Occurrence and fate of selected endocrine-disrupting chemicals in water and sediment from an urban lake

Effects of triclosan on lipid metabolism and underlying mechanisms in the cyprinid fish Squalidus argentatus

The ubiquitous presence of the disinfectant triclosan (TCS) has raised global concerns regarding its potential threat to aquatic organisms. However, the effects of TCS on lipid metabolism in fish and its underlying mechanisms remain unclear. This study investigated the effect of environmentally relevant levels of TCS on the lipid metabolism in the cyprinid fish Squalidus argentatus. Our results showed that the lipid metabolism in the cyprinid fish S. argentatus was perturbed by 28-day exposure to TCS, as evidenced by higher levels of lipid accumulation in both the liver and blood. To elucidate the mechanisms underlying toxicity, we evaluated oxidative stress, inflammatory status, and lipase activity in the liver. Our findings indicated increased ROS-specific fluorescence intensity, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) content in the livers of S. argentatus exposed to TCS, suggesting oxidative damage. Additionally, TCS treatment induced the production of proinflammatory cytokines in the liver of S. argentatus exposed to TCS, which suppressed hepatic lipase activity. Intestinal tissue morphology, inflammation, and blood lipopolysaccharide (LPS) levels were also examined. Significant increases in goblet cell count and MDA levels were observed in the intestinal tract. After 28 days of TCS exposure, the serum LPS levels were significantly elevated. 16S rRNA sequencing was conducted to analyze the effects of TCS on the diversity and composition of the intestinal microbiota. Transcriptomic analysis was performed to reveal global molecular alterations following TCS exposure. In conclusion, our results indicate that TCS may disrupt the lipid metabolism in S. argentatus by (i) inducing hepatic oxidative stress and inflammation, which suppress lipoprotein lipase activity, (ii) affecting the production of beneficial metabolites and endotoxins by dysregulating gut microbiota composition, and (iii) altering the expression levels of lipid metabolism-related pathways.

Unveiling the occurrence and ecological risks of triclosan in surface water through meta-analysis

Triclosan, a widely used antimicrobial agent, is frequently detected in aquatic environments, prompting concerns about its toxic effects on aquatic species. Understanding its occurrence and ecological risks is crucial for mitigating triclosan contamination, formulating water quality criteria, and protecting aquatic organisms. This study systematically analyzed triclosan occurrence and ecological risks in surface water across China using the Risk Quotient methodology. A total of 139 and 134 data points were collected for triclosan concentrations and toxicities of aquatic organisms, respectively. Triclosan concentrations in surface water across China ranged from 0.06 to 612 ng/L. Higher triclosan levels were observed in Eastern China compared to Central and Western China, with the average concentration being 4.21- and 7.25-fold higher, respectively. Specifically, the Southeast Rivers Basin (132.98 ng/L) and Pearl River Basin (86.64 ng/L) exhibited maximum triclosan levels, 2.57-19.58 times higher than the other river basins. Further analysis revealed elevated triclosan concentrations in small rivers and surface water within residential areas, with values of 246.1 ng/L in Zhejiang, 86.64 ng/L in Guangdong, 67.58 ng/L in Jiangsu, and 127.99 ng/L in Beijing. Additionally, species sensitivity distribution curves indicated that algae was the most sensitive species to triclosan exposure, followed by invertebrates, while fish exhibited the highest tolerance. The Predicted No-Effect Concentration for the algae, invertebrates, fish, and combined aquatic species were determined to be 0.09, 2.95, 4.44, and 1.51 μg/L, respectively. The occurrence of triclosan in surface water across China did not pose widespread ecological risks. However, targeted monitoring and mitigation efforts are needed, especially in highly developed regions. This study provides crucial insights into the status of triclosan contaminations and risks in China and contributes valuable knowledge to global efforts aimed at safeguarding aquatic ecosystems.

Preparation and characterisation of alkali-activated blast furnace slag and Na-jarosite catalysts for catalytic wet peroxide oxidation of bisphenol A

In this study, cost-effective alkali-activated materials made from industrial side streams (blast furnace slag and Na-jarosite) were developed for catalytic applications. The catalytic activity of the prepared materials was examined in catalytic wet peroxide oxidation reactions of a bisphenol A in an aqueous solution. All materials prepared revealed porous structure and characterisation expressed the incorporation of iron to the material via ion exchange in the preparation step. Furthermore, the materials prepared exhibited high specific surface areas (over 200 m2/g) and were mainly mesoporous. Moderate bisphenol A removal percentages (35%-37%) were achieved with the prepared materials during 3 h of oxidation at pH 7-8 and 50°C. Moreover, the activity of catalysts remained after four consecutive cycles (between the cycles the catalysts were regenerated) and the specific surface areas decreased only slightly and no changes in the phase structures were observed. Thus, the prepared blast furnace slag and Na-jarosite-based catalysts exhibited high mechanical stability and showed good potential in the removal of bisphenol A from wastewater through catalytic wet peroxide oxidation.

The exposure to UV filters: Prevalence, effects, possible molecular mechanisms of action and interactions within mixtures

Substances that can absorb sunlight and harmful UV radiation such as organic UV filters are widely used in cosmetics and other personal care products. Since humans use a wide variety of chemicals for multiple purposes it is common for UV filters to co-occur with other substances either in human originating specimens or in the environment. There is increasing interest in understanding such co-occurrence in form of potential synergy, antagonist, or additive effects of biological systems. This review focuses on the collection of data about the simultaneous occurrence of UV filters oxybenzone (OXYB), ethylexyl-methoxycinnamate (EMC) and 4-methylbenzylidene camphor (4-MBC) as well as other classes of chemicals (such as pesticides, bisphenols, and parabens) to understand better any such interactions considering synergy, additive effect and antagonism. Our analysis identified >20 different confirmed synergies in 11 papers involving 16 compounds. We also highlight pathways (such as transcriptional activation of estrogen receptor, promotion of estradiol synthesis, hypothalamic-pituitary-gonadal (HPG) axis, and upregulation of thyroid-hormone synthesis) and proteins (such as Membrane Associated Progesterone Receptor (MAPR), cytochrome P450, and heat shock protein 70 (Hsp70)) that can act as important key nodes for such potential interactions. This article aims to provide insight into the molecular mechanisms on how commonly used UV filters act and may interact with other chemicals.

