Abstract Agricultural applications of nanotechnologies inevitably introduce nanoparticles and pesticides into agroecosystems as complex mixtures, with unknown implications along terrestrial food chains. We investigated the joint effects of ZnO-NPs and imidacloprid (IMI) along a lettuce–snail food chain over 21days of uptake and 10 days of depuration, focusing on IMI biotransformation and the associated changes of gut microbiota. Coexposure to ZnO-NPs increased the uptake rate constants and the kinetic trophic transfer factor of IMI from lettuce to snail soft tissues by 1.98–2.14-fold and 1.78–1.92-fold, respectively. Higher biotransformation rate constants and 5-hydroxy-imidacloprid (5-OH-IMI) concentrations in mixture treatments suggested enhanced IMI metabolism under coexposure. IMI predominantly accumulated in soft tissues, whereas 5-OH-IMI was primarily excreted via feces, and Zn was retained in viscera. Coexposure was accompanied by larger shifts in gut bacteria and predicted xenobiotic-metabolism-related functional changes, which correlated with IMI and 5-OH-IMI toxicokinetic patterns. These findings underscore the relevance of nanoparticle–pesticide–microbiota–host interactions to agroecosystem risk assessment.

The detrimental effects of tire particles are closely related to additive leaching, yet how the exposure sequence of sunlight and natural organic matter (NOM) regulates this process remains unclear. We investigated the release dynamics of 11 additives, dissolved organic carbon, and nontarget molecular features in tire tread particle (TTP) leachates over 21 d under two exposure scenarios: (i) dry-photoaging followed by incubation in different NOM, and (ii) wet-photoaging occurring directly in humic acid (HA). For dry-photoaged TTPs, NOM suppressed the release of most organic additives with increasing photoaging duration and NOM concentration through surface passivation and depletion of leachable reservoirs, whereas Zn and diphenylguanidine release were enhanced by up to 44.5% and 47.2%, respectively. By comparison, HA facilitated organic additive release but suppressed Zn during wet-photoaging, with additive levels remaining below those from dry-photoaged TTPs. Compared to dry-photoaging, wet-photoaging in HA also resulted in lower contributions of quantified additives to measured DOC (2-5%), greater reduction in environmentally persistent free radicals (22%), and enhanced formation of 3HA* and 1O2, indicating the photosensitizing role of HA. Nontarget screening further revealed greater diversity of molecular features after prolonged HA incubation than in NOM-free or early stage HA treatments. These findings underscore the exposure-order-dependent divergence in reshaping chemical complexity and the fate of tire-derived mixtures.

Emerging evidence indicates that submicron particulate matter (PM1) poses greater respiratory health risks than coarser particles (e.g., PM2.5). Yet its specific toxicological mechanisms and effective mitigation strategies remain insufficiently understood. This study demonstrated that PM1 exposure induced significant dose-dependent pulmonary oxidative stress and inflammatory response in vivo and in vitro. Metabolomic analysis revealed that PM1 triggered more complex metabolic alterations than those induced by PM2.5, including disorders in amino acid metabolism, glycerophospholipid metabolism, and energy metabolism. A notable hormesis-like effect was observed in energy metabolism, where fatty acid β-oxidation was stimulated at a low dose but inhibited at high doses. It was also found that ten metabolites strongly correlated with the severity of oxidative stress and inflammatory response as potential biomarkers. Furthermore, both in vivo and in vitro experiments confirmed that epigallocatechin-3-gallate (EGCG) intervention effectively alleviated PM1-induced lung injury by restoring redox balance, suppressing inflammatory responses, and modulating the metabolic disorders. Our findings not only provided a new insight into the underlying mechanism of PM1 toxicity, advocating for enhanced regulatory attention and risk assessment specifically targeted at PM1, but also highlighted the potential of EGCG as a promising nutritional intervention against the adverse health effects of PM1 exposure.

