The plastisphere, which induces distinct microbial profiles involved in biogeochemical cycling in soils, has been increasingly studied; however, its potential effects on arsenic (As) cycling in soil ecosystems remain poorly understood. In this study, we used two contamination-level paddy soils and selected polyethylene (PE), polyvinyl chloride (PVC), and polylactic acid (PLA) for incubation experiments to evaluate As speciation, distribution, and the enrichment and community structure of As methylators in plastispheres. Our results showed that dimethylarsinic acid [(DMA(V)]) was enriched in most plastispheres. While PVC plastispheres have the highest As retention capacity, PE plastispheres exhibit the greatest accumulation of methylated arsenicals. In both Ascontaminated soils, the plastisphere networks of As methylators had a higher density than those in the soil networks, with an increase ranging from 1.96 % to 118.64 %. More than 50 % of the correlations among plastisphere As-methylator communities were positive. Longimicrobium, Gemmatimonas, and Rhodoplanes were the dominant keystone genera in the plastisphere arsenical-methylator networks. Overall, these findings demonstrate that the plastisphere constitutes a distinct microhabitat for methylarsenic production, offering new insights into the environmental risks posed by microplastic accumulation in agricultural soils.

Aryl phosphate esters have been detected throughout the natural environment and in human blood samples, making it important to determine the health risks associated with exposure to triphenyl phosphate (TPHP) and its metabolite diphenyl phosphate (DPHP). Here, C57BL/6J male mice were exposed to TPHP or DPHP for 12 weeks at estimated daily intake doses of 0.1 and 7 μg/kg bw/day. TPHP intake affected the levels of short-chain fatty acids and bile acids in the gut, enhancing the production of 29 medium- and long-chain fatty acids in the liver by 3.72-fold and significantly increasing hepatic lipid and cholesterol levels. Metabolomic and molecular analysis confirmed that elevated liver cholesterol levels persisted after an 8 week recovery period. Gut microbiota-dependent cholesterol alterations were the toxic end points observed in TPHP-fed mice, as supported by the results of fecal microbiota transplantation. In DPHP-fed mice, serotonergic and glutamatergic synapses were simultaneously altered in the liver and intestine, corresponding to the reduction of five brain neurotransmitters (15.4-60.8%). Decreased liver carbohydrate levels and insulin resistance were observed in the DPHP-fed mice. These results suggest that TPHP and DPHP affect metabolism via different toxic modes, mediated through the gut-liver axis, providing novel insights into the mechanisms of organophosphate-ester-mediated metabolic disruption.

The microplastic (MP) interaction with phosphorus (P) fertilizers and effects on P transformation and availability remain unclear. We conducted a 56-day soil incubation experiment with 1 % polyethylene (PE) and polylactic acid (PLA) microplastics (MPs) to analyze their influence on soil P fractions and availability under different P fertilizer regimes. While PE and PLA MPs had a negligible impact on P fraction and availability in unfertilized soils, they exhibited different effects in soils with organic fertilizer and calcium-magnesium-phosphate (CMP) fertilizer. Specifically, MPs decreased the available P content (13.95 %-28.99 %) in organic-fertilized soils after 28 days of incubation. This decreased available P was associated with reduced soil labile organic P content and soil acid phosphatase (ACP) activities. 16S rRNA high-throughput sequencing revealed that MP addition significantly reduced the relative abundance of Burkholderia-Caballeronia-Paraburkholderia (P < 0.05), potentially suppressing P mineralization and consequently decreasing soil P availability. In contrast to organic fertilizer-applied soils, available P content increased (4.48 %-26.95 %) in MP-treated soils with CMP fertilizer, leading to re-fixation of inorganic P by aluminum/iron (hydr)oxides. Arthrobacter and Streptacidiphilus might enhance P solubilization and mineralization in CMP fertilizer-applied soils after MP exposure. Traditional PE MPs exhibited a stronger influence on soil P availability than biodegradable PLA MPs, owing to their more pronounced effects on soil ACP activity and P-transforming microorganisms. These findings provided insights into the ecological risks of MP pollution in terrestrial ecosystems and emphasized the need to optimize P fertilizer application in the context of MP pollution and P resource limitation.