The effect of triclosan on intergeneric horizontal transmission of plasmid-mediated tigecycline resistance gene tet(X4) from Citrobacter freundii isolated from grass carp gut

The transmission of antibiotic resistance genes (ARGs) in pathogenic bacteria affects culture animal health, endangers food safety, and thus gravely threatens public health. However, information about the effect of disinfectants - triclosan (TCS) on ARGs dissemination of bacterial pathogens in aquatic animals is still limited. One Citrobacter freundii (C. freundii) strain harboring tet(X4)-resistant plasmid was isolated from farmed grass carp guts, and subsequently conjugative transfer frequency from C. freundii to Escherichia coli C600 (E. coli C600) was analyzed under different mating time, temperature, and ratio. The effect of different concentrations of TCS (0.02, 0.2, 2, 20, 200 and 2000 μg/L) on the conjugative transfer was detected. The optimum conditions for conjugative transfer were at 37 °C for 8h with mating ratio of 2:1 or 1:1 (C. freundii: E. coli C600). The conjugative transfer frequency was significantly promoted under TCS treatment and reached the maximum value under 2.00 μg/L TCS with 18.39 times that of the control group. Reactive oxygen species (ROS), superoxide dismutase (SOD) and catalase (CAT) activities, cell membrane permeability of C. freundii and E. coli C600 were obviously increased under TCS stress. Scanning electron microscope showed that the cell membrane surface of the conjugative strains was wrinkled and pitted, even broken at 2.00 μg/L TCS, while lysed or even ruptured at 200.00 μg/L TCS. In addition, TCS up-regulated expression levels of oxidative stress genes (katE, hemF, bcp, hemA, katG, ahpF, and ahpC) and cell membrane-related genes (fimC, bamE and ompA) of donor and recipient bacteria. Gene Ontology (GO) enrichment demonstrated significant changes in categories relevant to pilus, porin activity, transmembrane transporter activity, transferase activity, hydrolase activity, material transport and metabolism. Taken together, a tet(X4)-resistant plasmid could horizontal transmission among different pathogens, while TCS can promote the propagation of the resistant plasmid.

Bioprospecting photosynthetic microorganisms for the removal of endocrine disruptor compounds

Endocrine disruption compounds can be found in various daily products, like pesticides, along with cosmetic and pharmaceutical commodities. Moreover, occurrence of EDCs in the wastewater alarms the urgency for their removal before discharge owing to the harmful effect for the environment and human health. Compared to implementation of physical and chemical strategies, cultivation of photosynthetic microorganisms has been acknowledged for their high efficiency and eco-friendly process in EDCs removal along with accumulation of valuable byproducts. During the process, photosynthetic microorganisms remove EDCs via photodegradation, bio-adsorption, -accumulation, and -degradation. Regarding their high tolerance in extreme environment, photosynthetic microorganisms have high feasibility for implementation in wastewater treatment plant. However, several considerations are critical for their scaling up process. This review discussed the potency of EDCs removal by photosynthetic microorganisms and focused on the efficiency, mechanism, challenge, along with the prospect. Details on the mechanism's pathway, accumulation of valuable byproducts, and recent progress in scaling up and application in real wastewater were also projected in this review.

Reversing the damage: ecological restoration of polluted water bodies affected by pollutants due to anthropogenic activities

Aquatic ecosystems provide a large number of cultural, regulating, and supporting services to humans and play a pivotal role in sustaining freshwater-dependent ecosystems. However, an increase in human population coupled with economic growth in the last few decades has severely affected their functioning and ecological health. This has led to an increase in concentrations of pollutants originating from anthropogenic activities such as heavy metals, plastics, semi-volatile organic compounds, and endocrine disruptors. These pollutants provoke deleterious impacts on aquatic biodiversity and affect the water quality and functioning. In this paper, we discuss the sources and impacts of such pollutants as well as restoration techniques for reducing their impact on aquatic ecosystems. Several physical and chemical ecological restoration techniques, such as dredging, sediment capping, water diversion, adsorption, aeration, and flushing, can be employed to improve the water quality of water bodies. Additionally, biological techniques such as phytoremediation, phycoremediation, the use of biomembranes, and the construction of ecological floating beds can be employed to increase the population of aquatic organisms and improve the overall ecological health of aquatic ecosystems. Restoration techniques can effectively reduce the concentrations of suspended solids and dissolved phosphorus and increase the levels of dissolved oxygen. The restoration techniques for improving the ecological health of water bodies should not be limited to simply improving the water quality but should also focus on improving the biological processes and ecosystem functioning since it is essential to mitigate the adverse effects of pollutants and restore the vital ecosystem services provided by water bodies for future generations.

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.