Widespread tire wear emissions introduce substantial tire additives (TAs) into terrestrial ecosystems; however, the real-world occurrence and environmental risk of TAs accumulated in plants remain poorly understood. Here, all 20 target TAs were detected in 100% of roadside soil samples from southeastern China, while only 16 of these were identified in paired plants with lower detection frequency (38%-100%) due to their metabolic masking as conjugates. Using an in vitro gastrointestinal model, we demonstrated that these conjugates were efficiently converted back to parent compounds during digestion, greatly increasing the concentrations of 16 persistent TAs by 2.7-22.3-fold and enabling the detection of the 4 previously undetected TAs. Gastric acidity and intestinal enzymes promoted the deconjugation of TA conjugates during gastrointestinal digestion, significantly elevating the bioaccessibility of plant-sourced TAs and the associated dietary risks. Our findings uncover the prevalence of conjugated TAs in field vegetation impacted by vehicular traffic, underscoring the critical need to incorporate plant conjugation and digestive deconjugation into future risk assessment frameworks.

Bisphenol A (BPA) is one of the most used plasticizers and a known endocrine disrupting chemical. In plants, BPA is easily conjugated to form conjugates such as glycosyl BPA, and humans can be exposed to such conjugates when ingesting BPA-contaminated plant foods. This study considered the potential of deconjugation of glycosyl BPA in a simulated human gastrointestinal tract system and evaluated the subsequent changes in biological activity using the Caco-2 colon cell model. Glycosyl BPA was found in both soil and lettuce with concentrations ranging from not detected (ND) to 82.51 ng/g dry weight in edible plant tissues, and the level of glycosyl BPA was correlated significantly with that of BPA. Gastrointestinal digestion triggered progressive deglycosylation of glycosyl BPA with the deconjugation rate significantly higher in the intestinal phase (41.7-47.8%) than the gastric phase (13.4-23.3%). Deglycosylation of glycosyl BPA was associated with decreased Caco-2 cell activity and increased markers of oxidative stress and inflammatory responses in the cell. The re-released BPA may be key to the increased toxic effects. These findings highlight the underestimated health risks posed by plant-derived conjugated xenobiotics through transformation reactivation in the human digestive system.

The detrimental effects of tire particles are closely related to additive leaching, yet how the exposure sequence of sunlight and natural organic matter (NOM) regulates this process remains unclear. We investigated the release dynamics of 11 additives, dissolved organic carbon, and nontarget molecular features in tire tread particle (TTP) leachates over 21 d under two exposure scenarios: (i) dry-photoaging followed by incubation in different NOM, and (ii) wet-photoaging occurring directly in humic acid (HA). For dry-photoaged TTPs, NOM suppressed the release of most organic additives with increasing photoaging duration and NOM concentration through surface passivation and depletion of leachable reservoirs, whereas Zn and diphenylguanidine release were enhanced by up to 44.5% and 47.2%, respectively. By comparison, HA facilitated organic additive release but suppressed Zn during wet-photoaging, with additive levels remaining below those from dry-photoaged TTPs. Compared to dry-photoaging, wet-photoaging in HA also resulted in lower contributions of quantified additives to measured DOC (2-5%), greater reduction in environmentally persistent free radicals (22%), and enhanced formation of 3HA* and 1O2, indicating the photosensitizing role of HA. Nontarget screening further revealed greater diversity of molecular features after prolonged HA incubation than in NOM-free or early stage HA treatments. These findings underscore the exposure-order-dependent divergence in reshaping chemical complexity and the fate of tire-derived mixtures.

