Environmental Toxicology and Chemistry最新文献

Neotropical stingless bees have frequently been reported to possess high biodiversity, ecological significance, and sensitivity to insecticides. Surprisingly, few studies have been conducted so far to assess their sensitivity to neonicotinoid insecticides, although there are indications that this insecticide class is especially toxic to stingless bees. The aim of this study was therefore to evaluate the acute oral and topical toxicity of two neonicotinoids, imidacloprid and thiamethoxam, to the neotropical stingless bee Melipona scutellaris. Besides these active ingredients, commercial products containing them were also evaluated. The commercial products were more toxic to the bees than the active ingredients, which may be due to direct toxicity of coformulants and indirectly through their higher biological activity and facilitation of uptake by organisms. The neonicotinoids were more toxic through topical contact than oral exposure. This is the opposite trend to that previously reported for honeybees, which is explained through differences in life-history traits with stingless bees. M. scutellaris was more sensitive to the test substances than standard bee test species commonly used in (temperate) toxicity assessments. This thus stresses the need to include stingless bees in neotropical risk assessments. The relatively high mortality occasionally observed in control groups highlights the biological sensitivity of stingless bees to laboratory conditions rather than a methodological flaw. This finding reinforces the importance of refining experimental setups by minimizing handling stress and improving cage microclimate to enhance control survival and ensure even greater robustness in future toxicity assessments involving native species.

Saponins are natural plant metabolites with surface-active and bioactive properties against plant pests, making them promising biopesticides. However, their environmental fate in soil remains unclear. This study investigated the sorption properties of three triterpenoid saponins, two monodesmosidic α-hederin and hederacolchiside A1 saponins, and the bidesmosidic hederacoside C saponin, on common soil constituents including clay minerals (kaolinite, montmorillonite), metal oxides (gibbsite, goethite), black carbon, and topsoil. Batch sorption experiments assessed influences of structures, sorbent properties, and environmental factors. All saponins exhibited unexpectedly strong sorption (distribution coefficient [Kd] > 10³ L/kg on topsoil), with α-hederin showing the highest affinity (Kd = 229 × 10³ L/kg on goethite), attributed to its moderate hydrophobicity (octanol-water partition coefficient, [log Kow] ∼ 4.4), short sugar chain, and interactions involving carboxyl (-COOH) and hydroxyl (-OH) functional groups. In contrast, more polar hederacoside C (log Kow ∼ -1.2) showed weaker sorption with Kd of 1.56 × 10³ to 22.7 × 10³ L/kg. Sorption isotherms followed Freundlich behavior and increased by approximately 50% at acidic pH for α-hederin and hederacolchiside A1 due to protonation of carboxylic acid groups (acid dissociation constant, pKa ≈ 4.7-4.9), whereas hederacoside C lacking carboxylic acid groups remained unaffected. Salts and fulvic acid reduced α-hederin sorption (up to 80%), likely due to ion exchange and competitive complexation. Desorption studies showed α-hederin was strongly retained (<20% desorption), particularly on metal oxides. Scenario-based modeling indicates that at realistic saponin biopesticide doses (50 µM), α-hederin and hederacolchiside A1 remain largely immobile, whereas hederacoside C may slightly leach in low-sorption soils. These findings highlight the combined role of saponin structure and soil mineralogy in regulating environmental mobility with implications for biopesticide design and risk assessment.

Earthworm risk assessment for chemicals is normally based on toxicity tests performed in artificial test soils with either 5% or 10% organic matter. Soil characteristics, in particular organic matter content and pH, influence the bioavailability of chemicals, and one would therefore expect different levels of toxicity in natural soils. Predicting toxicity in different soils is a major challenge. Here we demonstrate a novel approach for predicting effect concentrations in untested soils by using the results of a toxicity test in a standard test soil together with a previously published empirical model for uptake of chemicals into earthworms. The model predicts the uptake and elimination rate constants of a one-compartment toxicokinetic model based on earthworm species properties (lipid content and specific surface area), topological polar surface area of the molecule, and the organic matter content and pH of the soil. The accuracy of the currently proposed model for predicting toxic effect concentrations (EC50 and LC50) was evaluated against an independent dataset, including 145 measured effect concentrations in non-standard soils, covering 30 synthetic organic compounds and 5 earthworm species. The model showed a high accuracy with 90% of predictions within a factor of 3 of observations. We show the current bias in European risk assessment related to differences in organic matter content between standardized test soils and common agricultural soils and demonstrate how application of the new approach removes that bias. An example with two fungicides illustrates how the model could be applied to increase the environmental realism of the risk assessment.