This study assesses heavy metal pollution, its ecological risks, and associated health impacts in the Hunhe River Basin and Dahuofang Reservoir, Liaoning Province, China, using 168 samples collected across multiple periods. The potential ecological risk index, hazard index, and heavy metal pollution index are employed to quantitatively evaluate ecological and health risks. The positive matrix factorization model is employed to evaluate pollution sources, with Monte Carlo simulations assessing uncertainties in risk assessment. The results indicate that Mn is the predominant contaminant, followed by Zn, Cd, Cu, Cr, and As. Ecological risk assessment identifies Mn, Zn, and Cd with the highest potential ecological risks, with respective mean single pollution index (PI) values of 8.74, 1.08, and 1.07, respectively. High-risk and extremely high-risk zones comprised 6.26 % of the whole investigated area. Source apportionment identifies iron mining (77.2 % of Mn), gold mining (94.6 % of As), copper mining (97.7 % of Cd and 77.5 % of Cu), anti-fouling enterprises (79.5 % of Zn), and traffic emissions (82.4 % of Pb) as primary contributors. The health risk assessment indicates that 8.7 %, 21.7 %, and 10.9 % of samples posed non-carcinogenic risks to infants, children, and adults, respectively. Moreover, the analysis indicates that non-carcinogenic risks associated with Cu, Cd, As, and Mn, along with carcinogenic risks from Cd, exceed acceptable thresholds. Carcinogenic risks from Cd also surpassed safety limits, with mining activities identified as the dominant anthropogenic source. This study establishes a methodological framework for aquatic system risk quantification.

Microplastics (MPs) in farmland soil may leach dissolved organic matter (DOM) and metal-based additives during rainfall and irrigation processes, potentially impacting agroecosystems. This study investigated the leaching characteristics of MPs commonly found in agricultural soils and irrigation water under varying acid rain conditions. The MP leachates were analyzed for their physicochemical properties, three-dimensional fluorescence characteristics, and heavy metal release. The results revealed that most MP leachates exhibited neutral to alkaline pH, likely due to the dissolution of inorganic fillers such as CaCO3. Dissolved organic carbon (DOC) leaching varied by polymer types, with biodegradable MPs and PET-based MPs exhibiting significantly higher DOC concentrations than other MPs. Heavy metal analysis identified antimony (Sb) and zinc (Zn) as the dominant leached metals, particularly in Gr-carpet, C-curtain, and G-cover. Evidence shows that Sb concentrations in these MP leachates exceed China's drinking water safety thresholds by 5.76-26.7 times. Additionally, DOC release was pH-dependent, with neutral conditions enhancing organic matter release, whereas acidic conditions may promoted metal leaching. Correlation analysis suggested that Sb and arsenic (As) interacted with MP-derived organic additives and amide/phenol-like substances, indicating potential metal-organic complexation. This study systematically investigates the leaching characteristics of MPs under simulated acid rain conditions, which helps better assess the environmental impact and potential risks of MPs.

The accumulation of plastic waste in the environment has raised widespread concern about the impact of microplastics (MPs) on human and environmental health, particularly regarding aged MPs. This study investigated the effects of subchronic dietary intake on pristine and aged polyethylene microplastics (PE-MPs) in C57BL/6J mice. Results revealed that both pristine and aged PE-MPs, at doses of 0.01 and 1 mg/day, induced plasma metabolic changes primarily associated with lipid metabolism and digestive processes. These alterations were reflected in the expression changes of proteins involved in unsaturated fatty acid pathways in the liver as well as a reduction in beneficial gut microbiota. Key contributors in the toxicity of aged PE-MPs included ATP-binding cassette transporters, gut bacteria alterations (notably Lactobacillus, Akkermansia, Parasutterella, and Turicibacter), and significantly altered proteins related to fatty acid elongation, such as acyl-CoA thioesterase enzyme family and elongation of very long chain fatty acid protein 5. These disruptions exacerbated lipid metabolism disorders, potentially contributing to metabolic diseases. Additionally, decreased levels of glutathione S-transferase A proteins, along with reduced hepatic glutathione and increased reactive oxygen species in both the small intestine and liver, suggested that aged PE-MPs aggravated hepatic and intestinal damage through oxidative stress. These findings indicated that aged PE-MPs caused more severe hepatic dysfunction and gut microbiota disruption. This effect was likely mediated by the transfer of fatty acids and signaling molecules through the gut-liver axis, ultimately leading to hepatic lipid metabolism disorders and oxidative stress.