Perfluorooctane sulfonate (PFOS) is an emerging organic pollutant that is prevalent in the environment. The high toxicity, bioaccumulation and environmental persistence of PFOS pose significant risks to ecosystems and human health, and remediation technologies are urgently needed. However, conventional treatment techniques have proven difficult, necessitating the development of more affordable alternatives to adsorbents. Biochar shows great potential as an inexpensive adsorbent for PFOS removal owing to its excellent pore structure, surface properties, and ability to generate persistent free radicals (PFRs). In this study, biochar is prepared from bamboo powder at 300, 500, and 700 degrees C (BP300, BP500, and BP700). BP500 showed a more developed pore structure, larger specific surface area, and higher PFR signals. The removal efficiency of PFOS on BP500 (49.45 %) was superior to that on BP300 and BP700. The influence of environmental factors (biochar dosage, pH, kinetics, isotherms, and inorganic anions) on the adsorption behavior of PFOS was determined. The removal of PFOS increased at low pH, reaching 63.77 % at pH 2, while the presence of inorganic anions in the solution inhibited PFOS removal by BP500. The presence of oxidants (H2O2 and S2O82- ) alongside BP500 in the solution improved PFOS removal efficiency. The oxidant added to biochar could degrade PFOS, as evidenced by the detection of F-, and the removal and degradation rates increased with the oxidant dosage. This study provides a new perspective for analyzing the mechanism of PFOS removal by biochar. In the future, the industrial-scale application of bamboo biochar for contaminant removal needs to be strengthened.

The continuous accumulation of metallic nanoparticles and pesticide residues in agroecosystems poses potential risks to food safety and plant health, yet their potential interactive toxicity remains poorly understood. Here, we investigated the mutual effects of zinc oxide nanoparticles (ZnONPs) and the imidacloprid (IMI) on their bioaccumulation, phytotoxicity and the underlying molecular mechanisms in lettuce. After 14 days of exposure, co-exposure to ZnONPs and IMI significantly aggravated phytotoxicity compared to individual treatments, as evidenced by greater biomass reduction, elevated oxidative stress, and intensified metabolic disruptions. Additionally, mixture treatments significantly increased both Zn and IMI accumulation in shoots, indicating enhanced uptake and upward translocation due to their coexistence. The biotransformation of IMI into 5-OH-IMI was enhanced by ZnONPs by 5.8-130 % in lettuce, with the magnitude depending on particle size and IMI concentration. For the comparison between different particle sizes, 90 nm ZnONPs led to higher Zn and IMI accumulation in shoots, whereas 30 nm ZnONPs more efficiently enhanced IMI metabolism. These accumulation patterns were closely linked to the distinct metabolic reprogramming. Co-exposure uniquely activated pathways related to amino acid and energy metabolism, indicating increased amino acid turnover and elevated energy demand for detoxification and damage repair. Altogether, the findings provide new mechanistic insights into nanoparticle-pesticide interactions in edible plants and emphasize the need to consider co-contaminant scenarios in environmental risk assessment.

Antibiotic resistance genes (ARGs), as emerging contaminants, pose a serious threat to food security and global public health. However, the impact and mechanisms of widely applied herbicides in agriculture, particularly their chiral configurations, on the transfer of ARGs to plants remain unclear. Results revealed that the herbicide napropamide (NAP) R-enantiomer, possessing stronger herbicidal activity against target weeds, reduced ARG accumulation in the nontarget plant Arabidopsis shoots and roots by 54.2 and 36.5%, respectively, compared to the S-enantiomer. In-depth analysis demonstrated this selective regulation linked closely to enantiomer-specific disruptions in plant physiology. R-NAP caused only mild growth inhibition, maintained relatively stable nutrient homeostasis, promoted accumulation of defensive secondary metabolites including nitrogen-containing compounds, flavonoids, and phenolic compounds, and preserved intact cell wall structure. In contrast, S-NAP triggered severe growth suppression, oxidative stress, significant nutrient imbalance, 3-4 fold changes in defense metabolites, and reducing pectin and hemicellulose by 23-32%. Correlation analysis and structural equation modeling quantified that shoot ARG accumulation was primarily governed by nutrient elements and cell wall parameters. Root ARG accumulation was coregulated by the direct action of NAP combined with synergistic effects involving nutrients, secondary metabolites, and cell wall integrity. This work provides a comprehensive theoretical basis for the rational application of herbicides and mitigation of ARG contamination in plants.

