Environmental Toxicology and Chemistry最新文献

{"title":"Multiple stressor effects of hypoxia and metals on ventilation, activity, bioaccumulation, and loss of equilibrium in fathead minnows.","authors":"Natalie M Nykamp, W Andrew Thompson, Isaac Beckford, Sigal Balshine, Erin M Leonard","doi":"10.1093/etojnl/vgag272","DOIUrl":"https://doi.org/10.1093/etojnl/vgag272","url":null,"abstract":"<p><p>Hypoxia is an increasing concern in freshwater ecosystems, driven by warming, stratification, and nutrient enrichment. Fish cope with hypoxia through behavioural and ventilatory adjustments, yet growing evidence suggests that certain metals can impair these critical compensatory mechanisms. It is currently unknown whether lead (Pb) and nickel (Ni), released in part through expanding mining operations, may alter these critical survival responses. We tested whether 48 hr Pb and Ni exposure impaired fathead minnows' (Pimephales promelas) responses to hypoxia by measuring their gill metal accumulation, ventilation rates, behaviour (movement), and hypoxia tolerance (as measured by % dissolved oxygen [DO] at loss-of-equilibrium [LOE]). Notably, Pb (43 μg/L) exposure during hypoxia resulted in 3.5 × greater gill bioaccumulation, indicating changes in gill uptake dynamics. Opercular movements were used as a proxy for the hypoxic ventilatory response (HVR) and the increase in ventilation in Ni exposed fish was 48% less than the increase in unexposed fish, indicating a blunted HVR. Ni (318 μg/L) increased fish activity, as measured by total distance moved, in both normoxia and hypoxia. Both metals increased hypoxia tolerance as measured by LOE. Together, it appears that co-exposure to Pb and hypoxia may increase gill Pb accumulation due to a maintained HVR, and short-term exposure to Ni can increase locomotion, without affecting ventilatory responses to hypoxia. These results underscore the importance of multiple-stressor research to better understand the interplay of hypoxia and metals to inform water quality guidelines.</p>","PeriodicalId":11793,"journal":{"name":"Environmental Toxicology and Chemistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149164695","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High Throughput Adaptation of Standardised Ecotoxicological Tests for the model freshwater invertebrate Daphnia magna.","authors":"Angel D Ceballos-Ramirez, Mark E Hodson, Colin D Brown, Thomas G Preuss, Elma Lahive, Daniel Burkow","doi":"10.1093/etojnl/vgag266","DOIUrl":"https://doi.org/10.1093/etojnl/vgag266","url":null,"abstract":"<p><p>Current environmental regulations require the standardised testing of chronic ecotoxicological endpoints as part of their approval processes. However, although such tests tend to be resource intensive, new high throughput methods have not been favoured to date due to their lack of standardisation. To address this, a high throughput experiment that captured the conditions specified in the standardised Organisation for Economic Co-operation and Development's (OECD) Test Guideline 211 was carried out. Daphnids (>400) were individually exposed to five concentrations of each of four polar narcotic chemicals (3,4-dichloroaniline (DCA), 2,4,5-trichloroaniline (TCA), 1,2-dichlorobenzene (DCB), 3-nitroaniline (3NA)) and four chemicals that are nACHhR inhibitors (acetamiprid, clothianidin, nitenpyram, thiacloprid) for a period of 21 days. Growth and reproduction were measured every other day using a spheroid counter. Mortality in controls was low (<20%) throughout the study period meeting OECD validity criteria. However, average cumulative reproduction of 52 neonates per Daphnid in controls was slightly below the OECD reproduction validity criteria of 60 neonates per Daphnid. Despite variations in average observed size of the animals due to their position during measurement, results show a clear dose-response effect for growth and reproduction, enabling ECx to be calculated for all chemicals at any time point. The results of this experiment demonstrate a robust methodology that can generate a large volume of time sensitive data for chronic and acute endpoints, under conditions consistent with standard OECD test guidelines in a cost and time efficient manner.</p>","PeriodicalId":11793,"journal":{"name":"Environmental Toxicology and Chemistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149166976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Toxicity-Weighted Multi-Criteria Decision-Making for the Prioritization of Nitrosamines in Drinking Water Using a Fuzzy Aggregation Framework.","authors":"Cihan Özgür","doi":"10.1093/etojnl/vgag268","DOIUrl":"https://doi.org/10.1093/etojnl/vgag268","url":null,"abstract":"<p><p>Nitrosamines are among the most concerning nitrogenous disinfection by-products in drinking water because of their high carcinogenic potency and frequent occurrence, particularly in chloraminated systems. However, current risk assessments are predominantly compound-specific and often rely on N-nitrosodimethylamine (NDMA) as a surrogate, limiting the interpretation of multi-compound exposure scenarios. In this study, a toxicity-weighted multi-criteria decision-making framework based on the fuzzy analytic hierarchy process (fuzzy AHP) was