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Understanding acids and bases at interfaces is relevant for a range of applications from environmental chemistry to energy storage. We present combined ab initio and force-field molecular dynamics simulations of hydrochloric acid and sodium hydroxide highly concentrated electrolytes at the interface with air and graphene. In agreement with surface tension measurements at the air–water interface, we find that HCl presents an ionic surface excess, while NaOH displays an ionic surface depletion, for both interfaces. We further show that graphene becomes less hydrophilic as the water ions concentration increases, with a transition to being hydrophobic for highly basic solutions. For HCl, we observe that hydronium adsorbs to both interfaces and orients strongly toward the water phase, due to the hydrogen bonding behavior of hydronium ions, which donate three hydrogen bonds to bulk water molecules when adsorbed at the interface. For NaOH, we observe density peaks of strongly oriented hydroxide ions at the interface with air and graphene. To extrapolate our results from concentrated electrolytes to dilute solutions, we perform single ion-pair ab initio simulations, as well as develop force-field parameters for ions and graphene that reproduce the density profiles at high concentrations. We find the behavior of hydronium ions to be rather independent of concentration. For NaOH electrolytes, the force-field simulations of dilute NaOH solutions suggest no hydroxide adsorption but some adsorption at high concentrations. For both interfaces, we predict that the surface potential is positive for HCl and close to neutral for NaOH. [ABSTRACT FROM AUTHOR]

This study aims to optimize ammonium removal from NH4Cl‐enriched groundwater at different concentrations using an electrodialysis (ED) process. A customized design (CD) based on response surface methodology (RSM) was employed to develop predictive models and improve the performance of the demineralization system. Ion removal efficiency was evaluated in 32 unique experimental configurations, taking into account variations in three input parameters: voltage (A), initial ammonium concentration (B) and demineralization rate (C). These parameters were selected for their impact on two response variables: electric conductivity (Y1) and final ammonium concentration (Y2). An in‐depth analysis of variance (ANOVA) was performed to examine the variables and their interactions. The results indicated that Y1 was significantly influenced by C, while Y2 was influenced by B. In addition, the predictive models demonstrated strong correlations, with a coefficient of determination (R2) greater than 0.88 for both response variables. The RSM approach applied to optimize the parameters studied identified the following optimum values: 14.17 V for A, 1 mg/L for B and 70 % for C, giving Y1 of 215.377 μS/cm and Y2 of 0.279 mg/L. [ABSTRACT FROM AUTHOR]

Substituted maleimides are customisable fluorescent linkers and probes with adaptable reactivity and optical properties. Their compact nature and tunability has led to their use in various applications. For example, their solvatochromic properties offer real‐time feedback on linking chemistry and environmental changes, essential for applications in material labelling, drug delivery, and nanoparticle functionalisation. This review focusses on developing, synthesising, and modifying substituted maleimides as environment‐sensitive fluorescent linkers and probes. It delves into their photophysical dynamics and strategic applications, highlighting their significant contributions to macromolecule conjugation and the development of self‐reporting materials. [ABSTRACT FROM AUTHOR]

Cluster formation has significant implications in atmospheric science and environmental chemistry. These clusters are characterized by complex interactions between their constituents, which influence their structure, stability, and growth. Experimental investigations are difficult for the initial stages of prenucleation cluster formation, which leads to larger aerosols. To understand the formation of clusters, the interactions between sea salts (NaCl, KCl, and MgCl2), water, and sulfuric acid molecules have been investigated. Each step has been comprehensively examined and thermodynamic parameters have been computed using DLPNO‐CCSD(T)/CBS//M06‐2X/6‐311++G(3df,3pd) to find the stabilities of the molecular complexes. Among all complexes, the binding energies of cluster (SS)1(W)1(SA)3 are found to be the lowest due to the formation of HCl, hydrogen bonding, and weak van der Waal forces. Sea salts have shown a more favorable interaction with H2SO4 compared to H2O molecules. The addition of H2SO4 increases the reactivity of the cluster (SS)1(W)n, while the addition of H2O molecules reduces the reactivity of the cluster (SS)1(SA)n. However, further addition of H2SO4 or H2O to the existing cluster (SS)1(W)n(SA)n increases the free energy of formation. Furthermore, the influence of temperature was also investigated, suggesting that complex formation is slightly more favorable at lower temperatures than at higher temperatures. The negative values of thermodynamic parameters indicate, that these complexes are spontaneous and exothermic over the colder regions. [ABSTRACT FROM AUTHOR]

Surface sterilization and hazardous chemical degradation under ambient conditions can provide significant benefits for public and environmental health. Materials with sterilization and chemical degradation capacity under sunlight can efficiently reduce infectious disease incidence rates and toxic chemical exposure. Utilizing renewable energy for sustainable sterilization and degradation is more desirable as it reduces the potential secondary contamination. Herein, we report functional structure design using lignin, a renewable carbon heterogeneous polymer, to synthesize a highly efficient and stable photocatalyst that degrades environmentally hazardous organic compounds rapidly. Through a hydrolysis reaction between Ti–OH and the hydroxyl groups of lignin, Ti–O–C and Ti–O–Ti bonds were established and a lignin based photocatalyst with a hollow sphere structure (Clignin@H-TiO2) was formed. The presence of a homozygous carbon modified TiO2 structure contributes to the enhanced photodegradation activity with solar light. The close hetero-interfacial contact between carbonized lignin and TiO2 further improves the photocatalytic efficiency by facilitating effective charge carrier separation. After synthesis optimization, the resulting Clignin@H-TiO2 photocatalyst exhibits excellent performance in the degradation of atenolol under solar light irradiation with 100% degradation within five minutes. Additionally, it efficiently removes approximately 50% of PFOA and kills about 90% of bacteria within three hours. The uniform distribution of lignin within the crosslinking structures ensures a durable carbon modified TiO2 framework, which remains stable after 10 cycles of usage. The robustness of the lignin-based photocatalyst enables incorporating the catalyst into diversified material formats and various usages. Coating of the photocatalyst onto device surfaces shows bacterial killing efficacy under sunlight. The photocatalysts based on lignin valorization present a green chemistry approach for environmental remediation and surface sterilization, which has long-term environmental protection benefits, with broad applications in toxin treatment and health protection against pathogen infection. [ABSTRACT FROM AUTHOR]

Nitrate esters hold pivotal roles in pharmaceuticals, energetic materials, and atmospheric processes, motivating the development of efficient synthesis routes. Here, we present a novel catalytic method for the synthesis of nitrates via the direct O‐nitration of alcohols, addressing limitations of current traditional methods. Leveraging bench‐stable and recoverable N,6‐dinitrosaccharin reagent, our catalytic strategy employs magnesium triflate to achieve mild and selective O‐nitration of alcohols, offering broad substrate scope and unprecedentedly large functional group tolerance (e.g. alkenes, alkynes, carbonyls). DFT mechanistic studies reveal a dual role of the magnesium catalyst in the activation of both the nitrating reagent and the alcohol substrate. They also unveil a barrierless proton transfer upon formation of a widely‐accepted – yet elusive in solution – nitrooxonium ion intermediate. Overall, our work contributes to the development of mild, selective, and sustainable approaches to nitrates synthesis, with potential applications in drug discovery, materials science, and environmental chemistry. [ABSTRACT FROM AUTHOR]

Traditional approaches for monitoring aquatic pollution primarily rely on chemical analysis and the detection of pollutants in the aqueous environments. However, these methods lack realism and mechanistic insight and, thus, are increasingly supported by effect‐based methods, which offer sensitive endpoints. In this context, daphnids, a freshwater species used extensively in molecular ecotoxicology, offer fast and noninvasive approaches to assess the impact of pollutants. Among the phenotypic endpoints used, feeding rate is a highly sensitive approach because it provides evidence of physiological alterations even in sublethal concentrations. However, there has been no standardized method for measuring feeding rate in daphnids, and several approaches follow different protocols. There is a diversity among tests employing large volumes, extensive incubation times, and high animal densities, which in turn utilize measurements of algae via fluorescence, radiolabeling, or counting ingested cells. These tests are challenging and laborious and sometimes require cumbersome instrumentation. In the present study, we optimized the conditions of a miniaturized fast, sensitive, and high‐throughput assay to assess the feeding rate based on the ingestion of fluorescent microparticles. The protocol was optimized in neonates in relation to the concentration of microplastic and the number of animals to increase reproducibility. Daphnids, following exposures to nonlethal concentrations, were incubated with microplastics; and, as filter feeders, they ingest microparticles. The new approach revealed differences in the physiology of daphnids in concentrations below the toxicity limits for a range of pollutants of different modes of action, thus proving feeding to be a more sensitive and noninvasive endpoint in pollution assessment. Environ Toxicol Chem 2024;43:2211–2221. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Bromine chemistry is responsible for the catalytic ozone destruction in the atmosphere. The heterogeneous reactions of sea‐salt aerosols are the main abiotic sources of reactive bromine in the atmosphere. Here, we present a novel mechanism for the activation of bromide ions (Br−) by O2 and H2O in the absence of additional oxidants. The laboratory and theoretical calculation results demonstrated that under dark conditions, Br−, O2 and H3O+ could spontaneously generate Br and HO2 radicals through a proton–electron transfer process at the air–water interface and in the liquid phase. Our results also showed that light and acidity could significantly promote the activation of Br− and the production of Br2. The estimated gaseous Br2 production rate was up to 1.55×1010 molecules cm−2 ⋅ s−1 under light and acidic conditions; these results showed a significant contribution to the atmospheric reactive bromine budget. The reactive oxygen species (ROS) generated during Br− activation could promote the multiphase oxidation of SO2 to produce sulfuric acid, while the increase in acidity had a positive feedback effect on Br− activation. Our findings highlight the crucial role of the proton‐electron transfer process in Br2 production; here, H3O+ facilitates the activation of Br− by O2, serves as a significant source of atmospheric reactive bromine and exerts a profound impact on the atmospheric oxidation capacity. [ABSTRACT FROM AUTHOR]