Following the restrictions on bisphenol A (BPA), the production and environmental release of bisphenol analogues (BPs) have increased. However, knowledge about the occurrence of bisphenol analogues other than BPA, especially in farmland soils and edible plants, remains limited. This study investigated the occurrence, contamination characteristics, and human health risks of eight bisphenol analogues in paired soil-plant samples from areas near factories in eastern China. Results indicated that the concentrations of Σ8BPs in the collected soil and plant samples ranged from 1.4 to 897.1 ng/g dw and 2.5 to 586.2 ng/g dw, respectively. BPA, bisphenol AF (BPAF), bisphenol F (BPF), and bisphenol S (BPS) were the primary components of BPs, with BPA having the highest detection frequency (74 %). In addition, a positive correlation was observed between the root concentration factor and the log Kow of BPs (R2 = 0.471, P < 0.05), whereas the translocation factor exhibited a negative correlation with the log Kow (R2 = 0.405, P < 0.05). The hazard index (HI) values of BPs in paired soil-plant samples were <1, suggesting that the current contamination levels of BPs in soils and plants are unlikely to pose significant health risks to humans. However, potential risks from long-term exposure require careful monitoring. This study offers new insights into the spatial distributions and contamination status of BPs in farmland soils and plants, highlighting the environmental behavior and health risks of other bisphenol analogues.

The environmental risks posed by microplastics (MPs) in soils have garnered global attention. Previous studies have mainly examined on the distribution of MPs in agricultural soils, which are heavily impacted by plastic films. However, knowledge about MPs pollution across diverse land-use types remains scarce. In the present study, we investigated the pollution of MPs in three types of soils (agricultural soil, industrial soil, and transportation soil). The results revealed that 100

In recent years, the pollution of microplastics (MPs) has attracted global attention because of their extensive distribution and significant impact on biota. Once MPs enter the ecosystem, the complex degradation process that MPs undergo will alter their surface properties and toxic effects. In order to address the global pollution issue caused by MPs, a range of technologies have been developed to degrade MPs. This study systematically summarizes the degradation methods of MPs reported recently, including physical, chemical and biological degradation processes. Dissolved organic matter (DOM), some reducing agents and sulfides are found to cause MPs aging and degradation. The roles of reactive oxygen species and biological enzymes in MPs degradation are elucidated. The chemical and biological degradation of various types of MPs are discussed and their degradation pathways are clarified. A number of factors affect the rates of MPs degradation in natural environment. Specifically, the influences of external factors and the intrinsic properties of MPs on their degradation are revealed. Furthermore, the potential environmental toxicity of MPs is investigated in greater depth, with particular attention paid to the release of plastic additives and DOM during the degradation process. This review article will assist in the comprehension of environmental degradation process and ecological risks of MPs and provide guidance for controlling the environmental pollution caused by MPs.

Chemical oxidation is extensively utilized to mitigate the impact of organic pollutants in wastewater. The non-radical oxidation driven by iron-based materials is noted for its environmental friendliness and resistance to wastewater matrix, and it is a promising approach for practical wastewater treatment. However, the complexity of heterogeneous systems and the diversity of evolutionary pathways make the mechanisms of non-radical oxidation driven by iron-based materials elusive. This work provides a systematic review of various non-radical oxidation systems driven by iron-based materials, including singlet oxygen (1O2), reactive iron species (RFeS), and interfacial electron transfer. The unique mechanisms by which iron-based materials activate different oxidants (ozone, hydrogen peroxide, persulfate, periodate, and peracetic acid) to produce non-radical oxidation are described. The roles of active sites and the unique structures of iron-based materials in facilitating non-radical oxidation are discussed. Commonly employed identification methods in wastewater treatment are compared, such as quenching, chemical probes, spectroscopy, mass spectrometry, and electrochemical testing. According to the process of iron-based materials driving non-radical oxidation to remove organic pollutants, the driving factors at different stages are summarized. Finally, challenges and countermeasures are proposed in terms of mechanism exploration, detection methods and practical applications of non-radical oxidation driven by iron-based materials. This work provides valuable insights for understanding and developing non-radical oxidation systems.