Per- and polyfluoroalkyl substances (PFAS) are man-made chemicals found in all environmental compartments. In surface waters, PFAS can bind to suspended solids (SS), which can affect their fate. In the present study, sorption of 22 PFAS to SS from 16 locations in the Netherlands was quantified, using monitoring data from the Dutch Ministry of Infrastructure and Water Management. A total of 2280 to 3105 (number depending on the data inclusion criterion) SS-water distribution coefficients (K  ss-w) were calculated, assuming equilibrium conditions, though these may not have applied to all locations, e.g.,, due to local discharges. Significant differences were observed between location-specific K  ss-w values. These could not be explained from SS or water characteristics, including the SS organic carbon content, which has previously been assumed to control PFAS sorption to SS. However, for about half the PFAS studied, an inverse relationship between logK  ss-w and the PFAS concentration in water was observed. This may suggest that sorption of (these) PFAS to SS is a nonlinear process, whereas in previous reports it has been considered concentration-independent. Location-averaged K  ss-w values varied between approximately 100 and 10,000 and increased with the number of PFAS carbon atoms, although the values for perfluorocarboxylic acids with <8 carbon atoms were statistically indistinguishable. These values and patterns are consistent with several previous reports from Asia and France. Using the K  ss-w values derived here, PFAS concentrations in SS could be estimated from measured PFAS concentrations in water within an average factor of 2. Therefore, the added value of analytical PFAS concentration determinations in SS in the Netherlands seems limited, also because PFAS masses associated with SS carried by the major rivers generally appeared to be negligible compared to the masses dissolved in water. Consequently, including SS as partitioning phase in PFAS fate models does not seem essential for north-European rivers.

Antibiotics, various environmental factors, and suspended particulate matter (SPM) exert a significant influence on the occurrence and dissemination of antibiotic resistance genes (ARGs). However, the current research on the mechanisms underlying the environmental factor-driven ARG dissemination in sediment-laden rivers, particularly the role of SPM, remains incomplete. This study systematically examined the distribution and interaction mechanisms among environmental factors, antibiotics, and ARGs in the Fenhe River Basin, a vital river traversing urban and agricultural areas of Shanxi Province, China. The research aims to fill the knowledge gap regarding the driving role of environmental factors in ARG spread within sediment-laden river systems. Surface water samples were collected from 6 sites across the basin, and the characteristics and relationship between antibiotics, ARGs mobile genetic elements (MGEs), and environmental factors were analyzed. Results showed that macrolide antibiotics (MLs) were dominant, with azithromycin reaching the highest concentration (584 ng/L, 23% of total antibiotics). Spatially, antibiotic and ARG levels peaked in the midstream; sulfonamide resistance genes sul2 and sul1 were the most abundant ARGs. Tetracycline resistance genes correlated positively with tetracyclines (TCs), MLs and sulfonamide antibiotics, while Quinolone Efflux Pump A (QepA) showed negative correlations with quinolone antibiotics and TCs. Mobile genetic elements (e.g., intI-1LC) promoted ARG propagation. Thirteen environmental factors showed variable correlations with ARGs: sand content positively correlated with 78% of ARGs, while flow velocity and pH negatively correlated with 72% of ARGs. This study clarifies the combined effects of urban-agricultural activities on antibiotic-ARG in multi-sediment-laden rivers, offering insights for river ecological risk management.

Syncrude's Base Mine Lake Demonstration (BML) is the first commercial demonstration of water capped tailings technology (WCTT) in the oil sands industry, with the goal of developing into a self-sustaining aquatic ecosystem over time. The partitioning of organic components of residual bitumen and naphtha present in the fluid fine tailing is a critical control on their potential transport and biodegradation. Methanogenesis and associated methane ebullition observed in BML is associated with transport of residual organic compounds to the lake surface, a process controlled by the physiochemical properties of the compounds involved. Though even comprehensive two-dimensional gas chromatography (GC × GC) is unable to resolve and/or identify every single compound from this mixture, we were able to use a GC × GC-based approach to estimate the physiochemical properties of the non-polar fraction of bitumen associated with gas bubbles trapped within ice from BML to assess their environmental behaviours. The modelled results indicated that the non-polar fraction of the transported bitumen generally exhibits low volatility (-5 < log PL <2.5 Pa), low solubility (-12 < log SwL < -1mol·m3), and high octanol-water partitioning coefficients (5 < log Ko-w <13). Furthermore, combining multiple partitioning coefficients allowed a first-order assessment of the aquatic bioaccumulation potential (ABP) and terrestrial biomagnification potential (TBP) of the compounds detected. The results indicated that the non-polar fraction of the transported bitumen is not likely to cause significant aquatic bioaccumulation or terrestrial biomagnification effects, due mainly to their high hydrophobicity. The ability to assess the environmental behaviour of compounds that cannot be individually identified or whose physiochemical properties have yet to be characterized, is an important capability in situations such as oil sands or elsewhere where complex mixtures of organic compounds are present.

