Toxics

Background: BDE-47, a pervasive environmental pollutant detected in >90% of human serum samples, is increasingly linked to metabolic disorders. This study investigates the specific impact of BDE-47 exposure on the gut microbiota in prediabetic mice and evaluates the efficacy of therapeutic interventions in mitigating these effects. Objectives: To determine whether BDE-47 exposure induces diabetogenic dysbiosis in prediabetic mice and to assess whether dietary interventions, such as grape exosomes and an antioxidant cocktail, can restore a healthy microbiota composition and mitigate diabetes risk. Methods: In this study, a prediabetic mouse model was established in 54 male SPF-grade C57BL/6J mice through a combination of high-sugar and high-fat diet feeding with streptozotocin injection. Oral glucose tolerance tests (OGTT) were conducted on day 7 and day 21 post-modeling to assess the establishment of the model. The criteria for successful model induction were defined as fasting blood glucose levels below 7.8 mmol/L and 2 h postprandial glucose levels between 7.8 and 11.1 mmol/L. Following confirmation of model success, a 3 × 3 factorial design was applied to allocate the experimental animals into groups based on two independent factors: BDE-47 exposure and exosome intervention. The BDE-47 exposure factor consisted of three dose levels—none, high-dose, and medium-dose—while the exosome intervention factor included three modalities—none, Antioxidant Nutrients Intervention, and Grape Exosomes Intervention. Fresh fecal samples were collected from mice two days prior to sacrifice. Cecal contents and segments of the small intestine were collected and transferred into 1.5 mL cryotubes. All sequences were clustered into operational taxonomic units (OTUs) based on defined similarity thresholds. To compare means across multiple groups, a two-way analysis of variance (ANOVA) was employed. The significance level was predefined at α = 0.05, and p-values < 0.05 were considered statistically significant. Bar charts and line graphs were generated using GraphPad Prism version 9.0 software, while statistical analyses were performed using SPSS version 20.0 software. Results: The results of 16S rDNA sequencing analysis of the microbiome showed that there was no difference in the α diversity of the intestinal microbiota in each group of mice (p > 0.05), but there was a difference in the Beta diversity (p < 0.05). At the gate level, the abundances of Proteobacteria, Campylobacterota, Desulfobacterota, and Fusobacteriota in the medium-dose BDE-7 group were higher than those in the model control group (p < 0.05). The abundance of Patellar bacteria was lower than that of the model control group (p < 0.05). The abundances of Proteobacteria and Campylobacterota in the high-dose BDE-7 group were higher than those in the model control group (p < 0.05). The abundance of Planctomycetota and Patescibacteria was lower than that of the model control group (p < 0.05), while the abundance of Campylobacterota in the grape exosome group was higher than that of the model control group (p < 0.05). The abundance of Patescibacteria was lower than that of the model control group (p < 0.05), while the abundance of Firmicutes and Fusobacteriota in the antioxidant nutrient group was higher than that of the model control group (p < 0.05). However, the abundance of Verrucomicrobiota and Patescibacteria was lower than that of the model control group (p < 0.05). At the genus level, the abundances of Bacteroides and unclassified Lachnospiraceae in the high-dose BDE-7 group were higher than those in the model control group (p < 0.05). The abundance of Lachnospiraceae NK4A136_group and Lactobacillus was lower than that of the model control group (p < 0.05). The abundance of Veillonella and Helicobacter in the medium-dose BDE-7 group was higher than that in the model control group (p < 0.05), while the abundance of Lactobacillus was lower (p < 0.05). The abundance of genera such as Lentilactobacillus and Faecalibacterium in the grape exosome group was higher than that in the model control group (p < 0.05). The abundance of Alloprevotella and Bacteroides was lower than that of the model control group (p < 0.05). In the antioxidant nutrient group, the abundance of Lachnospiraceae and Hydrogenophaga was higher than that in the model control group (p < 0.05). However, the abundance of Akkermansia and Coriobacteriaceae UCG-002 was significantly lower than that of the model control group (p < 0.05). Conclusions: BDE-47 induces diabetogenic dysbiosis in prediabetic mice, which is reversible by dietary interventions. These findings suggest that microbiota-targeted strategies may effectively mitigate the diabetes risk associated with environmental pollutant exposure. Future studies should further explore the mechanisms underlying these microbiota changes and the long-term health benefits of such interventions. Full article

