Environmental Science and Pollution Research最新文献

Poor indoor environmental quality (IEQ) remains a significant driver of paediatric morbidity, yet data on the interplay between particulate matter (PM), building design, and health in tropical schools are sparse—a gap exacerbated by severe data scarcity and policy deficits across sub-Saharan countries. In this study, the spatio-temporal dynamics of classroom air quality and thermal comfort were investigated to identify the key environmental determinants of respiratory health risks among primary and secondary school students in Benin City, Nigeria. A mixed-methods approach combining objective environmental monitoring and subjective assessments was deployed across six schools for 10 weeks. IEQ parameters (PM_2.5, PM₁₀, CO, and CO₂) and thermal indices were monitored, while health data were collected through modified British Medical Research (BMR) questionnaires and analysed using descriptive, inferential, and multivariate logistic regression. To estimate non-carcinogenic health risks, the hazard quotient (HQ) was calculated using the US States Environmental Protection Agency (US EPA) framework. The PM_2.5 and PM₁₀ concentrations ranged from 11.2 to 81.4 µg/m³ and 20.1 to 138.6 µg/m³, respectively. The CO₂ concentration peaked at 729.3 ± 28.4 ppm, while high temperature‒humidity index (THI) values (28.3–30.1) indicated severe heat discomfort. Health risk assessment revealed that all HQ values for PM_2.5 and PM₁₀ remained below unity (HQ < 1), suggesting that students were not at immediate risk of chronic non-carcinogenic effects; however, the high prevalence of reported respiratory symptoms—including coughing (58.2%), phlegm (32.5%), and chest pain (26.7%)—underscores that acute respiratory irritations frequently manifested well below these chronic regulatory thresholds. Multivariate analysis revealed that elevated PM exposure was strongly associated with an increased risk of coughing (p < 0.001) and significantly increased the odds of chest pain (crude OR = 2.74; p = 0.001). Poor sanitation was the strongest predictor of phlegm production (AOR = 5.54; 95% CI 1.35–22.80; p = 0.018) after adjustment for confounders, including age, sex, and socio-economic status. This study highlights a critical link between the school-built environment and student respiratory health. While chronic risk thresholds (HQs) were not exceeded, particulate matter and sanitation emerged as the primary drivers of acute respiratory symptoms, demonstrating that immediate health risks persist within poorly regulated tropical academic environments.

Spinel cobalt oxide (Co₃O₄) has the ability to activate peroxymonosulfate (PMS) for pollutant degradation, but agglomeration and poor active sites of pure Co₃O₄ limit its efficiency, even its mechanism is ambiguous. Herein, coal gangue (CG)-derived molecular sieve (CGMS) was prepared via an alkali fusion-hydrothermal method and the Co₃O₄/CGMS composite was fabricated by a simple calcination process. Co₃O₄/CGMS was utilized to activate PMS for methylene blue (MB) degradation. Under optimized conditions, 95.29% of MB was removed within 21 min in the Co₃O₄/CGMS-PMS system, outperforming the pristine Co₃O₄-PMS and CGMS-PMS systems. the catalyst also delivered excellent stability and reusability with MB removal efficiency over 90% after five cycles. Quenching experiments and EPR analysis indicated that ¹O₂ played the dominant role in MB degradation with the assistance of •OH, SO₄•⁻ and O₂•⁻ during the oxidation process. More importantly, Co₃O₄/CGMS can also degrade Acid Orange G, Rhodamine B, and Methyl Orange, confirming its ability to purify water. Electrochemical tests and X-ray photoelectron spectroscopy (XPS) analysis confirm that Co₃O₄/CGMS with the promoted Co²⁺/Co³⁺ redox, and oxygen-vacancy generation. These synergistic structural and catalytic effects collectively endowed Co₃O₄/CGMS with exceptional capabilities for PMS activation to remove organic dyes. This work not only provides a feasible strategy for converting coal gangue into functional catalytic materials, but also offers insight into PMS activation over supported cobalt-based catalysts.

The rational design of defect-engineered metal oxide photocatalysts via mild and sustainable routes remains a key challenge in environmental remediation. Herein, we report a novel in situ urea-assisted self-reduction strategy for the one-pot synthesis of chlorine-doped SnO₂ nanocrystals enriched with oxygen vacancies. By employing a confined dual-crucible configuration, thermal decomposition of urea at 300 °C generates a localized reducing microatmosphere, which simultaneously promotes the substitution of lattice oxygen by residual chlorine from the tin hydroxy chloride precursor and induces the formation of high-density oxygen vacancies. Comprehensive characterization reveals that the synergistic effect of chlorine doping and oxygen vacancies progressively narrows the bandgap from 3.50 to 2.76 eV, extends the photoresponse into the visible region, and significantly enhances photogenerated charge separation and interfacial charge transfer. As a result, the optimized sample achieves 97.5% degradation of methyl orange (20 mg/L) within 45 min under visible-light irradiation, with superoxide radicals identified as the predominant reactive species. This work presents a facile and scalable approach for the controlled synthesis of defect-rich metal oxides, offering new insights into the design of high-performance photocatalysts for water purification.

