Environmental Monitoring and Assessment最新文献

In our study, a rapid, low-cost analytical method was developed for the colorimetric determination of Sn(IV) using silver nanoparticles (AgNPs) synthesized with clove extract. The AgNPs synthesized have a surface plasmon resonance peak at 425 nm. When Sn(IV) standards at increasing concentrations are added to samples containing AgNPs, a color change proportional to the analyte concentration occurs. With increasing Sn(IV) concentration, the absorbance of the AgNPs decreases. In the analyses, the absorbance change based on analyte concentration was monitored. The detection limit of the developed method was calculated as 7.9 µM with the linear range as 20–300 µM. The analytical performance of the method in complex matrix media was demonstrated by conducting recovery experiments in tap water. Our percentage recovery value varies between 97% and 118.0%. The toxicological behavior of the AgNPs were also evaluated in Daphnia magna (D. magna) to justify the safety and ecotoxicity of the synthesized nanoparticles. According to the results, LC₅₀ was calculated as 0.2 mg L⁻¹ for 96 h.

This study comprehensively evaluates the dissipation dynamics, environmental persistence, dietary exposure, and ecotoxicological risks associated with the application of carbendazim (CBZ) and chlorantraniliprole (CAP) in Solanaceous cropping systems, specifically brinjal (Solanum melongena) and tomato (Solanum lycopersicum). Residue quantification was performed using a highly sensitive and validated liquid chromatography-tandem mass spectrometry (LC–MS/MS) method to ensure precise detection at trace levels. Initial concentration of CBZ in brinjal fruit (1.159‒2.110 mg/kg) declined substantially over 15 days, with 96.68–98.27% dissipation observed. Soil residues of carbendazim showed a comparable reduction of 96.09–97.03%. In tomato fruits, the dissipation ranged from 96.87 to 97.31% and from 95.15 to 95.24% in soil. For CAP, residue levels in brinjal fruits (1.110–2.100 mg/kg) dissipated by 96.43–97.30%, while soils demonstrated 95.34–96.82% reduction. Tomato fruits displayed higher dissipation of 98.47–99.53%, and soils showed 98.79–98.98% reduction. Both pesticides followed first-order dissipation kinetics, with calculated half-lives (t_1/2) ranging from 1.90 to 3.53 days. Probabilistic acute dietary exposure assessments, stratified by rural and urban dietary patterns, revealed that the estimated daily intakes of CBZ and CAP remained well within the acceptable daily intake (ADI) limits established by regulatory agencies, particularly following adherence to the recommended pre-harvest intervals (PHIs). Ecotoxicological risk assessment, based on risk quotient (RQ) values for representative non-target soil organisms, including earthworms and arthropods, demonstrated a transient risk immediately post-application especially under T2, which attenuated to acceptable levels within 15 days post-treatment. A computational study was used for chlorantraniliprole and carbendazim. The findings affirm that, when applied in accordance with good agricultural practices (GAPs), both CBZ and CAP pose minimal residual and ecological risk, thereby supporting their continued use in integrated pest management (IPM) frameworks. The findings of this investigation may serve as a valuable reference for the safe and judicious application of chlorantraniliprole (CAP) and carbendazim (CBZ) in brinjal and tomato cultivation.

Assessing soil quality is essential for effective monitoring, conservation, and management. However, most current assessment approaches tend to overlook the biological component of soils, limiting their value for sustainable resource management. The Soil Biological Quality index based on microarthropods (QBS-ar index) is one of the few tools that incorporates this biological dimension. Yet, its applicability has not been tested in tropical South American ecosystems, particularly under different land-use contexts, successional stages, or across climatic seasons. In this study, we evaluated the sensitivity of the QBS-ar index to changes in soil biological quality in response to different land-use systems, seasonal variation, and forest succession in tropical montane ecosystems of the Andes. We collected 186 soil samples across 20 plots (each 20 × 20 m) representing agroforestry systems and forests with secondary and mature successional stages in the Colombian Andes. Our results revealed significant differences in index values across land-use systems, demonstrating the index’s effectiveness in detecting soil biological quality based on the disturbance levels. The QBS-ar index was also sensitive to seasonal changes, showing lower values during dry periods, likely due to declines in the abundance and richness of eudaphic taxa. Additionally, the QBS-ar index was positively associated with forest biomass, as well as with the richness and abundance of soil microarthropods, supporting its potential as a reliable indicator of ecological succession. Overall, our findings support the QBS-ar index as a useful and cost-effective tool for monitoring soil biological quality and ecological succession in tropical Andean ecosystems.