As emerging contaminants, microplastics (MPs) are becoming a matter of global concern, and they have complex interactions with dissolved organic matter (DOM) widely present in aqueous environments. Here, we investigate the molecular interactions between aged polystyrene microplastics (PS-MPs) and fulvic acid (FA) under neutral conditions using a series of analytical techniques. The structural changes of FA and the binding interactions of PS-MPs with FA at a molecular level were explored by fluorescence and FT-IR combined with two-dimensional correlation spectroscopy (2D-COS). Results showed that photoaging of PS-MPs changed the sequence of structural variations with FA. Atomic force microscopy-infrared spectroscopy (AFM-IR) strongly demonstrated that the surface roughness of both pristine and aged PS-MPs greatly increased after FA addition. Meanwhile, AFM-IR and Raman spectroscopy revealed a stronger interaction between aged PS-MPs and FA. The content of oxygen-containing functional groups in PS-MPs increased after aging and after binding with FA, and surface distribution of these functional groups also changed. XPS analyses indicated that the oxygen content in PS-MPs increased after the interaction with FA and the increase in oxygen content was even greater in aged PS-MPs. Overall, these research findings are useful to understand the environmental impacts of DOM-MPs interactions and to address the uncertainty of MPs aging effect on their environmental behavior in aquatic ecosystems.

The application of iron-doped biochar in peroxymonosulfate (PMS) activation systems has gained increasing attention due to their effectiveness and environmental friendliness in addressing environmental issues. However, the behavioral mechanism of iron doping and the detailed 1O2 generation mechanism in PMS activation systems remain ambiguous. Here, we investigated the effects of three anions (Cl-, NO3-and SO42-) on the process of iron doping into bone char, leading to the synthesis of three iron-doped bone char (Fe-ClBC, Fe-NBC and Fe -SBC). These iron-doped bone char were used to catalyze PMS to degrade acetaminophen (APAP) and exhibited the following activity order: Fe-ClBC > Fe-NBC > Fe-SBC. Characterization results indicated that iron doping primarily occurred through the substitution of calcium in hydroxyapatite within BC. In the course of the impregnation, the binding of SO42- and Ca2+ hindered the exchange of iron ions, resulting in lower catalytic activity of Fe-SBC. The primary reactive oxygen species in the Fe-ClBC/PMS and Fe-NBC/PMS systems were both 1O2. 1O2 is produced through O2•- conversion and PMS self-dissociation, which involves the generation of metastable iron intermediates and electron transfer within iron species. The presence of oxygen vacancies and more carbon defects in the Fe-ClBC catalyst facilitates 1O2 generation, thereby enhancing APAP degradation within the Fe-ClBC/PMS system. This study is dedicated to in-depth exploration of the mechanisms underlying iron doping and defect materials in promoting 1O2 generation.

Tire additives, such as benzothiazole and its derivatives (collectively called BTs), are large-volume chemicals that are constantly emitted into agricultural environment via tire-road wearing and other actions. The potential accumulation of BTs in food crops depends largely on their metabolism in plants, which is poorly understood. Herein, we evaluated uptake and metabolism of six BTs in carrot callus and intact carrot plants to understand their structure-specific metabolism. All BTs were readily taken up by carrot roots, with their root concentration factors (RCF) ranging from 1.66 ± 0.01 to 2.95 ± 0.05. Although the tested BTs exhibited poor upward translocation from root to leaves (translocation factors < 1), the translocation factors of 2-methylbenzothiazole (0.79) and 2-aminobenzothiazole (0.65) were significantly higher than that of 2-methylbenzothiazole (0.18) and 2-(methylthio)benzothiazole (0.22). These results indicated the structure-dependent uptake and translocation of BTs in carrot. Correlation analysis between log Kow and log RCF or TF revealed that the hydrophobicity of BTs predominantly affected their root uptake and acropetal translocation in carrots. With the aid of high-resolution mass spectrometry, a total of 18 novel metabolites of BTs were tentatively identified, suggesting that BT compounds can be metabolized by carrot callus. The proposed metabolites of BTs include four hydroxylated products, one demethylated product, five glycosylated products and eight amino acid conjugated products, revealing that glycosylation and amino acid conjugation were the dominant transformation pathways for BT metabolism in carrot. However, the detected species of metabolites for six BTs varied distinctly, indicating structure-specific metabolism of BTs in plants. The findings of this study improve our understanding of structure-dependent fate and transformation of BTs in plants. Since BTs metabolites in food crops could present an unintended exposure route to consumers, the structure-specific differences of BTs uptake, metabolism and accumulation in plants must be considered when addressing human dietary exposure risks.