The enforcement of a global hydrofluorocarbon (HFC) refrigerant phase down led to the introduction of hydrofluoroolefins (HFOs) as a low Global Warming Potential (GWP) substitute, given their low atmospheric lifetime. However, to this date it is not fully clear the long‐term atmospheric fate of HFOs primary degradation products: trifluoro acetaldehyde (TFE), trifluoro acetyl fluoride (TFF), and trifluoroacetic acid (TFA). It particularly concerns the possibility of forming HFC‐23, a potent global warming agent. Although the atmospheric reaction networks of TFE, TFF, and TFA have a fair level of complexity, the relevant atmospheric chemical pathways are well characterized in the literature, enabling a comprehensive hazard assessment of HFC‐23 formation as a secondary HFO breakdown product in diverse scenarios. A lower bound of the HFOs effective GWP in a baseline scenario is found above regulatory thresholds. While further research is crucial to refine climate risk assessments, the existing evidence suggests a non‐negligible climate hazard associated with HFOs. [ABSTRACT FROM AUTHOR]

Variation in environmental chemistry affects animal health and demographics. For instance, acidification of aquatic ecosystems (e.g., due to acid rain) can have consequences for organismal fitness. Elevated atmospheric concentrations of CO2, which reacts with water to produce carbonic acid, may affect aquatic animal physiology in multiple ways, including via reductions in pH. Such impacts have been assessed to a large extent in marine systems. Similar effects are also likely occurring in freshwater ecosystems but are relatively understudied. The goal of this project was to determine how changes in pH and CO2 concentrations influence traits and survival of animals in freshwater systems, using larval American Bullfrogs (Lithobates catesbeianus (also known as Rana catesbeiana) [Shaw, 1802]) as a model. We hypothesized that elevated CO2 concentrations and reduced pH negatively affect larval frog immune function, growth, and survival, which we tested in a laboratory aquarium experiment. Over the 27-d experiment, tadpoles were exposed to 4 treatments: 1) near-neutral pH and no gas addition (mean ± SE pH = 7.17 ± 0.05), 2) CO2 gas sparged into aquariums (pH = 5.32 ± 0.04), 3) acidified water without gas addition (pH = 6.29 ± 0.08), and 4) ambient air sparged into aquariums (control for effects of gas addition) at near-neutral pH (pH = 7.46 ± 0.03). We measured tadpole innate immune response, growth, and survival. Results from the experiment partially supported our hypothesis, with lower immune function in tadpoles exposed to acidified water or elevated CO2 compared with the control treatments and lower final mass and survival under elevated CO2. These findings motivate additional research on pH and CO2 effects on freshwater animals and suggest that increased environmental acidity and elevated CO2 can lead to negative impacts, which could contribute to reductions in wildlife health and population declines in light of ongoing environmental changes. [ABSTRACT FROM AUTHOR]

Data from prior research indicate the prepupal stage of the monarch butterfly life cycle is more sensitive to clothianidin exposure than the larval stage. A set of experiments was conducted to determine if the dietary clothianidin exposures that cause prepupal mortality are environmentally relevant. Monarch larvae were raised from egg to pupae on clothianidin‐contaminated swamp milkweed plants (Asclepias incarnata). Larval growth as well as larval and prepupal survival were monitored throughout the experiments, in which the exposures ranged from 1.4 to 2793.1 ng/g leaf. Exposures of 5.4 to 46.9 ng/g leaf resulted primarily in prepupal mortality, whereas higher exposures of 1042.4 to 2793.1 ng/g leaf resulted exclusively in larval mortality, indicating the prepupal stage is more sensitive to clothianidin exposure than the larval stage. A median lethal concentration and a 10% lethal concentration of 37 and 6 ng/g leaf, respectively, were estimated for prepupal mortality. Both effect concentrations are within the range of clothianidin concentrations reported in leaves collected from wild milkweed plants, indicating prepupal mortality is an environmentally relevant effect. Environ Toxicol Chem 2024;43:2039–2044. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Benzotriazole ultraviolet stabilizers (BUVSs) are a group of widely used chemicals added to a variety of consumer (e.g., plastics) and industrial (e.g., metal coating) goods. Although detected globally as an environmentally persistent pollutant, BUVSs have received relatively little toxicological attention and only recently have been acknowledged to affect development and the endocrine system in vivo. In our previous study, altered behavior, indicative of potential neurotoxicity, was observed among rainbow trout alevins (day 14 posthatching) that were microinjected as embryos with a single environmentally relevant dose of 2,4‐di‐tert‐butyl–6‐(5‐chloro‐2H‐benzotriazol‐2‐yl) phenol (UV‐327). In the present follow‐up study, we performed whole‐transcriptome profiling (RNA sequencing) of newly hatched alevins from the same batch. The primary aim was to identify biomarkers related to behavior and neurology. Dose‐specifically, 1 to 176 differentially expressed genes (DEGs) were identified. In the group presenting altered behavior (273.4 ng g−1), 176 DEGs were identified, yet only a fraction was related to neurological functions, including water, calcium, and potassium homeostasis; acetylcholine transmission and signaling; as well insulin and energy metabolism. The second objective was to estimate the transcriptomic point of departure (tPOD) and assess if point estimate(s) are protective of altered behavior. A tPOD was established at 35 to 94 ng UV‐327 g−1 egg, making this tPOD protective of behavioral alterations. Holistically, these transcriptomic alterations provide a foundation for future research on how BUVSs can influence rainbow trout alevin development, while providing support to the hypothesis that UV‐327 can influence neurogenesis and subsequent behavioral endpoints. The exact structural and functional changes caused by embryonic exposure to UV‐327 remain enigmatic and will require extensive investigation before being deciphered and understood toxicologically. Environ Toxicol Chem 2024;43:2026–2038. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Harmful algal blooms (HABs) are a persistent and increasing problem globally, yet we still have limited knowledge about how they affect wildlife. Although semi‐aquatic and aquatic amphibians and reptiles have experienced large declines and occupy environments where HABs are increasingly problematic, their vulnerability to HABs remains unclear. To inform monitoring, management, and future research, we conducted a literature review, synthesized the studies, and report on the mortality events describing effects of cyanotoxins from HABs on freshwater herpetofauna. Our review identified 37 unique studies and 71 endpoints (no‐observed‐effect and lowest‐observed‐effect concentrations) involving 11 amphibian and 3 reptile species worldwide. Responses varied widely among studies, species, and exposure concentrations used in experiments. Concentrations causing lethal and sublethal effects in laboratory experiments were generally 1 to 100 µg/L, which contains the mean value of reported HAB events but is 70 times less than the maximum cyanotoxin concentrations reported in the environment. However, one species of amphibian was tolerant to concentrations of 10,000 µg/L, demonstrating potentially immense differences in sensitivities. Most studies focused on microcystin‐LR (MC‐LR), which can increase systemic inflammation and harm the digestive system, reproductive organs, liver, kidneys, and development. The few studies on other cyanotoxins illustrated that effects resembled those of MC‐LR at similar concentrations, but more research is needed to describe effects of other cyanotoxins and mixtures of cyanotoxins that commonly occur in the environment. All experimental studies were on larval and adult amphibians; there were no such studies on reptiles. Experimental work with reptiles and adult amphibians is needed to clarify thresholds of tolerance. Only nine mortality events were reported, mostly for reptiles. Given that amphibians likely decay faster than reptiles, which have tissues that resist decomposition, mass amphibian mortality events from HABs have likely been under‐reported. We propose that future efforts should be focused on seven major areas, to enhance our understanding of effects and monitoring of HABs on herpetofauna that fill important roles in freshwater and terrestrial environments. Environ Toxicol Chem 2024;43:1936–1949. Published 2024. This article is a U.S. Government work and is in the public domain in the USA. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Tire and road wear particles (TRWP) contain complex mixtures of chemicals and release them to the environment, and potential toxic effects of these chemicals still need to be characterized. We used a standardized surrogate for TRWP, cryogenically milled tire tread (CMTT), to isolate and evaluate effects of tire‐associated chemicals. We examined organic chemical mixtures extracted and leached from CMTT for the toxicity endpoints genotoxicity, estrogenicity, and inhibition of bacterial luminescence. The bioassays were performed after chromatographic separation on high‐performance thin‐layer chromatography (HPTLC) plates. Extracts of CMTT were active in all three HPTLC bioassays with two estrogenic zones, two genotoxic zones, and two zones inhibiting bacterial luminescence. Extracts of CMTT artificially aged with thermooxidation were equally bioactive in each HPTLC bioassay. Two types of aqueous leachates of unaged CMTT, simulating either digestion by fish or contact with sediment and water, contained estrogenic chemicals and inhibitors of bacterial luminescence with similar profiles to those of CMTT extracts. Of 11 tested tire‐associated chemicals, two were estrogenic, three were genotoxic, and several inhibited bacterial luminescence. 1,3‐Diphenylguanidine, transformation products of N‐(1,3‐dimethylbutyl)‐N′‐phenyl‐p‐phenylenediamine, and benzothiazoles were especially implicated through comparison to HPTLC retention factors in the CMTT samples. Other bioactive bands in CMTT samples did not correspond to any target chemicals. Tire particles clearly contain and can leach complex mixtures of toxic chemicals to the environment. Although some known chemicals contribute to estrogenic, genotoxic, and antibacterial hazards, unidentified toxic chemicals are still present and deserve further investigation. Overall, our study expands the understanding of potential adverse effects from tire particles and helps improve the link between those effects and the responsible chemicals. Environ Toxicol Chem 2024;43:1962–1972. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