Combining computational tools and experimental studies towards endocrine disruptors mitigation: A review of biocatalytic and adsorptive processes

The endocrine disruptors (EDCs) are an important group of emerging contaminants, and their mitigation has been a huge challenge due to their chemistry complexity and variety of these compounds. The traditional treatments are inefficient to completely remove EDCs, and adsorptive processes are the major alternative investigated on their removal. Also, the use of EDCs degrading enzymes has been encouraged due to ecofriendly approach of biocatalytic processes. This paper highlights the occurrence, classification, and toxicity of EDCs with special focus in the use of enzyme-based and adsorptive technologies in the elimination of EDCs from ambiental matrices. Numerous prior reviews have focused on the discussions toward these technologies. However, the literature lacks theoretical discussions about important aspects of these methods such as the mechanisms of EDCs adsorption on the adsorbent surface or the interactions between degrading enzymes - EDCs. In this sense, theoretical calculations combined to experimental studies may help in the development of more efficient technologies to EDCs mitigation. In this review, we point out how computational tools such as molecular docking and molecular dynamics have to contribute to the design of new adsorbents and efficient catalytic processes towards endocrine disruptors mitigation.

A bioanalytical approach for assessing the effects of soil extracts from solid waste dumpsite in Calabar (Nigeria) on lipid and estrogenic signaling of fish Poeciliopsis lucida hepatocellular carcinoma-1 cells in vitro and in vivo African catfish (Clarias gariepinus)

In applying bioanalytical approaches, the aim of this study was to determine the toxicity of contaminants derived from a solid waste dumpsite in Calabar (Nigeria), by investigating the alterations of lipid and estrogen signaling pathways in Poeciliopsis lucida hepatocellular carcinoma-1 (PLHC-1) cells and compared to in vivo African catfish (Clarias gariepinus), using polar, nonpolar and elutriate extraction methods. Cells were exposed for 48 hr period to different concentrations of the contaminant extracts. The PLHC-1 cells were evaluated for lipid responses as follows adipoRed assay, retinoid x receptor (rxr), peroxisome proliferator-activated receptor isoforms (ppar-α and γ), estrogen receptor (er-α) and vitellogenin (vtg) transcripts. The lipid signaling activation was also assessed in vivo using C. gariepinus, where hepatic levels of ppar-α were determined at both transcript and functional proteins levels. Data showed variable-, extract type and concentration-specific elevations in mRNA and protein levels for lipidomic and estrogenic effects. These effects were either biphasic at low and high concentrations, depending upon extract type, or concentration-dependent elevations. In general, these toxicological responses may be attributed to soil organic and inorganic contaminants burden previously derived from the dumpsite. Thus, our data demonstrate a unique lipid and endocrine-disruptive chemical (EDC) effects of each soil extract, suggesting multiple and complex contaminant interactions in the environment and biota. Analysis of numerous soil- or sediment-bound contaminants have numerous limitations and cost implications for developing countries. Our approach provides a bioanalytical protocol and endpoints for measuring the metabolic and EDC effects of complex environmental matrices for ecotoxicological assessment and monitoring.

Triclosan and triclocarban weaken the olfactory capacity of goldfish by constraining odorant recognition, disrupting olfactory signal transduction, and disturbing olfactory information processing

Recently, increased production and consumption of disinfectants such as triclosan (TCS) and triclocarban (TCC) have led to massive pollution of the environment, which draws global concern over the potential risk to aquatic organisms. However, the olfactory toxicity of disinfectants in fish remains elusive to date. In the present study, the impact of TCS and TCC on the olfactory capacity of goldfish was assessed by neurophysiological and behavioral approaches. As shown by the reduced distribution shifts toward amino acid stimuli and hampered electro-olfactogram responses, our results demonstrated that TCS/TCC treatment would cause deterioration of the olfactory ability of goldfish. Our further analysis found that TCS/TCC exposure suppressed the expression of olfactory G protein-coupled receptors in the olfactory epithelium, restricted the transformation of odorant stimulation into electrical responses by disturbing the cAMP signaling pathway and ion transportation, and induced apoptosis and inflammation in the olfactory bulb. In conclusion, our results demonstrated that an environmentally realistic level of TCS/TCC would weaken the olfactory capacity of goldfish by constraining odorant recognition efficiency, disrupting olfactory signal generation and transduction, and disturbing olfactory information processing.

Occurrence, health risk assessment and water quality criteria derivation of six personal care products (PCPs) in Huangpu River, China

Personal care products (PCPs) have shown adverse health effects on humans. However, their health risk associated with fish consumption and relevant water quality criteria are still not well documented. This study investigated the occurrence and health risk of six PCPs (triclosan, bisphenol-A, and four commonly used organic ultraviolet (UV) filters, i.e., homosalate (HMS), 4-methylbenzylidene camphor (4-MBC), oxybenzone (BP-3), and octocrylene (OC)). River water and three trophic levels of fish species were collected from Huangpu River in Shanghai. The concentration range of the six PCPs were 1.48-89.76 ng/L in water and 0.40-10.75 ng/g dry weight in fish. Estimated daily intake (EDI) and target hazard quotient (THQ) of the PCPs indicated that consuming these fish would not pose non-carcinogenic risks. The maximum allowable fish consumption rates ranged from 85 to 1760 and 155 to 3230 meals per month for children and adults, respectively. As to the four organic UV filters, it is the first time to report the fish consumption advisories. Finally, the human health ambient water quality criteria (AWQC) values of HMS, 4-MBC, BP-3, OC, TCS, and BPA (i.e., 0.1218, 0.7311, 0.3494, 0.0477, 235.8, and 154.7 μg/L, respectively) were proposed, and they can serve as a valuable technical reference for global development and revision of aquatic environmental quality standards for these emerging contaminants.