The maternal–fetal environment is influenced by multiple factors, including nutrition and environmental contaminants, which can impact long-term development. Perinatal exposure to organophosphate flame retardants (OPFRs) disrupts energy homeostasis and causes maladaptive behaviors in mice. Maternal obesity affects development by impairing blood–brain barrier (BBB) formation, influencing brain regions involved in energy regulation and behavior. This study examined the combined effects of maternal obesity and perinatal OPFR treatment on offspring development. Female mice were fed either a low-fat (LFD) or a high-fat diet (HFD) for 8 weeks, mated, and treated with either sesame oil or an OPFR mixture (tris(1,3-dichloro-2-propyl)phosphate, tricresyl phosphate, and triphenyl phosphate, 1 mg/kg each) from gestational day 7 to postnatal day 14. Results showed that both maternal diet and OPFR treatment disrupted blood–brain barrier integrity, energy balance, and reproductive gene expression in the hypothalamus of neonates. The expression of hepatic genes related to lipid and xenobiotic metabolism was also altered. In adulthood, LFD OPFR-treated female offspring exhibited increased avoidance behavior, while HFD OPFR-treated females demonstrated memory impairments. Metabolic assessments revealed decreased energy expenditure and nighttime activity in LFD OPFR-treated females. These findings suggest that maternal diet and OPFR treatment alter hypothalamic and liver gene expression in neonates, potentially leading to long-term metabolic and behavioral changes. Full article

Rapid industrialization and urbanization have progressed in Korea, yet public attention to hazardous pollutants emitted from industrial complexes remains limited. With the increasing coexistence of industrial and residential areas, there is a growing need for real-time monitoring and management plans that account for the rapid dispersion of hazardous air pollutants (HAPs). In this study, we conducted spatiotemporal data collection and analysis for the first time in Korea using real-time measurements obtained through mobile extractive differential optical absorption spectroscopy (Me-DOAS) mounted on a solar occultation flux (SOF) vehicle. The measurements were conducted in the Saha Sinpyeong–Janglim Industrial Complex in Busan, which comprises the Sasang Industrial Complex and the Sinpyeong–Janglim Industrial Complex. BTEX compounds were selected as target volatile organic compounds (VOCs), and real-time measurements of both BTEX and fine particulate matter (PM) were conducted simultaneously. Correlation analysis revealed a strong relationship between PM₁₀ and PM_2.5 (r = 0.848–0.894), indicating shared sources. In Sasang, BTEX levels were associated with traffic and localized facilities, while in Saha Sinpyeong–Janglim, the concentrations were more influenced by industrial zoning and wind patterns. Notably, inter-compound correlations such as benzene–m-xylene and p-xylene–toluene suggested possible co-emission sources. This study proposes a GIS-based, three-dimensional air quality management approach that integrates variables such as traffic volume, wind direction, and speed through real-time measurements. The findings are expected to inform effective pollution control strategies and future environmental management plans for industrial complexes. Full article

Mitochondrial dysfunction is a key contributor to neurodegeneration, particularly in Parkinson’s disease (PD), where dopaminergic neurons being highly metabolically active are vulnerable to oxidative stress and bioenergetic failure. In this study, we investigate the effects of rotenone, a Complex I inhibitor, and antimycin A, a Complex III inhibitor, on mitochondrial function in MN9D dopaminergic neuronal cells. Cells were treated with rotenone (1.5 µM) or antimycin A (10 µM) for one hour, and key biochemical parameters were assessed, including ATP levels, reactive oxygen species (ROS) production, dopamine metabolism, and neuromelanin formation. Our results indicate significant ATP depletion and ROS accumulation following treatment with both inhibitors, with antimycin A inducing a more pronounced oxidative stress response. Dysregulation of dopamine biosynthesis differed mechanistically from vesicular monoamine transporter (VMAT2) inhibition by tetrabenazine, suggesting alternative pathways of catecholamine disruption. Additionally, oxidative stress led to increased neuromelanin accumulation, indicating a possible adaptive response to mitochondrial dysfunction. These findings provide insights into the cellular mechanisms underlying dopaminergic neurotoxicity and highlight mitochondrial electron transport chain inhibition as a key driver of PD pathogenesis. Future research should explore therapeutic strategies aimed at enhancing mitochondrial function to mitigate neurodegenerative progression. Full article

