (4-NP) in the shells of the mature clam Rangia cuneata from the Vistula Lagoon (southern Baltic Sea) and to determine the influence of sex and shell length on bioaccumulation of these contaminants. Even though there is broad interest in EDCs influences on aquatic organisms, these basic parameters are poorly understood, yet necessary for assessing environmental risks for clams. Average proportions of the total body burden (ng/individual) deposited in shells of R. cuneata were more than 70% for BPA and 4-NP and up to 32% for 4-t-OP. These results indicate that shell storage can be an important route for elimination of specific EDCs. Relationships between EDCs concentrations and the size and sex of R. cuneata indicate that females and large individuals experience greater exposures to the adverse effects of these pollutants than males and smaller clams. This effect could have significant impacts on population ecology and ultimately affect the entire ecosystem, in which bivalves play an important role. In the context of using clams to assess water pollution, the co-variation of EDCs concentrations with the size and sex of bivalves could influence the quality of monitoring data, unless accounted for in sampling design and data analysis.

Occurrence and removal of 17α-ethynylestradiol (EE2) in municipal wastewater treatment plants: Current status and challenges

As a synthetic estrogen, 17α-ethynylestradiol (EE2) has been known to show the strong estrogenic potency. This work critically reviewed the occurrence and removal of EE2 in municipal wastewater treatment plants (WWTPs). Based on the on-site investigations from 282 municipal WWTPs across 29 countries, the concentrations of EE2 in influent and effluent ranged from n.d-7890 and n.d-549 ng/L, with respective average concentrations of 78.4 and 12.3 ng/L. The average effluent concentration of EE2 was more than 61 times higher than the reported lowest-observed-effect concentration, indicating an urgent need for removing EE2 in WWTPs. The calculated removal efficiencies of EE2 in different wastewater treatment processes varied from -100%-100%. Averagely, 47.5% of EE2 was removed in the primary treatment process, 55.3% by biological filter treatment, 59.4% by lagoon and 71.5% by activated sludge process. The observed removal of EE2 in municipal WWTP could be mainly attributed to adsorption and biodegradation, which could be predicted according to its solid-water distribution coefficients and biodegradation rate constants. However, it should be noted that the predicted removal of EE2 was found to deviate from the in-plant observation, likely attributing to the existence of EE2 conjugates in raw municipal wastewater. Therefore, the effect of EE2 conjugates on the EE2 removal in WWTPs should be taken into account in future.

Assessment of 17α-ethinylestradiol effects in Daphnia magna: life-history traits, biochemical and genotoxic parameters

The occurrence of pharmaceuticals in aquatic ecosystems and the need to study them have increased over the years since they enter continuously the environment. Besides, these compounds are not intended for applications with environmental purposes, and therefore, little is known about their ecological effects, particularly in non-target organisms, as invertebrate species. Inside these substances, endocrine disrupting compounds (EDCs) have recently come into the limelight, due to environmental concentrations and consequently their detrimental effects on different organisms. 17α-ethinylestradiol (EE2) has been detected in the aquatic environment in various locations around the globe since it is the main synthetic hormone used as a female oral contraceptive and is also applied in veterinary medicine and animal production. The present study was intended to assess the chronic effects of EE2, in the non-target organism as Daphnia magna. Thus, to analyze the individual and subindividual impact, this aquatic organism was chronically exposed (21 days) to 0.00 (control group), 0.10, 1.00, 10.0, and 100 μg/L of EE2. Results here obtained demonstrated that D. magna exposed to the EE2 concentrations had significant effects in individual (life-history) and sub-individual (biochemical levels) parameters. Alterations as anticipation in the age at first reproduction, a decrease of the growth rate, oxidative stress, and lipid peroxidation were detected, as well as genotoxic damage. Therefore, it was possible to infer that EE2 can disrupt several metabolic pathways and physiological functions of D. magna, since EE2 demonstrated ecotoxicity, at environmentally relevant concentrations. This work reinforces the importance of examining the effects of more relevant exposures (more prolonged and with ecologically pertinent concentrations) of potential endocrine disruptors like EE2, to the freshwater organisms and ecosystem.

