Environmental Geochemistry and Health最新文献

Titanium dioxide (TiO₂) nanoparticles were green-synthesized using whole Gracilaria edulis. The G. edulis was washed, dried, powdered and extracted, which is rich with various natural reducing, stabilizing, and capping agents. The TiO₂ nanoparticles confirmed with strong UV-Vis absorption with peaks between 250 and 350 nm, consistent with the anatase TiO₂ band gap. FTIR analysis revealed surface hydroxyl groups and organic residues from the algal extract, potentially facilitating reactive oxygen species (ROS) generation. XRD confirmed a highly crystalline nature of green-synthesized TiO₂ nanoparticles and showed irregular nanoscale morphology by SEM, while EDS confirmed Ti and O with minor algal-derived elements. TEM images showed mostly spherical, well-dispersed nanoparticles with minimal aggregation. Antimicrobial evaluation demonstrated stronger inhibition, with MIC values of 0.50 mg/mL for bacteria and 0.25 mg/mL for fungi. Photocatalytic degradation of methylene blue under sunlight achieved efficiencies of 90.1-94.4% at neutral pH (7) and 88.3-90.1% at alkaline pH (9), with performance improving at higher TiO₂ loadings (10-30 ppm), while acidic pH showed slightly lower but variable degradation. Immobilization within sodium alginate produced uniform, stable beads with minimal leaching, suitable for reuse, and biofilm assays demonstrated concentration-dependent inhibition of bacterial biofilm formation. These results highlight that G. edulis-mediated TiO₂ nanoparticles are promising sustainable materials in wastewater treatment and antimicrobial work because they have good physiochemical properties, strong antimicrobial and anti-biofilm action, and high dye degradation by photocatalysts.

Heavy metals, plastic-derived chemicals, and pharmaceuticals remain toxic, harming humans and the environment. Traditional methods for removing pollutants are effective but tedious and not fully successful, and prominent alternative techniques are essential. Several investigations revealed that engineered nanomaterials, plants, and their derived phytochemicals control the fate of emerging contaminants by altering their properties (physical and chemical). Therefore, combining these methods could produce a tool for removing the contaminants. Phytocompounds like alkaloids, terpenoids, and tannins chelate, absorb, and detoxify the contaminants. This gives out phytochemicals that result in the synthesis of engineered nanomaterials (ENMs) through an eco-friendly way acting as stabilizers capping agents together with reducing agents hence producing a safer nanoformulation which in turn eases elimination of pollutants. In addition to the polymer, carbon nanomaterials, and metal oxide nanoparticles provide larger surface areas with catalytic, adsorptive, and degradable surfaces that can trap pollutants. Thus, plant-derived products mixed with ENMs will create a synergistic effect that increases the reactivity of nano-formulations and their capacities toward clearing environmental contaminants from soils, sediments, and water. Thus, knowledge about ENMs interactive behavior with plant-associated chemicals is crucial for synthesizing a potential bio-nano remediation method. The current paper provides an in-depth discussion of the combined mechanisms of medicinal plant compounds and nanomaterials that could facilitate pollution impact assessments in a sustainable, nature-based manner.

Microplastic (MP) pollution in aquatic ecosystems has become a significant environmental concern worldwide. This study investigates the presence of MP in the main tributaries of the Morača river (Sitnica, Ribnica and Cijevna), the largest river flowing through the capital of Montenegro, aiming to enhance understanding of the presence, distribution, sources, and transport of MP in the Morača river basin. The present study will be covering the entire Morača river basin, yielding crucial data on MP contamination. The MP concentration in the studied rivers varied between mean values of 28.3 ± 12.2 MP/100 g dry sediment for the Sitnica, 24.9 ± 8.1 MP/100 g dry sediment for the Ribnica, and 27.3 ± 14.1 MP/100 g dry sediment for the Cijevna. The identified MPs were mainly fragments and fibers of blue, clear and red color, 0.5-1 mm in size and mainly composed of PE and PP. The results of the pollution load index indicate that the ecological status of the Morača river basin is subject to slight MP contamination, whereas the polymer hazard index results reveal a pronounced potential for adverse ecological effects. The main contribution of this study is a new insight into MP concentration in rivers and its tributaries, where the tributaries were identified as a potential important source of MP on the Morača river. This study represents a significant step towards a comprehensive understanding of the presence, distribution, sources and transport of MP pollution in the entire Morača river basin in Montenegro. The findings of this study will contribute to the growing body of knowledge about MP pollution in freshwater ecosystems, informing future research and the development of effective mitigation strategies to protect the ecological health and biodiversity of the basins.