Accurate reservoir storage forecasting is critical for water security and risk management, yet most data-driven approaches emphasize short-term predictive skill without accounting for long-term changes in storage capacity caused by sedimentation. This study addresses this gap by examining whether monthly, hydro-climatic machine learning forecasts of effective water storage capacity can be meaningfully evaluated against observed, multi-year capacity changes derived from bathymetric surveys. Forecasting performance is evaluated at the rainfall-driven Mingde Reservoir and the highly regulated Shihmen Reservoir in Taiwan using linear regularized regression and a nonlinear tree-based model forced by precipitation, temperature, humidity, and evaporation, deliberately focusing on hydro-climatic forcing due to the temporal unavailability or static nature of monthly sediment transport, land-use, and operational release records. Model outputs are assessed using conventional performance metrics together with independent bathymetric benchmarking and interpretability analysis. Results show that model suitability depends strongly on reservoir behavior and operational regulation. At Mingde Reservoir, the linear model provides stable and accurate forecasts (Nash–Sutcliffe efficiency of 0.968), whereas the nonlinear model performs better at the highly regulated Shihmen Reservoir (Nash–Sutcliffe efficiency of 0.952). Interpretability analysis reveals that forecasts are dominated by antecedent storage, leading to systematic bias during extreme drought conditions. Although the models accurately reproduce storage variability when static capacity curves are assumed, bathymetric benchmarking demonstrates a failure to capture multi-year capacity loss caused by sedimentation, with relative errors reaching up to 292%. These findings identify a structural limitation of hydro-climatic forecasting frameworks and highlight the need to explicitly incorporate sediment-related processes to support long-term reservoir management.

The new Urban Wastewater Treatment Directive (EU) 2024/3019 introduces a substantially more stringent regulatory framework by extending its scope to all urban agglomerations of at least 1000 population equivalents, in response to evidence showing that small agglomerations contribute significantly to pressure on approximately 11% of the European Union’s surface water bodies—a source of pollution not fully addressed by previous regulations. Against this background, this study assesses a nature-based treatment upgrade implemented at two wastewater treatment plants (WWTPs) in the province of Valencia (Spain): Carrícola and Los Monasterios. In both plants, the secondary effluent is further treated in constructed wetlands filled with aluminium-rich drinking water treatment sludge, enhancing phosphorus removal while integrating circular economy principles into the urban water cycle. To capture and monetise the resulting environmental and social benefits, the AMUVAM–ANP framework was applied. The framework combines a panel of 12 multidisciplinary experts, who assess the interdependencies among ecosystem services, with an economic valuation that monetises non-market benefits using a pivot value of €1.09/m³, corresponding to the market price of drinking water supply in Spain. Water availability emerged as the dominant service, accounting for 33.27% of total relevance. By category, overall relevance was distributed across provisioning (42.23%), fauna and flora (25.84%), cultural (22.54%), and regulating services (9.40%). Over a 25-year horizon, the systems generate substantial economic benefits, estimated at approximately €242,200 for Carrícola and €880,726 for Los Monasterios, with benefit–cost ratios of 6.6–7.5 that remain above unity even under conservative scenarios. By making benefits such as biodiversity enhancement and climate mitigation explicit, the approach provides a transparent and replicable economic basis for decision-making and supports the scalability of sustainable and resilient wastewater treatment models for small populations facing water stress.

Extractive waste (EW) from former mining activities poses long-term environmental impacts while representing a potential secondary resource. Within a circular economy framework, EW can be valorised to recover raw materials (RMs) and critical raw materials (CRMs) contributing to the supply of strategic resources. In the Anzasca Valley (Piedmont, Italy), gold mines of Crocette and Pestarena operated until the mid-20th century, producing large amount of EW. These materials have caused persistent contamination of soils and waters, particularly with As and other potentially toxic elements (PTEs). The aims of the study are i) to assess environmental contamination and ecological risk, and ii) to evaluate the potential for recovering CRMs from EW. To do so, the study combines mineralogical and geochemical data of soils and EW from different sampling campaigns. Results revealed significant enrichment of CRMs, particularly As, followed by W, Sb, Bi, and minor enrichment of some light REEs (La, Ce, Pr, Nd). The environmental impact assessment identified As as the main pollutant, classifying soils as heavily to extremely contaminated, with additional moderate contamination by Pb and Co, and indicating an overall moderate ecological risk. The estimated volumes of EW and residual amounts of selected CRMs (A, Bi, Sb, W) indicate a potential for concurrent recovery, with As as the primary target. The findings suggest that this approach can represent a sustainable intervention within remediation projects, combining environmental risk mitigation with the recovery of valuable resources and supply security.