The Removal of Hydrophobic Matter from Thermosensitive Poly[oligo(ethylene glycol) Monomethyl Ether Acrylate] Gel Ad-Sorbentin Alcohol–Water Mixtures

A thermosensitive gel that exhibits lower critical solution temperature (LCST) becomes hydrophilic at low temperatures and hydrophobic at high temperatures in water. A system for absorbing hydrophobic organic matters that exploits this property has been reported. While washing the gel at a low temperature with a good solvent is a possible method for removing the adsorbed matter, a process that then shrinks the gel is also required. Herein, we focused on poly[oligo(ethylene glycol) mono(m)ethyl ether acrylate] (POEGA) gels as thermosensitive gels suitable for use in this system. POEGAs are known to contain poly(ethylene glycol) (PEG) units in their side chains and exhibit upper critical solution temperature (UCST) behavior in aliphatic alcohols. By exploiting this property, we developed a method for removing hydrophobic matters that accumulate in these gels; we also evaluated the LCST and UCST behavior of POEGA gels in alcohol–water mixtures, and measured the LCSTs of these gels in water and their UCSTs in some alcohols.

Estrogen induces shift in abundances of specific groups of the coral microbiome

Synthetic estrogens such as ethinylestradiol (EE2) are persistent micropollutants that are not effectively removed from wastewater by conventional treatments. These contaminants are released into waterbodies, where they disrupt endocrine systems of organisms and cause harmful effects such as feminization, infertility, reproduction problems and genital malformations. The consequences of this pollution for key marine ecosystems such as coral reefs and their associated microbiomes are underexplored. We evaluated the effects of EE2 concentrations of 100 ng L-1 and 100 µg L-1 on the coral metaorganism Mussismilia harttii. The results indicated no effects on visible bleaching or Fv/Fm ratios in the corals during a 17-day microcosm experiment. However, next-generation sequencing of 16S rDNA revealed a statistically significant effect of high EE2 concentrations on OTU richness, and shifts in specific microbial groups after treatments with or without EE2. These groups might be bioindicators of early shifts in the metaorganism composition caused by EE2 contamination.

Toxicity assessment of Lemna solid waste dumpsite (Calabar, Nigeria) using different extraction methods and toxicological responses of PLHC-1 cells

In the present study, we have investigated the effects of three (elutriate, polar and non-polar) different soil extraction methods from the Lemna solid waste dumpsite (Calabar, Nigeria) on the biotransformation, antioxidant and cellular defense responses of PLHC-1 cell line. Following a 48 h exposure period to different concentrations of each extract, the PLHC-1 cells were evaluated for enzymatic activities - glutathione peroxidase (Gpx), glutathione reductase (Gr), glutathione S-transferase (Gst), 7-ethoxy-, pentoxy-, and benzyloxyresorufin O-deethylase (EROD, PROD and BROD) and mRNA expressions for catalase (cat), gpx, gst, cyp1a, cyp3a, mammalian target of rapamycin (mtor), nuclear factor erythroid 2-related factor 2 (nrf2) and Kelch-like erythroid cell-derived protein (keap-1). Overall, our results showed parameter-, extract- and concentration-specific increases in transcripts and functional product levels for biotransformation, antioxidant and cellular defense/cytoprotective responses, compared with control. These responses were mostly characterized by a biphasic pattern of effects by either, increasing at low concentration, and thereafter decrease, as the concentration increases or vice versa, depending on the extract type. These observations paralleled soil contaminants (organics and inorganics) burden from the dumpsite. Principal component analysis (PCA) showed that cells treated with the non-polar extract produced more pronounced effects on the measured toxicological responses, compared with the polar and elutriate extracts. Thus, our data highlight peculiar risks to cells exposed to each soil extract, indicating complex and multiple chemical interactions with diverse functional groups that contaminants may have in mixture scenarios. Given the limitations and cost implications of contaminants analysis for the numerous soil- or sediment-bound compounds, we propose that this approach represents an analytical benchmark and endpoints for assessing the risk of complex environmental matrices such as soil and sediments, for ecotoxicological monitoring programs.

Simultaneous determination of 11 antiseptic ingredients in surface water based on polypyrrole decorated magnetic nanoparticles

With the emergence and spread of coronavirus COVID-19, the use of personal cleansing, medical and household disinfectant products have increased significantly. In this work, a new magnetic solid-phase extraction (MSPE) method for the determination of 11 antiseptic ingredients in surface water by high performance liquid chromatography-mass spectrometry (HPLC-MS/MS) for 6 months based on Fe3O4@PPy magnetic nanoparticles (MNPs) was established. The MSPE method possessed the advantages of simple processing, little time consumption and less organic solvent consumption, and the MNPs could be reused several times. The analytical parameters influencing the extraction efficiency, such as sample pH, amount of MNPs and extraction time, were optimized in detail. It was indicated that the method had satisfactory linearities in the range of 0.50 to 1000.0 μg L-1 with the correlation coefficients (r) higher than 0.9996. Additionally, satisfactory spiked recoveries were achieved in the range of 80.21-107.33% with relative standard deviations (RSDs) from 1.98% to 8.05%. The limits of detection (LODs) and limits of quantitation (LOQs) were in the range of 0.20 to 2.0 μg L-1 and 0.50 to 5.0 μg L-1. Therefore, the developed MSPE-HPLC-MS/MS method has high selectivity and stability, and satisfactory quantitative capability for the antiseptic ingredients in surface water. Furthermore, this method can provide relevant technical support for the development of surface water standards.

