Environmental Geochemistry and Health最新文献

Although, NPs have potential to improved plant resistance against abiotic stress, increased nutrient usage efficiency, and sustenance of agricultural production. However, reactions of NPs in soil matrices, particularly their movement, perseverance, and biogeochemical reactions in soil-plant system under heavy metals (HMs) were not well understood. Therefore, this review presents the latest research in order to clarify the molecular interactions, beneficial transformations, and detoxification processes of NPs in plants and evaluates their roles in these processes. It further aims to quantify the benefits and risks, and give future directions for NPs design and applications in environmental remediation and agriculture. NPs significantly enhanced agricultural outcomes through mechanisms such as regulating HMs uptake, boosting antioxidant enzyme activity (up to a 60% increase), altering soil properties, and optimizing physiological metabolism. NPs amendments raised crop output by 20-55% while reducing disease and nutrient leaching to 50% and 30%, respectively, and improving the soil's carbon sink by 15%. Meanwhile, green-synthesized nanomaterials offer eco-friendly alternatives in remediation through processes like adsorption, oxidation, coprecipitation, ion-exchange, photocatalysis, and nanophytoremediation, achieving 100% pollutant removal efficiency for elements like hexavalent chromium using iron NPs. However, challenges such as NPs accumulation in food chains, potential toxicity to non-target species, and physiological disruptions necessitate solutions like microbiome co-delivery and stimuli-responsive systems to balance safety and effectiveness. In order to increase the available resources and address the worldwide food safety issue, the use of NPs in agroecosystems might be a crucial step towards sustainable farming. Therefore, the influence of NPs on soil, and plant antioxidant defense systems and oxidative stress activation under HMs should be studied using molecular, physiological, and biochemical techniques. For this purpose, real-time polymerase chain reaction (RT-PCR) analysis, illumina MiSeq sequencing, pyrosequencing analysis, metagenomics, metabolomics, proteomics, and functional assays etc. could be most useful for NPs risk/benefit evaluation.

In this study, the Cu-SA/g-C₃N₄@2MI(2) catalyst was synthesized using a preassembly strategy; briefly, 2-methylimidazole acts as a structure-directing agent to disperse and immobilize copper in the carbon nitride precursor through bridging. Subsequently, this catalyst was combined with H₂O₂ to construct a heterogeneous Fenton-like reaction system for the treatment of RhB wastewater. The microscopic morphology and physicochemical properties of the catalyst were characterized by SEM, TEM, XRD, FTIR and XPS. The results show that Cu-SA/g-C₃N₄@2MI(2) exhibits a tubular structure with a specific surface area of 77.15 m²/g, and copper exists in the Cu⁺ valence state. The Cu-SA/g-C₃N₄@2MI(2) catalyst exhibited the maximum Fenton-like catalytic performance under neutral conditions, with 94.5% degradation of 50 mg/L RhB within 1 h. The catalyst maintains excellent catalytic performance in a wide pH range (3-11) and has good stability after being recycled for 5 times. The free radical trapping experiments and EPR results showed that ¹O₂ and O₂^•⁻ were the main active species in the degradation process. Based on the characterization analysis and experimental results, a possible pre-assembly strategy for synthesizing the catalyst and the pollutant degradation mechanism are proposed. This innovative synthesis strategy of transition metal doped carbon nitride catalysts based on imidazole ligands provides a new method for rational design of efficient H₂O₂ activation systems with clear active sites, and establishes a theoretical model basis for the study of metal-nitrogen coordination regulation degradation mechanisms.