Soil heavy metal remediation is a key challenge for environmental scientists, with relevant techniques such as phytoremediation, animal remediation, and chemical remediation. Most studies have employed single treatment methods, yielding limited results. The current challenge is to find ways to enhance the efficiency of soil heavy metal removal through combined approaches. Therefore, this study compares the efficiency of biological remediation (B: 10 earthworms involving 3 transplanted sunflowers), chemical remediation (C: 1% biochar + 0.25% nZVI), and combined biological and chemical remediation (BC: 10 earthworms involving 3 transplanted sunflowers + 1% biochar + 0.25% nZVI) in reducing soil Pb and Cd pollution. The results indicated that under high concentrations, the BC remediation approach facilitated greater accumulation in sunflowers, whereas at lower concentrations, it benefited earthworm accumulation. In the BC remediation approach, sunflowers exhibited higher peroxidase (POD) activity and malondialdehyde (MDA) levels compared to B remediation, enhancing their tolerance to high levels of soil Pb and Cd stress. High-throughput sequencing analysis revealed that the BC remediation resulted in a higher soil microbial diversity index and a more complex soil microbial community structure. This study indicated that BC remediation enhances sunflowers' and earthworms' physiological and metabolic tolerance to soil Pb and Cd stress, as well as their accumulation ability.

Antibiotics contaminants, such as sulfamonomethoxine (SMM) pose significant environmental risks to biological wastewater treatment systems. This study systematically investigated the dose effects of SMM (0-500 μg/L) on anaerobic ammonium oxidation performance and evaluated the efficacy of voltage stimulation as a recovery strategy. Metabolomic profiling revealed that 10 μg/L SMM induced adaptive responses by promoting polysaccharide/lipid secretion. High SMM (≥100 μg/L) overwhelmed these defenses, inhibited the synthesis of essential amino acids and cofactors and ultimately degraded microbial communities by suppressing synthesis of purines and pyrimidines. Voltage stimulation (0.3-1.5 V) significantly shortened the recovery time by over one week by stabilizing membrane structures, promoting Heme c synthesis, and enhancing purine, pyrimidine, and amino acid metabolism. These findings highlight the severe inhibitory effects of SMM and demonstrate the potential of voltage stimulation as a promising strategy to mitigate antibiotic-induced disruptions, providing valuable insights for enhancing the resilience of wastewater treatment technologies.

Epilepsy is a prevalent neurological condition that greatly affects the quality of life of those affected, with increasing rates of incidence and prevalence. This study aims to evaluate the global, regional, and national burdens of idiopathic epilepsy (IE) in individuals aged 15 to 49 from 1990 to 2021 via data from the Global Burden of Disease (GBD) Study and to project trends through 2035. Using the GBD database 2021, we assessed the burden of IE through metrics involving incidence, prevalence, mortality, and disability-adjusted life years (DALYs). Statistical methods included joinpoint regression for annual percent change (APC), estimated annual percentage change (EAPC), and Bayesian age-period-cohort (BAPC) modeling for projections. In 2021, there were 11.48 million (95