Feasibility of using plastic wastes as constructed wetland substrates and potential for pharmaceuticals and personal care products removal

Each year, large amounts of plastic waste are generated and must be appropriately disposed. In this work, we studied the feasibility of using plastics as wetland substrates as an alternative plastic waste disposal method and the ability of the constructed wetland to remove pharmaceuticals and personal care products (PPCPs) from contaminated water. Wetland microcosms were constructed using polycarbonate, polyethylene terephthalate, quartz sand, and ceramsite substrates. Lake water spiked with methyl-paraben, ibuprofen, triclosan, 4-methybenzylidene camphor, carbamazepine, and 17α-ethinyl estradiol at 5 μg L^-1 was continuously loaded to the microcosms with a hydraulic retention time of approximately 11 days. After 70 days, methyl-paraben, triclosan, and 4-methybenzylidene camphor were effectively removed regardless of the substrate. However, ibuprofen, carbamazepine, and 17α-ethinyl estradiol were partially removed, and the removal efficiency was the best in wetlands with ceramsite substrate. Carbamazepine was the most persistent among the tested compounds. Phospholipid fatty acid (PLFA) analysis revealed that ceramsite supported the highest microbial biomass per bulk volume of substrate followed by quartz sand, polycarbonate, and polyethylene terephthalate, which might be related to the PPCP removal potential of the wetland microcosms.

Adsorption Characteristics and Mechanism of Bisphenol A by Magnetic Biochar

In this paper, biochar (BC) was prepared from discarded grapefruit peel and modified to prepare magnetic biochar (MBC). Physical and chemical properties of BC and MBC were characterized, and the results showed that the type of iron oxide loaded by MBC was γ-Fe₂O₃. Compared with BC, MBC has a larger specific surface area and pore volume, with more oxygen-containing functional groups on the surface. BC and MBC were used to adsorb and remove endocrine-disrupting chemical (EDC) bisphenol A (BPA) from simulated wastewater. The results showed that the adsorption kinetics and adsorption isotherm of BPA adsorption by BC and MBC were mainly in accordance with the pseudo-second-order kinetics model and the Langmuir model. This indicates that the adsorption of BPA on BC and MBC is mainly a chemically controlled monolayer adsorption. Adsorption thermodynamics show that BC and MBC adsorption of BPA is a spontaneous exothermic reaction, and lowering the temperature is conducive to the adsorption reaction. The effect of solution pH on the adsorption of BPA by both was significant. The optimum pH for BC and MBC to absorb BPA was 6 and 3, respectively. The concentration of Na⁺ in the range of 0–0.10 mol·L⁻¹ can promote the adsorption of BPA to MBC. MBC loaded with γ-Fe₂O₃ not only has excellent magnetic separation ability, but can also reach about 80% of the initial adsorption capacity after four cycles of adsorption. By analyzing the adsorption mechanism, it was found that the H-bond and the π–π electron donor–acceptor interaction (EDA) were the main forces for BC and MBC to adsorb BPA.

Removal of an Ethoxylated Alkylphenol by Adsorption on Zeolites and Photocatalysis with TiO2/Ag

Two advanced removal methods (adsorption and photocatalysis) were compared for the elimination of an ethoxylated alkylphenol (nonylphenol polyethylene glycol, NPEG). For the adsorption process, zeolites were used in their natural state, and the process was characterized by DRX (X-ray diffraction) and SEM–EDS (Scanning electron microscopy). The analysis of the results of the adsorption kinetics was carried out using different isotherms to interpret the removal capacity of zeolites. The Temkin kinetic model better predicted the experimental data and was satisfactorily adjusted to models of pseudo-second order (PSO). On the other hand, for photocatalysis, nano-particles of Ag (silver) were deposited on titanium oxide (TiO2) Degussa-P25 by photo-deposition, and the catalyst was characterized by diffuse reflectance and SEM–EDS. The data obtained using the two removal techniques were analyzed by UV–Vis (ultraviolet-visible spectrophotometry) and total organic carbon (TOC). The kinetic data were compared. The photocatalytic process showed the highest efficiency in the removal of NPEG, corresponding to >80%, while the efficiency of the adsorption process was <60%. This was attributed to the recalcitrant and surfactant nature of NPEG.

Ecotoxicological risk assessment due to the presence of bisphenol A and caffeine in surface waters in the Sinos River Basin - Rio Grande do Sul - Brazil

Abstract Bisphenol A (BPA) is an emerging contaminant, regularly detected in aquatic ecosystems, considered as an endocrine disrupting compound (EDC). Caffeine is another chemical related to human activity, often found in surface waters. The objective of this study was to evaluate the ecotoxicological risk due to BPA and caffeine in water samples from the Sinos River basin, Rio Grande do Sul, Brazil. Water samples were collected at three sites monthly from May 9 th, 2016 to April 11th, 2017 (n = 36). BPA concentrations in water samples collected were in the range of not detected to 517 ng L-1 and caffeine concentrations in the range of 41.7 to 28,439.6 ng L-1. The concentration of BPA in the analyzed samples had a moderate correlation with caffeine (rs = 0.402). High ecotoxicological risk for BPA was characterized in 77.77% of samples, with 11.11% presenting medium and 11.1% presenting low risk. For caffeine 13.9%, 50% and 36.11% of the samples presented high, medium and low risk, respectively. Caffeine concentrations in water can be used as predictors of BPA concentrations above 10 ng L-1, the lower concentration of ecotoxicological risk, with specificity of 66.7% and sensitivity of 70.4%. The assessment of aquatic risks has shown that both investigated compounds pose risks to organisms in the studied surface waters, mouth of the Pampa stream, mouth of the Luiz Rau stream and catchment point for public supply in Lomba Grande.