Concern over microplastic pollution has intensified in recent years as mounting evidence reveals its persistence, ubiquity, and potential biological impacts, with particular attention now turning to microfibers-one of the most abundant microplastic forms in the environment. Microfibers include more than just plastic textiles, as microfibers shed from non-plastic textiles are also ubiquitous in nature. To increase our understanding about how microfibers and associated chemicals affect aquatic ecosystems, we investigated the effects of clean microfibers and microfibers soaked in wastewater treatment plant final effluent (a common pathway for microfibers to reach aquatic ecosystems) on the benthic invertebrate Chironomus dilutus in a full-lifecycle test. We tested different microfiber types (polyester, cotton), and exposed animals to 50 and 500 microfibers L-1. No effects on percent emergence, fecundity, or hatchability were observed. There was a significant increase in time to emergence across all microfiber treatments at the higher concentration. Some effects were observed for growth and survival, although results were inconsistent among treatments. Overall, our results suggest that synthetic and natural microfibers can have developmental effects on C. dilutus and future work would benefit from assessing all environmentally-relevant microfibers, including different microfiber types and chemical mixtures.

The two-dimensional nanomaterial MXene Ti3C2Tx is widely used in biomedical and water treatment research. However, the biotoxic effects and mechanisms of Ti3C2Tx in aquatic organisms remain unclear. The present study combined non-targeted metabolomics techniques and traditional toxicological methods to investigate the developmental toxicity of two sheet sizes of Ti3C2Tx-large diameter (Ti3C2Tx-LD) and Ti3C2Tx-small diameter (Ti3C2Tx-SD) to zebrafish embryos and clarify the underlying mechanisms. The results showed that the 96-hr median lethal concentrations (LC50) of Ti3C2Tx-LD and Ti3C2Tx-SD were 35.09 and 50.33 mg/L for zebrafish embryos (96 hr post fertilization), respectively, and the larger sheet size was more toxic. Both Ti3C2Tx-LD and Ti3C2Tx-SD induced concentration-related developmental abnormalities of delayed hatching, excessive reactive oxygen species (ROS) production, pericardial edema, pericardial cell apoptosis and reduced heart rate in zebrafish embryos. Metabolomics revealed that both Ti3C2Tx-LD and Ti3C2Tx-SD caused cardiac developmental toxicity in zebrafish embryos, although via different pathways of action, as Ti3C2Tx-LD mainly disrupted the glycerolipid and glycerophospholipid metabolism pathways, whereas Ti3C2Tx-SD mainly interfered with the arginine biosynthesis pathway. The results of this study highlight that Ti3C2Tx has developmental toxicity and cardiotoxicity to zebrafish embryos and should be fully evaluated for biosafety and environmental risks before mass industrial applications.

Land application of biosolids and effluent is becoming increasingly common, yet the ecotoxicological impacts of complex contaminant mixtures found in these wastewater residuals remain poorly understood. Another key knowledge gap is how the delivery matrix (biosolids vs. effluent) governs these effects. To assess these complex questions, we employed a novel experimental framework using a high-sorption (high organic matter) soil to create a 'best-case scenario' for contaminant immobilization that limited bioaccessibility. This design allowed us to isolate and compare the ecotoxicological impacts of multi-class contaminant mixtures (delivered via aqueous effluent or solid biosolids) on plants, earthworms, and soil microbes across environmentally relevant concentrations. While the soil's sorptive capacity prevented harm to apical endpoints like growth and reproduction, a robust multi-component statistical analysis of sensitive sublethal biomarkers indicated concentration-dependent oxidative stress in both plants and earthworms. Microbial community structure was the most sensitive indicator, for which our data suggest two distinct toxicological mechanisms: highly bioavailable contaminant mixtures in effluent caused notable, albeit variable, reduction in microbial richness, whereas less-bioavailable biosolids-borne contaminants induced selective community restructuring. This work indicates that the contaminant delivery matrix is a critical driver of ecotoxicity. Sublethal harm in this highly sorptive soil suggests that ecological risks from contaminant mixtures in typical, lower organic matter agricultural soils-where bioavailability may be greater-may be underestimated, supporting the need for bioavailability-aware reuse policies.

Nanotechnology serves as a nanoscale interface that directly bridges our perception of the macroscopic world with the intricate nanoworld where individual biomolecules reside. This technology has emerged as a luminary in the domains of biology and medicine, paving the way for novel medical research. However, the widespread and indiscriminate use of nanomaterials raises significant concerns regarding environmental, health, and safety issues for the public. Hence, understanding the toxicological properties of nanomaterials in biological interactions becomes pivotal for their safe application. A key challenge in this field lies in the complex and dynamic nature of nano-bio interactions, the strong dependence of toxicity on the physicochemical properties of nanomaterials, and the lack of standardized and predictive toxicity assessment methods capable of supporting reliable risk evaluation and safe-by-design strategies. This review article delves into the potential biological risks and influencing factors contributing to the toxicity of common nanomaterials. Additionally, it explores the mechanisms underlying nano-bio interactions and applications of nanomedicine. The antiviral strategies based on nanomaterials are also introduced, and the possible risks and benefits of nanomaterials in specific nanomedicine applications are described through illustrative examples. Future research should focus on integrating artificial intelligence and advanced models for predictive toxicology, alongside long-term biosafety studies. The goal of this review is to facilitate a deeper understanding of the underlying biological processes between nanomaterials and biological systems. We strive for solving the problem of reducing the threats in the initial stage of nano-products design, ultimately providing theoretical support for better research on nanotoxicology.