As global water scarcity intensifies, water reuse has become a critical alternative source for agricultural irrigation, ecological recharge, and domestic use. However, considerable debate exists regarding the potential ecological risks posed by reclaimed water, particularly its impact on soil ecosystems. This study investigates the effects of reclaimed water at varying concentrations on physiological and biochemical responses, as well as gut microbiota and metabolites of earthworm Eisenia fetida. The results demonstrated that reclaimed water induced oxidative stress and damage to the gut microstructure and digestive function in earthworms. 16S rRNA sequencing and metabolomics analyses further revealed that reclaimed water exposure resulted in dysbiosis of earthworm gut microbiota, characterized by an increased abundance of pathogens and degradation-associated bacteria, and significant alterations in metabolites associated with pyrimidine and purine pathways were observed. Furthermore, reclaimed water led to reproductive toxicity in earthworms. By integrating physiological indicators and analysis of cross-talk patterns among the effects, we concluded that exposure to reclaimed water instigates systemic toxicity in earthworms. These findings demonstrate that reclaimed water induces toxic effects in soil-dwelling organisms and potentially impair the reproductive success of subsequent generations, underscoring the need for attention to the ecological risks associated with reclaimed water application in terrestrial environments.

Sensitive biomarkers are urgently required for the ecological risk assessment of heavy metal-contaminated soils. However, the synergistic defense mechanism involving oxidative stress and mucus metabolism in earthworms under cadmium (Cd) stress remains poorly understood, limiting insights into soil animal adaptation strategies. This study employed the earthworm 'Eisenia fetida' as a model organism. Key findings include: (1) Antioxidant enzymes (SOD, POD, CAT) exhibited a characteristic biphasic effect of "low-concentration induction followed by high-concentration inhibition". Metallothionein (MT) levels initially increased then decreased, while malondialdehyde (MDA) and glutathione S-transferase (GST) activities showed a sustained upward trend, collectively revealing the dynamic equilibrium of oxidative stress. (2) Mucus composition underwent dose-dependent restructuring: primarily consisting of proteins, amino acids, and carbohydrates, mucus pH decreased significantly, whereas electrical conductivity (EC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), and metal element content increased dose-dependently. (3) Metabolomic analysis identified the top 10 core differential metabolites, including glutamine (Gln), arginine (Arg), and alanine (Ala). Notably, amino acid dynamics displayed a significant positive correlation with key oxidative stress indicators (SOD, POD, MT), indicating an "enzyme-mediated antioxidant - amino acid chelation" synergistic defense mechanism. This study establishes, for the first time, a three-tiered defense mechanism in earthworms under Cd stress: "antioxidant biphasic response - mucus component regulation - enzymatic-metabolic coupling". It provides a novel perspective for understanding heavy metal adaptation in soil fauna and lays the foundation for screening pollution biomarkers and developing ecological restoration strategies in contaminated soils.

Aryl phosphorus flame retardants (aryl-PFRs), such as triphenyl phosphate (TPHP) and diphenyl phosphate (DPHP), are widely used worldwide. Understanding the fates of aryl-PFRs in vivo is crucial to assessing their toxicity and the risks they pose. Seven TPHP metabolites, including Phase I hydrolysis and hydroxylation and Phase II glucuronidation products, were identified in C57BL/6J male mice following subacute dietary exposure to aryl-PFRs (70 μg/kg body weight (bw)/day) for 7 days. TPHP was almost completely metabolized by mice (∼97%), with DPHP the major metabolite formed (34%-58%). In addition, mice were exposed to aryl-PFRs (7 μg/kg bw/day) for 12 weeks. Both TPHP and DPHP occurred at higher concentrations in the digestive tract (intestine and stomach), liver and heart. The total concentration of DPHP in all organs was 3.55-fold greater than that of TPHP. Recovery analysis showed that the rate of TPHP elimination from mouse organs reached 38%, while only 3%-5% of DPHP was removed, suggesting that the rates of degradation and elimination of DPHP were slower than TPHP and its bioaccumulation potential was higher. These results highlight the critical role of DPHP in the biotransformation, bioaccumulation, and bioelimination of TPHP, providing valuable insights into the fate of aryl-PFRs in vivo.

