Environmental Geochemistry and Health最新文献

Atmospheric deposition plays a significant role in introducing cadmium (Cd) into agroecological systems; however, the understanding of its accumulation and toxic effects on crops through foliar and root uptake remains limited. In this study, we simulated atmospherically deposited Cd using cadmium sulfide (CdS) nanoparticles. A factorial pot experiment with both foliar and soil exposure to CdS was conducted to investigate the bioaccumulation and phytotoxic effects of simulated deposited Cd in wheat. The results indicated that Cd concentrations in various wheat tissues (roots, stems, leaves, husks, and grains) significantly increased (p < 0.05) under both exposure pathways. For grains, foliar exposure increased Cd levels by 14-fold with a low dose of exposure and by 90-fold with a high dose of exposure. Under soil exposure, grain Cd levels increased threefold in the low-dose exposure and ninefold in the high-dose exposure. Foliar exposure led to a greater increase in Cd accumulation in grains compared to soil exposure, suggesting that foliar absorption may be the primary pathway for Cd accumulation from simulated atmospheric deposition in the edible parts of wheat. Additionally, foliar exposure resulted in more pronounced reductions in leaf antioxidant enzyme activities (SOD and CAT, 23-39%) and sulfhydryl (-SH, 17-50%) content, indicating potentially more severe oxidative damage from foliar exposure. However, the concentrations of essential mineral elements (Ca, Mn, Zn, Fe) of grains significantly decreased under both exposure pathways. Furthermore, both exposure modes significantly altered the protein and amino acid content of the grains. Under high exposure levels, the tyrosine content of grains significantly decreased (approximately 9.5%) with foliar exposure, while the levels of valine, methionine, and isoleucine significantly decreased (11-59%) under soil exposure. These findings underscore the significant role of foliar absorption in Cd accumulation in wheat grains and suggest the phytotoxic effects of soil exposure to atmospherically deposited Cd.

Springs in tropical volcanic regions are vital resources for drinking water, irrigation, and sustaining local communities. However, rapid land use changes and intensified anthropogenic activities have contributed to the degradation of spring water quality. This study analyzed 13 physicochemical parameters in 30 spring samples from the southern slopes of Mt. Merapi, Indonesia, during the dry and rainy seasons to characterize seasonal hydrogeochemical dynamics, evaluate spring water quality, and assess associated health risks. The Water Quality Index (WQI) and Irrigation Water Quality Index (IWQI) were applied to determine suitability for drinking and irrigation, alongside a non-carcinogenic risk assessment based on nitrate (NO₃^-) and fluoride (F^-) ingestion. The results indicated that the groundwater facies were dominated by Ca-Mg-HCO₃ and mixed Ca-Na-HCO₃ types. Most springs had good to excellent WQI, confirming drinking suitability, whereas those influenced by agriculture and urban activities showed lower quality. The IWQI assessments similarly indicated generally good water quality, with low salinity and sodicity hazards, supporting the suitability of the water for irrigation. Statistical analysis revealed that seasonal variations did not significantly affect the hydrogeochemical composition or overall groundwater quality. Furthermore, NO₃^- and F^- contamination was closely linked to surface runoff and infiltration from agricultural and domestic wastewater. The Total Hazard Index (THI) of NO₃^- and F^- indicated that infants are more vulnerable to non-carcinogenic health effects than children and adults. These findings emphasize the link between spring water quality and human health, providing evidence for sustainable groundwater management in volcanic regions.

This study assesses the spatial variation, sources, and environmental and ecological risks of heavy metal and metalloid pollution in the surface soil of the Singrauli coal mine area, Madhya Pradesh, India. It analyses the intensity of pollution through the major pollution indices. Composite soil samples were collected from 14 sampling locations using the quartering method. Collected samples were digested and analysed for 14 elements by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The concentration of these elements is used to compute 7 pollution Indices to determine the severity of pollution in the study area. Multivariate statistical analysis was conducted to identify the sources and processes contributing to metal pollution in the study area. The abundance of elements followed the order: Fe > Al > Mn >Ba > Zn > Cr > Cu > Ni > Pb > Co > B > As > Ag > Cd. The concentration of Cd (0.43 ± 0.18 mg/kg), Pb (15.73 ± 10.48 mg/kg), and Zn (83.00 ± 53.55 mg/kg) exceeded the mean USEPA recommended concentration for soil. The geo-accumulation Index showed a positive value for Pb (I_geo = 1.52). The enrichment factor showed a high enrichment for Mn, Cu, As, and Cd. Mean Contamination Factor values ranged between 0.03 (Ag) and 4.77 (Cd). Nemerow pollution index (NPI) values ranged from 1.08 to 5.67, suggesting slight to heavy pollution. The enrichment factor for Cd fell in a very high-risk zone (Er > 120). The potential risk index (PERI) across sites ranged from 47.46 to 275.07, suggesting a low to moderate ecological risk. Mean ERM quotient (MERMQ) values indicated the potential soil toxicity in the study area. The global implications of studying heavy metal pollution in soil, especially around coal mining areas, are widespread and impact various aspects of the environment, viz., sustainability, scientific research, agricultural productivity, human health and socio-economic development worldwide. This issue is recognised globally as a significant environmental problem that requires urgent global attention.