developed to prioritize nine commonly reported nitrosamines: NDMA, N-nitrosodiethylamine (NDEA), N-nitrosodi-n-propylamine (NDPA), N-nitrosodibutylamine (NDBA), N-nitrosomethylethylamine (NMEA), N-nitrosopyrrolidine (NPYR), N-nitrosopiperidine (NPIP), N-nitrosomorpholine (NMOR), and N-nitrosodiphenylamine (NDPhA). The framework initially considered toxicological properties, exposure indicators, environmental prevalence, evidence availability, data reliability, and practical management considerations. Following fuzzy weighting, the final aggregation was driven by oral slope factor, mean concentration, chronic daily intake (CDI), and toxicity-data reliability. To account for dataset heterogeneity, three contexts were evaluated separately: Formation potential, distribution network, and treatment plant effluent. NDEA ranked first in all three contexts, primarily because of its high carcinogenic potency. NDMA ranked second in the formation-potential and treatment-plant-effluent contexts but third in the distribution-network context, where NDPA ranked second. The high priority of NDMA reflected its combined contributions from carcinogenic potency, concentration, and CDI, whereas the priority of NDPA was largely driven by its comparatively high CDI. Mid-ranked compounds showed context-dependent variation: NPIP and NMOR received relatively higher priorities in the treatment-plant-effluent and formation-potential contexts, while NMEA ranked higher in the distribution-network context. Across all three contexts, the lowest rank was consistently assigned to NDPhA. Overall, the findings demonstrate that nitrosamine prioritization requires the joint consideration of toxicity and exposure and that the proposed framework provides a transparent and transferable tool for risk-informed monitoring and management in drinking-water systems.</p>","PeriodicalId":11793,"journal":{"name":"Environmental Toxicology and Chemistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149135419","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In silico toxicity assessment of diverse organic chemicals in channel catfish (Ictalurus punctatus): Duration-specific (24-96 hr) QSAR modeling, mechanistic interpretation, and data gap filling.","authors":"Aniket Nath, Probir Kumar Ojha","doi":"10.1093/etojnl/vgag267","DOIUrl":"https://doi.org/10.1093/etojnl/vgag267","url":null,"abstract":"<p><p>The channel catfish (Ictalurus punctatus) is vital to aquatic ecosystems and the aquaculture industry, regulating food webs, cycling nutrients, and indicating ecosystem health because of its habitat adaptability. The rise of harmful industrial organic chemicals exposes the limits of traditional toxicity tests, such as animal testing, which are often unreliable, costly, time-consuming, and ethically problematic. To overcome these issues, in silico methods, especially Quantitative Structure-Activity Relationships (QSARs), can offer a reliable, animal-free alternative for predicting toxicity. Using toxicity endpoint data from the U. S. Environmental Protection Agency's (USEPA) ECOTOXicology database (ECOTOX), we developed the first species-specific QSAR models for I. punctatus, based on two-dimensional (2D) molecular descriptors, enabling safer and more ethical environmental assessments. We developed four duration-specific (24, 48, 72, and 96 hr) QSAR models using curated mortality datasets comprising 187, 89, 49, and 246 compounds, respectively. The models demonstrated strong goodness-of-fit, robustness, and predictive power, validated both internally (R2=0.711 - 0.828; Q2LOO=0.646 - 0.769) and externally (Q2F1=0.717 - 0.773; Q2F2=0.715 - 0.761). To ensure our models are practically reproducible, we predicted toxicity for over 1,500 new chemicals, identifying the ten most and least toxic compounds and their specific structural characteristics, which will help design safer chemicals and manage sustainable channel catfish populations to support a healthy aquatic ecosystem.</p>","PeriodicalId":11793,"journal":{"name":"Environmental Toxicology and Chemistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149126898","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The risk posed by exposure to pesticides through beeswax to adult western honey bees (Apis mellifera).","authors":"Louise Petit, Cameron J Jack, James D Ellis","doi":"10.1093/etojnl/vgag262","DOIUrl":"https://doi.org/10.1093/etojnl/vgag262","url":null,"abstract":"<p><p>In western honey bee (Apis mellifera) colonies, beeswax can help manage bee exposure to lipophilic compounds via absorption, making the compounds bio-unavailable. However, trapped chemicals may be slowly released into the nest environment, posing risks to bees through chronic exposure. Due to their lipophilic properties (logP > 1), many insecticides used in agriculture or for Varroa destructor control in the honey bee nest can accumulate in beeswax. Via in vitro cage assays, we determined the LC50 values of six pesticides (coumaphos, amitraz, acrinathrin, chlorpyrifos, chlorfenvinphos, and bifenthrin) frequently detected in beeswax and determined if the concentrations found in beeswax pose a risk to honey bees. The LC50 values on adult bees exposed to these pesticides in beeswax did not follow