The effects of urbanization and rainfall on the distribution of, and risks from, phenolic environmental estrogens in river sediment

There is increasing concern about phenolic environmental estrogens (PEEs) in river systems, especially in economically developed regions, because of their potential to impact ecological systems. We studied the distribution of, ecological risks from, and factors that influenced PEEs in the sediments from the Duliujian River in the Beijing-Tianjin-Hebei Urban Agglomeration and the Pearl River in Guangdong Province in China. The three target PEEs, nonyl phenol (4-NP), octyl phenol (4-t-OP), and bisphenol A (BPA), were detected in the sediments at concentrations ranging from 204.4 to 12604.3, 32.6 to 297.3, and from 12.8 to 298.4 ng g^-1 in the Pearl River, and from 153.5 to 3614.9, 90.7 to 990.0, and 83.5-913.3 ng g^-1 in the Duliujian River, respectively. The PEE concentrations were significantly and positively correlated with total organic carbon in the river sediments (p < 0.1). Urbanization influenced the distribution of PEEs and applications and discharges of PEEs were associated with large populations and industries. Rainfall and wastewater discharge patterns also influenced how PEEs were distributed in river sediments. The potential ecological risks from 4-NP, 4-t-OP, and BPA in these two rivers were high. Measures should be put in place to control the transport and storage of these compounds in river systems.

Multi-phase distribution and risk assessment of endocrine disrupting chemicals in the surface water of the Shaying River, -Huai River Basin, China

Herein we investigated the multi-phase distribution and estrogenic effects of endocrine disrupting chemicals (EDCs) in suspended particulate matter (SPM), colloids, and soluble phases from the Shaying River to assess the composition of estrogenic compounds and associated estrogenic risk. The yeast two hybrid (YES) method, cross-flow ultrafiltration (CFUF), and LC-MS/MS were employed. Risk quotient (RQ) values ranged from 0.72 to 3.88, revealing that the Shaying River posed high estrogenic risk to aquatic organisms. The contribution ratios of the target EDCs to the EEQ_YES ranged from 62.7% to 92.5%, indicating that these chemicals were major contributors of estrogenic effects in the Shaying River. Further, 54.0-77.8% of the detected EDCs were distributed in the soluble phase, 15.1-31.7% were bound to colloidal substances, and 3.90-19.4% EDCs were associated with SPM. Significant correlation between total EDC abundance and COD contents was detected, and the concentrations of endogenous estrogens (E1, E2, and E3) were positively correlated with total nitrogen (TN) and total phosphorus (TP). In addition, the in-situ SPM-soluble (Kpoc) and colloid-soluble partition (Kcoc) coefficients were calculated. The log Kpoc values of target compounds varied from 4.10 to 5.19, while log Kcoc values ranged from 4.25 to 5.56. Their Kcoc values were larger than the Kpoc values, indicating that organic colloids were the most important carriers of EDCs in the aquatic environment.

Toxicity effects of the organic UV-filter 4-Methylbenzylidene camphor in zebrafish embryos

Ultraviolet (UV) filters are widely used in personal care products and due to their lipophilicity these chemicals tend to bioaccumulate in the aquatic biota. 4-Methylbenzylidene camphor (4-MBC) is one of the most used UV-filters, and it is commonly detected in freshwater fish tissues. This substance is suspected to be an endocrine disruptor due to its interaction with Hypothalamus-Pituitary-Gonadal (HPG) and HP-Thyroid (HPT)-axis. The main objective of this study was to evaluate the effects of 4-MBC on apical endpoints, biochemical markers and on genes involved in endocrine pathways in Danio rerio. Zebrafish embryos were exposed to 4-MBC (0.083-0.77 mg/l) from 0 to 96 h post-fertilization (hpf). Hatching, heart rate and malformations were the apical endpoints assessed. Alterations on neurotransmission and oxidative stress were evaluated through acetylcholinesterase (AChE), catalase (CAT) and glutathione S-transferase (GST) enzymatic activities. Endocrine effects were analysed by the expression of genes involved in HPG and HPT-axis of embryos exposed 96 h to the EC₁₀ of 4-MBC (0.19 mg/l). Exposure to 4-MBC induced morphological abnormalities during embryonic development, including notochord curvature, delayed absorption of yolk sac and pericardial oedema. Concentration of 0.77 mg/l 4-MBC decreased embryo heart rate at 48h. At neurotransmission level, an induction of AChE at concentrations above 0.15 mg/l was observed. Malformations and decreased heart rate along with alterations observed at neurotransmission level might have compromised zebrafish larvae equilibrium. Glutathione S-transferase induction above 0.15 mg/l 4-MBC suggests activation of detoxification processes. Furthermore, observed brain aromatase gene down-regulation by 4-MBC suggests impairment of normal functioning of HPG axis in zebrafish.

Assessing the effects of Awba dam sediment (Nigeria) on the steroidogenesis of H295R cells using different extraction methods

In the present study, H295R human cells were used to investigate the endocrine disruptor potential of three different sediments extracts taken from a Nigerian tropical freshwater dam (Awba Dam), using three extraction methods that allowed a selective consideration of contaminants based on their binding affinity, which is mainly driven by polarity, to sediment particles. After exposure to different concentration of each extract, H295R cells were evaluated for the expression profiles of 10 steroidogenic enzyme genes and estradiol (E2) and testosterone (T) levels. Our results showed a comparable concentrated-related increase in the expression of 17β-hsd1, 3β-hsd2 and cyp21 in cells treated with the polar and non-polar extracts. The star, hmgr, cyp11b2 and 17β-hsd4 were slightly decreased, in an apparent concentration-specific manner, after treatment with the polar extract and decreased in the non-polar treatment. The cyp11a and cyp17 showed an opposite trend in the polar and non-polar treatments. E2 was significantly higher in cell treated with the non-polar extract. Elutriate exposure produced less pronounced variation in mRNA and hormones levels. Overall the extract with non-polar compounds produced the most severe effects in H295R cells. Thus, direct ingestion of detritus and mud from fishes and other benthonic organisms represent possible transfer of contaminants in the trophic web, and mainly account for alteration of the endocrine system previously observed in fish from the same study site.

