Search Results (288)

As bisphenol A (BPA) has gradually become restricted in production scenarios, the ecological risk level of its main replacement chemicals, i.e., bisphenol S (BPS) and bisphenol F (BPF), should be noted. To overcome the limitations of toxicity data, two kinds of in silico toxicology models (quantitative structure–activity relationship (QSAR) and interspecies correlation estimation (ICE) models) were used to predict enough toxicity data for multiple species. The accuracy of the coupled in silico toxicology models was verified by comparing experimental and predicted data results. Reliable predicted no-effect concentrations (PNECs) of 8.04, 35.2, and 34.2 μg/L were derived for BPA, BPS, and BPF, respectively, using species sensitivity distribution (SSD). Accordingly, the ecological risk quotient (RQ) values of BPA, BPS, and BPF for aquatic organisms were assessed in 32 major Chinese surface waters; they ranged from nearly 0 to 1.86, but were <0.1 in most cases, which indicated that the overall ecological risk level of BPA and its alternatives was low. However, in some cases, the ecological risks posed by BPA alternatives have reached equivalent levels to those posed by BPA (e.g., Liuxi River, Taihu Lake, and Pearl River), which requires further attention. This study provides evidence that the application of coupled in silico toxicology models can effectively predict toxicity data for new chemicals, avoiding time-consuming and laborious animal experiments. The main findings of this study can support environmental risk assessment and management for new chemicals that lack toxicity data. Full article

Tarragon extracts, especially from Artemisia dracunculus, have shown their potential as natural pesticides and can harm aquatic ecosystems. In addition, waste from tarragon essential oil production can also contribute to aquatic pollution if not properly managed. In this study, a hydrodistillate and a commercial tarragon essential oil were considered to evaluate their effects on aquatic ecosystems. A growth inhibition test was performed using Lemna minor to evaluate the potential ecotoxicity of tarragon extracts, and a biochemical test was performed to investigate the potential effects of the lowest volume of oil, which did not cause any visible impact on this organism. The results showed that the hydrodistillate did not show toxic effects on L. minor, but the essential oil demonstrated potential ecotoxicity, with volumes of 0.5 µL and above leading to percentage reductions in frond numbers of 50% and higher. The biochemical assay revealed no significant differences between the negative control and the lowest volume of oil tested, suggesting the absence of biochemical effects at low exposure levels. The effects of compounds identified at higher concentrations in the tarragon extracts on other aquatic organisms were predicted using the admetSAR3.0 tool, and potential toxicity against numerous aquatic organisms was emphasized, particularly for cis-beta-ocimene, trans-beta-ocimene, and caryophyllene oxide. These findings emphasize the need for careful consideration of both the application dose and disposal practices of tarragon-based products. Full article

The contamination of drinking water sources with selenium (Se) oxyanions, including selenite (Se(IV)) and selenate (Se(VI)), contains serious health hazards with an oral intake exceeding 400 µg/day and therefore requires urgent attention. Various natural and anthropogenic sources are responsible for high Se concentrations in aquatic environments. In addition, the chemical behavior and speciation of selenium can vary noticeably depending on the origin of the source water. The Se(VI) oxyanion is more soluble and therefore more abundant in surface water. Se levels in contaminated waters often exceed 50 µg/L and may reach several hundred µg/L, well above drinking water limits set by the World Health Organization (40 µg/L) and Germany (10 µg/L), as well as typical industrial discharge limits (5–10 µg/L). Overall, Se is difficult to remove using conventionally available physical, chemical, and biological treatment technologies. The recent literature has therefore highlighted promising advancements in Se removal using emerging technologies. These include advanced physical separation methods such as membrane-based treatment systems and engineered nanomaterials for selective Se decontamination. Additionally, other integrated approaches incorporating photocatalysis coupled adsorption processes, and bio-electrochemical systems have also demonstrated high efficiency in redox transformation and capturing of Se from contaminated water bodies. These innovative strategies may offer enhanced selectivity, removal, and recovery potential for Se-containing species. Here, a current review outlines the sources, distribution, and chemical behavior of Se in natural waters, along with its toxicity and associated health risks. It also provides a broad and multi-perspective assessment of conventional as well as emerging physical, chemical, and biological approaches for Se removal and/or recovery with further prospects for integrated and sustainable strategies. Full article