This study investigates the sulfate durability performance of concrete incorporating lead-zinc tailings sand (LZTS) as partial replacement for fine aggregates. Greater emphasis is placed on long-term resistance to sulfate attack rather than on strength enhancement, ensuring full consistency with the manuscript title. Sulfate exposure conducted in a 5% Na₂SO₄ solution for periods of up to 180 days, during which mass change, linear expansion, surface degradation, and residual mechanical strength were systematically evaluated. The results demonstrate that optimized levels of LZTS replacement, in combination with low-dosage hybrid nanomaterials, significantly enhance the sulfate resistance while maintaining satisfactory mechanical performance. From a sustainability perspective, replacement of up to 50% of natural river sand is achievable, contributing to reduced depletion of natural resources. Microstructural observations obtained from SEM, supported by XRD and FTIR analyses, provide indirect yet consistent evidence of matrix densification and suppression of sulfate reaction products. FTIR spectra confirmed these observations by intensifying Si-O-Si and Al-O-Si bands and weakening Sulfate-associated vibrations with Heavy metal immobilization efficiency exceeding 90%. The findings reveal the potential of LZTS-based concrete as a durable and environmentally responsible construction material for sulfate-rich environments.

Graphitic carbon nitride (g-C₃N₄), a metal-free polymeric semiconductor, has attracted increasing attention for photocatalytic and biomedical applications due to its visible-light responsiveness, tunable electronic structure, and chemical robustness. However, its practical utility remains constrained by poor crystallinity, limited active surface sites, and rapid electron-hole recombination. In this study, a facile one-step calcination strategy was employed to synthesize highly crystalline, non-metal-doped g-C₃N₄ nanostructures with enhanced physicochemical properties. Structural and optical characterizations revealed improved crystallinity, expanded surface area, defect-rich architecture, and extended visible-light absorption. These features significantly boosted the photocatalytic performance for the degradation of Reactive Blue 222, achieving up to 89% removal within 90 min under visible light, with the degradation kinetics following a pseudo-first-order model (k = 0.97 min⁻¹). Beyond environmental remediation, the modified g-C₃N₄ also demonstrated notable anticancer activity against HCT-15 (colon cancer) cell lines. Cytotoxicity assays revealed concentration-dependent inhibition, with IC₅₀ values of 7.10 µg/mL, respectively, indicating its potential as a photodynamically active nanomaterial for cancer therapy. The dual functionality of visible-light-driven photocatalysis and selective anticancer activity underscores the potential of engineered g-C₃N₄ as a sustainable platform for integrated environmental and biomedical applications.

Radon, a naturally occurring radioactive gas produced from the decay of uranium in the subsurface, migrates upward through soil by diffusion and advection before being released into the atmosphere. As the second leading cause of lung cancer after smoking, understanding its behavior in the near-surface environment is essential for assessing environmental radiation risks. This study investigates depth-wise radon concentrations in soil gas, surface exhalation rates, and transport parameters in the soil of Chakrata region,  Garhwal Himalaya, India. Radon measurements were performed using a portable Smart RnDuo monitor at depths (Z) of 15, 30, and 45 cm. Soil-gas radon concentrations ranges from 237 to 6540 Bq m^-3 at 15 cm, 854 to 7831 Bq m^-3 at 30 cm, and 1020 to 8540 Bq m^-3 at 45 cm, indicating a systematic increase with depth. Surface exhalation rates varies between 1.25 and 16.19 Bq m^-2 h^-1, with a mean value of 6.42 Bq m^-2 h^-1, respectively. Radon transport parameters were derived using Fick's diffusion model, resulting in average values of 0.49 m for diffusion length (l_s) and 0.002 m²s^-1 for diffusion coefficient (D_s). Spearman's rank correlation analysis revealed that surface radon exhalation and diffusion parameters exhibit strong correlations. These findings provide baseline information on radon mobility and soil-gas dynamics in the region and will support future radon hazard assessment and environmental monitoring efforts in the Chakrata area of the Lesser Indian Himalaya.

