Identification, contribution, and estrogenic activity of potential EDCs in a river receiving concentrated livestock effluent in Southern Taiwan

Effective simultaneous removal of 17β-estradiol and tetracycline by a novel Alkalibacterium strain: characteristics, mechanisms, and application in livestock wastewater treatment

The environmental risk posed by 17β-estradiol (E2) and tetracycline (TC) contamination within livestock wastewater has been widely concerned. Especially, the co-occurrence of these pollutants poses a tremendous challenge to their efficient bioremediation, highlighting the need for strains capable of simultaneous E2 and TC removal. In this study, a novel strain of Alkalibacterium sp. AEPI-S25 was successfully isolated from the sediments of Qinghai Lake, demonstrating the ability to remove 89.91% of 20 mg L-1 E2 and nearly 100% of 20 mg L-1 TC simultaneously within 5 days. AEPI-S25 exhibited remarkable environmental adaptability and maintained high simultaneous removal efficiency under various stress conditions and the presence of two typical livestock wastewater samples. Based on Ultra-Performance Liquid Chromatography coupled with Orbitrap High-Resolution Mass Spectrometry (UPLC-Orbitrap-HRMS) analysis, dehydrogenation and monooxygenation were identified as the key steps in the removal pathways of E2 and TC, respectively. Whole-genome sequencing further identified the potential E2/TC removal genes, and the detected potential E2-dehydrogenation (S25_gene0393) and TC-monooxygenation (S25_gene0878) genes were subsequently validated through transcription analysis and heterologous expression. Notably, S25_gene0878 exhibited significant differences from the well-characterized TC removal gene TetX, extending a new understanding of the bacterial TC removal mechanism. Overall, this study provides the first report of a single microbial strain capable of simultaneously removing E2 and TC, offering valuable insights for the application of microbial technologies in addressing typical E2-TC combined pollution in livestock wastewater. KEY POINTS: • AEPI-S25 can remove nearly 90% and 100% of 20 mg L-1 E2 and TC within 5 days • Key E2 (S25_gene0393) and TC (S25_gene0878) removal genes were cloned and expressed • A novel TC-monooxygenase gene distinct from TetX was discovered within the strain.

Hormonal disruption from plastic ingestion in northern fulmars: Activation and inhibition of estrogen receptors

Plastic pollution is of global concern, yet documented harmful effects from plastic ingestion in wild species is limited. Procellariiformes, such as northern fulmars (Fulmarus glacialis, fulmar), have high levels of plastic ingestion, and we investigated their potential hormonal disruption. As human estrogen receptors (ERs) are commonly used to assess risk of hormonal disruption for wild species, we first compared human and fulmar ER responses to plastic-associated chemicals using a luciferase-reporter gene assay. ERs from both species were activated by bisphenol-A (BPA), bisphenol-S (BPS), 4-octylphenol (4-OP), and benzyl butyl phthalate (BBP), and inhibited by tetrabromobisphenol-A (TBBPA), 2,5,2',5'tetrachloro-biphenyl (PCB-52), and 2,2',3,4,4',5'-hexachlorobiphenyl (PCB-138), although we observed species-specific differences in sensitivity. To assess if ingested plastic had the potential to alter fulmar hormone function, plastic recovered from fulmar stomachs (n = 27) were leached for 14 days with daily solvent renewal and leachates were exposed to fulmar ERs. Almost 50 % of the birds (13 out of 27) had ingested plastic that leached chemicals which caused ER activation and/or inhibition on day 1, with ∼70 % of these (9 out of 13) also showing a response on day 5 and/or 14. The polymer composition of the recovered plastic pieces (n = 142) was identified with infrared spectroscopy. Polyethylene (PE) (60 %) was the most abundant polymer, followed by polypropylene (PP) (35 %), polyethylene terephthalate (PET) (3 %) and unidentifiable (2 %). Polymer type was not associated with ER response, suggesting that chemical additives, not polymer composition, were responsible for the observed hormonal disruption. To our knowledge, we provide the first data on a seabird's ER response to plastic-associated chemicals. Overall, we highlight the potential for plastic ingestion to disrupt fulmar hormone function, providing important information about the harmful effects of plastic pollution.

Enhanced endoplasmic reticulum stress signaling disrupts porcine sertoli cell function in response to Bisphenol A exposure

Bisphenol A (BPA), a pervasive substance in our daily lives and livestock excreta, poses significant threats due to its infiltration into foods and water sources. BPA has adverse impacts on male reproductive function, particularly affecting the critical Sertoli (ST) cells that play a pivotal role in the process of spermatogonia differentiating into spermatozoa. In this study, we examined the prevalence of BPA within the pig industry and delved into the impact of BPA exposure on the motility of boar sperm, the function of pig ST cells, as well as the underlying molecular mechanisms involved. This study revealed spatial disparities in the global distribution of BPA and its analogue contamination, utilizing data compiled from 130 comprehensive studies. The average concentration of BPA found in pig feed ranges from 9.7 to 47.9 μg/kg, while in serum, it averages between 55.1 and 75.6 ng/L. The BPA concentration in feed exhibits a negative correlation with sperm viability and the percentage of progressive motile spermatozoa. Exposure to BPA reduced sperm motility in boar and ST cell activity at both 6 and 24 h. The transcriptome analysis revealed that, compared to untreated control cells, endoplasmic reticulum stress (ERS)-related genes were upregulated in ST cells exposed to BPA at 6 and 24 h. This activation of ERS in ST cells was mediated by receptor protein kinase RNA-like endoplasmic reticulum kinase (PERK), inositol-requiring protein-1α (IRE1α), and activating transcription factor 6 (ATF6). Additionally, BPA exposure triggered oxidative stress and a proinflammatory response mediated by the transcription factor NF-κB, accompanied by an increase in downstream proinflammatory cytokines. BPA exposure also led to apoptosis in ST cells and upregulated the expression levels of pro-apoptosis proteins. However, inhibiting ERS activity with 4-PBA attenuated the BPA-induced inflammatory response and apoptosis in ST cells. Our findings suggest that BPA induced apoptosis and inflammatory response in porcine ST cells through persistent activation of ERS, thereby compromising the normal function of these cells.