the same ranking as their topical or oral LC50 values reported in the literature. The observed LC50 values (mg/g of beeswax) were: Amitraz (1.31), chlorfenvinphos (0.731), acrinathrin (0.504), bifenthrin (0.237), coumaphos (0.104), and chlorpyrifos (0.012). Based on mean beeswax residues of these compounds reported in the literature, the relative risk ranking to honey bees, from greatest to lowest risk, was: Coumaphos > acrinathrin > chlorpyrifos > amitraz > chlorfenvinphos > bifenthrin. Based on maximum beeswax residues reported in the literature, the relative risk ranking was: Coumaphos > chlorpyrifos > amitraz > acrinathrin > chlorfenvinphos > bifenthrin. Our data showed that the compounds tested do not appear to pose a significant risk to honey bee survival at concentrations in beeswax reported in the literature.</p>","PeriodicalId":11793,"journal":{"name":"Environmental Toxicology and Chemistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149106090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The toxicity of neodymium substances to soil invertebrates in a boreal soil, and the impacts of soil type, aging, and leaching on metal bioavailability and toxicity.","authors":"Patrick Boyd, Dina Schwertfeger, Heather Lemieux, Jessica Velicogna, Rick Scroggins, Juliska Princz","doi":"10.1093/etojnl/vgag156","DOIUrl":"10.1093/etojnl/vgag156","url":null,"abstract":"<p><p>A clear gap in ecotoxicological data was identified regarding the impacts of the technologically critical lanthanide neodymium (Nd) on soil invertebrates in boreal soil. To address this gap, two inorganic metal salts (NdCl3 and Nd2(SO4)3), an organometallic compound Nd-2-ethylhexanoate (Nd-2-EHA) and its organic component 2-ethylhexanoic acid (2-EHA) were examined. Toxicity exposures were conducted using the earthworm Dendrodrilus rubidus, the collembolan Proisotoma minuta, and the oribatid mite Oppia nitens, in two Canadian boreal soil horizons (i.e., organic and mineral), using standardized soil toxicity test methods; effects included survival and reproduction. Different exposure scenarios were investigated, including aging of test soil for 6 months, and the impact of leaching on toxicity test endpoints. Differences in species sensitivity were observed, with D. rubidus identified as the most sensitive test species. The study highlighted the importance of reporting chemical parameters within toxicity tests, such as electrical conductivity and pH, to better understand test system influences and factors affecting toxicity. Toxicity estimates from leached and aged NdCl3 exposures provided the least confounded assessment of Nd toxicity (reproductive median inhibitory concentration [IC50] for D. rubidus: 890 [767-950] mg Nd kg-1 dry soil), as leaching reduced salt-related effects. Incorporating measures of extractable Nd proved valuable for comparing toxicity across the substances. Despite the lowest measured extractable and total Nd, the organometallic, Nd-2-EHA, was the most toxic compound tested (reproductive IC50 for D. rubidus: 17 [10-30] mg Nd kg-1 dry soil), largely influenced by the organic component (2-EHA) when tested at equivalent concentrations. Exposure to 2-EHA and Nd-2-EHA demonstrated a significant decrease in toxicity with aging. These findings aligned with existing frameworks such that a metal-moiety approach may be insufficient for organometallics, wherein inorganic and organic influences must be considered.</p>","PeriodicalId":11793,"journal":{"name":"Environmental Toxicology and Chemistry","volume":" ","pages":"2897-2911"},"PeriodicalIF":3.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148338262","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variability in site-specific pyrethroid KOC and KDOC partition coefficients and implications for predicted aquatic toxicity.","authors":"Berkley N Anderson, Thomas M Young","doi":"10.1093/etojnl/vgag182","DOIUrl":"10.1093/etojnl/vgag182","url":null,"abstract":"<p><p>The equilibrium partitioning methodology has been used to estimate the bioavailable or freely dissolved concentrations (Cfree) of pyrethroid insecticides in both sediments and the water column of aquatic systems. Typically, single default values for the organic carbon-water (KOC) and dissolved organic carbon-water (KDOC) partition coefficients are used to estimate the bioavailability of a given pyrethroid across sample sites. However, sorption capacities can vary across samples due to the varying quality of organic carbon among other factors. In this study, KOC and KDOC coefficients were experimentally measured for 6 pyrethroids (bifenthrin, cyfluthrin, cypermethrin, esfenvalerate, lambda-cyhalothrin, and permethrin) in 19 streambed sediment samples collected across California, USA. The purpose of this study was to examine the variability of site-specific coefficients, compare site-specific with established default coefficients, and use statewide sediment/water chemistry and Hyalella azteca toxicity testing data to assess the variability in predicted pyrethroid toxic units and organism survival. Across all pyrethroids tested, measured site-specific log KOC values ranged from 5.32 to 7.11 and log KDOC values ranged from 5.28 to 7.41. Toxic units estimated using site-specific coefficients and default coefficients derived from the geometric means of measured values, explained a comparable amount of the variance in reported H. azteca survival and closely aligned with 50% organism survival. We recommend the use of the default coefficients derived from this study, which are reflective of 19 unique sediment samples. However, the uncertainties associated with site-specific considerations should be acknowledged.