Tebuconazole (TBZ), a triazole-class fungicide widely used in agriculture, is frequently detected in aquatic environments due to runoff and leaching, where it poses a threat to non-target aquatic organisms. This study investigates the acute toxicity of TBZ on juvenile rainbow trout (Oncorhynchus mykiss), a commercially important cold-water fish species. The 96 h LC₅₀ value was determined to be 9.05 mg/L using probit analysis. In addition to mortality, the physiological responses of fish exposed to both LC₅₀ and maximum tolerance concentration (MTC; 6 mg/L) were evaluated through haematological and histological assessments. TBZ exposure significantly suppressed key haematological parameters, particularly WBC, RBC, HGB, HCT, and LYM, indicating immunosuppression and potential hypoxia. Histological examination revealed progressive and regressive damage in gill tissues, including epithelial lifting, hyperplasia, and hypertrophy, which were more severe in the LC₅₀ group. These alterations were quantified using a semi-quantitative scoring system. Additionally, significant changes in biochemical parameters such as ALT, AST, creatinine, total protein, and glucose levels were observed, further indicating hepatic and renal dysfunctions induced by TBZ exposure. The findings demonstrate that TBZ exposure induces substantial physiological and structural impairments in rainbow trout, highlighting the importance of assessing the ecological risks of fungicide contamination in aquatic environments. The study also provides a dose–response model that can be used to estimate mortality risk in aquaculture operations exposed to TBZ. Full article

This study evaluates the risk assessment and hazard identification of hydrothermal liquefaction (HTL)-derived bio-oil from the MARINES project, which converts military organic waste into fuel. The high oxygen content (35–50 wt%), acidic pH (2–4), and viscosity (10–1000 cP) of bio-oils pose unique challenges, including oxidative polymerization, corrosion, and micro-explosions during combustion. Key hazards include storage instability, particulate emissions (20–30% higher than diesel), and aquatic toxicity (LC50 < 10 mg/L for phenolics). Mitigation strategies such as inert gas blanketing, preheating, and spill containment are proposed. While offering renewable fuel potential, HTL bio-oil demands rigorous safety protocols for military/industrial deployment, warranting further experimental validation. Full article

This study provides an assessment of BTEX compounds—benzene, toluene, ethylbenzene, and xylene isomers—in urban precipitation collected in the city of Novi Sad, Republic of Serbia, during autumn and winter 2024, analyzed by gas chromatography-mass spectrometry (GC-MS). By combining chemical analysis with meteorological observations and HYSPLIT backward trajectory modeling, the study considers the mechanisms of BTEX removal from the atmosphere via wet scavenging and highlights the role of local weather conditions and long-range atmospheric transport in pollutant concentrations. During the early observation period (September to late November), average concentrations were 0.45 µg/L benzene, 3.45 µg/L ethylbenzene, 4.0 µg/L p-xylene, 2.31 µg/L o-xylene, and 1.32 µg/L toluene. These values sharply dropped to near-zero levels in December for benzene, ethylbenzene, and xylenes, while toluene persisted at 1.12 µg/L. A pronounced toluene spike exceeding 6 µg/L on 28 November was likely driven by transboundary air mass transport from Central Europe, as confirmed by trajectory modeling. The environmental risks posed by BTEX deposition, especially from toluene and xylenes, underline the need for regulatory frameworks to include precipitation as a pathway for pollutant deposition. It should be clarified that the identified risk primarily concerns aquatic organisms, due to the potential for BTEX infiltration into surface waters and subsequent ecotoxicological impacts. Incorporating such monitoring into EU policies can improve protection of air, water, and ecosystems. Full article