Multiphase Partitioning of Estrogens in a River Impacted by Feedlot Wastewater Discharge

Estrogens in river systems can significantly impact aquatic ecosystems. This study aimed to investigate the multiphase partitioning of estrogens in Wulo Creek, Taiwan, which receives animal feedlot wastewater, to understand their distribution and potential environmental implications. Water samples were separated into suspended particulate matter (SPM), colloidal, and soluble phases using centrifugation and cross-flow ultrafiltration. Concentrations of estrone (E1), 17β-estradiol (E2), and estriol (E3) in each phase were analyzed using LC/MS/MS. Partition coefficients were calculated to assess estrogen distribution among phases. Estrogens were predominantly found in the soluble phase (85.8-87.3%). The risk assessment of estrogen equivalent (EEQ) values suggests that estrogen concentration in water poses a higher risk compared to SPM, with a majority of the samples indicating a high risk to aquatic organisms. The colloidal phase contained 12.7-14.2% of estrogens. The log KCOC values (4.72-4.77 L/kg-C) were significantly higher than the log KOC and log KPOC values (2.02-3.40 L/kg-C) for all estrogens. Colloids play a critical role in estrogen distribution in river systems, potentially influencing their fate, transport, and biotoxicity. This finding highlights the importance of considering colloidal interactions in assessing estrogen behavior in aquatic environments.

Environmental health hazards of untreated livestock wastewater: potential risks and future perspectives

Due to technological and economic limitations, waste products such as sewage and manure generated in livestock farming lack comprehensive scientific and centralized treatment. This leads to the exposure of various contaminants in livestock wastewater, posing potential risks to both the ecological environment and human health. This review evaluates the environmental and physical health risks posed by common pollutants in livestock wastewater and outlines future treatment methods to mitigate these risks. Residual wastes in livestock wastewater, including pathogenic bacteria and parasites surviving after epidemics or diseases on various farms, along with antibiotics, organic wastes, and heavy metals from farming activities, contribute to environmental damage and pose risks to human health. As the livestock industry's development increasingly impacts society's future negatively, addressing the issue of residual wastes in livestock wastewater discharge becomes imperative. Ongoing advancements in wastewater treatment systems are consistently updating and refining practices to effectively minimize waste exposure at the discharge source, mitigating risks to environmental ecology and human health. This review not only summarizes the "potential risks of livestock wastewater" but also explores "the prospects for the development of wastewater treatment technologies" based on current reports. It offers valuable insights to support the long-term and healthy development of the livestock industry and contribute to the sustainable development of the ecological environment.

Survey on the Environmental Risks of Bisphenol A and Its Relevant Regulations in Taiwan: An Environmental Endocrine-Disrupting Chemical of Increasing Concern

Bisphenol A (BPA) has been identified as one of the endocrine disruptors or endocrine disrupting chemicals (EDCs). Due to its massive production (over 700,000 tons per year) and the extensive use of BPA-based plastics (i.e., polycarbonate and epoxy resin) in Taiwan, it was thus included as a toxic substance by the Ministry of Environment. This work surveyed the updated information about the production of BPA and its environmental distribution in Taiwan over the past decade. Furthermore, the regulatory strategies and countermeasures for managing the environmental risks of BPA by the Taiwan government were summarized to show the cross-ministerial efforts under the relevant acts, including the Toxic and Concerned Chemical Substances Control Act (TCCSCA), the Food Sanitation Management Act (FSMA) and the Commodity Inspection Act (CIA). The findings showed that most monitoring data were far below the acceptable risks. However, people may pose an adverse threat to the aquatic environment and human health via ecological and food chains. In addition, some countermeasures were further recommended to echo the international actions on environmental endocrine disruptors in recent years.

Simultaneous electrochemical detection of dimethyl bisphenol A and bisphenol A using a novel Pt@SWCNTs-MXene-rGO modified screen-printed sensor

Since bisphenol A (BPA) and dimethyl bisphenol A (DM-BPA) are human endocrine disruptors (EDCs) with tiny potential differences (44 mV) and widespread applications, there is a lack of published reports on their simultaneous detection. Therefore, this study reports a novel electrochemical detection system capable of simultaneous direct detection of BPA and DM-BPA using screen-printed carbon electrodes (SPCE) as a sensing platform. To improve the electrochemical performance of the SPCE, the SPCE was modified by using a combination of Pt nanoparticles modified with single-walled carbon nanotubes (Pt@SWCNTs), MXene (Ti₃C₂), and graphene oxide (GO). In addition, the GO in Pt@SWCNTs-MXene-GO was reduced to reduced graphene oxide (rGO) by the action of electric field (-1.2 V), which significantly improved the electrochemical properties of the composites and effectively solved the problem of dispersion of the modified materials on the electrode surface. Under optimal experimental conditions, Pt@SWCNTs-Ti₃C₂-rGO/SPCE exhibited a suitable detection range (0.006-7.4 μmol L^-1) and low detection limits (2.8 and 3 nmol L^-1, S/N = 3) for the simultaneous detection of BPA (0.392 V vs. Ag/AgCl) and DM-BPA (0.436 V vs. Ag/AgCl)). Thus, this study provides new insights into detecting compounds with similar structures and slight potential differences. Finally, the developed sensor's reproducibility, stability, interference resistance and accuracy were demonstrated with satisfactory results.

