Environmental Geochemistry and Health最新文献

This study presents a mineralogical and multielement assessment of kidney stones from Iraqi patients, a region where epidemiological and geochemical data are limited. A total of 52 stones were analysed by ICP-QQQ to determine the concentrations of 43 elements, including rare earth elements (REEs). A subset of 49 stones was further characterised by FTIR and XRPD to identify the mineral phases present. Four regional groups were identified, with most patients originating from the Sulaymaniyah region. Whewellite (calcium oxalate monohydrate) was the most common mineral phase (32.7%), followed by uricite (28.6%), while the remaining samples exhibited mixed or layered compositions. Uricite stones were more frequent in women, older patients, and individuals from outside the Sulaymaniyah region, whereas whewellite-dominated stones were more common in men. Trace element concentrations varied by several orders of magnitude. Stones containing whewellite and mixed calcium-bearing phases showed the highest enrichments in Ba, Sr, Zn, Pb, and Ti, whereas uricite stones consistently had low trace element contents. Several samples exhibited notable anomalies, including very high Zn (> 1 g/kg), Sr (> 600 mg/kg), and Pb (> 30 mg/kg) levels, indicating pronounced geochemical heterogeneity and possible environmental contributions. REE patterns were dominated by light REEs, except for two stones with pronounced Gd anomalies, likely reflecting prior exposure to Gd-based MRI contrast agents. Statistical analysis revealed clear geochemical signatures distinguishing whewellite-rich, mixed, and uricite stones. Overall, the results highlight strong links between mineralogy, trace element uptake, and environmental or physiological factors, emphasising the importance of integrated mineralogical and geochemical characterisation for understanding kidney stone formation in this region.

This critical review delves into non-methane hydrocarbons (NMHCs), a class of volatile organic compounds (VOCs) that consist of carbon and hydrogen atoms, and are distinguished from methane due to their higher reactivity in the atmosphere. NMHCs play a critical role in tropospheric ozone formation and secondary aerosol production, with implications for air quality and human health. This review synthesizes existing findings on NMHC species, sources, and measurement techniques across diverse regions of India, highlighting elevated BTEX levels in urban-industrial regions, and the significant data scarcity in rural settings. Major gaps include fragmented datasets, inconsistent measurement protocols, and limited adoption of advanced techniques such as online GC-FID and PTR-MS. Health-based risk assessments indicate concerning levels of excess lifetime cancer risk from benzene exposure in megacities. The review underscores the need for harmonized monitoring practices, integrated source apportionment frameworks, and robust spatiotemporal datasets. It also outlines the limitations of conventional gas chromatography and highlights emerging NMHC species requiring further study. Quantitative evaluations, including ozone formation potentials and cancer risk assessments, reveal substantial public health and agricultural vulnerabilities. This assessment advocates for a nationwide NMHC monitoring network and the integration of atmospheric, geochemical, and epidemiological data to inform evidence-based mitigation strategies and policy interventions.

The microbial degradation of petroleum hydrocarbons is a fundamental biogeochemical process and a cornerstone of environmental bioremediation. While traditional culture-based studies have outlined the basic principles, the advent of metagenomics has revolutionised our understanding by revealing the full genetic and functional diversity of hydrocarbon-degrading communities in situ. This review synthesises the current state of knowledge on both aerobic and anaerobic hydrocarbon biodegradation, providing a critical comparative analysis of traditional versus multi-omics methodologies. We provide an in-depth examination of aerobic mechanisms, initiated by oxygenases (e.g., alkB, PAH-RHDα), and contrast them with the diverse array of anaerobic activation pathways, including fumarate addition (bssA) and the recently elucidated direct carboxylation pathway for polycyclic aromatic hydrocarbons (PAHs). Furthermore, we highlight groundbreaking metagenomic insights into anaerobic benzene degradation and the critical role of syntrophic networks driven by interspecies electron transfer. Finally, we present specific case studies demonstrating the translation of genomic data into practical bioremediation strategies, such as the rational design of synthetic consortia. This review charts these recent advances, highlights remaining knowledge gaps, and outlines future directions for harnessing multi-omics to translate genomic potential into effective, field-scale environmental solutions.

Biochar, a carbon-rich material, is usually prepared by thermochemical processes from a diversified biomass or organic waste. It is a plentiful and environmentally sustainable product commonly used as an adsorbent to eradicate various organic contaminants, including heavy metals and nutrients, from wastewater. When compared with conventional biochar, the engineered or modified biochar usually possesses improved properties, including developed surface area with high adsorption capacity or more surface functional groups (SFG) chemically. This makes it a potential material for a variety of wastewater treatment applications. The present paper summarizes research work of various investigators and researchers pertaining to biochar and modifications of its properties in terms of its synthesis, usage, and regeneration as compared with conventional biochar. It is also inferred that precursor material composition, preparation parameters, and modification methods have a major impact on biochar properties. The chemical alkali treatment produces the most surface-functionalized biochar. Also, the chemical changes that outperform steam activation enhance the biochar surface functioning. It is reported that biochar composites, when treated with alkali or that have been impregnated with nanomaterials, enhance the adsorption of different types of wastewater and thereby prove to be very beneficial and cost-effective. Similarly, biochar surfaces with acidic treatment have a higher concentration of oxygenated functional groups. The present review work further depicts the modified biochar process as the most economical and ecologically friendly method for removing toxic pollutants from different types of wastewater. It is further concluded that for heavy metals and anionic pollutants, the sorption equilibrium is best designated by the Langmuir isotherm model. Also, for emerging contaminants, the Freundlich isotherm model is more appropriate, while the pseudo-second-order model best captures the sorption kinetics for all pollutants.

Road dust in urban areas is a significant carrier of heavy metals (HMs), posing serious environmental and health threats to humans. This study investigates the concentration, sources, and associated health risks of HMs (Cr, Mn, Ni, Cu, Zn, Cd, and Pb) in road dust collected from 27 metro bus stations in Lahore, Pakistan. The mean concentrations (mg/kg) of Cr, Mn, Ni, Cu, Zn, Cd, and Pb in road dust were 51.83, 364.79, 22.36, 93.57, 421.50, 3.37, and 50.64, respectively, following the descending order: Zn > Mn > Cu > Cr > Pb > Ni > Cd. Pollution indices revealed severe contamination by Cd (CF > 6), significant contamination by Zn, and a high ecological risk index (RI = 329.90), while the pollution load index (PLI = 2.49) indicated overall high pollution. Pearson correlation analysis showed strong associations among traffic-related metals (Ni-Cr, r = 0.92; Cu-Zn, r = 0.91). PCA and HCA grouped the metals into three clusters, and PMF identified three major sources: industrial traffic mixed emissions, non-exhaust vehicular emissions, and mixed urban deposition. Health risk assessment indicated ingestion as the dominant exposure pathway. Non-carcinogenic risks (HI < 1) were within safe limits; however, carcinogenic risks for Cr (2.84 × 10^-4) and Ni (4.16 × 10^-4) in children exceeded the acceptable threshold. This study proposes that non-exhaust traffic emissions are the dominant contributors to HMs loading in metro-corridor dust, with children facing elevated long-term carcinogenic risks, highlighting the need for targeted mitigation strategies in urban transport environments.

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.