Mining activities in tropical savanna regions can severely disrupt soil structure and vegetation, yet the factors influencing soil moisture content in post-mining landscapes are not fully understood. This study focused on the factors associated with soil moisture in a mining-induced degraded landscape. This study hypothesized that there is no significant relationship between soil moisture and the presence of open grasses, open shrubs, and closed shrubs. Through a field survey, soil moisture data were collected from an abandoned, unreclaimed mine land in Ghana. Ten univariate and two multivariable GIS-based generalized linear regression models were constructed to assess the relationship between soil moisture and several independent variables, including the presence of vegetation. The results show that the presence of open grasses, open shrubs, and closed shrubs significantly explains 52% of the variation in soil moisture (R² = 0.520, p < 0.05). Soil moisture is 18.04%, 15.56%, and 14.30%, significantly higher in open grasses, open shrubs, and closed shrubs, respectively, compared to bare soil (p < 0.05). While soil temperature significantly predicts soil moisture values in the univariate model, its statistical significance is masked by factors, including open grasses, open shrubs, closed shrubs, elevation, slope, topographic wetness index, north-facing direction, and south-facing direction, in the multivariable model. Our results suggest that in savanna areas where moisture-laden soil is essential for reclaiming mine-degraded landscapes, and enhancing the likelihood of achieving Sustainable Development Goal 15, it is necessary first to improve grass cover to moisten the soil, followed by planting tree- and non-tree shrubs.

Octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) are notable cyclic volatile methyl siloxane (cVMS) compounds primarily used in the production of silicone polymers, which are extensively utilized across a wide range of industries, including construction, automotive, electronics, and more. The widespread use of cVMS, particularly D4, D5, and D6, in industrial applications has raised environmental concerns due to their persistence, bioaccumulation potential, and possible toxicity. Despite their low water solubility, cVMS are found to adsorb strongly to organic matter in sediments and soil, raising questions about their long-term environmental effect. Given Tokyo Bay's strategic economic importance and the high level of industrial and urban activities in its catchment, this study aimed to provide a comprehensive understanding of cVMS contamination in the area. The spatial and temporal distribution of cVMS concentrations in the sediments and fish of Tokyo Bay were systematically examined from 2011 to 2021. The results showed that cVMS were widely distributed across the bay's sediments. Regarding the samples collected in 2021, the concentration of D4, D5 and D6 ranged from <1.04 to 14.5 ng/g- dry weight (dw), from 6.3 to 494 ng/g-dw, and from 2.3 to 89.5 ng/g-dw, respectively. A clear decline of observed concentrations in the seaward direction underscored the influence of riverine inputs. Temporal trends indicated a general decline in cVMS concentrations in sediments at multiple sites, while concentrations in fish varied by species and trophic level. Ecological risk assessment revealed that current cVMS concentrations in the sediments do not pose a threat to benthic organisms. This study is the first to provide a long-term analysis of cVMS in Tokyo Bay, contributing valuable data for environmental monitoring efforts. The findings underscore the importance of continuous assessment of these compounds to understand persistence, bioaccumulation and risks to ecosystems.

Artisanal and small-scale mining (ASM) is contributing to land degradation and loss of fertility of agricultural soils in Ghana. Although there is a legal requirement for soil restoration after mining, it is rarely carried out, and when it is done, it is often inconsistent with regulatory requirements. Community lands are therefore left impoverished since they no longer support crop farming. This study investigates the extent of soil degradation caused by alluvial mining in the West Akim Municipality of the Eastern Region, Ghana, by examining the physicochemical properties of three soil types: undisturbed/unmined, rehabilitated, and mined. Physico-chemical properties were analysed using depth-function plots and Index of Deterioration (I.D). Mined soils exhibited the highest levels of physical and chemical degradation., The surface horizon of mined lands exhibited greater deterioration, with I.D. values of 59%, 66.2%, and 77.5% for CEC, organic carbon, and Ca²⁺, respectively. The mean bulk density of rehabilitated soil is high (1.4), which is likely to diminish the soil's ability to support crop production. Similarly, mining decreases the bioavailability of nutrients. Pb, Cd, and Hg exceeded guideline limits across all soil horizons, with maximum values of 129 mg/kg, 43.45 mg/kg, and 2.50 mg/kg, respectively, recorded in mined soils. Multi-element contamination, enrichment factor, contamination factor and geoaccumulation indices indicate anthropogenic sources of the heavy metals in both mined and rehabilitated soils. It is concluded that both the mined and the rehabilitated lands are degraded, though to a lesser extent in the rehabilitated land. The lower ID of the rehabilitated land suggests that it is still beneficial to undertake rehabilitation, irrespective of how poorly it may be done.