Water a major source of endocrine-disrupting chemicals: An overview on the occurrence, implications on human health and bioremediation strategies

Endocrine disrupting chemicals (EDCs) are toxic compounds that occur naturally or are the output of anthropogenic activities that negatively impact both humans and wildlife. A number of diseases are associated with these disruptors, including reproductive disorders, cardiovascular disorders, kidney disease, neurological disorders, autoimmune disorders, and cancer. Due to their integral role in pharmaceuticals and cosmetics, packaging companies, agro-industries, pesticides, and plasticizers, the scientific awareness on natural and artificial EDCs are increasing. As these xenobiotic compounds tend to bioaccumulate in body tissues and may also persist longer in the environment, the concentrations of these organic compounds may increase far from their original point of concentrations. Water remains as the major sources of how humans and animals are exposed to EDCs. However, these toxic compounds cannot be completely biodegraded nor bioremediated from the aqueous medium with conventional treatment strategies thereby requiring much more efficient strategies to combat EDC contamination. Recently, genetically engineered microorganism, genome editing, and the knowledge of protein and metabolic engineering has revolutionized the field of bioremediation thereby helping to breakdown EDCs effectively. This review shed lights on understanding the importance of aquatic mediums as a source of EDCs exposure. Furthermore, the review sheds light on the consequences of these EDCs on human health as well as highlights the importance of different remediation and bioremediation approaches. Particular attention is paid to the recent trends and perspectives in order to attain sustainable approaches to the bioremediation of EDCs. Additionally, rigorous restrictions to preclude the discharge of estrogenic chemicals into the environment should be followed in efforts to combat EDC pollution.

Oestrogenic Activity in Girls with Signs of Precocious Puberty as Exposure Biomarker to Endocrine Disrupting Chemicals: A Pilot Study

The relationship between endocrine disrupting chemical (EDC) exposure and Precocious Puberty (PP) was investigated in this pilot study, involving girls with signs of PP (P) and pre-pubertal girls (C). Risk factors for PP were assessed through questionnaires, while 17β-oestradiol (E2) levels and oestrogenic activity were quantified on sera. The oestrogenic activity, expressed as E2 equivalent concentration (EEQ), was applied as EDC exposure biomarker. Questionnaires showed a low EDC knowledge, a high EDC exposure, and a potential relationship between some habits at risk for EDC exposure and PP. EEQs were similar between C and P; however, they were significantly higher in girls living in an urban environment than in girls living in a rural environment, suggesting a potential higher EDC exposure in cities. The results of this pilot study highlighted the need to raise awareness on EDCs and can be considered a starting point to clarify the relationship between EDC exposure and PP.

Carbon Black: A Good Adsorbent for Triclosan Removal from Water

Industrial grade carbon black was pretreated and used for adsorption of triclosan (TCS) in water, and its adsorption performance was investigated by static adsorption experiments and fixed bed adsorption experiments. The effects of pH and temperature on the adsorption capacity were investigated and the adsorption performance of carbon black and activated carbon on TCS was compared. As the pH or temperature decreased, the adsorption of TCS by carbon black increased. Carbon black had a maximum adsorption capacity of 18.62 mg/g on TCS, which was somewhat lower than the activated carbon. Furthermore, the breakthrough time increased with increasing bed height, decreasing flow rate and decreasing initial TCS concentration in the fixed bed adsorption studies. The breakthrough time was 14.33 days at a bed depth of 4.2 mm, a flow rate of 2 mL/min, and an initial TCS concentration of 0.5 mg/L TCS. The model from The Bed Depth Service Time (BDST) was well-fitting.

Evaluation of estrogenic and antiestrogenic activity in sludge and explanation of individual compound contributions

Mixture toxicity, including agonistic and antagonistic effects, is an unrevealed environmental problem. Estrogenic endocrine disruptors are known to cause adverse effects for aquatic biota, but causative chemicals and their contributions to the total activity in sewage sludge remain unknown. Therefore, advanced analytical methods, a yeast bioassay and mixture toxicity models were concurrently applied for the characterization of 8 selected sludges with delectable estrogenic activity (and 3 sludges with no activity as blanks) out of 25 samples from wastewater treatment plants (WWTPs). The first applied full logistic model adequately explained total activity by considering the concentrations of the monitored compounds. The results showed that the activity was primarily caused by natural estrogens in municipal WWTP sludge. Nevertheless, activity in a sample originating from a car-wash facility was dominantly caused by partial agonists - nonylphenols - and only a model enabling prediction of all dose-response curve parameters of the final mixture curve explained these results. Antiestrogenic effects were negligible, and effect-directed analysis identified the causative chemicals.

Twelve natural estrogens in urines of swine and cattle: Concentration profiles and importance of eight less-studied

Although four major natural estrogens (i.e., estrone (E1), 17β-estradiol (E2), estriol (E3) and 17α-estradiol (αE2)) have been commonly found in livestock urine, this study reports the occurrence of eight other less-studied natural estrogens in urine of swine and cattle, i.e. 2-hydroxyestone (2OHE1), 4-hydroxyestrone (4OHE1), 2-hydroxyestradiol (2OHE2), 4-hydroxyestradiol (4OHE2), 16-epiestriol (16epiE3), 16α-hydroxyestrone (16αE1), 16-ketoestradiol (16ketoE2), and 17epiestriol (17epiE3). Results showed that each estrogen was found in at least one urine sample, and 6 of 8 the less-studied estrogens were present at frequencies of ≥90% in boars, ≥70% in sows, and ≥50% in dairy cattle. Five of eight the less-studied estrogens were present at frequencies of ≥33.3% in four beef cattle and one bull. On a concentration basis, the 8 less-studied natural estrogens represented 73.2%, 85.2%, 39.9%, 47.7%, 26.9%, 56.0% and 44.1% of total concentrations of the twelve natural estrogens when combining data from all animals. Similar results were observed based on estrogen equivalence, which indicated these newly detected eight less-studied natural estrogens were not negligible. This work is the first to figure out the importance of these less-studied natural estrogens in livestock urine, and their potential environmental risks associated with discharge of livestock wastewater should be urgently assessed in a holistic manner.