Groundwater contamination threatens agricultural sustainability in hard-rock regions. This study presents a novel integration of Fuzzy C-Means (FCM) clustering and Fuzzy Shannon Entropy for evaluating groundwater quality at a micro-watershed scale-an approach not previously applied in the Bandu sub-watershed within Purulia district, India. A total of 64 groundwater samples were collected during the post-monsoon season from dug wells, tube wells, and submersible pumps, and analysed for physicochemical parameters, major ions, and irrigation indices (SAR, MAR, PI, RSC) using standard protocols. Hydrogeochemical assessment showed that 83% of samples fall within the Ca-Mg-HCO3 facies, indicating dominant rock-water interaction. Sodium hazards were low (SAR 0.23-2.81), with most samples classified as C2S1. However, magnesium posed a major constraint, as 60% of samples exceeded the critical MAR limit, and PCA was used to extract and analyze magnesium-salinity processes. FCM clustering delineated two hydrogeochemical zones: Cluster I (64% of samples) with good irrigation suitability and Cluster II (36%) with higher salinity stress (PC = 0.866, ASW = 0.640). Entropy-based prioritization classified the watershed into high (22%), moderate (63%), and low (15%) irrigation potential zones, with a prediction accuracy of 77.3% (AUC = 0.841). The integrated fuzzy-statistical framework offers an effective decision-support tool for micro-watershed management. The findings provide actionable insights for policy formulation, including targeted soil amendment strategies, improved irrigation scheduling, and sustainable agricultural planning in magnesium-affected hard-rock terrains.

Emerging contaminants (ECs), such as pharmaceuticals, endocrine-disrupting compounds (EDCs), and microplastics, increasingly accumulate in soils, posing ecological and health risks. Phenolic compounds, derived from natural and anthropogenic sources, undergo enzyme-mediated humification that governs interactions with co-occurring ECs. This review systematically evaluates multidisciplinary studies to elucidate enzyme-driven phenolic transformations and their influence on ECs dynamics, with emphasis on oxidative enzymes (e.g., phenol oxidase, laccase) that catalyze lignin-like polymerization. Evidence regarding the generation of reactive intermediates and humic polymers, and their regulatory roles in adsorption, degradation, mobility, and persistence of ECs, is synthesized. Representative case studies illustrate the environmental implications of these processes. Results show that phenolic humification produces radical intermediates and humic substances (HS) enriched with redox-active and functional groups, which modulate ECs speciation, enhance degradation or transformation pathways, and alter transport in soils. Humic polymers function as both sorbents and carriers, exerting dual effects on risk propagation. Enzyme activity, substrate availability, and soil physicochemical conditions are critical factors controlling these interactions. Overall, soil enzyme-catalyzed humification of phenolic compounds plays a central role in shaping ECs behavior and ecological risks. Elucidating these mechanisms provides a scientific foundation for risk assessment and supports the integration of enzymatic processes into predictive models and remediation practices for sustainable management of ECs.

The study assessed outdoor gamma radiation levels associated with fly ash dispersion from a 2820 MW coal-fired super thermal power plant located in Jhajjar district, Haryana, India. Gamma dose rates (GDR) were measured at 46 locations within a 20 km radius of the plant and at six reference locations beyond 20 km, during summer and winter seasons. The spatial distribution of radiation was heterogeneous, with two distinct hotspots identified along the east-west axis, attributable to increased fly ash deposition driven by prevailing local wind conditions. Measured GDR ranged from 92 to 206 nSv/h, with a mean value of 140.86 ± 32 nSv/h, which is notably higher than the regional background mean of 93.8 ± 20 nSv/h recorded beyond 20 km. The estimated annual effective dose (AED) varied between 0.112 and 0.257 mSv/y with a mean value of 0.171 mSv/y, remaining below the internationally recommended public dose limit. Excess lifetime cancer risk (ELCR) within the hotspot zones ranged from 4.20 × 10^-4 to 9.64 × 10^-4 with a mean value of 6.45 × 10^-4, compared with a mean of 4.16 × 10^-4 at locations beyond 20 km. These values correspond to approximately 645 and 412 excess cancer cases per million individuals, respectively. The findings highlighted the potential long-term radiological health risks in the vicinity of coal-based thermal power plants. Furthermore, the study established radiological baseline data that  would be essential for ongoing and future environmental monitoring programs.