The gastrointestinal tract mediates the absorption of nutrients from the diet, which is increasingly contaminated with toxic metal(loid) species (TMs) and thus threatens food safety. Evidence in support of the influx of TMs into the bloodstream of the general and vulnerable populations (babies, children, pregnant women, and industrial workers) has been obtained by accurately quantifying their blood concentrations. The interpretation of these TM blood concentrations, however, is problematic, as we cannot distinguish between those that are tolerable from those that may cause the onset of environmental diseases. Since TMs that have invaded the bloodstream may perturb biochemical processes therein that will eventually cause organ damage it is crucial to better understand their bioinorganic chemistry as these processes collectively determine their organ availability. Thus, bioinorganic processes of TMs in the bloodstream represent selectivity filters which protect organs from their influx and ultimately determine the corresponding exposure-response relationships. The need to better understand selectivity filters prompted us to mechanistically disentangle them into the major bioinorganic chemistry processes. It is argued that the detoxification of TMs in the bloodstream and the biomolecular mechanisms, which mediate their uptake into target organs, represent critical knowledge gaps to revise regulatory frameworks to reduce the disease burden. Full article

Strobilurins are a prominent class of fungicides capable of entering aquatic environments via runoff and leaching from the soil. Findings from previous studies suggest that strobilurins are highly toxic in aquatic environments, and evidence of acute developmental toxicity and altered behavioral responses have been emphasized. The objective here was to determine the effects of a new strobilurin, metyltetraprole (MTP), on zebrafish using developmental endpoints, gene expression, and behavioral locomotor assays. We hypothesized that MTP would cause developmental toxicity and induce hyperactivity in zebrafish (Danio rerio). To test this, developing zebrafish embryos/larvae were exposed to environmentally relevant levels of MTP (0.1, 1, 10, and 100 µg/L) until 7 days post-fertilization. Survival percentages did not differ among the treatment groups. No change in reactive oxygen species production was detected, but two genes involved in the mitochondrial electron transport chain (mt-nd3 and uqcrc2) were altered in abundance following MTP exposure. Moreover, the highest concentration (100 µg/L) of MTP caused notable hyperactivity in the zebrafish in the visual motor response test. Overall, results from this study increase our knowledge regarding sub-lethal effects of MTP, helping inform risk assessment for aquatic environments. Full article

Cadmium (Cd) contamination in rice (Oryza sativa L.) poses serious health risks for human, necessitating effective mitigation strategies. This study investigated the effects of Cd stress on iron (Fe), manganese (Mn), zinc (Zn), and Cd accumulation and translocation in rice varieties with high (MY46) or low (ZS97B) Cd accumulation capacities grown in acidic and alkaline soils. Results demonstrated that Cd stress significantly inhibited plant growth, reducing plant height, shoot biomass, and grain yield in both soil types. Cd accumulation increased in roots, shoots, and grains, while Fe, Mn, and Zn concentrations decreased markedly. Molecular analysis revealed upregulation of metal transporter genes (OsIRT1, OsNRAMP1, OsNRAMP5) and the vacuolar sequestration gene (OsHMA3) in roots under Cd exposure. The translocation factor (TF) values of Mn and Zn from root to shoot were reduced in acidic soils, whereas Mn and Zn TFs exhibited an increasing trend in alkaline soils despite Cd exposure. Furthermore, correlation analyses indicated Mn and Zn play crucial roles in suppressing Cd accumulation in both acidic and alkaline soils. These findings provide critical insights for developing soil-specific strategies to reduce Cd accumulation in rice through micronutrient management. Full article

This study investigates the heavy metal contamination in urban and peri-urban soils of Thessaloniki, Greece, over a two-year period (2023–2024). A total of 208 composite soil samples were systematically collected from 52 sites representing diverse land uses, including high-traffic roadsides, industrial zones, residential neighborhoods, parks, and mixed-use areas, with sampling conducted both after the wet (winter) and dry (summer) seasons. Soil physicochemical properties (pH, electrical conductivity, texture, organic matter, and calcium carbonate content) were analyzed alongside the concentrations of heavy metals such as Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn. A pollution assessment employed the Geoaccumulation Index (I_geo), Contamination Factor (Cf), Pollution Load Index (PLI), and Potential Ecological Risk Index (RI), revealing variable contamination levels across the city, with certain hotspots exhibiting a considerable to very high ecological risk. Multivariate statistical analyses (PCA and HCA) identified distinct anthropogenic and geogenic sources of heavy metals. Health risk assessments, based on USEPA models, evaluated non-carcinogenic and carcinogenic risks for both adults and children via ingestion and dermal contact pathways. The results indicate that while most sites present low to moderate health risks, specific locations, particularly near major transport and industrial areas, pose elevated risks, especially for children. The findings underscore the need for targeted monitoring and remediation strategies to mitigate the ecological and human health risks associated with urban soil pollution in Thessaloniki. Full article