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.

Removal efficiencies and risk assessment of endocrine-disrupting chemicals at two wastewater treatment plants in South China

Endocrine-disrupting chemicals (EDCs) in the effluent from wastewater treatment plants (WWTPs) are an important pollutant sources of the aquatic system. In this study, the removal efficiencies of eight typical EDCs at two domestic WWTPs in Dongguan City, China, are reported based on instrumental analysis and bioassay results. Bioactivities, including steroidogenesis-disrupting effects, estrogen receptor (ER)-binding activity, and aryl hydrocarbon receptor (AhR)-binding activity were evaluated using the H295R, MVLN, and H4IIE cell bioassays, respectively. The potential environmental risks of these residual EDCs were also evaluated. The results of instrumental analysis showed that nonylphenol was the major chemical type present among the eight tested EDCs. Meanwhile, concentrations of estrogen compounds including estrone, 17β-estradiol (E2), estriol, 17α-ethinyl estradiol, and diethylstilbestrol were relatively low. The removal rates of all eight EDCs were relatively high. Although the chemical analysis indicated high removal efficiency, the bioassay results showed that steroidogenesis-disrupting effects as well as ER-binding and AhR-binding activities remained, with E2-equivalent values of effluent samples ranging from 0.16 to 0.9 ng·L^-1, and 2,3,7,8-tetrachlorodibenzo-p-dioxin-equivalent values ranging from 0.61 to 4.09 ng L^-1. Principal component analysis combined with regression analysis suggests that the chemicals analyzed in this study were partly responsible for these ER and AhR activities. Ecological risk assessment of the residual EDCs showed that estrone was the most hazardous chemical among the eight EDCs tested, with a risk quotient of 1.44-5.50. Overall, this study suggests that, despite high apparent removal efficiencies of typical EDCs, their bioactivities and potential ecological risks cannot be ignored.

Occurrence of parabens, triclosan and triclocarban in paired human urine and indoor dust from two typical cities in China and its implications for human exposure

Parabens, triclosan (TCS) and triclocarban (TCC) are emerging endocrine disrupting chemicals, which are commonly used in personal care products and household applications in daily life. Due to their adverse health effects, human exposure to these chemicals has been a public concern. Despite evidence showing different exposure pathways of these chemicals, few studies have examined contribution of certain exposure to total human exposure. In this study, we measured six parabens, TCS and TCC in 129 indoor dust samples and these chemicals plus four paraben metabolites in 203 urine samples from two different cities in China (Suizhou, a typical small city in central China and Beijing, the capital of China). The median concentrations of ∑₆Parabens (1050 ng/g) and ∑TCS + TCC (565 ng/g) in dusts from Beijing were 1.9-3.3 times higher than those from Suizhou (∑₆Parabens: 314, ∑TCS + TCC: 294 ng/g). The ∑₆Parabens in urines from Suizhou and Beijing were in the range of 0.208-645 and 0.455-2300 μg/g Creatinine (Cr), respectively. The ∑TCS + TCC concentrations in urine were 1-2 orders of magnitude lower than those found for ∑₆Parabens. Comparatively, women had relatively higher body burden of parabens than men, which was more noticeable when considering the use of skin care products. In this regard, relatively higher levels of parabens were also found in women in couples. Positive correlations were found between concentrations of methyl-paraben (MeP) and ethyl-paraben (PrP) in paired dust and urine samples (p < 0.05). Human exposure to such chemicals was evaluated. Based on the measured concentrations in paired human urine and indoor dust samples, our results provided direct evidence that the contribution of indoor dust ingestion to the total exposure was minor. These findings are essential for clarifying the sources and potential exposure routes of these chemicals in humans.

Human exposure and health risk assessment of an increasingly used antibacterial alternative in personal care products: Chloroxylenol

The ban of some antibacterial ingredients, such as triclosan (TCS) and triclocarban (TCC), in personal care products (PCPs) in some countries (but not in China) has resulted in the increasing use of antibacterial alternatives, such as chloroxylenol (PCMX). However, the underlying human health risks and environmental impacts of PCMX exposure are largely unknown. Thus, the distribution characteristics of PCMX in PCPs and susceptible populations and the major routes and health risks of human exposure to PCMX were investigated. The PCMX, TCS, and TCC concentrations in PCPs, urine, drinking water, and surface water were determined using high-performance liquid chromatograph system equipped with diode array detector or triple quadrupole mass spectrometer. Results showed that PCMX is widely used in antibacterial hand sanitizers and household disinfectants in China. The addition of PCMX as an antibacterial ingredient in PCPs showed an increasing trend. The geomean concentrations of urinary PCMX in children and pregnant women were 21.6 and 31.9 μg·L^-1, respectively, which were much higher than TCS and TCC. A considerable concentration of PCMX ranging from 1.62 to 9.57 μg·L^-1 was observed in the aquatic environment, suggesting a potential massive-use of PCMX by humans. Human PCMX exposure via drinking was negligible because the PCMX concentrations in drinking water were less than 2.00 ng·L^-1. During human simulation experiment, we found that dermal contact was the dominant route of human PCMX exposure, accounting for 92.1% of the urinary PCMX concentration. The estimated daily intake of PCMX in 9.68% of children and 5.66% of pregnant women was higher than the reference dose. However, the urinary 8-hydroxy-2'-deoxyguanosine concentrations remained stable despite the elevated PCMX concentrations, thereby suggesting that daily PCMX exposure may not cause oxidative DNA damage in humans. Nevertheless, the potential ecotoxicity and health risks induced by chronic PCMX exposure cannot be ignored because of its increasing use.