Microplastic pollution in freshwater ecosystems poses a growing threat to biodiversity and human health. Microplastics (0.5–5 mm), derived from the degradation of larger plastics or manufactured as microbeads, can accumulate in aquatic organisms and serve as indicators of ecosystem health. This study investigated the abundance, shapes, and colors of microplastics in water, sediment, and aquatic insects from the Owena River, Osun State, Nigeria, to assess spatial trends and ecological implications. Monthly sampling was carried out between July 2024 and June 2025 across the up, middle, and down sections of the river. Aquatic insects were identified to order level, while microplastics were visually identified under a stereomicroscope without spectroscopic confirmation. Results revealed widespread microplastic contamination, with concentrations increasing from the up section towards the down section in both water and sediment. Fragments were the most abundant shape, and black particles dominated color composition. Hemiptera and Odonata were the most represented insect orders, indicating potential bioaccumulation pathways within the aquatic food web. This study provides the first report of microplastic occurrence in aquatic insects of the Owena River, Nigeria, and underscores the urgent need for improved plastic waste management to safeguard freshwater biodiversity and ecosystem health.

Groundwater is a vital yet increasingly vulnerable resource, with nitrate contamination posing a significant risk to human beings and the ecosystem. The present study offers an integrated, sustainability-focused assessment of groundwater quality in India’s eastern littoral state, based on groundwater quality data from 422 sampling locations. In 2024, nitrate concentrations peaked at 387 ppm, with an average of over 37 ppm; notably, more than 20% and 17% of samples exceeded the Bureau of Indian Standards and World Health Organization guidelines, respectively. Both non-carcinogenic and carcinogenic health risks were assessed, revealing that nitrate poses risks through oral and dermal exposure, while nitrite contributes to cancer risk through ingestion. Principal component analysis multiple linear regression highlighted strong correlations among nitrate and macro-elements such as sodium, chloride, calcium, magnesium, and potassium, indicating common anthropogenic sources such as fertilizer runoff and wastewater infiltration. Multivariate analysis showed that nitrate is the dominant contaminant influencing groundwater quality shifts from 2020 to 2024, largely driven by agricultural intensification and sewage disposal contributions. These findings underscore the critical importance of adopting strategic intervention policies and promoting resilient groundwater governance frameworks across national and international scales.

Chloride (Cl) concentrations in urban surface waters and groundwaters in temperate climate regions have been rising, with this primarily attributed to the application of road salt. While this may be the case in many locations, other anthropogenic sources of Cl, such as wastewater, landfill leachate, softened water, and fertilizers, may play an important role but are often overlooked. Natural Cl sources must not be overlooked either. Proper identification of the chloride source is necessary to guide potential mitigation measures. This study demonstrates and assesses a unique suite of five techniques that have been used to characterize Cl sources affecting freshwater systems, including established and more novel methods—temporal Cl concentration patterns (including continuous specific conductance and water pressure monitoring), Cl/Na ratios, Cl/Br ratios, water isotopes, and artificial sweeteners. These were applied to an urban site with a variety of groundwater and river/stream end members, with additional groundwater—surface water interactions between them. Together, these five techniques identified influences at the site of several chloride sources, including road salt, wastewater, landfill leachate, and natural deeper groundwater. Moreover, spatial and temporal patterns in their influence were revealed. No one method was successful at clearly identifying the salt sources impacting a given water or location, especially across the entire year. The methods were further assessed on the benefits and limitations of the assessment they provide, including relative cost, to aid fellow practitioners in selection of source characterization methods.

River ecosystems are vital to Earth’s biogeography and environmental health by facilitating material cycling, energy transfer, and information exchange. However, human activities, including hydraulic engineering, land use changes, industrial and agricultural expansion, and overfishing, have significantly disrupted natural river morphology and ecological patterns. These interventions have altered the river’s physical and chemical properties, resulting in biodiversity loss and ecosystem services degradation, prompting increased global attention to river ecological management. This review analyzes the major threats to river ecosystems, emphasizing their collective and interconnected impacts on ecosystem degradation. Current international methods for ecological assessment and restoration are critically evaluated, noting their effectiveness at small to medium scales but limitations when applied to entire river systems. To address these challenges, the review proposes an integrated approach combining macroscopic ecological restoration measures with microscopic analyses of river feedback mechanisms. This holistic perspective considers both upstream and downstream activities, as well as complex interactions between human interventions and river ecosystems. The paper aims to provide new insights for river ecology research, inform policymaking, and suggest future research directions. By advocating for a more comprehensive understanding of river ecosystems, this review contributes to the development of sustainable and effective river governance practices.