The toxicity of neonicotinoids and many of their replacement insecticides to nontarget soil invertebrates such as earthworms has previously been established. However, the long‐term effects of these substances on these organisms are largely unknown. In the field of soil ecotoxicology, lumbricid earthworms such as Eisenia andrei are used extensively due to the availability of standardized test methods and their adaptability to laboratory culture and testing. Multigenerational studies have gained popularity and attention in recent years, with a shift toward the use of long‐term assays and lower concentrations of test chemicals. The use of exposure concentrations that include those measured in a monitoring program carried out by the Government of Ontario presents a realistic exposure scenario that may not show significant effects in contemporary, shorter term studies. We used current standardized test methods as a basis for the development of multigenerational studies on E. andrei. The effects of exposure to a single application of the insecticides thiamethoxam and cyantraniliprole on the survival and reproduction of E. andrei were observed over three (thiamethoxam) or two (cyantraniliprole) generations using consecutive reproduction tests. No significant impacts on adult survival were reported in any generation for either insecticide, whereas reproduction decreased between the first and second generations in the thiamethoxam test, with median effective concentration (EC50) values of 0.022 mg/kg dry weight reported for the first generation compared with 0.002 mg/kg dry weight in the second generation. For cyantraniliprole, an EC50 of 0.064 was determined for the first generation compared with 0.016 mg/kg dry weight in the second generation. A third generation was completed for the thiamethoxam test, and a significant decrease in reproduction was observed in all treatments and controls compared with previous generations. No significant difference between thiamethoxam treatments and the control treatment was reported for the third generation. Collectively, these data indicate that exposure of oligochaetes to these two insecticides at concentrations representative of field conditions may result in long‐term stresses. Environ Toxicol Chem 2024;43:2058–2070. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Energy content, moisture content, and energy assimilation efficiency are essential parameters in the food intake rate (FIR) and exposure calculations for bird and mammal risk assessments. The updated European Food Safety Authority guidance document on risk assessment for birds and mammals summarizes these parameters for different food items. For seed treatments, values for cereal seeds are proposed as surrogates for other crops. Oil‐containing seeds are expected to have a higher energy content than cereal seeds. This would result in lower FIR and, thus, exposure from consuming such seeds. To be able to calculate reliable exposure values for risk‐assessment purposes, we conducted a systematic literature review to collect information on these three parameters for oil‐containing seeds (sunflower, oilseed rape, soybean, peanut, sesame, safflower, linseed [flax], white mustard, and castor bean). The search yielded 401 papers, of which 151 contained values for at least one of the parameters of the crops in focus. The overall average energy content value of oil‐containing seeds was 24.25 kJ/g (n = 124, SD = 3.00), whereas that for moisture content was 6.57% (n = 296, SD = 1.15). Energy assimilation values were only available for peanut, oilseed rape, soy, linseed, and sunflower for a limited number of bird and mammal species. Mean energy assimilation efficiency for mammals was 82.69% (n = 4, SD = 1.55), whereas values for birds were 57.54% (n = 2, SD = 6.77) for Galliformes and 79.25% (n = 2, SD = 1.82) for Passeriformes. The values presented can be used to calculate appropriate FIR values for future bird and mammal risk assessments. Environ Toxicol Chem 2024;43:2080–2085. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Microplastics in the aquatic environment are susceptible to colonization by surrounding microorganisms, which form biofilms over the microplastic's surface. These biofilm‐laden microplastics can then interact with a diverse array of contaminants. In the present study, biofilms were grown on microplastics in a laboratory setting using Pseudomonas aeruginosa as a model biofilm‐forming bacterium for periods of 5 to 15 days. The sorption of three organic compounds representing different levels of hydrophobicity, namely methylene blue (MB), phenanthrol, and phenanthrene, was used to evaluate the effect of biofilm biomass on the adsorption of organic contaminants to microplastics. The sorption of MB and phenanthrol was found to increase with biofouling time, indicating affinity between these contaminants and the biofilm biomass on the particle. However, the presence of a biofilm did not influence the sorption of phenanthrene on the microplastics. These results suggest that the hydrophobicity of organic contaminants plays a major role in how biofouling of microplastics will influence contaminant sorption by microplastics. For some contaminants, biofilm can enhance the role of microplastics as contaminant vectors. These findings emphasize the need to understand the biomass load on environmental microplastics and the contaminants that associate with it for an accurate representation of the risk associated with microplastics in the environment. Environ Toxicol Chem 2024;43:1973–1981. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Extracellular electron transfer (EET) by sulfate-reducing bacteria (SRB), such as Desulfovibrio ferrophilus IS5, enables bacterial interactions with minerals, which are vital for biogeochemical cycling and environmental chemistry. Here, we explore the direct EET mechanisms through outer-membrane cytochromes (OMCs) using IS5 as a model SRB. We employed nanostructured electrodes arrayed with 0, 50, 200, and 500 nm long nanowires (NWs) coated with indium–tin–doped oxide to examine the impact of electrode morphology on the direct EET efficacy. Compared to flat electrodes, NW electrodes significantly enhanced current production in IS5 with OMCs. However, this enhancement was diminished when OMC expression was reduced. Differential pulse voltammetry revealed that NW electrodes specifically augmented redox peaks associated with OMCs without affecting those related to redox mediators, suggesting that NWs foster direct EET through OMCs. Scanning electron microscopy observations following electrochemical analyses revealed a novel vertical cell attachment and aggregation on NW electrodes, contrasting with the horizontal monolayer cell attachment on flat electrodes. This study presents the first evidence of the critical role of electrode nanoscale topography in modulating SRB cell orientation and aggregation behavior. The findings underscore the significant influence of electrode morphology on the direct EET kinetics, highlighting the potential impact of mineral morphology on mineral reduction and biogeochemical processes. [ABSTRACT FROM AUTHOR]

High school chemistry teachers typically share a passion to engage students with hands-on practical experiences. However, teachers worldwide face similar challenges of lack of time and resources for laboratory activities. National standards and traditions can also constrain and dictate the level and content of school chemistry practical experiences. In recent years, some national curricula have included a growing focus on the relevance of chemistry to sustainability and environmental issues. Until now, little has been known about what practical activities teachers actually do with their students, and whether practical activities concerning green and sustainable chemistry are being implemented in schools. In this project, we aimed to determine a baseline of teacher perspectives – how often they run practical activities with their students, what factors are important when choosing a practical activity, what barriers they face in running practical activities, and whether their activities relate to sustainability. This was approached through a major international survey of in-service high school chemistry teachers conducted in over 35 local languages in over 60 countries. Here, we present the initial stages of the project: design of the survey, recruitment of country coordinators, translation, and the implementation process. [ABSTRACT FROM AUTHOR]

In recent years, the presence of Pharmaceutical Active Compounds (PhACs) in ecosystems has become a serious environmental problem due to their capacity to induce harmful effects at extremely low concentrations in both humans and wildlife. Water treatment plants have not been designed to remove these types of compounds efficiently. Thus, the detection of these pollutants is essential to evaluate their negative impacts and is one of the emerging issues in environmental chemistry. The main objective of this study is to determine the bacterial toxicity of two PhACs (both individually and as a mixture) through the quantification of bioluminescence inhibition in the marine bacteria Aliivibrio fischeri, a commonly used method in short-term toxicity tests. In this work, Acetaminophen and Edaravone, two drugs approved by the Food and Drug Administration, have been studied. The acute toxicity of these PhACs has been tested at two exposure times (5 and 15 min) and different concentrations, by estimation of the median effective concentration (EC50) for each individual compound or in combination at different concentrations. Moreover, the EC50 of the binary mixtures Acetaminophen/Edaravone have been forecast using two traditional predictive models, Concentration Addition and Independent Action. The results show that toxicity decreases with exposure time and depends on the concentration tested. Furthermore, a novel semi-empirical Van Laar-based model has been proposed and validated with the experimental data from this study and literature data, obtaining satisfactory estimations of the EC50 for binary mixtures. Highlights: The bacterial toxicity of Acetaminophen and Edaravone, as well as their binary mixtures, was evaluated using an Aliivibrio fischeri bioluminescence assay. The predictive power of Concentration Addition and Independent Action models was evaluated for combined bacterial toxicity of PhACs. A new semi-empirical Van Laar-based model was developed and validated to predict the bacterial toxicity of binary mixtures of Acetaminophen and Edaravone, providing accurate estimations with limited experimentation. [ABSTRACT FROM AUTHOR]