Human milk has been used for over 70 years to monitor pollutants such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs). Despite the growing body of data, our understanding of the pollutant exposome, particularly co-exposure patterns and their interactions, remains limited. Artificial intelligence (AI) offers considerable potential to enhance biomonitoring efforts through advanced data modelling, yet its application to pollutant dynamics in complex biological matrices such as human milk remains underutilized. This study applied an AI-based framework, integrating machine learning, metaheuristic hyperparameter optimization, explainable AI, and postprocessing, to analyze PCB-170 levels in breast milk samples from 186 mothers in Zadar, Croatia. Among 24 analyzed POPs, the most influential predictors of PCB-170 concentrations were hexa- and hepta-chlorinated PCBs (PCB-180, -153, and -138), alongside p,p’-DDE. Maternal age and other POPs exhibited negligible global influence. SHAP-based interaction analysis revealed pronounced co-behavior among highly chlorinated congeners, especially PCB-138–PCB-153, PCB-138–PCB-180, and PCB-180–PCB-153. These findings highlight the importance of examining pollutant interactions rather than individual contributions alone. They also advocate for the revision of current monitoring strategies to prioritize multi-pollutant assessment and focus on toxicologically relevant PCB groups, improving risk evaluation in real-world exposure scenarios. Full article

Tebuconazole (TBZ), a triazole-class fungicide widely used in agriculture, is frequently detected in aquatic environments due to runoff and leaching, where it poses a threat to non-target aquatic organisms. This study investigates the acute toxicity of TBZ on juvenile rainbow trout (Oncorhynchus mykiss), a commercially important cold-water fish species. The 96 h LC₅₀ value was determined to be 9.05 mg/L using probit analysis. In addition to mortality, the physiological responses of fish exposed to both LC₅₀ and maximum tolerance concentration (MTC; 6 mg/L) were evaluated through haematological and histological assessments. TBZ exposure significantly suppressed key haematological parameters, particularly WBC, RBC, HGB, HCT, and LYM, indicating immunosuppression and potential hypoxia. Histological examination revealed progressive and regressive damage in gill tissues, including epithelial lifting, hyperplasia, and hypertrophy, which were more severe in the LC₅₀ group. These alterations were quantified using a semi-quantitative scoring system. Additionally, significant changes in biochemical parameters such as ALT, AST, creatinine, total protein, and glucose levels were observed, further indicating hepatic and renal dysfunctions induced by TBZ exposure. The findings demonstrate that TBZ exposure induces substantial physiological and structural impairments in rainbow trout, highlighting the importance of assessing the ecological risks of fungicide contamination in aquatic environments. The study also provides a dose–response model that can be used to estimate mortality risk in aquaculture operations exposed to TBZ. Full article

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental pollutants that continue to raise concern owing to their ability to accumulate in living organisms. In recent years, a growing body of research has shown that PFAS can exert their toxicity through disruption of both DNA integrity and epigenetic regulation. This includes changes in DNA methylation patterns, histone modifications, chromatin remodeling, and interference with DNA repair mechanisms. These molecular-level alterations can impair transcriptional regulation and cellular homeostasis, contributing to genomic instability and long-term biological dysfunction. In neural systems, PFAS exposure appears particularly concerning. It affects key regulators of neurodevelopment, such as BDNF, synaptic plasticity genes, and inflammatory mediators. Importantly, epigenetic dysregulation extends to non-coding RNAs (ncRNAs), including microRNAs (miRNAs) and long non-coding RNAs (lncRNAs), which mediate post-transcriptional silencing and chromatin remodeling. Although direct evidence of transgenerational neurotoxicity is still emerging, animal studies provide compelling hints. Persistent changes in germline epigenetic profiles and transcriptomic alterations suggest that developmental reprogramming might be heritable by future generations. Additionally, PFAS modulate nuclear receptor signaling (e.g., PPARγ), further linking environmental cues to chromatin-level gene regulation. Altogether, these findings underscore a mechanistic framework in which PFAS disrupt neural development and cognitive function via conserved epigenetic and genotoxic mechanisms. Understanding how these upstream alterations affect long-term neurodevelopmental and neurobehavioral outcomes is critical for improving risk assessment and guiding future interventions. This review underscores the need for integrative research on PFAS-induced chromatin disruptions, particularly across developmental stages, and their potential to impact future generations. Full article