</p>","PeriodicalId":11793,"journal":{"name":"Environmental Toxicology and Chemistry","volume":" ","pages":"2840-2852"},"PeriodicalIF":3.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148548275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of Insecticide Exposure Duration on Heptageniid Mayflies.","authors":"D Riley Rackliffe, Jason Hoverman","doi":"10.1093/etojnl/vgag264","DOIUrl":"https://doi.org/10.1093/etojnl/vgag264","url":null,"abstract":"<p><p>Neonicotinoids like clothianidin are commonly applied in agricultural areas where they leach into aquatic systems and expose sensitive aquatic insects. While mayflies are known to be highly sensitive to clothianidin, the connection between laboratory toxicity assays and exposure dynamics in natural systems is poorly explored. We conducted low dose clothianidin exposures on the mayfly Stenacron interpunctatum to better understand how the temporal dynamics of insecticide pulses into stream systems might impact aquatic insects. We found that short duration (<24 hr) exposures to clothianidin (0.7-8.9 µg/L) failed to produce noticeable lethal or sublethal effects within 10 days after the exposure ended. With continuous exposure, we found that toxic effects began within 72 hr of exposure to our highest concentration (8.9 µg/L) while lower concentrations required longer exposures to have toxic effects. These results indicate that, given the low concentrations of neonicotinoids commonly observed in agricultural surface waters, a single typical pulse duration is unlikely to have acutely toxic effects on mayfly populations. However, repeated pulses could have additive effects resulting in greater impacts.</p>","PeriodicalId":11793,"journal":{"name":"Environmental Toxicology and Chemistry","volume":" ","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149106109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Can forensic aggregate exposure pathways support exposure evaluation in toxic torts?","authors":"Edmond Sanganyado","doi":"10.1093/etojnl/vgag178","DOIUrl":"10.1093/etojnl/vgag178","url":null,"abstract":"","PeriodicalId":11793,"journal":{"name":"Environmental Toxicology and Chemistry","volume":" ","pages":"2795-2797"},"PeriodicalIF":3.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148351042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A bioavailability model for chronic silver toxicity to the freshwater alga Raphidocelis subcapitata.","authors":"Nada Bašić, Stephen Lofts, Charlotte Nys, Gijs Du Laing, Karel A C De Schamphelaere","doi":"10.1093/etojnl/vgag154","DOIUrl":"10.1093/etojnl/vgag154","url":null,"abstract":"<p><p>Silver (Ag) is widely used across industries and in society, leading to releases into fresh waters. To implement bioavailability-based environmental quality standards, robust tools are needed to account for site-specific water chemistry. While an acute biotic ligand model (BLM) exists for Ag, a chronic model is lacking. Here, we investigated the influence of key water chemistry variables-pH, calcium, magnesium, sodium, chloride, and natural organic matter (NOM) concentration-on chronic silver toxicity to Raphidocelis subcapitata, across conditions representing 90% of European rivers, and developed a chronic bioavailability model. Two NOM sources and NOM fractions (humic and fulvic) were compared. NOM exerted the dominant protective effect on toxicity. Default Ag-NOM binding parameters in WHAM7 and default assumptions (that NOM consists of 65% active fulvic acid) could not explain NOM effects on toxicity, because computed free Ag+ activities at EC10 level were not equal across NOM concentrations. Increasing the binding strength parameters improved consistency in Ag+ activities at EC10, suggesting that default parameters underestimated Ag-NOM binding. Increasing chloride did not reduce toxicity of dissolved Ag, indicating AgCl0aq complex bioavailability, resulting in incorporation of AgCl0aq as toxicologically active in the model. Toxicity decreased with decreasing pH, and magnesium enhanced toxicity. Both effects could not be explained by classic BLM mechanisms and were incorporated empirically in the model. Model performance was evaluated against the development data set and a validation data set in which magnesium and chloride varied simultaneously. Predicted EC10s deviated up to twofold from observations, indicating good model performance. This algae model may represent a first step toward incorporating chronic bioavailability models into risk assessment frameworks for silver.</p>","PeriodicalId":11793,"journal":{"name":"Environmental Toxicology and Chemistry","volume":" ","pages":"2879-2896"},"PeriodicalIF":3.6,"publicationDate":"2026-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148250067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}