Nanomaterials possess unique physicochemical properties that position them as promising candidates for environmental remediation, particularly in the removal of persistent organic pollutants (POPs) from aqueous systems. Their high surface area, tunable functionality, and strong adsorption capabilities have attracted significant attention. In this context, this paper reviews the mechanisms of nanomaterial-based POP decontamination, also providing a critical overview of the limitations and challenges in applying these methods. Specifically, issues of stability, reusability, and aggregation are discussed, which can lead to performance decay during repeated use. In addition, the practical application requires nanocomposites to enable efficient separation and mitigate agglomeration. Environmental concerns also arise from nanomaterials’ fate, transport, and potential toxicity, which may impact aquatic ecosystems and non-target organisms. When checking for large-scale application feasibility, impurities typically add to production costs, recovery problems, and general infrastructure limitations. In addition to these points, there are no standard guidelines or clear risk assessment procedures for registering a product. Unprecedented cross-disciplinary research between natural, human, and technological studies and outreach programs is needed to facilitate the development and diffusion of the results. The barriers will eventually be breached to move from laboratory success in developing the desperately needed new water purification technologies to field-ready water treatment solutions that can address the global POP contamination problem. Full article

Background/Objectives: Silicon dioxide nanoparticles (SiO₂NPs) do not exist in isolation in the environment but can interact with other substances, thus influencing their toxic effects on aquatic organisms. We assessed the combined impact of SiO₂NPs and N-acetylcysteine (NAC), an antioxidant with the potential to counteract nanoparticle-induced oxidative stress (OS). Methods: Behavioral assessments, including the social interaction test and color preference test, were performed to evaluate neurobehavioral changes. OS biomarkers, including malondialdehyde (MDA) levels for lipid peroxidation and the activity of key antioxidant enzymes such as glutathione peroxidase (GPx), catalase (CAT), and superoxide dismutase (SOD), were assessed to evaluate the extent of cellular damage. Results: The results indicate that prolonged exposure to SiO₂NPs induces significant behavioral disruptions, including reduced exploratory behavior and increased anxiety-like responses. Furthermore, biochemical analysis revealed increased OS, suggesting nanoparticle-induced cellular toxicity. NAC co-treatment partially reversed these effects, particularly improving locomotor outcomes and antioxidant response, but was less effective on social behavior. Conclusions: These findings highlight the ecological and health risks posed by SiO₂NPs and point toward the need for further toxicological studies on their long-term biological effects. Full article

Annually, more than 10,000 synthetic dyes are produced worldwide, generating around 280,000 tons of waste, posing risks to human and aquatic life, and potentially creating even more toxic products than the dyes themselves. This study aims to immobilize organic dyes, forming hybrid pigments using ZnO as support obtained through starch combustion. ZnO was obtained by starch (sago) combustion and characterized by XRD, SEM and the BET method. It was then used for the adsorption of orange and green textile dyes, evaluating the adsorbent dosage, initial dye concentration, contact time, and selectivity with copper ions. The removal studies indicated up to 100% removal of both dyes at low concentrations. The co-adsorption system showed excellent performance, with removal percentages exceeding 90% for both textile dyes and Cu (II) ions. Hybrid pigments were assessed for solvent resistance and durability under extended white light exposure. ZnO immobilized the dyes, showing resistance to organic solvents and good stability under prolonged white light exposure. Full article

Agriculture relies on the widespread application of nitrogen fertilisers to improve crop yields and meet the demands of a growing population. However, the excessive use of these fertilisers has led to significant water quality challenges, posing risks to aquatic life, ecosystems, and human health. This study examines the relationship between synthetic nitrogen fertiliser usage and water pollution while identifying gaps in existing research to guide future studies. A systematic search across databases (Scopus, Web of Science, and Greenfile) identified 18 studies with quantitative data, synthesised using a single-group meta-analysis of means. As the data were continuous, the mean was used as the effect measure, and a random-effects model was applied due to varied study populations, with missing data estimated through statistical assumptions. The meta-analysis found an average nitrate concentration of 34.283 mg/L (95% confidence interval: 29.290–39.276), demonstrating the significant impact of nitrogen fertilisers on water quality. While this average remains marginally below the thresholds set by the World Health Organization (50 mg/L NO₃⁻) and EU Nitrate Directive, it exceeds the United States Environmental Protection Agency limit (44.3 mg/L NO₃⁻), signalling potential health risks, especially in vulnerable or unregulated regions. The high observed heterogeneity (I² = 100%) suggests that factors such as soil type, agricultural practices, application rate, and environmental conditions influence nitrate levels. While agriculture is a key contributor, other anthropogenic activities may also affect nitrate concentrations. Future research should comprehensively assess all influencing factors to determine the precise impact of nitrogen fertilisers on water quality. Full article