Rationale: The sources and chemical compositions of organic aerosol (OA) exert a significant influence on both regional and global atmospheric conditions, thereby having far‐reaching implications on environmental chemistry. However, existing mass spectrometry (MS) methods have limitations in characterizing the detailed composition of OA due to selective ionization as well as fractionation during cold‐water extraction and solid‐phase extraction (SPE). Methods: A comprehensive MS study was conducted using aerosol samples collected on dusty, clean, and polluted days. To supplement the data obtained from electrospray ionization (ESI), a strategy for analyzing OAs collected using the quartz fiber filter directly utilizing laser desorption ionization (LDI) was employed. Additionally, the ESI method was conducted to explore suitable approaches for determining various OA compositions from samples collected on dusty, clean, and polluted days. Results: In situ LDI has the advantages of significantly reducing the sample volume, simplifying sample preparation, and overcoming the problem of overestimating sulfur‐containing compounds usually encountered in ESI. It is suitable for the characterization of highly unsaturated and hydrophobic aerosols, such as brown carbon‐type compounds with low volatility and high stability, which is supplementary to ESI. Conclusions: Compared with other ionization methods, in situ LDI helps provide a complementary description of the molecular compositions of OAs, especially for analyzing OAs in polluted day samples. This method may contribute to a more comprehensive MS analysis of the elusive compositions and sources of OA in the atmosphere. [ABSTRACT FROM AUTHOR]

One of the critical principles of green chemistry and environmental sustainability is to avoid using harmful solvents in chemical processes. In this study, a novel solvent‐free method was employed to prepare poly (vinylidene fluoride) (PVDF) hollow fiber composite membranes with stable crystalline and porous structures. Utilizing the cold‐hot stretching method, the crystalline structure and orientation of PVDF were effectively redesigned, resulting in improved mechanical and penetration properties of the membrane. Additionally, an investigation into the internal crystalline structure of the PVDF hollow fiber membrane was conducted, focusing on crystalline changes induced by ion‐dipole interactions. Results indicated that the addition of neutral ion‐dipole functional particles (N‐P) promoted the conversion of α crystalline to β crystalline, leading to stable β crystalline and controllable pore sizes in the prepared PVDF hollow fiber membrane. Furthermore, the internal crystalline structure significantly contributed to enhancing the membrane's mechanical properties and penetration performance. Notably, a PVDF hollow fiber with high β crystalline content was achieved through 150% cold‐hot stretching and the addition of 20. wt% N‐P further enhanced the β‐crystalline content in the membrane. This study presents a promising approach for reducing solvent consumption and minimizing environmental impact in the field of environment‐friendly membrane fabrication. [ABSTRACT FROM AUTHOR]

Converting spent lithium‐ion batteries (LIBs) cathode materials into environmental catalysts has drawn more and more attention. Herein, we fabricated a Co3O4‐based catalyst from spent LiCoO2 LIBs (Co3O4‐LIBs) and found that the role of Al and Cu from current collectors on its performance is nonnegligible. The density functional theory calculations confirmed that the doping of Al and/or Cu upshifts the d‐band center of Co. A Fenton‐like reaction based on peroxymonosulfate (PMS) activation was adopted to evaluate its activity. Interestingly, Al doping strengthened chemisorption for PMS (from −2.615 eV to −2.623 eV) and shortened Co−O bond length (from 2.540 Å to 2.344 Å) between them, whereas Cu doping reduced interfacial charge‐transfer resistance (from 28.347 kΩ to 6.689 kΩ) excepting for the enhancement of the above characteristics. As expected, the degradation activity toward bisphenol A of Co3O4‐LIBs (0.523 min−1) was superior to that of Co3O4 prepared from commercial CoC2O4 (0.287 min−1). Simultaneously, the reasons for improved activity were further verified by comparing activity with catalysts doped Al and/or Cu into Co3O4. This work reveals the role of elements from current collectors on the performance of functional materials from spent LIBs, which is beneficial to the sustainable utilization of spent LIBs. [ABSTRACT FROM AUTHOR]

Though bioaccumulation of pharmaceuticals by aquatic organisms continues to receive scientific attention, the internal disposition of these contaminants among different tissue compartments of fish species has been infrequently investigated, particularly among fish at different trophic positions. We tested a human to fish biological read‐across hypothesis for contaminant disposition by examining tissue‐specific accumulation in three understudied species, longnose gar (Lepisosteus osseus; piscivore), gizzard shad (Dorosoma cepedianum; planktivore/detritivore), and smallmouth buffalo (Ictiobus bubalus; benthivore), from a river influenced by municipal effluent discharge. In addition to surface water, fish plasma, and brain, gill, gonad, liver, and lateral muscle fillet tissues were analyzed via isotope dilution liquid chromatography tandem mass spectrometry. Caffeine and sucralose, two common effluent tracers, were quantitated at low micrograms per liter levels in surface water, while an anticonvulsant, carbamazepine, was observed at levels up to 37 ng/L. The selective serotonin reuptake inhibitors (SSRIs) fluoxetine and sertraline and primary metabolites were detected in at least one tissue of all three species at low micrograms per kilogram concentrations. Within each species, brain and liver of select fish contained the highest levels of SSRIs compared to plasma and other tissues, which is generally consistent with human tissue disposition patterns. However, we observed differential accumulation among specific tissue types and species. For example, mean levels of sertraline in brain and liver tissues were 13.4 µg/kg and 1.5 µg/kg in gizzard shad and 1.3 µg/kg and 7.3 µg/kg in longnose gar, respectively. In contrast, smallmouth buffalo did not consistently accumulate SSRIs to detectable levels. Tissue‐specific eco‐exposome efforts are necessary to understand mechanisms associated with such marked bioaccumulation and internal dispositional differences among freshwater fish species occupying different trophic positions. Environ Toxicol Chem 2024;43:1894–1902. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

A subgroup of endocrine‐disrupting chemicals have the ability to disrupt metabolism. These metabolism‐disrupting chemicals (MDCs) can end up in aquatic environments and lead to adverse outcomes in fish. Although molecular and physiological effects of MDCs have been studied in adult fish, few studies have investigated the consequences of metabolic disruption in fish during the earliest life stages. To investigate the processes affected by metabolic disruption, zebrafish embryos were exposed to peroxisome proliferator–activated receptor gamma (PPARγ) agonist rosiglitazone, the PPARγ antagonist T0070907, and the well‐known environmentally relevant MDC bisphenol A. Decreased apolipoprotein Ea transcript levels indicated disrupted lipid transport, which was likely related to the observed dose‐dependent increases in yolk size across all compounds. Increased yolk size and decreased swimming activity indicate decreased energy usage, which could lead to adverse outcomes because the availability of energy reserves is essential for embryo survival and growth. Exposure to T0070907 resulted in a darkened yolk. This was likely related to reduced transcript levels of genes involved in lipid transport and fatty acid oxidation, a combination of responses that was specific to exposure to this compound, possibly leading to lipid accumulation and cell death in the yolk. Paraoxonase 1 (Pon1) transcript levels were increased by rosiglitazone and T0070907, but this was not reflected in PON1 enzyme activities. The present study shows how exposure to MDCs can influence biochemical and molecular processes involved in early lipid metabolism and may lead to adverse outcomes in the earliest life stages of fish. Environ Toxicol Chem 2024;43:1880–1893. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Exposure to per‐ and polyfluoroalkyl substances (PFAS) has been associated with toxicity in wildlife and negative health effects in humans. Decades of fire training activity at Joint Base Cape Cod (MA, USA) incorporated the use of aqueous film‐forming foam (AFFF), which resulted in long‐term PFAS contamination of sediments, groundwater, and hydrologically connected surface waters. To explore the bioconcentration potential of PFAS in complex environmental mixtures, a mobile laboratory was established to evaluate the bioconcentration of PFAS from AFFF‐impacted groundwater by flow‐through design. Fathead minnows (n = 24) were exposed to PFAS in groundwater over a 21‐day period and tissue‐specific PFAS burdens in liver, kidney, and gonad were derived at three different time points. The ∑PFAS concentrations in groundwater increased from approximately 10,000 ng/L at day 1 to 36,000 ng/L at day 21. The relative abundance of PFAS in liver, kidney, and gonad shifted temporally from majority perfluoroalkyl sulfonamides (FASAs) to perfluoroalkyl sulfonates (PFSAs). By day 21, mean ∑PFAS concentrations in tissues displayed a predominance in the order of liver > kidney > gonad. Generally, bioconcentration factors (BCFs) for FASAs, perfluoroalkyl carboxylates (PFCAs), and fluorotelomer sulfonates (FTS) increased with degree of fluorinated carbon chain length, but this was not evident for PFSAs. Perfluorooctane sulfonamide (FOSA) displayed the highest mean BCF (8700 L/kg) in day 21 kidney. Suspect screening results revealed the presence of several perfluoroalkyl sulfinate and FASA compounds present in groundwater and in liver for which pseudo‐bioconcentration factors are also reported. The bioconcentration observed for precursor compounds and PFSA derivatives detected suggests alternative pathways for terminal PFAS exposure in aquatic wildlife and humans. Environ Toxicol Chem 2024;43:1795–1806. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