China's soil is experiencing significant microplastic contamination. We developed a machine-learning model to assess microplastic pollution from 1980 to 2050. Our results showed that the average abundance of microplastics in topsoil increased from 45 items per kilogram of soil in 1980 to 1156 items by 2018, primarily due to industrial growth (39 %), agricultural film usage (30 %), tire wear (17 %), and domestic waste (14 %). During the same period, microplastic levels in cropland rose from 98 to 2401 items per kilogram of soil, and exposure levels for the Chinese population increased from 808 to 3168 items per kilogram. By 2050, a reduction in the use of agricultural films is expected to decrease cropland contamination by half. However, overall levels are anticipated to remain steady due to other persistent sources, indicating a continued spread of microplastics into subterranean environments, water bodies, and human systems. This study highlights China's microplastic challenges and suggests potential global trends, emphasizing the need for increased awareness and intervention worldwide.

The extensive application of phthalate esters (PAEs) as plasticizers has raised considerable concern regarding their en-vironmental load, but the associated occurrence of PAE metabolites has often been ignored. The soil-plant system is a vital source of human exposure to PAEs via crop intake. Here, paired soil-plant samples were collected from eastern China to investigate the occurrence characteristics of seven PAE congeners and two primary monoester phthalate me-tabolites (mPAEs) in farmland. The detection frequencies of PAEs and mPAEs in the investigated soil-plant systems were 100 %. The total concentrations of PAEs in the collected soil and plant samples ranged from 0.07 to 1.83 mg/kg (dw) and from 3.9 to 24 mg/kg (dw), respectively. Moreover, di-(2-ethylhexyl) phthalate, diisobutyl phthalate and di-n-butyl phthalate were the predominant PAE congeners in the farmlands of eastern China, collec-tively accounting for >90 % of the total concentration of PAEs. In addition, the total concentrations of the two mPAEs were markedly higher in plant samples (49 ng/g dw to 549 ng/g dw) than in soil samples (3 ng/g dw to 22 ng/g dw), indicating that PAEs are readily metabolized in plants. The hazard index (HI) values of all PAEs in all crops were <1, demonstrating that the risks of PAEs in the crops were acceptable. However, the daily intake of mPAEs from the consumption of cabbage was higher than or comparable to that of some PAEs (such as di-n-octyl phthalate). This highlights the importance of taking metabolites into consideration in further environmental investiga-tions and risk assessments of PAEs.

Various organic pollutants have been released into the environment because of anthropogenic activities. These pollutants can be taken up by crop plants, causing potential threats to the ecosystem and human health throughout the food chain. The biotransformation of pollutants in plants generates a number of metabolites that may be more toxic than their parent compounds, implying that the metabolites should be taken into account during the toxicity assessment. However, the metabolites of pollutants in plants are extremely complex, making it difficult to comprehensively obtain the toxicological information of all metabolites. This study proposed a strategy to assess the integral cytotoxicity of pollutant metabolites in plants by treating them as a whole during toxicological tests. Triazole pesticides, a class of broad-spectrum fungicides, have been widely applied in agricultural production. Their residue pollution in farmland has drawn increasing attention. Hence, four triazole pesticides, including flusilazole, diniconazole, tebuconazole, and propiconazole, were selected as the tested pollutants. The metabolites were generated by the treatment of carrot callus with tested triazole pesticides. After treatment of 72 h, the metabolites of pesticides in carrot callus were extracted, followed by toxicological tests using the Caco-2 cell line. The results showed that the metabolites of tested pesticides in carrot callus did not significantly inhibit the viability of Caco-2 cells (P>0.05), demonstrating no cytotoxicity of pesticide metabolites. This proposed method opens a new avenue to assess the cytotoxicity of pollutant metabolites in plants, which is expected to provide valuable data for precise toxicity assessment.