The development of efficient and sustainable adsorbents is crucial for remediation heavy metal contamination in both aqueous and terrestrial environments. Biomass-derived biochar shows great promise, yet its adsorption performance is highly dependent on both the feedstock properties and the pyrolysis temperature. However, a systematic understanding of how temperature dictates the adsorption mechanisms, especially for multi-metal systems, remains limited for novel biomass precursors. Therefore, the stem pith of Medulla stachyuri (MS) was utilized to prepare biochars at different pyrolysis temperatures (400, 600, and 800 °C, denoted as MBCs) and to investigate their adsorption behavior for Pb²⁺ and Cu²⁺. The results indicated that higher pyrolysis temperatures significantly enhanced the specific surface area (reaching 322.94 m²/g for MBC-800) and ash content but decreased the oxygen-containing functional groups. MBC-800 exhibited superior adsorption capacities for Pb²⁺ (2139.25 mg/g) and Cu²⁺ (970.68 mg/g), with remarkable selectivity for Pb²⁺ in binary systems. Mechanistic studies revealed that the dominant adsorption mechanism shifted from surface complexation at lower temperatures to precipitation induced by the biochar's inherent inorganic components (e.g., SO₄²⁻ forming PbSO₄) at higher temperatures. Component contribution analysis quantitatively confirmed that the water-soluble fraction in MBC-800 was responsible for over 78% of Pb²⁺ immobilization. Furthermore, MBC-800 demonstrated excellent stability with the lowest desorption rate, indicating a low risk of secondary pollution. This work highlights the superiority of high-temperature biochar from MS for efficient and stable heavy metal removal, providing new insights into the precipitation-dominated mechanism and the high-value utilization of medicinal plant residues.

Sugar production generates high-strength wastewater that poses a persistent threat to aquatic ecosystems, particularly in water-scarce regions. While wastewater treatment plants (WWTPs) are deployed to mitigate this impact, their performance is traditionally evaluated through pollutant removal efficiency, a metric that can mask the significant residual environmental pressure of the final effluent. This study employs the grey water footprint (GWF) to conduct a holistic, five-year (2021-2025) assessment of a sugar production facility in Isfahan, Iran, quantifying the volume of freshwater required to assimilate the pollutant load from both raw and treated wastewater. The analysis of raw wastewater revealed an exceptionally high pollution load, culminating in a Nitrate-dominated GWF of 167.3 m³ per ton of sugar produced. Following treatment via an upflow anaerobic sludge blanket (UASB) system, the effluent was monitored for key pollutants (BOD, COD, Nitrate, Phosphate). Diagnostic ratio, Principal Component Analysis (PCA), and a 95% confidence interval uncertainty analysis collectively and unequivocally identified Nitrate as the most unstable and critical parameter, consistently dictating the annual GWF. The treatment process achieved a substantial reduction, lowering the average GWF to 1.4 m³/ton, a decrease of over 99%. It was demonstrated that the GWF provides a more accurate and environmentally relevant benchmark than removal percentages alone, transforming the perception of treatment efficacy. The findings underscore the imperative to optimize treatment trains for robust Nitrate removal and to integrate GWF metrics into regulatory frameworks for sustainable water resource management in the sugar industry and analogous sectors.

Small reservoirs are under-researched despite their critical role in rural water supply, particularly regarding spatio-temporal variability and livestock-specific health thresholds. Most regional studies focus on water quality for human consumption not livestock, hence, this study, which aimed to assess physicochemical properties of the Makoye Reservoir and evaluate their implications on livestock using water samples collected during the 2023/24 rainy season through stratified random sampling, where sections of the reservoir were divided into strata and sampling points selected. Laboratory analyses included total suspended solids (TSS), turbidity, pH, nutrients (nitrates and phosphates), major ions (sodium, calcium, magnesium, and sulphates), and heavy metals (iron, lead, cadmium, and copper). Spatial heterogeneity was mapped using Inverse Distance Weighting interpolation in ArcGIS 10.2, having been the freely accessible version. Results showed that pH, nitrates, conductivity, sodium, and sulphates largely conformed to FAO thresholds, indicating generally acceptable seasonal quality. Phosphate averaged 0.48 mg/L, nearly five times the FAO maximum of 0.1 mg/L, raising concerns about eutrophication and reproductive health. Iron averaged 4.82 mg/L, over sixteen times the 0.3 mg/L limit. TSS averaged 2885.9 mg/L, almost three times the recommended 1000 mg/L, contributing to high turbidity and reduced palatability. Lead and cadmium were negligible, suggesting minimal industrial impact. Spatial analysis revealed nitrate hotspots in the northwest linked to agricultural runoff, sulphate peaks centrally associated with mineral dissolution, elevated iron near shorelines, and peripheral increases in calcium, magnesium, and sodium due to shoreline grazing. Although most parameters met FAO guidelines, critically high phosphates, iron, and suspended sediments pose risks to livestock health and reservoir ecology. Integrated livestock water quality needs assessment model, erosion control, improved manure management, and regular livestock-focused monitoring are recommended. The study suggests a novel water quality monitoring framework for livestock.