Review on the fate of antimicrobials, antimicrobial resistance genes, and other micropollutants in manure during enhanced anaerobic digestion and composting

While manure has been used as nutrient-rich fertilizer for centuries, anaerobic digestion (AD) of manure has only been recognized recently as a promising renewable energy source for producing methane-rich biogas. Various forms of AD have been evaluated for the removal of manure contaminants, such as antimicrobials, antimicrobial resistance genes (ARGs), hormones, and pesticides that pose risks to human health and the environment. Increasing demand for cleaner energy prompts examination of the fate of manure contaminants in conventional and advanced AD techniques. This review reveals that removal of contaminants differs based on type (e.g. antimicrobials vs hormones) or class (e.g. tetracyclines vs sulfonamides) of chemicals being treated. Increasingly, pre-treatment techniques are incorporated into AD systems to enhance biogas production and degrade manure contaminants. For instance, activated carbon with microwave pretreatment removed 87-95% of ARGs. Advanced anaerobic digestion and solid-state anaerobic digestion reduced various ARGs associated with sulfonamides, macrolides, and tetracyclines. Further, total hormone reduction improved using high-temperature pretreatment prior to mesophilic AD. Finally, several studies revealed partial removal of antimicrobials and ARGs during managed composting. Although AD can independently decrease manure contaminants prior to use as fertilizer, augmenting AD with composting and other physical treatment processes can further enhance their removal.

The sinking behavior of micro-nano particulate matter for bisphenol analogues in the surface water of an ecological demonstration zone, China

Bisphenol analogues (BPs) have been widely used in industrial production as substitutes of bisphenol A (BPA). The demand and production of BPs are growing rapidly in China. In this study, the pollution levels and distribution characteristics of five BPs were investigated in surface water from rivers located in different land-use types of an ecological demonstration zone. All BPs were detected at least once in the traditionally dissolved phase, colloidal phase and suspended particulate matter (SPM) with the mean total concentrations of 465.1 ng L-1, 114.4 ng L-1 and 11.3 μg g-1 dry weight, respectively. BPA is the dominant BP in the traditionally dissolved phase and colloidal phase, with the mean contribution rates of 77.6% and 70.7%, respectively, followed by bisphenol F (BPF) and/or bisphenol S (BPS). The colloids as the important sinks of contaminants contributed 42.3% of bisphenol Z, 37.3% of BPF, 24.9% of BPA, 22.3% of BPAF and 18.4% of BPS in the traditionally dissolved phase. However, BPA alternatives are found primarily in the SPM, in which the contribution rate of BPA ranges from 0.6% to 48.1%, with the mean contribution of 12.4%. Based on BP concentrations in the traditionally dissolved phase, moderate ecological risk levels of BPA and BPF towards aquatic organisms were posed. Fish and/or algae are the most sensitive aquatic organisms, and hence chronic toxicological effects should not be ignored especially in fish.

Effect of Notch pathway on lipid accumulation induced by mono-2-ethylhexyl phthalate on 3T3-L1 cells

BACKGROUND

Mono-2-ethylhexyl phthalate (MEHP) is a major metabolite of di (2-ethylhexyl) phthalate (DEHP). Our previous researches have shown that MEHP can induce lipid accumulation in preadipocytes, while, the underlying mechanism is unclear. The present study was undertaken to clarify the effect of Notch pathway on lipid accumulation induced by MEHP.

METHODS

3T3-L1 preadipocytes were exposed to MEHP (0, 10, 50, 250 µM and 0.1%DMSO) for the whole differentiation phase. Then the level of TG and cell cycle were detected. RT-PCR was used to detect the mRNA expression and Western blot was used to detect the expression of protein by Notch pathway genes and lipid metabolic related genes.

RESULTS

In this study, the level of TG in the 250 µM and 250 µM MEHP groups was significantly higher than that in the control, DMSO and 10 µM MEHP groups (P < 0.05). The relative mRNA level of Notch-1, Notch-3, Notch-4, Jagged-2 and Dll-4 in 250 µM group was higher than other groups (P < 0.05). The expression of Notch signal pathway proteins increased in MEHP treated groups, and the expression of Notch-2, Jagged-1, Jagged-2, Dll-1 and Dll-4 in 250 µM group were significantly higher than control group (P < 0.05). The expression of lipid metabolic related gene mRNA and protein increased in MEHP treated groups, and 250 µM MEHP group was higher than other groups (P < 0.05). The intracellular TG content was significantly correlated with the expression levels of Notch-1 and Jagged-2 mRNA (P < 0.05).

CONCLUSION

In this study, we have found that MEHP exposure could increase the TG content in 3T3-L1 cells. The expression of Notch pathway mRNA and proteins were disturbed by the MEHP. Notch-1 and its ligand Jagged-2 play a critical role in the abnormal lipid metabolism in 3T3-L1 cells caused by MEHP.