Pharmaceuticals such as fluoxetine, paroxetine, sertraline, and mianserin occur in aquatic environments at low yet persistent concentrations due to their incomplete removal in wastewater treatment plants. Although frequently detected, these neuroactive compounds remain underrepresented in ecotoxicological assessments. Given their pharmacodynamic potency, environmentally relevant concentrations may induce sublethal effects in non-target organisms. In this study, we applied untargeted LC-MS-based metabolomics to investigate the sublethal effects of four widely used antidepressants—paroxetine, sertraline, fluoxetine (SSRIs), and mianserin (TeCA)—on two ecologically relevant freshwater invertebrates: S. ambiguum and D. magna. Organisms were individually exposed to each compound for 48 h at a concentration of 100 µg/L and 25 µg/L, respectively. Untargeted metabolomics captured the sublethal biochemical effects of these antidepressants, revealing both shared disruptions—e.g., in glycerophospholipid metabolism and cysteine and methionine metabolism—and species-specific responses. More pronounced pathway changes observed in D. magna suggest interspecies differences in metabolic capacity or xenobiotic processing mechanisms between taxa. Among the four antidepressants tested, sertraline in D. magna and fluoxetine in S. ambiguum exerted the most extensive metabolomic perturbations, as evidenced by the highest number and pathway impact scores. In D. magna, fluoxetine and mianserin produced similar metabolic profiles, largely overlapping with those of sertraline, whereas paroxetine affected only a single pathway, indicating minimal impact. In S. ambiguum, paroxetine and mianserin elicited comparable responses, also overlapping with those of fluoxetine, while sertraline triggered the fewest changes. These results suggest both compound-specific effects and a conserved metabolic response pattern among the antidepressants used. They also underscore the considerable potential of metabolomics as a powerful and sensitive tool for ecotoxicological risk assessments, particularly when applied across multiple model organisms to capture interspecies variations. However, further research is essential to identify which specific pathway disruptions are most predictive of adverse effects on organismal health. Full article

Cresols are aromatic organic compounds widely used in industrial and agricultural production. They have been detected in large quantities in aquatic environments, posing health risks such as skin irritation, gastrointestinal stimulation, and chronic neurological effects. In this study, we investigated the exposure concentration of cresols in the water bodies of Lake Xingkai (i.e., Daxingkai and Xiaoxingkai Lakes) during four typical hydrological periods (30 April, 22 June, 5 September, and 1 November 2021), assessed the human health risk from phenolic contaminants using the mean value method, and determined the health risk of adult cresol exposure in the Lake Xingkai watershed based on local population exposure parameters. This study developed a water environmental pollution health risk assessment model based on the methodology proposed by the United States Environmental Protection Agency (US EPA). It further evaluated the health risks to humans posed by phenolic pollutants via the drinking water pathway. The results revealed that the concentration range of cresols in water bodies was between 5.91 × 10⁻¹ ng·mL⁻¹ and 6.68 ng·mL⁻¹. The adult drinking water health risk values of cresols in the Lake Xingkai watershed were between 3.15 × 10⁻⁴ and 3.57 × 10⁻³, and all water samples from the 10 sites had hazard quotient (HQ) values less than 1, indicating that the non-carcinogen risk was small or negligible. The cresol HQ value in the water of Xiaoxingkai Lake was 4.6 times that found in Daxingkai Lake. Full article