Red mud storage sites pose significant environmental and health risks due to the accumulation and dispersion of toxic heavy metals (HMs). This study presents a novel framework integrating Self-Organizing Maps (SOM) with the APCS-MLR model for source apportionment and health risk assessment of soil heavy metal contamination near a red mud site in Shandong, China. Unlike traditional receptor models or SOM alone, this approach combines SOM's ability to reveal nonlinear spatial patterns with the quantitative strength of APCS-MLR to estimate source contributions. Additionally, we incorporate a source-oriented health risk assessment to directly link pollution sources with health impacts. These were further coupled with Monte Carlo simulation-based probabilistic health risk assessment and Getis-Ord Gi* spatial hotspot analysis to attribute health risks to specific sources and localize high-risk zones. Four major sources were identified: natural sources (46.34% ± 3.21%), red mud storage (20.08% ± 1.54%), coal combustion (2.84% ± 0.56%), and agricultural-industrial activities (2.81% ± 0.45%), along with 27.93% (± 4.12%) from unknown sources. Although red mud contributed less to total heavy metal loads, it dominated health risks, accounting for 63.84% of carcinogenic and 58.91% of non-carcinogenic risks, primarily due to its high arsenic content. This finding highlights the disproportionate health impact of red mud despite its lower contribution to the overall contamination. Spatial risk clusters corresponded strongly with red mud proximity and As concentrations. This study demonstrates the effectiveness of a multi-model integrative approach for resolving complex source-risk-space linkages and informing precision pollution control strategies.

Sustainable water management in regions impacted by artisanal gold mining (ASGM) requires a clear understanding of hydrochemical evolution and salt transformation processes. This study examines hydrochemical changes in the Wadi Abbady through a combined approach of geochemical modeling and stable isotope analysis, with the aim of disentangling the roles of natural processes and human activities in alternating water quality. Physicochemical parameters, major ions, and isotopic signatures were analyzed to trace both natural and anthropogenic influences. Results reveal pronounced chemical evolution within the Nubian Sandstone Aquifer (NSA), primarily controlled by reverse ion exchange. Mining activities induce a hydrogeochemical transformation, converting meteoric surface water assemblages (Ca (HCO₃)₂-Mg (HCO₃)₂-NaHCO₃-NaCl-Na₂SO₄) into slightly brackish water characterized by elevated sulfate salt concentrations (NaCl-Na₂SO₄-CaSO₄-MgSO₄-Ca (HCO₃)₂). Isotopic evidence indicate that the Quaternary Aquifer (QA) is not hydraulically connected to the deeper NSA, and is instead predominantly recharged by surface water through Wadi Abbady canals and irrigation return flows. End-Member Mixing Analysis (EMMA) using Cl^- and δ¹⁸O indicates that irrigation canals contribute approximately 60-90% of the total recharge to the QA, while amalgamation ponds provide a smaller but consistent contribution of 10-40%. This mixing pattern highlights both the hydrogeological connection between surface and shallow groundwater systems and the increased vulnerability of the QA to contamination originating from ASGM activities. These findings advance current understanding of water quality evolution in mining-affected environments and highlight the vulnerability of local aquifer systems to unregulated mining practices. This study emphasizes the need for continuous monitoring and long-term hydrochemical assessment in comparable settings to support sustainable water management and mitigate the impacts of artisanal mining.