Emerging contaminants and nutrients in a saline aquifer of a complex environment

The quality and availability of water has become a pressing issue worldwide, being particularly important in semi-arid regions, where climate change has aggravated the problem. The use of anthropogenic chemicals, classified as emerging pollutants, adds to the problem representing a treat, since they are not regulated and have a potential impact on human and environmental health. This pressing problem has not been studied widely in complex environments like the one we present here. Distribution and seasonal variability of fecal sterols, alkylphenols, pesticides (emerging pollutants) and nutrients were determined in 35 wells used for agriculture and human consumption in the Valley of Maneadero, located in the semi-arid region of Baja California, Mexico. The presence of the tested pollutants in the saline aquifer was heterogeneous, showing important differences in concentration and distribution. Wells destined for household use showed the highest variability. In these wells, anthropogenic fecal sterols were detected and, alkylphenols, such as octyphenol and nonylphenol had maximum concentrations (2.7 ng/mL). In agriculture and urban wells, we identified DDT and organochlorine pesticides, as well as myclobutanil, which is considered a modern pesticide. Nitrates were identified in concentrations above international standards, mainly during the dry season, in both the agricultural and urban areas. As emerging pollutants represent a negative effect on environmental and human health, this is the first paper showing the importance of measuring this type of pollutant in agricultural/semi-urban areas, especially in aquifers that have been overexploited and communities that have relied on the use of septic tanks for decades.

Typical Endocrine Disrupting Compounds in Rivers of Northeast China: Occurrence, Partitioning, and Risk Assessment

Liao River Basin (LRB), located in northeast China, is one of seven largest river basins in China. The Daliao River Watershed (DLRW) is severely disturbed by human activities in the LRB. In this study, three rivers within the DLRW-Xi River (XR), Hun River (HR), and Daliao River (DLR)-were selected as sampling locations. The distribution, partitioning, and risk assessment of four endocrine-disrupting compounds (EDCs), e.g., bisphenol A (BPA), 17β-estradiol (E2), estrone (E1), and 17α-ethinyl estradiol (EE2), in the rivers were investigated. The results showed that the concentration of BPA was generally higher than those of the other three steroidal estrogens in the sampling locations. The estrogen levels in the XR were greater than those in the HR and DLR. As a result of a decreasing river flow rate during the frozen season and irregular wastewater discharge from human domestic activities and manufacture processing, the total concentration of selected EDCs in the frozen season was much greater than those in nonfrozen season with the highest concentration in surface water of the XR at 1131.0 ng/L for BPA, 1235.0 ng/L for E1, 1253.5 ng/L for E2, and 17,111.5 ng/L for EE2, respectively. Based on the field-measured BPA concentrations in the sediment and water, the organic carbon-normalized partition coefficient (K _oc) of BPA were calculated with the values of 2884-45,031 L/kg; the concentration of BPA in sediment was positive correlated with the content of OC (R ² = 0.932). The risk assessment made by estradiol equivalent (EEQ) and risk quotient (RQ) showed that 64.7% of sampling sites were exposed to high estrogenic activity (∑EEQ > 1) and high risk in surface water, whereas the RQ values of all selected estrogens in sediment were in medium or minimal risk. Both EE2 and E1 were the major contributors to the total estrogenic activity and risk quotient in surface water.

Water contamination by endocrine disruptors: Impacts, microbiological aspects and trends for environmental protection

Hormone active agents constitute a dangerous class of pollutants. Among them, those agents that mimic the action of estrogens on target cells and are part of the group of endocrine-disruptor compounds (EDCs) are termed estrogenic EDCs, the main focus of this review. Exposure to these compounds causes a number of negative effects, including breast cancer, infertility and animal hermaphroditism. However, especially in underdeveloped countries, limited efforts have been made to warn people about this serious issue, explain the methods of minimizing exposure, and develop feasible and efficient mitigation strategies at different levels and in various environments. For instance, the use of bioremediation processes capable of transforming EDCs into environmentally friendly compounds has been little explored. A wide diversity of estrogen-degrading microorganisms could be used to develop such technologies, which include bioremediation processes for EDCs that could be implemented in biological filters for the post-treatment of wastewater effluent. This review describes problems associated with EDCs, primarily estrogenic EDCs, including exposure as well as the present status of understanding and the effects of natural and synthetic hormones and estrogenic EDCs on living organisms. We also describe potential biotechnological strategies for EDC biodegradation, and suggest novel treatment approaches for minimizing the persistence of EDCs in the environment.

Distribution and fate modeling of 4-nonylphenol, 4-t-octylphenol, and bisphenol A in the Yong River of China

In this study, the concentrations of 4-nonylphenol (4-NP), 4-tert-octylphenol (4-t-OP), and bisphenol A (BPA) in the water column of the Yong River were investigated and found to be in the range of 140-3948, 6-828, and 15-1415 ng L^-1, respectively. A fate and transport model coupled with the Water Quality Analysis Simulation Program (WASP) was developed. After model calibration and validation, the distributions of 4-NP, 4-t-OP, and BPA in the Yong River were modeled for the duration of 2015. The total contaminant loads from the upstream boundary, four tributaries and two wastewater treatment plants were determined to be 2318 kg yr^-1 for 4-NP, 506 kg yr^-1 for 4-t-OP, and 970 kg yr^-1 for BPA. Both measured and modeled results reported higher concentrations of the selected contaminants near river confluences and at the outfalls of the wastewater treatment plants. Peak concentrations were found to always appear in months with relatively reduced precipitation. The influences of adsorption and degradation on the dissolved concentrations of the selected chemicals were also modeled. The combined effects of adsorption and degradation were found to reduce dissolved concentrations of 4-NP, 4-t-OP, and BPA by 17.9%, 30.7%, and 12.1%, respectively. Adsorption was shown to reduce 4-NP concentrations in the Yong River more than degradation. Conversely, adsorption and degradation caused almost equal reductions in the dissolved concentrations of 4-t-OP and degradation caused larger decreases than adsorption in the dissolved concentrations of BPA.