Domoic acid (DA) is a potent neurotoxin that poses public health concerns, especially for children and adolescents during critical neurodevelopmental periods. In the present study, urinary DA concentrations in 216 children and adolescents at the age of 6 to 18 in southern China were determined using a novel dansyl-chloride (DNS-Cl) derivatization high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) method with ultrahigh sensitivity (LOQ: 0.087 ng/mL). The median urinary DA concentration was 2.17 ng/mL (interquartile range (IQR): 0.87–4.08 ng/mL). When analyzed by age group, the medians were 1.40 ng/mL (6–9 years; IQR: 0.55–3.49 ng/mL), 2.16 ng/mL (10–13 years; IQR: 0.94–4.07 ng/mL), and 2.93 ng/mL (14–18 years; IQR: 1.06–5.06 ng/mL). Our findings revealed that urinary DA concentrations increased with age and varied significantly across different body mass index groups (p < 0.05), while no significant gender differences were observed. The estimated daily intake (1.73–374 ng/kg/day) remained below established safety thresholds. This study represents the first systematic biomonitoring of urinary DA exposure in children and adolescents from southern China’s coastal communities, addressing critical knowledge gaps and establishing baseline data amid rising harmful algal bloom frequency. Full article

Due to widespread use of silver nanoparticles (AgNPs), the assessment of their potential harm to microalgal photosynthesis is crucial, as microalgae, together with cyanobacteria, contribute to approximately 50% of global oxygen production. This study investigated photosynthetic pigments, photosynthetic rate, chlorophyll a fluorescence, and the expression of photosynthesis-related genes and proteins in green alga Chlorella vulgaris after 72 h exposure to citrate- and cetyltrimethylammonium bromide (CTAB)-stabilized AgNPs, as well as silver ions (AgNO₃), at concentrations allowing 75% cell survival (EC₂₅). All treatments impaired photosynthetic performance. The most pronounced decreases in chlorophyll fluorescence parameters and photosynthetic rate, alongside elevated energy dissipation, were observed after exposure to AgNP-CTAB and AgNO₃. AgNP-citrate had milder effects and induced compensatory responses, reflected in an increased performance index and upregulation of photosynthesis-related proteins. AgNP-CTAB induced the strongest downregulation of gene and protein expression, likely due to its higher EC₂₅ concentration and cationic surface promoting interaction with photosynthetic structures. Although AgNO₃ caused fewer molecular changes, it significantly disrupted photosynthetic function, suggesting a direct effect of Ag⁺ ions on photosynthesis-related proteins. Overall, the results highlight the role of AgNPs’ surface coatings and dosage in determining their phytotoxicity, with photosystem disruption and oxidative stress emerging as key mechanisms of action. Full article

This study aims to investigate the release of potentially toxic elements from disposable paper and plastic cups when exposed to hot water, simulating the scenario of their use in hot beverage consumption, and to assess the associated health risks. By using ICP-MS, twelve potentially toxic elements, namely As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Pb, Sb, V, and Zn, were determined in leachates, revealing significant variability in mass fractions between paper and plastic cups, with plastic cups demonstrating greater leaching potential. Health risk assessments, including hazard quotient (HQ) and excess lifetime cancer risk (ELCR), indicated minimal non-carcinogenic and carcinogenic risks for most elements, except Pb, which posed elevated non-carcinogenic risk, especially in plastic cups. Children showed higher relative exposure levels compared to adults due to their lower body weights (the HQ in children is two times greater than in adults). Overall, the findings of the current study underscore the need for stricter monitoring and regulation of materials used in disposable cups, especially plastic ones, to mitigate potential health risks. Future investigations should assess the leaching behavior of potentially toxic elements under conditions that accurately mimic real-world usage. Such investigations ought to incorporate a systematic evaluation of diverse temperature regimes, varying exposure durations, and different beverage types. Full article