Effects of a mixture of glyphosate, 17α-ethynylestradiol and amyl salicylate on cellular and biochemical parameters of the mussel Mytilus galloprovincialis

In this study the effects of a mixture of glyphosate (herbicide), 17a-ethinylestradiol (synthetic estrogen) and amyl salicylate (fragrance) to the mussel Mytilus galloprovincialis were evaluated. Mussels were exposed for 7 days to two realistic concentrations of the mixture (10 and 100 ng/L) and the effects on total haemocyte counts, haemocyte diameter and volume, haemocyte proliferation, haemolymph lactate dehydrogenase activity and haemocyte lysate lysozyme activity were measured. In addition, superoxide dismutase, catalase, acetylcholinesterase, glutathione-S-transferase and glutathione reductase activities were measured in gills and digestive gland. The survival-in-air test was also performed. Results demonstrated that the mixture affected both cellular and biochemical biomarkers, but not tolerance to aerial exposure of M. galloprovincialis. The negative effects recorded in this study suggested that more efforts should be done to assess the ecotoxicological risks posed by contaminant mixture to aquatic invertebrates.

Developing and applying a classification system for ranking the biological effects of endocrine disrupting chemicals on male rockfish Sebastiscus marmoratus in the Maowei Sea, China

Endocrine disrupting compounds (EDCs) in marine environments has become a major environmental concern. Nonetheless, the biological effects of EDCs on organisms in coastal environments remain poorly characterized. In this study, biomonitoring of EDCs in male fish Sebastiscus marmoratus was carried out in the Maowei Sea, China. The results showed that the concentration of 4-nonylphenol (4-NP) was below the detection limit, the concentrations of 4-tert-octylphenol (4-t-OP) and bisphenol A (BPA) in seawater were moderate compared with those in other global regions, and the possible sources are the municipal wastewater discharge. Nested ANOVA analyses suggest significant differences of the brain aromatase activities and plasma vitellogenin (VTG) expression between the port area and the oyster farming area. A new fish expert system (FES) was developed for evaluating the biological effects of EDCs on fish. Our findings show that the FES is a potential tool to evaluate the biological effects of marine pollutants.

Recent Advances in the Rejection of Endocrine-Disrupting Compounds from Water Using Membrane and Membrane Bioreactor Technologies: A Review

Water is a critical resource necessary for life to be sustained, and its availability should be secured, appropriated, and easily obtainable. The continual detection of endocrine-disrupting chemicals (EDCs) (ng/L or µg/L) in water and wastewater has attracted critical concerns among the regulatory authorities and general public, due to its associated public health, ecological risks, and a threat to global water quality. Presently, there is a lack of stringent discharge standards regulating the emerging multiclass contaminants to obviate its possible undesirable impacts. The conventional treatment processes have reportedly ineffectual in eliminating the persistent EDCs pollutants, necessitating the researchers to develop alternative treatment methods. Occurrences of the EDCs and the attributed effects on humans and the environment are adequately reviewed. It indicated that comprehensive information on the recent advances in the rejection of EDCs via a novel membrane and membrane bioreactor (MBR) treatment techniques are still lacking. This paper critically studies and reports on recent advances in the membrane and MBR treatment methods for removing EDCs, fouling challenges, and its mitigation strategies. The removal mechanisms and the operating factors influencing the EDCs remediation were also examined. Membranes and MBR approaches have proven successful and viable to eliminate various EDCs contaminants.

Design and application of metal-organic frameworks and derivatives as heterogeneous Fenton-like catalysts for organic wastewater treatment: A review

Advanced oxidation process (AOP), with a high oxidation efficiency, fast reaction speed (relatively no secondary pollution), has become one of the core technologies of industrial wastewater and advanced drinking water treatment. Heterogeneous Fenton-like oxidation process (HFOP) is a kind of AOP, which developed rapidly in recent years in such a way to overcome the disadvantages of traditional Fenton reaction. Metal-organic frameworks (MOFs) and their derivatives become essential heterogeneous catalysts for organics mineralization due to the large specific surface area, abundant active sites, and ease of structural regulation. However, the knowledge gap on the mechanism and the fate of heterogeneous catalyst species during organics degradation activities by MOFs presents considerable impediments, particularly for a wide application and scaling up the process. This work has the potential to provide guidance and ideas for researchers and engineers in the fields of environmental remediation, environmental catalysis and functional materials. This review focuses on clarifying the critical mechanism of •OH production from MOFs and derivatives as well as its action on the organic's degradation process. The recent developments in MOF based HFOP are compared, and more attention is paid for the following aspects in this review: (1) classifies systematically progressive modification methods of MOFs by chemical and physical treatments; (2) analyzes the fate of catalytic species during treating organic wastewater; (3) proposes design ideas and principles for improving the performance of MOFs catalysts; (4) discusses the main factors influencing the catalytic properties and practical application; (5) summarizes the possible research challenges and directions for MOFs and their derivatives as catalysts applied to wastewater treatment in the future.