Environmental pollution driven by rapid industrialization, intensive agriculture, and urban expansion has resulted in widespread contamination of soil and water by heavy metals and organic pollutants, posing persistent ecological and human health risks. This study addresses a critical scientific gap by experimentally evaluating nano-geochemical interfaces as dynamic reaction zones that integrate nanomaterial surface chemistry with soil-water geochemical controls, rather than considering nanomaterials as isolated adsorbents. The work investigates the potential of engineered and green-synthesized nanomaterials to enhance pollutant immobilization and transformation through interactions with natural geochemical and biogeochemical processes. Metal and metal-oxide nanoparticles, including Fe-based oxides, TiO₂, and nanosilica, were synthesized on functionalized nanocomposite surfaces via chemical and green routes. The materials were comprehensively characterized using TEM, SEM, XRD, BET, FTIR, XPS, and zeta potential analyses. Batch remediation experiments were conducted in contaminated soil and aqueous systems containing heavy metals (Pb²⁺, Cd²⁺, As³⁺) and natural pollutants such as dyes and pesticide residues under varying pH and ionic strength conditions. Under optimized conditions, heavy metal removal efficiencies of 75-85% were achieved, with reductions in bioavailable soil metal fractions exceeding 80%, as confirmed by sequential extraction analysis. Adsorption behavior followed Langmuir and Freundlich isotherms, while kinetic data were best described by pseudo-second-order models, indicating chemisorption-dominated mechanisms. For organic pollutants, combined adsorption and photocatalytic processes resulted in 85-95% removal under UV and solar irradiation, with composite nanomaterials exhibiting enhanced charge separation and faster degradation rates. Reusability studies demonstrated high material stability, with less than 10% performance loss over five cycles and negligible metal leaching (< 1 mg L^-1). Overall, the results establish nano-geochemical interfaces as a robust, interface-centric framework for sustainable environmental remediation.

Geophagy, the intentional consumption of clay and related earth materials is a culturally entrenched practice in Nigeria with potential public health implications. Considering Nigeria's large population, its role as a regional economic hub, and the widespread prevalence of geophagy, a comprehensive synthesis is urgently needed to inform risk mitigation and culturally sensitive health interventions. This scoping review included 26 peer-reviewed studies spanning 27 locations across 22 Nigerian states, focusing on clay (46.2% of samples), 53.8% on geophargic salts (trona, and natron). The review aimed to explore sociocultural and behavioral drivers, map chemical composition and toxicological profiles, evaluate risk assessment practices (including EDI and THQ), and assess health outcomes from human and animal studies. Heavy metal analyses revealed that 92.3% of clay samples exceeded WHO limits for lead (0.1 mg/kg), 42.9% exceeded cadmium limits (0.3 mg/kg), and 82.3% of studies reporting arsenic contamination surpassed EFSA limits (3 mg/kg). Risk assessments indicate elevated exposure for children, with some THQ values exceeding 1, suggesting potential non-carcinogenic health effects. Sociocultural drivers, particularly pregnancy-related cravings, traditional medicine use, and culinary practices, underpin persistent geophagy. This review integrates toxicological, behavioral, and risk assessment evidence, highlighting the need for public health strategies that are simultaneously culturally sensitive and scientifically informed to mitigate the health risks of geophagy in Nigeria.