The on‐going anthropogenic degradation of freshwater habitats has drastically altered the environmental supply of both nutrients and common pollutants. Most organisms living in these altered habitats experience interactive effects of various stressors that can initiate adjustments at multiple levels impacting their fitness. Hence, studies measuring response to a single environmental parameter fail to capture the complexities of the status quo. We tested both the individual and the interactive effect of arsenic (As) exposure, food quantity, and dietary phosphorus (P)‐supply on six life‐history traits (Juvenile Growth Rate; Adult Growth Rate; Age and Size at Maturity, Lifespan, and Fecundity) as surrogates for organismal fitness in the keystone aquatic grazer Daphnia pulex. We also tested the effect of food quantity and P‐supply on somatic As accumulation in Daphnia. Our results indicated an influence of P‐supply on neonatal growth and an influence of As and food quantity on growth and maintenance later in life. Maturation was strongly influenced by all three variables, with no reproduction observed in the presence of two or more environmental stressors. We found a strong interaction between As and dietary P, with increased P‐supply intensifing the toxicity effect of As. No such effects were seen between As and food quantity, indicating a differential role of quantity versus quality on As toxicity. We found a nominal effect of diet on somatic As accumulation. The results from the present study emphasize the importance of considering such interactions between co‐occurring environmental stressors and the dietary status of organisms, to better predict and manage impacts and risks associated with common environmental toxicants in highly vulnerable ecosystems. Environ Toxicol Chem 2024;43:1807–1819. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Neonicotinoids are insecticides used worldwide in phytosanitary and biocidal products and veterinary pharmaceuticals. Recently, some restrictions and bans have been imposed due to their adverse effects on nontarget invertebrates, including pollinators. Although they may have direct and indirect effects on wild vertebrates, few studies have assessed exposure to these compounds in wild birds, so our knowledge remains limited. In the present pilot study we have assessed the prevalence of seven neonicotinoid insecticides and some of their metabolites in whole blood samples from 19 European roller (Coracias garrulus) nestlings and five adult common kestrels (Falco tinnunculus) in an area treated with neonicotinoids to control the palm weevil (Rynchophorus ferrugineus) in southeastern Spain. One European roller nestling born in a palm tree was positive for thiamethoxam, with a concentration of 2.26 ng mL−1, but no residues of neonicotinoids or their metabolites were found in adult common kestrels. Future studies are needed to elucidate potential exposure to neonicotinoids at different times of the year. To our knowledge, this is the first report of the presence of thiamethoxam residues in whole blood of a wild bird species after its ban in Spain. Environ Toxicol Chem 2024;43:1836–1843. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Pharmaceuticals have been classified as an environmental concern due to their increasing consumption globally and potential environmental impact. We examined the toxicity of sediment‐associated diclofenac and citalopram administered as both single compounds and in a mixture to the sediment‐living amphipod Corophium volutator. This laboratory‐based study addressed the following research questions: (1) What is the toxicity of sediment‐associated diclofenac and citalopram to C. volutator? (2) Can the mixture effect be described with either of the two mixture models: concentration addition (CA) or independent action (IA)? (3) What is the importance of the choice of (i) exposure measure (start concentration, time‐weighted average [TWA], full exposure profile) and (ii) effect model (concentration–response vs. the toxicokinetic–toxicodynamic model general unified threshold model for survival in its reduced form [GUTS‐RED]) for the derived effect concentration values? Diclofenac was more toxic than citalopram to C. volutator as a single compound (10‐day exposure). Diclofenac exposure to C. volutator provided median lethal concentrations (LC50s) within the same range (11 µg g−1 dry wt sediment) using concentration–response based on TWA and both GUTS‐RED models. However, concentration–response based on measured start concentrations provided an approximately 90% higher LC50 (21.6 ± 2.0 µg g−1 dry wt sediment). For citalopram, concentration–response parameters were similar regardless of model or concentration used (LC50 85–97 µg g−1 dry wt sediment), however, GUTS‐RED with the assumption of individual tolerance resulted in a lower LC50 (64.9 [55.3–74.8] µg g−1 dry wt sediment). The mixture of diclofenac and citalopram followed the CA quite closely, whereas the result was synergistic when using the IA prediction. In summary, concentration–response based on TWA and GUTS‐RED provided similar and reasonably good fits compared to the data set. The implications are that GUTS‐RED will provide a more flexible model, which, in principle, can extend beyond the experimental period and make predictions based on variable exposure profiles (toxicity at different time frames and at different variable exposure scenarios) compared to concentration–response, which provides contaminant toxicity at one point in time. Environ Toxicol Chem 2024;43:1767–1777. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Sediments are an integral component of aquatic systems, linking multiple water uses, functions, and services. Contamination of sediments by chemicals is a worldwide problem, with many jurisdictions trying to prevent future pollution (prospective) and manage existing contamination (retrospective). The present review assesses the implementation of sediment toxicity testing in environmental regulations globally. Currently, the incorporation of sediment toxicity testing in regulations is most common in the European Union (EU), North America, and Australasian regions, with some expansion in Asia and non‐EU Europe. Employing sediment toxicity testing in prospective assessments (i.e., before chemicals are allowed on the market) is most advanced and harmonized with pesticides. In the retrospective assessment of environmental risks (i.e., chemicals already contaminating sediments), regulatory sediment toxicity testing practices are applied inconsistently on the global scale. International harmonization of sediment toxicity tests is considered an asset and has been successful through the widespread adoption and deployment of Organisation for Economic Co‐operation and Development guidelines. On the other hand, retrospective sediment assessments benefit from incorporating regional species and protocols. Currently used toxicity testing species are diverse, with temperate species being applied most often, whereas test protocols are insufficiently flexible to appropriately address the range of environmental contaminants, including nanomaterials, highly hydrophobic contaminants, and ionized chemicals. The ever‐increasing and ‐changing pressures placed on aquatic resources are a challenge for protection and management efforts, calling for continuous sediment toxicity test method improvement to insure effective use in regulatory frameworks. Future developments should focus on including more subtle and specific toxicity endpoints (e.g., incorporating bioavailability‐based in vitro tests) and genomic techniques, extending sediment toxicity testing from single to multispecies approaches, and providing a better link with ecological protection goals. Environ Toxicol Chem 2024;43:1697–1716. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Sediment toxicity tests have applications in ecological risk and chemical safety assessments. Despite the many years of experience in testing and the availability of standard protocols, sediment toxicity testing remains challenging with very hydrophobic organic chemicals (VHOCs; i.e., chemicals with a log octanol/water partition coefficient of more than 6). The challenges primarily relate to the chemicals' low aqueous solubilities and slow kinetics, due to which several experimental artifacts may occur. To investigate the potential artifacts, experiments were performed, focusing on spiking and equilibrating (aging) sediments, as well as exposure quantification with passive sampling. The results demonstrated that generally applied, Organisation for Economic Co‐operation and Development–recommended spiking (coating) methods may lead to significant chemical losses and the formation of nondissolved, nonbioavailable VHOCs. Direct spiking appeared to be the most optimal, provided that intensive mixing was applied simultaneously. Passive dosing was tested as a novel way of spiking liquid VHOCs, but the approach proved unsuccessful. Intensive postspiking mixing during sediment equilibration for 1 to 2 weeks was shown to be essential for producing a homogeneous system, minimizing the presence of nondissolved chemical (crystals or nonaqueous phase liquids; NAPLs), and creating a stable toxicological response in subsequent toxicity tests. Finally, exposure quantification of VHOCs in sediments through passive sampling was found to be feasible with different polymers, although prolonged equilibration times may be required, and determining sampler/water partition coefficients can be extremely challenging. The results of additional experiments, focusing on toxicity test exposure duration, concentrations above which NAPLs will occur, and ways to distinguish actual toxicity from false‐positive results, are presented in Part 2 of this publication series. Environ Toxicol Chem 2024;43:1717–1727. © 2024 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Sediment toxicity testing with very hydrophobic organic chemicals (VHOCs) is challenging because of the chemicals' low aqueous solubilities and slow kinetics. The present study presents the results of experiments investigating whether the standard exposure duration of 28 days with benthic invertebrates is sufficient for VHOCs; above which concentrations in sediment VHOCs are present as "free phase," that is, crystals or non‐aqueous‐phase liquids (NAPLs); and whether it is possible to discriminate between actual VHOC toxicity and physical effects caused by NAPLs through fouling of the test organisms. The results suggest that the standard sediment toxicity test duration is sufficient for obtaining steady‐state VHOC concentrations in Hyalella azteca and Lumbriculus variegatus, provided that spiking and equilibration are performed properly (i.e., no free phase present). Under these conditions, transient (days 3–20) peak‐shaped toxicokinetics were observed, with steady‐state concentrations reached at approximately 28 days. The concentration above which NAPLs are present, the so‐called critical separate phase concentration (CSPC), was determined for several VHOCs by modeling and two experimental methods. Modeling resulted in unrealistic and variable data and therefore should be applied with caution. Experimentally determining CSPCs was successful and yielded values of approximately 1000 (400–2000) mg/kg dry weight, depending on the chemical. Finally, it was demonstrated that distinguishing actual toxicity from physical effects is possible by applying a well‐considered test setup, combining toxicity tests with multiple invertebrates (including Lumbriculus, which serves as a negative control for fouling); a broad test concentration range, preferably up to at least 30 000 mg/kg; and passive sampling to localize the CSPC. Applying this setup, false‐positive effects due to fouling, as well as false‐negative results due to testing at too low concentrations (trying to stay below the CSPC), can be avoided. Environ Toxicol Chem 2024;43:1728–1739. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