Utilizing a multi-biomarker approach, we assessed the potential adverse effects of pollutants on subcellular responses in the digestive gland of the freshwater mussel Unio crassus from a historically contaminated lowland section (KIZ) of the river Mrežnica compared to its less impacted upstream karstic section (REF) and their seasonality (spring vs. autumn). This approach accounted for the diverse modes of action of pollutants by including biomarkers of metal exposure (metallothioneins, MT), general stress (total cytosolic proteins, TP), antioxidative capacity (catalase, CAT; glutathione, GSH; glutathione-S-transferase, GST), oxidative damage (malondialdehyde, MDA), and neurotoxicity (acetylcholinesterase, AChE). Only in spring, MT concentrations were 15% higher at the REF site (4.38 ± 1.06 µg mg proteins⁻¹) compared to the KIZ site (3.69 ± 0.63 µg mg proteins⁻¹), likely related to elevated Cd bioaccumulation due to the karstic substrate. Regardless of the season, mussels from KIZ showed consistently lower TP and GSH, with significantly higher CAT, GST, and MDA levels, indicating elevated stress, activation of antioxidant defenses, and oxidative damage from chronic exposure to pro-oxidant pollutants, including metal(loid)s and organic contaminants (e.g., ibuprofen, nicotine). Compared to the REF site, AChE activity at the KIZ site was higher in late spring and lower in early autumn, indicating seasonal variability in AChE activity at the contamination-impacted location driven by fluctuating exposure to neurotoxicants, such as drugs and insecticides. Overall, biomarker responses indicated that mild historical pollution, reinforced by current low-capacity sources, has an observable impact on mussel health, posing long-term risks to sediment-dwelling aquatic organisms. Full article

The widespread application of pesticides in agriculture has raised increasing concerns regarding their ecological impact, particularly in aquatic environments. Among these, α-cypermethrin, a highly active isomeric form of cypermethrin, has been extensively used due to its potent insecticidal efficacy and low mammalian toxicity. However, its toxicity to non-target aquatic organisms remains insufficiently understood at the metabolic level. In this study, a targeted metabolomics approach was employed to investigate the biochemical effects of α-cypermethrin in adult zebrafish. Acute toxicity was first determined to establish sublethal exposure concentrations (0.15 µg/L and 1.5 µg/L), followed by a 48 h exposure under a controlled flow-through system. GC-MS/MS-based analysis quantified 395 metabolites, and multivariate statistical models (principal component analysis (PCA) and partial least square-discriminant analysis (PLS-DA)) revealed clear dose-dependent metabolic alterations at two time points. Pathway analysis identified disruptions in glycolysis, glycerolipid metabolism, amino acid turnover, and glutathione pathways. Notably, glutamate depletion and associated reductions in GABA (4-Aminobutanoate) and TCA (Tricarboxylic acid) cycle intermediates suggest oxidative stress-induced metabolic bottlenecks. These results provide mechanistic insights into α-cypermethrin-induced toxicity and demonstrate the utility of metabolite-level biomarkers for environmental monitoring. This study contributes to a systems-level understanding of how sublethal pesticide exposure affects vertebrate metabolism, offering a basis for improved ecological risk assessment and pesticide regulation. Full article

Glufosinate-ammonium (GLA) is a broad-spectrum herbicide widely used for weed control. However, its potential toxic effects on non-target aquatic organisms, especially in freshwater ecosystems, are of growing concern. This study investigates the toxic effects of GLA on Biomphalaria glabrata, a freshwater snail highly sensitive to environmental pollutants and commonly used as a model organism in toxicological studies. Acute toxicity tests revealed that the 96-h LC50 of GLA for adult snails was 3.77 mg/L, indicating moderate toxicity, while the LC50 for embryos was 0.01576 mg/L, indicating extremely high toxicity. Chronic exposure experiments further showed that at high concentrations (0.5 mg/L), the shell diameter and body weight of the snails not only failed to increase but also decreased, and they ceased to lay eggs. Moreover, their hepatopancreas and gonads suffered significant damage. Even at an environmentally relevant concentration of 0.05 mg/L, the body length, body weight, and reproductive capacity of the snails were inhibited, and damage to the hepatopancreas and gonads was observed. These findings provide important data for assessing the potential risks of GLA to aquatic ecosystems and offer a scientific basis for formulating environmental protection policies and optimizing herbicide usage standards. Full article