Contaminated groundwater is a major pathway of human exposure to geogenic pollutants. This study investigates the occurrence and spatial distribution of arsenic and other trace elements in groundwater of the Qorveh-Dehgolan plain. Despite the high arsenic levels previously reported in this region, the hydrogeochemical processes controlling its enrichment remain poorly understood. To address this gap, groundwater hydrochemistry and quality were evaluated using an integrated approach that combines multivariate statistical analysis with Self-Organizing Maps (SOM), supported by Piper and Gibbs diagrams and cation-exchange indices. SOM analysis produced thirty neurons that grouped into three clusters, revealing distinct hydrochemical patterns across the study area. The dominant hydrochemical facies are Ca-Mg-HCO₃ (Cluster I), Ca-SO₄ (Cluster II), and mixed types (Clusters I and III), and groundwater chemistry is mainly governed by silicate and carbonate dissolution. Arsenic concentrations vary widely from 0.01 to 183.64 µg/L, with approximately 71% of the samples surpassing the WHO recommended limit of 10 µg/L for drinking water. Carcinogenic Risk (CR) calculations show that more than 70% of sampling locations exceed acceptable limits, with arsenic being the primary driver of both carcinogenic and non-carcinogenic health risks. The results suggest that arsenic is predominantly of geogenic origin, mainly linked to geothermal activity and the alteration of young acidic rocks, while localized mining activities likely enhance arsenic levels in the northern sector of the plain.

To investigate the potential impact of PM_2.5-bound heavy metals on the water source area, four monitoring sites were established in the Xichuan Reservoir area of the Danjiangkou Reservoir, a core component of the South-to-North Water Diversion Project. PM_2.5 samples were collected from June 2022 to April 2023 (n = 112), and concentrations of nine heavy metals (Cr, Mn, Fe, Ni, Cu, Zn, As, Cd, and Pb) were analyzed. The study identified major pollution sources and atmospheric transport pathways and assessed potential health risks. Results indicated that the total average concentration of the nine heavy metals was found to be 1.9062 μg m^-3, with Zn and Fe being the most abundant, contributing 72% and 23% of the total mass concentration, respectively. Seasonal variations were observed, with higher concentrations during spring and lower levels in summer and winter. No non-carcinogenic health risks were detected for any of the metals. However, As and Cr(VI) exhibited measurable carcinogenic risks. PMF analysis resolved four primary emission sources: traffic (35%), agriculture (33%), dust (23%), and coal combustion (9%). Among the sources, agricultural emissions were predominantly of local origin, whereas traffic and dust sources resulted from a combination of local emissions and regional transport. In contrast, coal combustion sources were primarily attributed to long-range transport. Notably, despite it's relatively low mass contribution, coal combustion constituted the primary source of both carcinogenic and non-carcinogenic risk, accounting for 81% and 65-67%, respectively. These findings address a critical research gap regarding heavy metals in PM_2.5 within the reservoir area, providing a theoretical foundation and data support for future air pollution control measures in the Danjiangkou Reservoir region.

This study presents a novel synthesis of amino-modified X zeolite (NH₂-NaX) derived from low-grade coal gangue via an alkaline fusion-hydrothermal method coupled with a grafting technique. The material was systematically evaluated for its adsorption performance toward lead (Pb) and cadmium (Cd), its efficacy in immobilizing these metals in contaminated soil, and its long-term stability under simulated acid rain leaching. Batch adsorption experiments demonstrated high maximum capacities of 214.123 mg/g for Pb and 256.740 mg/g for Cd. Adsorption kinetics followed a pseudo-second-order model, indicative of a chemisorption-dominated process, while the Freundlich isotherm provided a superior fit over the Langmuir model, suggesting multilayer adsorption involving physiochemical interactions. A 30-day soil incubation revealed that NH₂-NaX application significantly increased soil pH from an initial 6.4 to a range of 7.42-8.13 and effectively reduced the bioavailable fractions of Pb and Cd. The amendment promoted the transformation of exchangeable Pb and Cd into more stable residual and reducible fractions, with an optimal dosage identified at 1.5% (w/w). Dynamic leaching experiments under simulated acid rain (pH 5.0) confirmed that NH₂-NaX substantially reduced the cumulative release of both metals. Speciation analysis post-leaching showed a marked increase in residual/reducible fractions and a controlled rise in exchangeable metals compared to the untreated control, demonstrating effective inhibition of metal remobilization. These findings collectively establish gangue-based NH₂-NaX as a highly efficient, stable, and sustainable amendment for the immobilization of Pb and Cd in multi-metal contaminated soils.