The US Environmental Protection Agency (USEPA) considers sediment toxicity tests as conditional registration requirements for pesticides with soil Kd ≥50 L/kg‐solid, Koc ≥1000 L/kg‐organic carbon, or log Kow ≥3. The hydrophobicity of these compounds often necessitates use of solvents to ensure accurate and homogeneous dosing of spiked‐sediment studies. For sediment tests, a volatile solvent (e.g., acetone) is generally used as a transient carrier. Due to low water solubility, test material is dissolved in a volatile solvent to create stock solutions. A measured aliquot of stock solution is then mixed with sand substrate, after which the solvent is evaporated. This spiking process results in negligible solvent exposure to organisms. In 2016, USEPA released final ecotoxicity test guidelines for subchronic freshwater (850.1735) and marine (850.1740) sediment test. These methods provide an option for conducting experiments with only a solvent control and no negative control. To adopt this testing strategy, functional equivalency between the negative and solvent control must be demonstrated. These test guidelines describe specific factors that should be considered for evaluating functional equivalency, including (a) the concentration of solvent in the test sediment after evaporation, (b) the levels of solvent that are known to affect organism health, (c) the known impurities in the solvent and their potential impact on organism health, and (d) the historical organism performance of solvent versus negative controls. Our analysis considers these factors and overall supports the elimination of the negative control requirement because this change is unlikely to impact the robustness or interpretability of spiked‐sediment toxicity tests. Environ Toxicol Chem 2024;43:1740–1746. © 2023 CropLife America. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Aquatic toxicity tests with benthic organisms are used to predict the toxicity of hydrophobic organic chemicals (HOCs) in sediments, assuming that the freely dissolved concentration (Cfree) is a good surrogate of bioavailability in the exposure system. However, Cfree of HOCs is difficult to control in water‐only setups. Moreover, the role of dissolved organic carbon (DOC) in the occurrence of toxicity needs clarification because DOC concentrations in sediment porewater can be substantially higher than in typical test water. We introduced biocompatible polyethylene meshes with high sorptive capacities and fast release kinetics as a novel passive dosing phase, which maintained Cfree and Cwater (i.e., free + DOC‐bound) in Hyalella azteca water‐only tests. Adding the supernatant fraction of peat to test water as a DOC source increased Cwater to an extent comparable to sediment porewater and significantly increased and decreased the observed toxicity of permethrin and benzo[a]pyrene, respectively, to H. azteca. This result indicates that DOC can both benefit and harm test species likely due to the increased health after ingestion of DOC and to the uptake of DOC‐bound HOCs, respectively. Passive dosing in combination with the addition of sediment DOC surrogates may better reflect exposure and habitat conditions in sediment porewater than conventional aquatic tests. Environ Toxicol Chem 2024;43:1747–1756. © 2022 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

A third of 1990-1 Gulf-deployed personnel developed drug/chemical-induced multisymptom illness, Gulf War illness (GWI). Veterans with GWI (VGWI) report increased drug/exposure adverse effects (AEs). Using previously collected data from a case-control study, we evaluated whether the fraction of exposures that engendered AEs (AE Propensity) is increased in VGWI (it was); whether AE Propensity is related to self-rated chemical sensitivity (it did); and whether specific exposures predicted AE Propensity (they did). Pesticides and radiation exposure were significant predictors, with copper significantly protective-in the total sample (adjusted for GWI-status) and separately in VGWI and controls, on multivariable regression. Mitochondrial impairment and oxidative stress (OS) underlie AEs from many exposures irrespective of nominal specific mechanism. We hypothesize that mitochondrial toxicity and interrelated OS from pesticides and radiation position people on the steep part of the curve of mitochondrial impairment and OS versus symptom/biological disruption, amplifying impact of new exposures. Copper, meanwhile, is involved in critical OS detoxification processes.

Toxicokinetic–toxicodynamic (TKTD) modeling has received increasing attention in terms of the regulatory environmental risk assessment of chemicals. This type of mechanistic model can integrate all available data from individual‐level bioassays into a single framework and enable refined risk assessments by extrapolating from laboratory results to time‐variable exposure scenarios, based, for instance, on surface water exposure modeling (e.g., FOCUS). Dynamic energy budget (DEB) models coupled with TKTD modules (DEB–TKTD) constitute the leading approach to assess and predict sublethal effects of chemicals on individual organisms. However, thorough case studies are rare. We provide a state‐of‐the‐art example with the standard aquatic test species Ceriodaphnia dubia and the fungicide azoxystrobin, including all steps, from bespoke laboratory toxicity tests to model calibration and validation, through to environmental risk assessment. Following the framework proposed in the European Food Safety Authority Scientific Opinion from 2018, we designed bespoke good laboratory practice–compliant laboratory toxicity studies based on test guideline 211 of the Organisation for Economic Co‐operation and Development and then identified robust parameter values from those data for all relevant model parameters through model calibration. The DEB–TKTD model, DEBtox2019, then informed the design of the validation experiment. Once validated, the model was used to perform predictions for a time‐variable exposure scenario generated by FOCUS. A moving time‐window approach was used to perform the environmental risk assessment. This assessment method reduces uncertainty in the risk assessment while maintaining consistency with the traditional measures of risk. Environ Toxicol Chem 2024;43:2409–2421. © 2024 Syngenta Crop Protection AG. ibacon GmbH and The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Parabens are alkyl esters of p‐hydroxybenzoic acid that are commonly used as preservatives in personal care products such as cosmetics. Recent studies have revealed the presence of parabens in surface and tap water because of their use as disinfection products; however, little is known about their occurrence in biological samples and their bioaccumulation potential, particularly in raptor birds known as sentinels for pollutant detection. We examined the occurrence and tissue distribution of parabens, their metabolites, and halogenated byproducts in the liver, kidney, brain, and muscle of birds of prey from Texas and North Carolina (USA). Methylparaben (MeP), propylparaben (PrP), and butylparaben (BuP) were detected in more than 50% of all tissues examined, with the kidney exhibiting the highest concentration of MeP (0.65–6.84 ng/g wet wt). Para‐hydroxybenzoic acid (PHBA), a primary metabolite, had the highest detection frequency (>50%) and a high accumulation range in the liver, of 4.64 to 12.55 ng/g. The chlorinated compounds chloromethylparaben and chloroethylparaben were found in over half of the tissues, of which dichloromethylparaben (2.20–3.99 ng/g) and dichloroethylparaben (1.01–5.95 ng/g) in the kidney exhibited the highest concentrations. The dibrominated derivatives dibromideethylparaben (Br2EtP) was detected in more than 50% of samples, particularly in muscle and brain. Concentrations in the range of 0.14 to 17.38 ng/g of Br2EtP were detected in the kidney. Dibromidepropylparaben (Br2PrP) was not frequently detected, but concentrations ranged from 0.09 to 21.70 ng/g in muscle. The accumulations of total amounts (sum) of parent parabens (∑P), metabolites (∑M), and halogenated byproducts (∑H) in different species were not significantly different, but their distribution in tissues differed among the species. Positive correlations were observed among MeP, PrP, BuP, and PHBA in the liver, suggesting similar origins and metabolic pathways. Environ Toxicol Chem 2024;43:2365–2376. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