Unveiling complex responses at the molecular level: Transcriptional alterations by mixtures of bisphenol A, octocrylene, and 2'-ethylhexyl 4- (dimethylamino)benzoate on Chironomus riparius

Living organisms are exposed to mixtures of pollutants in the wild. Inland aquatic ecosystems contain many compounds from different sources that pollute the water column and the sediment. However, majority of toxicological research is focused on the effects of single exposures to toxicants. Furthermore, studies have been principally oriented toward ecologically relevant effects of intoxication, and lack an analysis of the cellular and molecular mechanisms involved in the response to toxicants. Effects of single, binary, and ternary mixtures of three compounds, bisphenol A, octocrylene, and 2'-ethylhexyl 4- (dimethylamino)benzoate, were assessed using a Real-Time PCR array. Forty genes, and additional six reference genes, were included in the array. The genes were selected based on their association with hormone responses, detoxification mechanisms, the stress response, DNA repair, and the immune system. The study was performed on Chironomus riparius, a benthic dipteran with an essential role in the food web. Transcriptional responses were assessed both 24 and 96 h post-exposure, to determinate short- and medium-term cellular responses. Individual fourth instar larvae were exposed to 0.1 and 1 mg/L of each of the toxic compounds and compound mixtures. A weak response was detected at 24 h, which was stronger in larvae exposed to mixtures than to individual toxicants. The response at 96 h was complex and principally involved genes related to the endocrine system, detoxification mechanisms, and the stress response. Furthermore, exposure to mixtures of compounds altered the expression patterns of an increased number of genes than did individual compound exposures, which suggested complex interactions between compounds affected the regulation of transcriptional activity. The results obtained highlight the importance of analyzing the mechanisms involved in the response to mixtures of compounds over extended periods and offer new insights into the basis of the physiological responses to pollution.

Characterization of an efficient estrogen-degrading bacterium Stenotrophomonas maltophilia SJTH1 in saline-, alkaline-, heavy metal-contained environments or solid soil and identification of four 17β-estradiol-oxidizing dehydrogenases

The efficient bioremediation of estrogen contamination in complex environments is of great concern. Here the strain Stenotrophomonas maltophilia SJTH1 was found with great and stable estrogen-degradation efficiency even under stress environments. The strain could utilize 17β-estradiol (E2) as a carbon source and degrade 90% of 10 mg/L E2 in a week; estrone (E1) was the first degrading intermediate of E2. Notably, diverse pH conditions (3.0-11.0) and supplements of 4% salinity, 6.25 mg/L of heavy metal (Cd²⁺ or Cu²⁺), or 1 CMC of surfactant (Tween 80/ Triton X-100) had little effect on its cell growth and estrogen degradation. The addition of low concentrations of copper and Tween 80 even promoted its E2 degradation. Bioaugmentation of strain SJTH1 into solid clay soil achieved over 80% removal of E2 contamination (10 mg/kg) within two weeks. Further, the whole genome sequence of S. maltophilia SJTH1 was obtained, and a series of potential genes participating in stress-tolerance and estrogen-degradation were predicted. Four dehydrogenases similar to 17β-hydroxysteroid dehydrogenases (17β-HSDs) were found to be induced by E2, and the four heterogenous-expressed enzymes could oxidize E2 into E1 efficiently. This work could promote bioremediation appliance potential with microorganisms and biodegradation mechanism study of estrogens in complex real environments.

Assessment of water contamination and health risk of endocrine disrupting chemicals in outdoor and indoor swimming pools

The occurrence of endocrine disrupting chemicals (EDCs) in swimming pool waters has been scarcely investigated. In this study, the concentrations of 20 EDCs (4 phenols, 6 estrogens, 4 progestogens, 5 androgens, and 1 pharmaceutical) in 40 outdoor and indoor swimming pools in Changsha, China were investigated. Out of them, two phenols (bisphenol A and 4-tert-octylphenol), three estrogens (17β-estradiol, 17ɑ-ethinlestradiol (EE2), and hexestrol), one pharmaceutical (caffeine), and two progestogens (progesterone and levonorgestrel) were detected in the collected samples. The androgens were not detected. Bisphenol A and caffeine were the dominant EDCs at concentrations of ND-23.22 ng/L and ND-39.08 ng/L, respectively. The levels of caffeine were significantly higher in indoor swimming pools (11.15 ng/L in average) than those in outdoor pools (1.90 ng/L in average) (p < 0.05), owing to the less sun's UV radiation and less use of sunscreens containing caffeine. The progestogens (progesterone and levonorgestrel) and estrogens (17β-estradiol and hexestrol) were only detected in outdoor swimming pools. The detection frequencies and concentrations of bisphenol A and caffeine in downtown pools were significantly higher than those in outskirt pools. Besides, the correlations between the concentrations of EDCs and water quality parameters evaluated by the Spearman correlation analysis implied that residual chlorine had strong oxidant capable to bisphenol A and suggested that caffeine could be a potential indicator of organic contamination in swimming pool water. Finally, a quantitative risk assessment revealed that non-athletic child and athletic adult female were vulnerable subpopulations. The EDI_total of EE2 for athletic child, non-athletic female, non-athletic male, and non-athletic child were higher than ADI_EE2 adopted by Australia and the EDI_total of EE2 for athletic female and athletic male were higher than ADI_EE2 adopted by the United States.