Recent research has highlighted the ecological risk posed by microplastics (MPs) from mulching film and heavy metals to soil organisms. However, most studies overlooked real environmental levels of MPs and heavy metals. To address this gap, pristine and aged polyethylene (PE) mulching film-derived MPs (PMPs, 500 mg/kg; AMPs, 500 mg/kg) were combined with cadmium (Cd, 0.5 mg/kg) to assess the acute toxicity to earthworms and investigate associated molecular mechanisms (oxidative stress, osmoregulation pressure, gut microbiota, and metabolic responses) at environmentally relevant concentrations. Compared to Cd alone and Cd + PMPs treatments (11.15 ± 4.19 items/g), Cd + AMPs treatment resulted in higher MPs bioaccumulation (23.73 ± 13.14 items/g), more severe tissue lesions, and increased cell membrane osmotic pressure in earthworms’ intestines. Cd + AMPs induced neurotoxicity through elevated levels of glutamate and acetylcholinesterase. Earthworm intestines (0.98 ± 0.49 to 3.33 ± 0.37 mg/kg) exhibited significantly higher Cd content than soils (0.19 ± 0.01 to 0.51 ± 0.06 mg/kg) and casts (0.15 ± 0.01 to 0.25 ± 0.05 mg/kg), indicating PE-MPs facilitated Cd transport in earthworms’ bodies. Metabolomic analysis showed Cd + AMPs exposure depleted energy and nucleotide metabolites, disrupted cell homeostasis more profoundly than Cd and Cd + PMPs treatments. Overall, co-exposure to AMPs + Cd induced more severe neurotoxicity and disruption of homeostasis in earthworm than Cd and PMPs + Cd treatments. Our study, using Cd and MPs with environmental relevance, underscores MPs’ role in amplifying Cd accumulation and toxicity in earthworms.

In the present study, based on continuous acid–base potentiometric titration experiments of argillaceous limestone-derived yellow soil obtained at different depths in Pingba, Guizhou, a 1-site/2-pKa generalized composite surface complexation model (SCM) was established to obtain relevant parameters and explore soil surface acid–base properties. The model was employed to simulate cadmium (Cd) adsorption behavior. Combining the physicochemical properties of yellow soil and acid–base titration curves, the SCM-derived concentrations (Hs) and densities (Ds) of the surface-active sites for three soil layers showed decreasing trends with an increase in depth, whereas the calculated soil charge zero point (pHpzc) values matched the experimental values, indicating the applicability of SCM in studying the surface acid–base properties of yellow soil. Furthermore, as the pH increased, Cd shifted gradually from the dissolved to the adsorbed state, achieving complete adsorption at a pH of 7. The model-simulated Cd adsorption curve matched well with the experimental curve; the Cd adsorption behavior corresponded with the simulated distribution of surface sites at different pH levels, with ≡SOH2+ and ≡SO− being the main forms at pH < pHpzc and pH > pHpzc, respectively. Correlation analysis indicated that organic matter and goethite played a major role in Hs, whereas the charge zero points of soils at different depths were determined mainly by clay minerals, such as illite and iron-aluminum oxides. Our study established a scientific and reasonable relationship between the soil physicochemical properties and model parameters, providing a basis for preventing heavy metal pollution behavior via the effective application of model predictions.