England's 10 national parks are renowned for their landscapes, wildlife, and recreational value. However, surface waters in the national parks may be vulnerable to pollution from human‐use chemicals, such as active pharmaceutical ingredients (APIs), because of factors like ineffective wastewater treatment, seasonal tourism, a high proportion of elderly residents, and the presence of low‐flow water bodies that limit dilution. The present study determined the extent of API contamination in the English national parks by monitoring 54 APIs in 37 rivers across all national parks over two seasons. Results were compared to existing data sets for UK cities and to concentration thresholds for ecological impacts and antimicrobial resistance selection. Results revealed widespread contamination of the national parks, with APIs detected at 52 out of 54 sites and in both seasons. Thirty‐one APIs were detected, with metformin, caffeine, and paracetamol showing the highest mean concentrations and cetirizine, metformin, and fexofenadine being the most frequently detected. While total API concentrations were generally lower than seen previously in UK cities, locations in the Peak District and Exmoor had higher concentrations than most city rivers. Fourteen locations had concentrations of either amitriptyline, carbamazepine, clarithromycin, diltiazem, metformin, paracetamol, or propranolol above levels of concern for fish, invertebrates, and algae or for selection for antimicrobial resistance. Therefore, API pollution of the English national parks appears to pose risks to ecological health and potentially human health through recreational water use. Given that these parks are biodiversity hotspots with protected ecosystems, there is an urgent need for improved monitoring and management of pharmaceutical pollution and pollution more generally not only in national parks in England but also in similar environments across the world. Environ Toxicol Chem 2024;43:2422–2435. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Adverse outcome pathways (AOPs) can aid with chemical risk assessment by providing plausible links between chemical activity at the molecular level and effect outcomes in intact organisms. Because AOPs can be used to infer causality between upstream and downstream events in toxicological pathways, the AOP framework can also facilitate increased uptake of alternative methods and new approach methodologies to help inform hazard identification. However, a prevailing challenge is the limited number of fully developed and endorsed AOPs, primarily due to the substantial amount of work required by AOP developers and reviewers. Consequently, a more pragmatic approach to AOP development has been proposed where smaller units of knowledge are developed and reviewed independent of full AOPs. In this context, we have developed an upstream network comprising key events (KEs) and KE relationships related to decreased androgen signaling, converging at a nodal KE that can branch out to numerous adverse outcomes (AOs) relevant to androgen‐sensitive toxicological pathways. Androgen signaling represents an extensively studied pathway for endocrine disruption. It is linked to numerous disease outcomes and can be affected by many different endocrine‐disrupting chemicals. Still, pathways related to disrupted androgen signaling remain underrepresented in the AOP‐wiki, and endorsed AOPs are lacking. Given the pivotal role of androgen signaling in development and function across vertebrate taxa and life stages of both sexes, this upstream AOP network serves as a foundational element for developing numerous AOPs. By connecting the upstream network with various downstream AOs, encompassing different species, it can also facilitate cross‐species extrapolations for hazard and risk assessment of chemicals. Environ Toxicol Chem 2024;43:2329–2337. © 2024 The Author(s). Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

Per‐ and polyfluoroalkyl substances (PFAS) are a class of chemicals present in a wide range of commercial and consumer products due to their water‐repellency, nonstick, or surfactant properties, resulting from their chemical and thermal stability. This stability, however, often leads to persistence in the environment when they are inevitability released. We utilized microbial microcosms from wastewater treatment plant (WWTP) sludge to determine how employing different functional groups such as heteroatom linkages, varying chain lengths, and hydrofluoroethers (HFEs) will impact the ultimate fate of these novel PFAS structures. A suite of five novel fluorosurfactant building blocks (F7C3OCHFCF2SCH2CH2OH (FESOH), F3COCHFCF2SCH2CH2OH (MeFESOH), F7C3OCHFCF2OCH2CH2OH (ProFdiEOH), F7C3OCHFCF2CH2OH (ProFEOH), and F3COCHFCF2OCH2CH2OH (MeFdiEOH)) and their select transformation products, were incubated in WWTP aerobic microcosms to determine structure–activity relationships. The HFE alcohol congeners with a thioether (FESOH and MeFESOH) were observed to transform faster than the ether congeners, while also producing second‐generation HFE acid products (F7C3OCHFC(O)OH (2H‐3:2 polyfluoroalkyl ether carboxylic acid [PFECA]) and F3COCHFC(O)OH (2H‐1:2 PFECA). Subsequent biodegradation experiments with 2H‐1:2 PFESA and 2H‐1:2 PFECA displayed no further transformation over 74 days. Surface water Photofate experiments compared 2H‐1:2 PFECA, and 2H‐1:2 polyfluorinated ether sulfonate (PFESA) with their fully fluorinated ether acid counterparts, and demonstrated the potential for both HFE acid species to completely mineralize over extended periods of time, a fate that highlights the value of studying novel PFAS functionalization. Environ Toxicol Chem 2024;43:2297–2305. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

[Display omitted] The highly efficient photo-oxidation of alcohols has sparked significant potential to cope with environmental pollution and the ever-increasing energy crisis. This study reports a unique Ti 3 C 2 /BiOBr (TB) heterojunction with a rich inter-face based on in situ exfoliation of MXene and subsequently anchored onto BiOBr sheets. The TB nano-composites exhibited substantially improved photo-catalytic activity towards the photo-oxidation of benzyl alcohol (BA) to benzaldehyde and achieved a formation rate of 1.73 mmol g−1 h−1, greater than pristine BiOBr. The ultra-thin inter-facial contact boosted the oxygen vacancies (O v) and Ti3+ and possessed the most negative adsorption energy, which boosted the transfer and separation of inter-facial charge carriers and the adsorption and dissociation of BA. Overall, the successful synthesis of TB composite, along with its exceptional photo-catalytic performance, offers valuable insights for applications in green chemistry and environmental remediation. [ABSTRACT FROM AUTHOR]

Many sampling and analytical methods can estimate the abundance, distributions, and diversity of birds and other wildlife. However, challenges with sample size and analytical capacity can make these methods difficult to implement for resource‐limited monitoring programs. To apprise efficient and attainable sampling designs for landbird monitoring programs with limited observational data, we used breeding season bird point survey data collected in 2016 at four forest restoration sites in Indiana, USA. We evaluated three subsets of observed species richness, total possibly breeding landbirds, Partners in Flight Regional Conservation Concern (PIF RCC) landbirds, and interior forest specialists (IFSs). Simulated surveys based on field data were used to conduct Bayesian Michaelis–Menten curve analyses estimating observed species as a function of sampling effort. On comparing simulated survey sets with multiple habitat types versus those with one habitat, we found that those with multiple habitat types had estimated 39%–83% greater observed PIF RCC species richness and required 41%–55% fewer visits per point to observe an equivalent proportion of PIF RCC species. Even with multiple habitats in a survey set, the number of visits per point required to detect 50% of observable species was 30% higher for PIF RCC species than for total breeding landbird species. Low detection rates of IFS species at two field sites made precise estimation of required effort to observe these species difficult. However, qualitatively, we found that only sites containing mature forest fragments had detections of several bird species designated as high‐confidence IFS species. Our results suggest that deriving specialized species diversity metrics from point survey data can add value when interpreting those data. Additionally, designing studies to collect these metrics may require explicitly planning to visit multiple habitat types at a monitoring site and increasing the number of visits per survey point. Integr Environ Assess Manag 2024;20:1954–1968. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA. Key Points: Four forest restoration sites in Indiana supported a variety of potentially breeding migratory bird species, including interior forest specialists and regional conservation concern species.At forest restoration sites in Indiana with various habitat types, it was necessary to visit both open and woody plant‐dominated habitats to efficiently detect bird species of regional conservation concern.When analyzing bird point survey data, deriving specialized species diversity metrics, such as richness of habitat specialist species or conservation concern species, can add value when interpreting those data. [ABSTRACT FROM AUTHOR]

Estimates of ambient background concentrations in surface waters, referred to as natural background concentrations (NBCs) in European guidance documents, may be an important factor in determining whether a monitoring site meets the legally binding Environmental Quality Standard (EQS) when assessing naturally occurring substances. Here, we focus on utilizing routine regulatory surface water monitoring data to provide risk assessors and environmental practitioners with a transparent, implementable, repeatable, and resource‐effective approach to estimate NBCs. The methodology does not use additional environmental sampling beyond that which is routine or require advanced statistical methods, or the incorporation of highly specialist, and not always readily accessible, local knowledge. It determines both whether a site is suitable for NBC assessment as well as the identification of suitable surrogate sites and local NBCs using 11 criteria: six for identifying if a site is suitable for NBC correction, and five for identifying suitable surrogate sites for local NBC values. The criteria consider both the extent of any EQS exceedance, after accounting for bioavailability in line with the European guidance and potential anthropogenic impacts at the site, and can be applied in a simple sequential procedure. The method has been applied to derive NBCs for nickel on three case‐study countries—Cyprus, France, and Spain—to determine its useability and impact on compliance. The methodology presented addresses a gap in the current guidance regarding the practical and consistent implementation of NBCs and could be applied to other naturally occurring substances in an EQS or Water Quality Guideline compliance assessment process. Integr Environ Assess Manag 2024;20:2128–2141. © 2024 WCA Environment Ltd and NiPERA Inc. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: A methodology is presented utilizing routine regulatory surface water monitoring data to provide risk assessors and environmental practitioners with a transparent, implementable, repeatable, and resource‐effective approach to estimate natural background concentrations (NBCs).The methodology determines both whether a site is suitable for NBC assessment as well as the identification of suitable surrogate sites and local NBCs using 11 criteria: six for identifying if a site is suitable for NBC correction, and five for identifying suitable surrogate sites for local NBC values.The method has been applied to derive NBCs for nickel on three case‐study countries—Cyprus, France, and Spain—to determine its useability and impact on compliance. [ABSTRACT FROM AUTHOR]