Occurrence of endocrine-disrupting chemicals (EDCs) in river water and sediment of the Mahakam River

The study was performed to examine the occurrence of endocrine disrupting chemicals (EDCs), including four steroid estrogens, one plasticizer, and three preservatives in the Mahakam River, Indonesia. The physicochemical analysis of river water and sediment quality parameters were determined as well as the concentration of EDCs. The range of values for pH, total dissolved solids (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD), total suspended solids (TSS), nitrate, ammonium, phosphate, and oil/grease in river water and sediment were higher than recommended limits prescribed by the World Health Organization's Guidelines for Drinking-water Quality (GDWQ). Bisphenol A (BPA) was the most widely found EDC with the highest concentration level at 652 ng/L (mean 134 ng/L) in the river water and ranged from ND (not detected) to 952 ng/L (mean 275 ng/L) in the sediment. Correlation analysis to investigate the relationship between the EDCs' concentrations in water and sediment also revealed a significant correlation (R² = 0.93) between the EDCs' concentrations. High concentrations of EDCs are found in urban and residential areas because these compounds are commonly found in both human and animal bodies, resulting in the disposal of EDCs into canals and rivers in urban and suburban areas, as well as livestock manure and waste that is generated from intensive livestock farming around the suburban area.

Ecofriendly laccases treatment to challenge micropollutants issue in municipal wastewaters

In this study, a multidisciplinary approach investigated the enzymatic degradation of micropollutants in real, not modified, municipal wastewaters of a plant located in Italy. Stir Bar Sorptive Extraction combined to Gas Chromatography-Mass Spectrometric detection (SBSE-GC-MS) was applied to profile targeted pollutants in wastewaters collected after the primary sedimentation (W1) and the final effluent (W2). Fifteen compounds were detected at ng/L - μg/L, including pesticides, personal care products (PCPs) and drugs. The most abundant micropollutants were bis(2-ethylhexyl) phthalate, diethyl phthalate and ketoprofen. Laccases of Trametes pubescens MUT 2400 were very active against all the target micropollutants: except few cases, their concentration was reduced more than 60%. Chemical analysis and environmental risk do not always come together. To verify whether the treated wastewaters can represent a stressor for the aquatic ecosystem, toxicity was also evaluated. Raphidocelis subcapitata and Lepidium sativum tests showed a clear ecotoxicity reduction, even though they did not evenly respond. Two in vitro tests (E-screen test and MELN assay) were used to evaluate the estrogenic activity. Treatments already operating in the plant (e.g. activated sludge) partially reduced the estradiol equivalent concentration, and it was almost negligible after the laccases treatment. The results of this study suggest that laccases of T. pubescens are promising biocatalysts for the micropollutants transformation in wastewaters and surface waters.

Combination of Counter Current Salting-Out Homogenous Liquid-Liquid Extraction with Dispersive Liquid-Liquid Microextraction for the High-Performance Liquid Chromatographic Determination of Environmental Estrogens in Water Samples

In this paper, counter current salting-out homogenous liquid-liquid extraction was combined with dispersive liquid-liquid microextraction for the determination of environmental estrogens in water samples by high-performance liquid chromatography. In this method, initially, sodium chloride was filled into a syringe and a mixture of water sample and acetonitrile was driven to pass through the syringe. Due to salting-out effect, fine droplets of acetonitrile went up through the remaining mixture and aggregated as a separated layer on the top. Then, the collected organic phase (acetonitrile) was removed with a syringe and mixed with carbon tetrachloride (extraction solvent). In the second step, the mixed organic phase was rapidly injected into 5 mL of distilled water to further enrich the analytes. Good linearity was obtained in the concentration range of 2.0~200 ng/mL for diethylstilbestrol (DES) and 8.0~200 ng/mL for octylphenol (OP), respectively. Limits of detection were 0.09 ng/mL for DES and 0.20 ng/mL for OP, respectively. Relative standard deviations for intra- and inter-day precisions were less than 2.1 and 3.1%, respectively. Finally, the established method was successfully applied to determine DES and OP in river water, well water, bottled water and campus drinking water samples with recoveries in the range from 81.0 to 105.9%.

Sperm Quality in Mouse After Exposure to Low Doses of TCDD

Background:

In the last decade, the harmful use of dioxin has been demonstrated in human health and in the whole environment. It is well known among scientists that 2, 3, 7, 8-tetrachloro dibenzo-p-dioxin (TCDD) is an environmental pollutant that causes endocrine disruption, which causes male reproductive toxicity.

Objective:

The objective of the present study was to evaluate the toxicity effect of low doses of TCDD in male CD1 mice.

Materials and Methods:

Three concentrations of TCDD (0.375, 0.75, 1.5 mg / kg) were analyzed and the effects on spermatozoa were evaluated 10 days after oral administration of the product. As bioindicators of TCDD toxicity, an exhaustive analysis of several spermatic parameters including motility, vitality, count, morphology and viability, flow cytometry was used to determine the affected sperm population by cytotoxicity and apoptosis. In addition, a morphometric analysis of testicles was performed.

Results:

The results show that the body weight of the treated animals was reduced in medium and high doses (0.75, 1.5 mg / kg) with respect to the control groups. In the groups treated with TCDD, the abnormal head of the sperm increased by 52.5% more than the control group. Significant differences in apoptosis were observed between the negative control and vehicle control, including the median dose (0.75 mg / kg).

Conclusion:

It is concluded that at these low doses there was an impact on the quality of the mouse sperm, adding an effect on apoptosis and cytotoxicity of sperm exposed to these doses of TCDD.