Mycotoxins represent a group of highly toxic secondary metabolites produced by diverse fungal pathogens. Mycotoxin contaminations frequently occur in foods and feed and pose significant risks to human and animal health due to their carcinogenic, mutagenic, and immunosuppressive properties. Notably, deoxynivalenol, zearalenone, fumonisins (mainly including fumonisins B1, B2, and FB3), aflatoxin B1 (AFB1), and T-2/HT-2 toxins are the major mycotoxin contaminants in foods and feed. Undoubtedly, exposure to these mycotoxins can disrupt gut health, particularly damaging the intestinal epithelium in humans and animals. In this review, we summarized the detrimental effects caused by these mycotoxins on the intestinal health of humans and animals. The fundamental molecular mechanisms, which cover the induction of inflammatory reaction and immune dysfunction, the breakdown of the intestinal barrier, the triggering of oxidative stress, and the intestinal microbiota imbalance, were explored. These signaling pathways, such as MAPK, Akt/mTOR, TNF, TGF-β, Wnt/β-catenin, PKA, NF-kB, NLRP3, AHR, TLR2, TLR4, IRE1/XBP1, Nrf2, and MLCK pathways, are implicated. The abnormal expression of micro-RNA also plays a critical role. Finally, we anticipate that this review can offer new perspectives and theoretical foundations for controlling intestinal health issues caused by mycotoxin contamination and promote the development of prevention and control products. Full article

Bis(2-ethylhexyl) phosphate (P204) is widely used in extraction processes in the nuclear and rare earth industries. However, its high solubility in water results in high levels of total organic carbon and phosphorus in aqueous environments, and may also lead to radioactive contamination when it is used to combine with radionuclides. In this paper, we characterized a coconut shell activated carbon (CSAC) and a coal-based activated carbon (CBAC) for the adsorption of P204 and then evaluated their adsorption performance through batch and column experiments. The results found that, except for the main carbon matrix, CSAC and CBAC carried rich oxygen-containing functional groups and a small amount of inorganic substances. Both adsorbents had porous structures with pore diameters less than 4 nm. CSAC and CBAC showed good removal performance for P204 under low pH conditions, with removal efficiencies significantly higher than those of commonly used adsorption resins (XAD-4 and IRA900). The adsorption kinetics of P204 conformed to the pseudo-second-order kinetic model, and the adsorption isotherms conformed to the Langmuir model, indicating a monolayer chemical reaction mechanism. Both adsorbents exhibited strong anti-interference capabilities; their adsorption performance for P204 did not change greatly with the ambient temperature or the concentrations of common interfering ions. Column experiments demonstrated that CSAC could effectively fix dissolved P204 with a removal efficiency exceeding 90%. The fixed P204 could be desorbed with acetone. The findings provide an effective method for the recovery of P204 and the regeneration of spent activated carbon, which shows promise for practical applications in the future. Full article

Low-concentration N₂O (≤5%) emissions from agricultural fields and waste treatment facilities in China reach 7.333 × 10⁵ t annually, making them a significant but inadequately controlled contributor to global warming. Agricultural wastes were selected as precursors to prepare biochar, including pecan shell (SH), poplar sawdust (JM), wheat straw (XM), and corn straw (YM), which were subsequently acid-modified with 0.1 mol L⁻¹ HCl. The objectives were (i) to quantify the enhancement in N₂O capture achievable by acid treatment, (ii) to elucidate the underlying chemisorption mechanism, and (iii) to identify the most efficient feedstock for practical deployment. Acid modification increased the oxygen content, specific surface area, and the number of hydroxyl and carboxyl groups on the biochar surface. Both modified and unmodified biochar followed the pseudo-second-order kinetic model (R² ≥ 0.960), indicating chemisorption-dominated processes. The adsorption performance ranked as XM > JM > SH > YM, with XM exhibiting the highest adsorption capacity (26.000 mol/kg unmodified, 43.088 mol/kg modified, 65.72% increase). The Langmuir model provided a better fit for N₂O adsorption, suggesting dynamic multilayer heterogeneous adsorption. The findings demonstrate that acid-modified biochar derived from agricultural waste is a scalable, economical, and environmentally friendly adsorbent for mitigating low-concentration N₂O emissions. Full article