The assessment of pesticide risks to bees in North America currently relies in part on Tier 1 honey bee laboratory toxicity studies to support the registration and registration review processes for crop protection chemicals. For immature stages, the studies follow two standardized test designs recommended by the Organization for Economic Cooperation (OECD), evaluating acute (seven‐day single‐dose, TG OECD 237) and chronic (22‐day repeated‐dose, GD OECD 239) toxicity in bee larvae. In this article, we aim to evaluate the current approach for generating and interpreting honey bee larval toxicity data, enhancing pesticide risk assessment for pollinators. First, by considering that the repeated‐dose larval study covers all stages of honey bee brood development up to adult emergence, we compared endpoints (larval LD/ED50 and LC/EC50 values) from seven‐day acute exposure studies with the 22‐day chronic exposure studies. Our goal was to identify the study design offering greater sensitivity in assessing pesticide toxicity to immature bees. Our second objective involved analyzing available weight data from emerged adults and comparing it to survival endpoints (e.g., NOEL and LD50) to determine if the weight after adult emergence would accurately represent a sensitive indicator of pesticide effects on developing honey bees. Our analysis determined that the use of a single 22‐day chronic exposure study adequately covers all immature stages and that the toxicity values based on cumulative dose are more accurate and representative measures of exposure for immature bees than using endpoints based on estimated daily doses. Furthermore, our analysis suggests that measuring the weight of emerged adults was a more sensitive indicator than mortality of treatment‐related effects in 22% of the compounds included in our analysis. Here we also discuss the importance of standardized protocols for proper collection of weight after emergence and the need for further discussion on the relevance of this parameter at risk assessment scheme. Integr Environ Assess Manag 2024;20:2283–2293. © 2024 Pollinator Research Task Force. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: A meta‐data assessment was conducted to evaluate the current approach for generating and interpreting honey bee larval toxicity data.The chronic larval study tends to provide a more robust screening‐level risk determination than the acute larval study design.The weight after adult emergence from chronic exposure larval study may be an indicator of pesticide effects on growth.Standardized protocols for measuring the weight of emerged adults are needed. [ABSTRACT FROM AUTHOR]

Microbial electrochemical technologies represent innovative approaches to contaminated soil and groundwater remediation and provide a flexible framework for removing organic and inorganic contaminants by integrating electrochemical and biological techniques. To simulate in situ microbial electrochemical treatment of groundwater plumes, this study investigates Cr(VI) reduction within a bioelectrochemical continuous flow (BECF) system equipped with soil‐buried electrodes, comparing it to abiotic and open‐circuit controls. Continuous‐flow systems were tested with two chromium‐contaminated solutions (20–50 mg Cr(VI)/L). Additional nutrients, buffers, or organic substrates were introduced during the tests in the systems. With an initial Cr(VI) concentration of 20 mg/L, 1.00 mg Cr(VI)/(L day) bioelectrochemical removal rate in the BECF system was observed, corresponding to 99.5% removal within nine days. At the end of the test with 50 mg Cr(VI)/L (156 days), the residual Cr(VI) dissolved concentration was two orders of magnitude lower than that in the open circuit control, achieving 99.9% bioelectrochemical removal in the BECF. Bacteria belonging to the orders Solirubrobacteriales, Gaiellales, Bacillales, Gemmatimonadales, and Propionibacteriales characterized the bacterial communities identified in soil samples; differently, Burkholderiales, Mycobacteriales, Cytophagales, Rhizobiales, and Caulobacterales characterized the planktonic bacterial communities. The complexity of the microbial community structure suggests the involvement of different microorganisms and strategies in the bioelectrochemical removal of chromium. In the absence of organic carbon, microbial electrochemical removal of hexavalent chromium was found to be the most efficient way to remove Cr(VI), and it may represent an innovative and sustainable approach for soil and groundwater remediation. Integr Environ Assess Manag 2024;20:2033–2049. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: The research offers valuable insights that can contribute to advancing microbial electrochemical remediation systems designed to reduce Cr(VI) in water‐saturated soils.There were substantial differences from previously reported studies: acclimatization and/or adaptation and transfer of the electroactive bacterial community to Cr(VI) to a bioelectrochemical continuous flow system, no ion exchange membranes, and no nutrients and/or organic carbon added.The research was conducted to simulate most realistically the real conditions of Cr(VI)‐contaminated aquifers, in terms of solid‐to‐liquid ratio, interactions among soil phases, and physicochemical parameters (pH and electrical conductivity).The outcomes achieved in the system for Cr(VI) reduction in water‐saturated soil can demonstrate the feasibility of employing microbial electrochemical technology for the in situ treatment of contaminated aquifers, with interesting implications for economic and environmental sustainability. [ABSTRACT FROM AUTHOR]

In 2023, European governments submitted a proposal to comprehensively ban per‐ and polyfluoroalkyl substances (PFAS), prompting a shift toward PFAS‐free alternatives. However, recent research has emphasized the need for an integrated approach to chemical assessment and environmental management rather than abrupt PFAS substitution, as alternatives may pose similar or greater risks. The PFAS Guide was developed to aid corporations in this critical transition. Its goal is to simplify PFAS identification, safe substitution, and gradual elimination. This study applies the Technology Acceptance Model (TAM) to assess how perceived usefulness (PU) and ease of use of the PFAS Guide impact corporate intentions to adopt it. Our analysis, based on responses from 104 European companies, demonstrates a positive link between PU, ease of use, and a company's intent to adopt the PFAS Guide. This underscores the importance of corporations perceiving the PFAS Guide as a valuable and user‐friendly resource, given its substantial impact on PFAS phase‐out. Descriptive statistics revealed an interesting finding: 51.9% of the participants fell into the "other" group, as outlined in the PFAS Guide. This raises questions regarding the grouping of companies into various sectors. Based on our results, we propose improvements to the PFAS Guide by broadening sector representation to encompass a more diverse range of industries with sector‐specific guidance, ensuring content relevance, and accentuating user experience using interactive resources. Future research should focus on the actual adoption and use of the guide to gain deeper insights into adoption rates and long‐term PFAS Guide utilization. Furthermore, additional investigations should incorporate subgroup analyses, data triangulation, and a longitudinal approach to enhance our understanding of the factors that support and hinder integrated chemical assessment and environmental management. These research efforts are pivotal in guiding chemical policy and management practices, contributing to a PFAS‐free future. Integr Environ Assess Manag 2024;20:2175–2188. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: The study reveals a strong correlation between perceived usefulness and ease of use of the PFAS Guide with a company's intention to adopt it, emphasizing its crucial role in supporting effective PFAS phase‐out strategies.In the PFAS Guide, 51.9% of participants fell into the "other" group, indicating challenges with sector‐based categorization and underscoring the need for more nuanced classification methods.Recommendations include broadening sector representation, ensuring content relevance, and enhancing user experience to facilitate PFAS Guide adoption among corporations transitioning to PFAS‐free alternatives.Focus on actual adoption rates, subgroup analyses, and longitudinal approaches is essential to inform policy decisions and advance sustainable chemical management practices toward a PFAS‐free future. [ABSTRACT FROM AUTHOR]

Commercialization of rechargeable lithium‐ion (Li‐ion) batteries has revolutionized the design of portable electronic devices and is facilitating the current transition to electric vehicles. The technological specifications of Li‐ion batteries continue to evolve through the introduction of various high‐risk liquid electrolyte chemicals, yet critical evaluation of the physical, environmental, and human health hazards of these substances is lacking. Using the GreenScreen for Safer Chemicals approach, we conducted a chemical hazard assessment (CHA) of 103 electrolyte chemicals categorized into seven chemical groups: salts, carbonates, esters, ethers, sulfoxides–sulfites–sulfones, overcharge protection additives, and flame‐retardant additives. To minimize data gaps, we focused on six toxicity and hazard data sources, including three empirical and three nonempirical predictive data sources. Furthermore, we investigated the structural similarities among selected electrolyte chemicals using the ChemMine tool and the simplified molecular input line entry system inputs from PubChem to evaluate whether chemicals with similar structures exhibit similar toxicity. The results demonstrate that salts, overcharge protection additives, and flame‐retardant additives contain the most toxic components in the electrolyte solutions. Furthermore, carbonates, esters, and ethers account for most flammability hazards in Li‐ion batteries. This study supports the complementary use of quantitative structure–activity relationship models to minimize data gaps and inconsistencies in CHA. Integr Environ Assess Manag 2024;20:2231–2244. © 2024 The Author(s). Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC). Key Points: Chemical hazard assessment was conducted for 103 electrolyte chemicals, categorized into seven groups, used in lithium‐ion batteries.Most of the 103 electrolyte chemicals exhibited high levels of concern relative to human health and environmental hazard endpoints.Nonempirical predictive data sources are essential for filling data gaps commonly encountered in empirical data sources.Structure similarity analysis highlights that chemicals with structure similarity correlate with similar hazard endpoints, increasing the value of predictive data sources. [ABSTRACT FROM AUTHOR]