Environmental Toxicology and Chemistry最新文献

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.

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.

Negligible depletion micro-extraction (nd-ME) is widely used for determining the freely dissolved concentration of pollutants. However, it typically requires a long equilibrium time. In this study, an in situ electrochemical approach based on nd-ME was developed to assess the sorption coefficient of methyl parathion (MP) onto humic acid, as well as the freely dissolved MP concentration in the real water samples, using a beta-cyclodextrin modified reduced graphene oxide composite electrode (β-CD/RGO/GCE). The sorption behavior of MP toward two representative humic acids-Acros humic acid (AcHA) and Suwannee River humic acid (SRHA)-across a dissolved organic carbon (DOC) range of 0 to 25 mg L-1 was investigated with the proposed method and validated using the conventional negligible depletion-solid phase microextraction (nd-SPME) technique. Equilibrium between freely dissolved MP and the β-CD/RGO composite was achieved within 16 min, representing a reduction to less than 1/22 of the time required by nd-SPME. Under equilibrium conditions, the obtained sorption coefficients (log K  DOC) were 4.56 for AcHA and 4.58 for SRHA, which align closely with the values derived from nd-SPME (log K  DOC = 4.23 for AcHA and 4.27 for SRHA). Moreover, the measured freely dissolved MP concentrations in water samples ranged from 3.96 to 4.44 μg L-1, basically consistent with the nd-SPME results (freely dissolved concentration, C  free = 4.17-4.76 μg L-1), demonstrating the reliability of the proposed method. Meanwhile, if combined with a portable electrochemical workstation, this study holds promise for providing a method applicable to on-site detection of the freely dissolved concentration of various compounds.

Spill treating agents (STAs) such as surface washing agents (SWA), surface collecting agents (or chemical herders) and solidifiers are designed to alter the behavior of crude oil by enhancing its removal from affected surfaces, aggregating it for easier recovery, or by transforming it into a more manageable solid form. They may be authorized for use under the United States National oil and Hazardous Substances Pollution Contingency Plan to support oil spill mitigation efforts. By the nature of their role in spill response, direct application to oil or around oil slicks, STA yields various mixtures of oil components and STA chemicals. This study evaluated the acute toxicity of mixtures of Alaska North Slope (ANS) crude oil and six STAs (three SWAs, two herders, and one solidifier) using standard freshwater and marine test species. A combination of traditional (frequentist) and Bayesian statistical approaches were used to analyze dose-response data. Results showed that SWAs significantly increased oil toxicity by enhancing the bioavailability of toxic hydrocarbons, where oil and agent mixtures were more toxic than oil alone in approximately 80% of expected cases for the four aquatic species. Meanwhile, herders and solidifiers generally caused minimal changes to oil toxicity. Bayesian credible intervals provided more nuanced differentiation between oil and STA-oil mixtures, revealing the potential for increased ecological risk from certain STA-oil combinations that may be indistinguishable using conventional methods. These findings support a more comprehensive understanding of the toxicity of oil spills treated with STAs and expands the knowledgebase for agents with only limited toxicity data.

Plastic pollution poses a global threat to aquatic ecosystems due to its persistence, and widespread dispersion. Antarctic ecosystems are no exception, with plastics detected in seawater, marine sediments, meltwater streams, and marine organisms. However, no prior studies have investigated microplastics (MPs) pollution in Antarctic lakes and its consumption by invertebrates. This research assessed MPs densities in an Antarctic lake and experimentally evaluated their ingestion on a native copepod (Boeckella poppei) and an anostracan (Branchinecta gaini) under varying conditions, including MPs concentrations and biofilm presence. Water samples from Ionosférico Lake (King George/25 de Mayo Island, Antarctica) were collected in 2023, and MPs were analyzed using micro-FTIR. Microplastic densities ranged from 0.35 to 1.61 items/m³ with average sizes of 2.0 ± 1.5 mm, and fibers were the most abundant particle type (>80%). The primary polymers identified were polyester (65%) and acrylic (16%). As model organisms, B. gaini and B. poppei were collected from the same lake and used in bioassays, including the use of lake water and irregularly shaped polyethylene and polypropylene particles, two of the most widely produced plastics globally. Experimental results showed no significant alteration in survival but confirmed MPs ingestion in both species, albeit with low grazing rates, and B. poppei ingested more biofilm-coated MPs. This study provides the first evidence of MPs in an Antarctic lake and their ingestion by two key species in this ecosystem, establishing a baseline for understanding MPs contamination and biological interactions in Antarctic freshwater environments.

This study assesses pesticide in crops from Togo's Plateaux region and evaluates health risks associated with farmers' exposure during pesticide application. A survey was conducted involving 350 farmers and 48 pesticide sellers. Operator exposure was assessed using the British Predictive Operator Exposure Model (U.K.-POEM) and the European Food Safety Authority (EFSA) calculator. A multi-residue analysis of 51 pesticides was carried out after a QuECHERS extraction and purification, using a gas chromatography system on six types of agricultural products during both rainy and dry seasons. The survey established the profile of pesticides in use. The herbicide spectrum was dominated by glyphosate, 2,4-dichlorophenoxyacetic acid, nicosulfuron, paraquat, and propanil. For insect control, applications primarily relied on λ-cyhalothrin, cypermethrin, acetamiprid, imidacloprid, and chlorpyrifos. Notably, 83% of operators reported not using personal protection equipment during mixing, loading or spraying. Modelling indicated high-risk exposure levels (Risk Quotient >1) for all pesticides, highlighting inadequate phytosanitary practices Residue analysis detected 13 pesticides. The most frequently detected were chlorpyrifos, endosulfan sulfate, acetamiprid and lambda-cyhalothrin. In the most contaminated produce, lettuce and cabbage, total pesticides concentrations ranged from 69 to 219 and 192 to 330 ng/kg respectively with higher contamination levels observed in the dry season. This study reveals the likelihood of elevated pesticide exposure in Togo, taking into account agriculture products contamination and operator exposure, raising concerns about long-term health risks such as chronic cancer and autism. Further assessment of drinking water contamination by these organic pollutants is warranted.