[Objective]This study aims to to understand the adsorption characteristics and mechanisms of Plumbum(Pb)and cadmium(Cd)elements,which have strong pollution toxicity,in Guizhou yellow soil,thus providing theoretical basis for the prevention and control of heavy metal Pb and Cd pollution in agricultural soil.[Method]Basalt parent yellow soil from different sites in Guizhou Province was selected as the research object.According to the relevant formulas of the 1-site/2-p Ka Generalized Complex Surface Complexation Model(SCM)theory,combined with soil physicochemical property determination experiments,potentiometric titration experiments,and Pb and Cd adsorption edge experiments,the surface acid-base property parameters,namely model parameters,of yellow soil were obtained.Then,using the 1-site/2-p Ka SCM,the morphological distribution of three active sites on the yellow soil surface and the adsorption behavior of Pb and Cd at different pH levels were simulated to explore the adsorption characteristics and mechanisms of Pb and Cd by yellow soil.Correlation analysis was conducted to analyze factors influencing the adsorption of Pb and Cd by yellow soil.[Result]According to the relevant formulas of the SCM theory,the charge zero pHpzc,SCM of the four yellow soil samples were obtained as 5.040,5.549,7.984,and 4.297,respectively.The surface site concentrations(Hs)were 0.137,0.183,0.181,and 0.308 mol/kg,and the surface site densities(Ds)were 4.519,2.571,2.122,and 3.664 sit/nm2,respectively.Changes in the forms of ≡SOH2+,≡SOH,and ≡SO-on the yellow soil surface under different pH conditions were simulated by SCM,and the adsorption mechanisms of Pb and Cd on the yellow soil surface were preliminarily explained.The adsorption behavior of Pb and Cd on the yellow soil surface was fitted at different pH levels(correlation coefficient R≥0.96),indicating that SCM was suitable for describing the adsorption characteristics of Pb and Cd on the yellow soil surface.Adsorption edge experiments showed that the initial concentrations of Pb、Cd and the pH of the soil environment both affect the adsorption behavior of Pb and Cd on the yellow soil surface,and there are differences in the adsorption of Pb and Cd on the yellow soil surface;The adsorption capacity of yellow soil for Pb was greater than that for Cd,which was not only due to Pb having a smaller hydrated ion radius and a larger hydrolysis constant,but also because the calculated complexation equilibrium constant lg KSOPb was greater than lg KSOCd,indicating that the complex formed by Pb on the yellow soil surface was more stable than that formed by Cd.The correlation analysis indicated that Hs in yellow soil was primarily influenced by iron-aluminum oxides and organic matter.pH had a significant impact on pHpzc and lg KSOCd,as well as lg KSOPb in yellow soil.[Conclusion]The 1-site/2-p Ka SCM is highly applicable for accurately describing the adsorption characteristics of Pb and Cd on the surface of basalt parent yellow soil in Guizhou Province and explaining the adsorption mechanisms of Pb and Cd,.It could provide reference for the study of the migration and transformation of heavy metals in agricultural soil.

Organophosphate esters (OPEs) have been demonstrated to induce various forms of toxicity in aquatic organisms. However, a scarcity of evidence impedes the conclusive determination of whether OPEs manifest sex-dependent toxic effects. Here, we investigated the effects of tris (1-chloro-2-propyl) phosphate (TCPP) and resorcinol bis (diphenyl phosphate) (RDP) on the intestines of both female and male zebrafish. The results indicated that, in comparison to TCPP, RDP induced more pronounced intestinal microstructural damage and oxidative stress, particularly in male zebrafish. 16S rRNA sequencing and metabolomics revealed significant alterations in the species richness and oxidative stress-related metabolites in the intestinal microbiota of zebrafish under exposure to both TCPP and RDP, manifesting gender-specific effects. Based on differential species analysis, we defined invasive species and applied invasion theory to analyze the reasons for changes in the male fish intestinal community. Correlation analysis demonstrated that alien species may have potential effects on metabolism. Overall, this study reveals a pronounced gender-dependent impact on both the intestinal microbiota and metabolic disruptions of zebrafish due to OPEs exposure and offers a novel perspective on the influence of pollutants on intestinal microbial communities and metabolism.