Air pollution - the leading environmental threat to human health originates from natural and human sources that emit particles with PM2.5, PM10 and other toxic compounds as lead escalating alongside industrialization, urban growth and economic expansion. This study conducts the assessment for annual monitoring and health risk of PM2.5, PM10, and lead in ambient air across Bangkok, during 2021. Hourly PM data from 12 Pollution Control Department stations (7 residential, 5 roadside) and Pb measurements collected from 11 stations. Peak average values occurred at the Kanchanaphisek Road station (PM10 = 114.5 $\mu$ g /m $_{}^3$ in February; PM2.5 = 56.9 $\mu$ g/m $_{}^3$ in January), exceeding both Thai standards (120 $\mu$ g/m $_{}^3$ and 37.5 $\mu$ g/m $_{}^3$ ) and WHO 2021 guidelines (45 $\mu$ g/m $_{}^3$ and 15 $\mu$ g/m $_{}^3$ ). The mean Pb concentration , calculated from the station-specific averages of 11 air quality monitoring stations, was 0.041 $\mu$ gm $_{}^3$ (range 0.006-0.27 $\mu$ gm $_{}^3$ ), remaining well below the WHO guideline value of 0.5 $\mu$ g/m $_{}^3$ . A screening-level non-carcinogenic health risk assessment was conducted using the USEPA methodology based on hazard quotient (HQ) calculations. The HQ results indicated that PM10 posed potential health risks (HQ $\ge$ 1) for the sensitive population at roadside stations (03t and 54t), while PM2.5 was associated with potential health risks (HQ $\ge$ 1) for the sensitive population across all air quality monitoring stations. In contrast, HQ values for Pb in both sensitive and general populations, as well as HQ values for PM2.5 and PM10 in the general population, remained below the risk threshold (HQ<1), indicating no adverse health effects at the screening level. These findings highlight PM2.5 and PM10 as significant health threats in Bangkok, requiring environmental strategies to protect sensitive populations.

Persian Gulf is one of the most important oil producing regions in the world with a serious problem of marine pollution because of industrialization and growing population. This study examines the potential of the marine sponge Haliclona caerulea as a bioindicator for detecting heavy metal pollution, specifically nickel (Ni) and cadmium (Cd), by analyzing marine water and sponge tissues from Qeshm and Larak. Water and sponge samples were collected in both winter and summer to evaluate how pollutant levels change with the seasons. The findings showed that Qeshm Island had notably higher levels of Ni and Cd than Larak. The metal concentrations in sponge tissues ranged from 34.85 to 75.11 mg/kg for Ni and 14.67 to 41.85 mg/kg for Cd. The bioconcentration factor (BCF) analysis showed that H. caerulea from Qeshm Island accumulated metals at a significantly higher rate than those from Larak. Notably, Cd exhibited a much higher accumulation factor (37,095.24) compared to Ni (1,804.24). The result of this study indicates that H. caerulea serves as a reliable bioindicator of environmental pollution, especially for tracking heavy metal contamination in the Persian Gulf. The study highlights the need to reduce industrial and urban runoff to avoid additional environmental harm in this vital marine ecosystem.