Cardiovascular diseases (CVDs) remain the leading cause of mortality worldwide and are strongly influenced by both environmental and socioeconomic determinants. Populations engaged in informal and hazardous occupations, such as brickmaking, may experience elevated cardiovascular risk due to chronic exposure to environmental pollutants, including heavy metals (arsenic and lead) and polycyclic aromatic hydrocarbons (PAHs). This study aimed to assess occupational exposure to heavy metals and PAHs and to evaluate atherogenic indices as indicators of cardiovascular risk among brickmakers in the Bajío region of Mexico. A cross-sectional study was conducted among 113 male adults from brickmaking communities in San Luis Potosí (SLP), Guanajuato (GTO), and Querétaro (QRO). Urine and blood samples were analyzed to quantify heavy metals and PAHs, while lipid profiles were used to calculate Castelli's Risk Indices (CRI-I and CRI-II) and the Atherogenic Index of Plasma (AIP). GTO exhibited the highest urinary arsenic concentrations (42.5 µg/l), whereas SLP showed the highest blood lead levels (1.52 µg/dl). PAH exposure was also highest in GTO (2.25 µmol/mol creatinine). Correspondingly, the highest atherogenic index values were observed in GTO: CRI-I (4.28 ± 0.97), CRI-II (2.54 ± 0.64), and AIP (0.145 ± 0.28). A considerable proportion of participants presented moderate to high CVD risk profiles. Significant associations were found between arsenic and lead exposure and elevated CRI-II values, suggesting potential disruption of lipid metabolism. These findings confirm occupational exposure to environmental pollutants in brickmaking populations and indicate that chronic exposure to arsenic and lead may contribute to increased cardiovascular risk, as reflected by higher atherogenic indices.

This study examines two hypotheses: (i) Geogenic metal(loid)s in the Geita region contribute to high cancer rates. (ii) Poor waste management in artisanal and small-scale gold mining (ASGM) activities increases the mobility of carcinogenic metal(loid)s, thereby increasing health risks. Using pollution and ecological risk indices, this study evaluated the contamination of toxic metal(loid)s and assessed their associated carcinogenic risks. The findings reveal that As, Cr, and Ni pose significant threats, with Cr exceeding the unacceptable carcinogenic risk level (1 × 10^-4) for both adults and children. The mean concentrations of As and Ni in both topsoil and subsoil exceed Tanzania's agricultural soil standards. Moreover, pollution indices, including the enrichment factor, geo-accumulation index, and contamination factor, confirm the high pollution levels of these metal(loid)s. The results further reveal that Cr and Ni are geogenic, originating from the weathering of mafic rocks within the Geita Greenstone Belt, while As is predominantly associated with gold ores. One of the five analyzed gold ores had a pH of 3.01 and As concentration of 99.3 mg/kg, while some tailings exhibited a pH of 9.3 and As concentration of 11.2 mg/kg. Under neutral conditions, As concentrations ranged from 0.05 mg/kg to 2.39 mg/kg, indicating a significant variation. This suggests that some gold ores in Geita are acid-forming, while certain tailings are alkaline. Consequently, the mobility of toxic metal(loid)s is enhanced by both acid and alkaline drainage. These findings support both hypotheses. Assessing acid mine drainage in ASGM sites should be prioritized globally to reduce associated health risks.

Wastewater treatment plants (WWTPs) and landfill represent critical point sources for per- and polyfluoroalkyl substance (PFAS) emission to the atmosphere. This study aimed to (1) quantitatively characterize both neutral and ionizable PFAS in air samples from these sources, and (2) estimate the potential emission contributions of unknown PFAS precursors. Using an optimized cartridge-based active air sampler, we collected atmospheric samples from a WWTP and landfill in Tianjin, China. Quantitative analysis revealed comparable concentration ranges for neutral (Σn-PFAS: 2,816-564,343 pg/m³) were higher than ionizable PFAS (Σi-PFAS: 4,275-13,360 pg/m³), with 8:2 fluorotelomer alcohol (8:2 FTOH; 2,273-13,360 pg/m³) dominating neutral species and trifluoroacetic acid (TFA; 2,490-10,575 pg/m³) prevailing among ionizable compounds. The total oxidizable precursor assay demonstrated that unknown precursors accounted 46.4-58.4 mol% of total PFAS. These findings provide the quantitative evidence of airborne PFAS speciation and associated unknown precursor-derived emission contributions in the WWTP and landfill.