Resorcinol bis(diphenylphosphate) (RDP) is an emerging pollutant that has been frequently detected in aquatic environments, although its toxicity is poorly characterized. To understand how RDP affects the neural system, two-month-old zebrafish were exposed to RDP at concentrations of 0.1 and 10 μg/L for 60 days. Following exposure, behavioral assessments were conducted, revealing the emergence of anxiety-like symptoms and memory deficits among the adult fish exposed to RDP, especially at the higher concentration. The increased blood-brain barrier (BBB) permeability (4.67-5.58-fold higher than the control group), reduced expression of tight junction proteins and the rapid brain RDP bioaccumulation (15.63 ± 2.34 ng/g wet weight) indicated the neurotoxicity of RDP. Excess reactive oxygen species synthesis (2.20-2.50-fold) was induced by RDP, leading to mitochondrial dysfunction and decreased production of neurotransmitters in the brain, specifically serotonin (5-HT; 16.3 %) and dopamine (DA; 18.1 %). Metabolomic analysis revealed that the low-toxicity RDP dose up-regulated lipid-related metabolites, while the high-toxicity dose up-regulated arachidonic acid metabolism and disrupted amino acid metabolism, including tryptophan and tyrosine metabolism related to dopaminergic and serotonergic pathways. The dysregulation of genes in various cellular processes was identified by transcriptomics, mainly involved in cell adhesion molecules and gap junctions, and oxidative phosphorylation, which were directly associated with BBB permeability and oxidative stress, respectively. Correlation analysis of microbiome-metabolite-host links built a mechanistic hypothesis for alterations in gut microbiota (Actinobacteriota and Proteobacteria) induced by high-dose RDP leading to the alteration of tryptophan, tyrosine, and arachidonic acid metabolism, decreasing the production of 5-HT and DA through the gut-brain axis. This study provides valuable insights into the mechanism underlying RDP-induced neurotoxicity in zebrafish, which can inform ecological risk assessments.

Abstract Bioassays, as an addition to physico-chemical water quality evaluation, can provide information on toxic effects of pollutants present in the water. In this study, a broad evaluation of environmental health risks from industrial wastewater along the Yangtze River, China, was conducted using a battery of bioassays. A total of 10 polycyclic aromatic hydrocarbons (PAHs), which were identified as potential major toxic chemicals of concern were measured in the samples of W, J, and T wastewater treatment plants. Toxicity tests showed that the wastewater treatment processes were effective at lowering acetylcholinesterase (AChE) inhibition, HepG2 cells cytotoxicity, estrogenic effect in T47D-Kbluc cells, DNA damage of Euglena gracilis and mutagenicity of Salmonella typhimurium in analyzed wastewater samples. However, the potential harm to the aquatic organisms has remained. Based on the health risk assessment model, the PAHs risk index of wastewater from the industrial parks along the Yangtze River was below 1, indicating that the PAHs in wastewater were less harmful to human health through skin contact or respiratory exposure. Overall, biological toxicity tests used in this study provide good basis for the health risk assessment of industrial wastewater and a scientific reference for the optimization and operation of the treatment process.

Triclosan (TCS), a commonly used antibacterial preservative, has been demonstrated to have high toxicological potential and adversely affects the water bodies. Since algae are one of the most significant primary producers on the planet, understanding the toxicological processes of TCS is critical for determining its risk in aquatic ecosystems and managing the water environment. The physiological and transcriptome changes in Euglena gracilis were studied in this study after 7 days of TCS treatment. A distinct inhibition ratio for the photosynthetic pigment content in E. gracilis was observed from 2.64% to 37.42% at 0.3–1.2 mg/L, with TCS inhibiting photosynthesis and growth of the algae by up to 38.62%. Superoxide dismutase and glutathione reductase significantly changed after exposure to TCS, compared to the control, indicating that the cellular antioxidant defense responses were induced. Based on transcriptomics, the differentially expressed genes were mainly enriched in biological processes involved in metabolism pathways and microbial metabolism in diverse environments. Integrating transcriptomics and biochemical indicators found that changed reactive oxygen species and antioxidant enzyme activities stimulating algal cell damage and the inhibition of metabolic pathways controlled by the down-regulation of differentially expressed genes were the main toxic mechanisms of TCS exposure to E. gracilis. These findings establish the groundwork for future research into the molecular toxicity to microalgae induced by aquatic pollutants, as well as provide fundamental data and recommendations for TCS ecological risk assessment.