Removal of nutrients and pharmaceuticals and personal care products from wastewater using periphyton photobioreactors

In this work, periphyton photobioreactors were built and were used for the treatment of synthetic wastewater spiked with PPCPs under different operational conditions. The removal rates of total nitrogen were relatively stable and varied from 39% to 77% overtime in different treatments. However, the removal rates of soluble reactive phosphorus decreased overtime from 42% to 68% on day 2 to 15.8% to 44% on day 22. For the selected PPCPs, only bisphenol A was effectively removed (72%-86.4%), hydrochlorothiazide and ibuprofen were moderately removed (26.2%-48.7%), and carbamazepine and gemfibrozil were poorly removed (6.45%-20.6%). Longer hydraulic retention time enhanced the treatment efficiency but illumination period showed contrasting effects on the removal of the nutrients and the PPCPs.

Distribution and bioaccumulation of endocrine disrupting chemicals in water, sediment and fishes in a shallow Chinese freshwater lake: Implications for ecological and human health risks

The occurrence, distribution and bioaccumulation of six endocrine disrupting compounds (EDCs) were investigated in water, sediment and biota samples from Luoma Lake, a shallow Chinese freshwater lake. Total concentrations of ∑phenolic EDCs were much higher than ∑estrogens EDCs in both waters and sediments. There were not obvious differences on the concentrations of target compounds [except nonylphenol (NP)] in upstream, lake and downstream locations, these may be suggested that they were mainly affected by non-point discharges in this area. However, the high concentration of NP in water may be associated with the discharge of rural domestic wastewater without thorough treatment. Furthermore, concentrations of NP were about 2-3 order magnitude higher than those of OP in both water and sediment compartments. Relatively higher bioaccumulation factors (BAF) were obtained for DES and EE2. Ecological risk assessment revealed greater risk of NP in surface water, which may pose a serious threat to aquatic ecosystems. The estrogen equivalent concentration (EEQ) of male were higher than those in female, and occurred in the order of city >rural-urban>countryside.

Occurrence, distribution and risk assessment of suspected endocrine-disrupting chemicals in surface water and suspended particulate matter of Yangtze River (Nanjing section)

The occurrence and distribution of eight selected endocrine-disrupting chemicals were investigated in samples of surface water and suspended particulate matter (SPM) in Nanjing section of Yangtze River over a year (the flow period, the wet period and the dry period). All target compounds were detected at least once in surface water with 4-tert-butylphenol (4-TBP), nonyphenol (NP) and bisphenol A (BPA) as the dominant compounds, with concentrations in the range of 225-1121ng/L, 1.4-858ng/L and 1.7-563ng/L, respectively. Except for December, all selected compounds for the other sampling times were not found in all sampling points. NP (mean concentration 69.8µg/g) and BPA (mean concentration 51.8µg/g) were also the dominant estrogens in SPM. In addition, the highest total compounds concentrations were found in December in both phases, which could be due to the low flow conditions and temperature during this season. Meanwhile, a significant positive correlation was found between the total compounds concentrations in the water phase and those in SPM phase. Risk assessment based on the calculated risk quotients (RQ) showed that low and moderate risk for the aquatic environment from presence of the target compounds at all sampling points with exception of 4-TBP and NP which might pose a high risk to aquatic organisms.

Rapid, portable detection of endocrine disrupting chemicals through ligand-nuclear hormone receptor interactions

Recent advances in biosensing technology are enabling rapid and portable detection of nuclear hormone receptor ligand endocrine disrupting chemicals.

Occurrence, distribution, and risk assessment of alkylphenols, bisphenol A, and tetrabromobisphenol A in surface water, suspended particulate matter, and sediment in Taihu Lake and its tributaries

The occurrence and distribution of nine selected compounds were investigated in surface water, suspended particulate matter (SPM), and sediment in Taihu Lake and its tributaries. With the exception of 4-Butylphenol, all compounds were detected in at least two phases, and nonylphenol (NP) and 4-tert-Octylphenol (4-OP) were the predominant alkylphenols (APs) in the lake. A significant correlation was observed between NP and 4-OP, indicating that they may share the same source. Moreover, surface water phase was the dominant sink of Bisphenol A (BPA) in the aquatic environment. The concentrations of BPA between the surface water and SPM phases were closely related to each other. In addition, Tetrabromobisphenol A (TBBPA) exhibited relatively higher concentrations and detection frequencies in the SPM. Risk assessment revealed greater risk associated with the surface water than the sediment, indicating that the discharge of industrial wastewater and domestic sewage poses a serious threat to aquatic ecosystems.

A review on bisphenol A occurrences, health effects and treatment process via membrane technology for drinking water

Massive utilization of bisphenol A (BPA) in the industrial production of polycarbonate plastics has led to the occurrence of this compound (at μg/L to ng/L level) in the water treatment plant. Nowadays, the presence of BPA in drinking water sources is a major concern among society because BPA is one of the endocrine disruption compounds (EDCs) that can cause hazard to human health even at extremely low concentration level. Parallel to these issues, membrane technology has emerged as the most feasible treatment process to eliminate this recalcitrant contaminant via physical separation mechanism. This paper reviews the occurrences and effects of BPA toward living organisms as well as the application of membrane technology for their removal in water treatment plant. The potential applications of using polymeric membranes for BPA removal are also discussed. Literature revealed that modifying membrane surface using blending approach is the simple yet effective method to improve membrane properties with respect to BPA removal without compromising water permeability. The regeneration process helps in maintaining the performances of membrane at desired level. The application of large-scale membrane process in treatment plant shows the feasibility of the technology for removing BPA and possible future prospect in water treatment process.