The kinetics and mechanisms of perfluorooctanoic acid (PFOA, CF₃–(CF₂)₆–COOH) defluorination were investigated in alkaline dimethyl sulfoxide/water (DMSO/H₂O) solutions under various conditions. PFOA and its by-products were characterized and relatively quantified using ultra-high-pressure liquid chromatography coupled with mass spectrometry, while degradation efficiency was assessed by potentiometric fluoride measurements with an F⁻-selective electrode, complemented by scanning electron microscopy and energy-dispersive spectroscopy. The redox degradation mechanisms of PFOA were projected through a detailed description of redox reactions involving only carbon atoms within PFOA and its by-products, driven by OH·/OH⁻ and H₂O/H· redox couples, into which OH· and H· are transient redox intermediates associated with electron-transfer events, rather than freely diffusing radical species; OH· and H· originated from the redox reactions between the electron donor OH⁻ and the electron acceptors O₂, PFOA and H₂O. The nucleophilic and/or electrophilic nature of redox reactions depends on the carbon oxidation state. The most favorable PFOA degradation pathway involves the stepwise oxidation of carbon driven solely by OH·/OH⁻ redox couple, leading to the elimination of a –CF₂– unit as 2 F⁻ and CO₃²⁻. The OH·/OH⁻ and H·/H₂O redox couples mediate secondary electron-transfer pathways, resulting in the simultaneous oxidation and reduction of two different carbon atoms within the same molecule. Water content and its continuous formation during the redox reactions limit the process by enhancing the solvation of OH⁻, thereby decreasing the oxidizing capacity of the OH·/OH⁻ redox couple. The higher the NaOH/PFOA molar ratio (≥ 62:1), the lower the H₂O content (DMSO/H₂O volume ratio ≥ 3.87:1) and the higher the temperature (≥ 120 °C), the greater the PFOA defluorination.

Artificial groynes are used globally for activities like recreational fishing and have the potential to accumulate debris, which can subsequently be released into the marine environment, representing a potential threat to marine ecosystems and human health. Mar del Plata is the largest coastal city in Argentina, hosting the country’s most significant commercial harbour, and serving as a key destination for recreational fishing activities. Fishing-related debris was recorded across 45 artificial groynes and classified by origin as either recreational or non-recreational. Debris abundance was evaluated based on groyne construction material, orientation, and location. A total of 2146 fishing-related debris was recorded. A higher abundance of recreational debris and a greater accumulation on groynes constructed with orthoquartzite rocks was estimated. Monofilament, bait bags, and ropes dominated both in terms of abundance and frequency of occurrence. Furthermore, the chemical composition of 357 plastic fishing debris was identified using FTIR. The dominant polymers were polyamide, polyethylene, and polystyrene. This research constitutes the first study in Argentina to quantify and perform a polymeric determination of fishing-related debris disposed on artificial groynes. Trapped fishing recreational debris primarily originates from fishers using the immediate or nearby groyne areas, thus identifying preferential fishing sectors would allow for concentrated efforts in waste management policies.

This study reports the synthesis, characterization, and environmental application of a nanocatalytic system prepared by immobilizing copper nanoparticles on a compact film made from chitosan (CS) and polyvinyl alcohol (PVA) blend. The resulting dip catalyst, CuNPs@CS/PVA, was evaluated for the catalytic reduction of 4-nitrophenol (4-NP) and two organic dyes: Congo red (CR), an anionic dye, and methylene blue (MB), a cationic dye. The catalyst exhibits exceptional catalytic activity, as CuNPs@CS/PVA film efficiently mediated the reduction of CR, MB, and 4-NP, as well as their mixed-pollutant system, within 4 min. Furthermore, the structural design of catalyst film allows for easy, rapid retrieval from treated solutions. The catalyst retained more than 90% reduction efficiency for CR over eight consecutive cycles, while the recycling studies for MB and 4-NP also demonstrated high catalytic activity over the investigated cycles. These results demonstrate the mechanical stability and reusability of the CS/PVA-supported catalyst. Overall, the novelty of this work lies in achieving rapid pollutant reduction in complex, mixed-pollutant matrices using a highly recoverable and reusable dip catalyst system for environmental remediation.

Microplastics (MPs) represent an important global environmental threat, and, among the different environmental compartments, the aquatic systems are particularly impacted by the MPs problem. River sediments act as sinks and as major pathways for MPs transportation to marine systems. Therefore, there is an increasing need for comprehensive, basin-scale monitoring of MPs in river sediments to elucidate their spatial and temporal accumulation patterns, providing data essential for risk assessment and the development of effective mitigation strategies by stakeholders. MPs extraction from complex environmental samples remains challenging as the presence of organic and inorganic matter often interferes with the analytical identification. To address this gap, we optimized a low-cost, high-throughput sample preparation protocol specifically designed for analysis of large riverine sediment sets and accurate Raman identification. The protocol was validated across a wide cross-section of sediment matrices, from the Arno River (Pisa and Florence, Italy) with different grain size distribution and organic matter concentrations. This validation, with both spiked matrices and real environmental sediments, demonstrates a workflow that is tailored to handle sediments rich in organic and inorganic matter while enabling accurate identification of MPs.