Investigating the role of colloids on the distribution of bisphenol analogues in surface water from an ecological demonstration area, China

Owing to the widespread use of bisphenol analogues (BPs) as substitutes for bisphenol A (BPA), the presence of BPs in multiple environments is of increasing concern. However, there is a limited understanding of the effects of colloids on the distribution and risk assessment of BPs traditionally dissolved in surface water. In this study, seven BPs were investigated in both the truly dissolved (<5 kDa) and colloidal (5 kDa to 1 μm) phases with water, with mean concentrations in the range of 71.6-671 ng/L and 5.84-76.6 ng/L, respectively. BPA and bisphenol S (BPS) were the dominant BPs in both phases, but a clear positive correlation was found between the adsorption contribution proportions of colloids to BPs and their hydrophobicity (octanol-water partition coefficient). The colloids contributed 50.4% of bisphenol AF, 33.4% of tetrabromobisphenol A, 25.2% of bisphenol F, 10.9% of BPA and 9.50% of BPS in the traditionally dissolved phase (<1 μm), which suggests that colloids play an important role in regulating the transformation and transportation of BPs in aquatic environments. Based on BP concentrations in the truly dissolved phase, only moderate risk levels for BPs towards algae, daphnia and fish were posed, and no oestrogenic risk existed in the study area.

In situ measurement of estrogenic activity in various aquatic systems using organic diffusive gradients in thin-film coupled with ERE-CALUX bioassay

Organic-diffusive gradients in thin-film samplers (o-DGT), were developed and applied for accumulation of estrogen and estrogen-like compounds on a XAD18 resin and deployed in situ in the effluents of Beijing Gaobeidian Wastewater Treatment Plant (GWWTP) and Brussels North Wastewater Treatment Plant as well as in several aquatic systems in Belgium, including the Zenne River, the Belgian Oostende Harbor and the North Sea. Estrogenic compounds accumulate on the XAD18 resin and the estrogenic activity of the resin extract was measured with the Estrogen Responsive Elements-Chemically Activated LUciferase gene eXpression (ERE-CALUX) bioassay. With this result and by applying Fick's diffusion law, it is possible to calculate the estrogenic activity in the aquatic system, if the diffusion boundary layer (DBL) is known or negligible compared to the hydrogel diffusive layer thickness. The DBL thickness in our study varied from 0.010 to 0.023 cm and ignoring the DBL thickness would for instance, underestimate the estrogenic activity by 10-20%. Estrogenic activities in the secondary effluent of GWWTP were the highest (29 ± 4 ng E2-equivalents L^-1), while the lowest level was found at the Belgian Oostende Harbor (0.05 ± 0.01 ng E2-equivalents L^-1). Comparable estrogenic activities in water samples measured by o-DGT and grab sampling were obtained, confirming that o-DGT can be efficiently used in various aquatic systems. The advantage of our sampling and measuring method is that very low, time averaged estrogenic activities can be determined, with a minimum of sample treatment. The risk of sample contamination is very low as well as the cost of the whole analytical procedure.

Watershed scale patterns in steroid hormones composition and content characters at a typical eutrophic lake in southeastern China

Natural steroid hormones in the aquatic environment have attracted increasing attention because of their strong endocrine disrupting potency. Seven steroid hormones (estrone, 17α-estradiol, 17β-estradiol, estriol, testosterone, androstenedione, and progesterone) were analyzed from surface water and sediment sampled from Chaohu Lake, its upstream rivers (the Hangbu River, Nanfei River, Shiwuli River, and Pai River), drainage from the adjacent farmland, and treated and untreated municipal sewage. Concentrations of the seven target steroid hormones ranged from below the detection limit (ND) to 69.5 ng L^-1 in the water of Chaohu Lake and the upstream rivers. Three steroids-estrone, estriol, and 17α-estradiol-were found in relatively high residual concentrations in the water, with maximum concentrations of 69.5 ng L^-1, 51.5 ng L^-1, and 23.3 ng L^-1, respectively. All of the target steroid hormones except estriol were detected in the sediment in concentrations of ND-16344 ng kg^-1. The dominant steroid hormone in the sediment of Chaohu Lake and the upstream rivers was 17α-estradiol. In the Shiwuli River and the Pai River, the dominant steroid hormones (estrone and estriol) were the same as those in the untreated municipal sewage. This confirmed the deduction that untreated municipal sewage was the major source of steroid hormone residues in these two rivers. The main steroid hormone in the water of the Hangbu River and Chaohu Lake was 17α-estradiol, the same as that in the farmland drainage. In addition, 17α-estradiol was verified as the major factor in the contribution of farmland drainage to the pollution in these rivers. The water in the Nanfei River had high concentrations of estriol and 17α-estradiol. This indicates that both untreated municipal sewage and farmland drainage were the major sources. The discharge of steroid hormones from the four rivers to Chaohu Lake was approximately 75.1 kg year^-1, with the highest contributor being 17α-estradiol (24 kg year^-1). Therefore, based on the results of this study, the farmland drainage should be controlled to reduce the steroid hormone pollution in Chaohu Lake.

Investigating landfill leachate toxicity in vitro: A review of cell models and endpoints

Landfill leachate is a complex mixture characterized by high toxicity and able to contaminate soils and waters surrounding the dumpsite, especially in developing countries where engineered landfills are still rare. Leachate pollution can severely damage natural ecosystems and harm human health. Traditionally, the hazard assessment of leachate is based on physicochemical characterization but the toxicity is not considered. In the last few decades, different bioassays have been used to assess the toxicity of this complex matrix, including human-related in vitro models. This article reviews the cell bioassays successfully used for the risk assessment of leachate and to evaluate the efficiency of toxicity removal of several processes for detoxification of this wastewater. Articles from 2003 to 2018 are covered, focusing mainly on studies that used human cell lines, highlighting the usefulness and adequacy of in vitro models for assessing the hazard involved with exposure to leachate, particularly as an integrative supporting tool for chemical-based risk assessment. Leachate is generally toxic, mutagenic, genotoxic and estrogenic in vitro, and these effects can be measured in the cells exposed to already low concentrations, confirming the serious hazard of this wastewater for human health.