Search Results (190)

Emerging and persistent contaminants (EPCs) were detected at high concentrations in Chiang Mai’s Mae Kha Canal, identifying urban waterways as important sources of pollution in the Ping River system in northern Thailand. Maximum levels of metformin (20,000 ng/L), fexofenadine (15,900 ng/L), gabapentin (12,300 ng/L), sucralose (38,000 ng/L), and acesulfame (23,000 ng/L) point to inadequately treated wastewater as a plausible contributor. Downstream enrichment patterns relative to upstream sites highlight the cumulative impact of urban runoff. Five compounds—acesulfame, gemfibrozil, fexofenadine, TBEP, and caffeine—consistently emerged as reliable tracers of urban wastewater, forming a distinct chemical fingerprint of the riverine exposome. Median EPC concentrations were highest in Mae Kha, lower in other urban canals, and declined with distance from the city, reflecting spatial gradients in urban density and pollution intensity. Although most detected concentrations fell below predicted no-effect thresholds, ibuprofen frequently approached or exceeded ecotoxicological benchmarks and may represent a compound of ecological concern. Non-targeted analysis revealed a broader “chemical cocktail” of unregulated substances—illustrating a witches’ brew of pollution that likely escapes standard monitoring efforts. These findings demonstrate the utility of wide-scope surveillance for identifying key compounds, contamination hotspots, and spatial gradients in mixed-use watersheds. They also highlight the need for integrated, long-term monitoring strategies that address diffuse, compound mixtures to safeguard freshwater ecosystems in rapidly urbanizing regions. Full article

Melissa officinalis L. (Lamiaceae) is a perennial plant species widely used in the pharmaceutical and food industries, particularly valued for its sedative properties. This study investigates the impact of synthetic mulch film and planting density as two experimental factors on agronomic performance, raw material quality, and economic efficiency in lemon balm production. The experiment was conducted at three locations in Serbia (L1: Bačko Novo Selo, L2: Bavanište, L3: Vilandrica) from 2022 to 2024, using two planting densities on synthetic mulch film (F1: 8.3 plants m⁻²; F2: 11.4 plants m⁻²) and a control treatment without mulch (C). The synthetic mulch film used was a synthetic black polypropylene film (Agritela Black, 90 g/m²), uniformly applied in strips across the cultivation area, covering approximately 78% of the soil surface. The results showed consistent increases in morphological parameters and yield across the years. Plant height in F1 and F2 treatments ranged from 65 to 75 cm, while in the control it reached up to 50 cm (2022–2024). Fresh biomass yield varied from 13.4 g per plant (C) to 378.08 g per plant (F2), and dry biomass yield from 60.3 g (C) to 125.4 g (F2). The highest essential oil content was observed in F2 (1.2% in 2022), while the control remained at 0.8%. The F2 treatment achieved complete weed suppression throughout the experiment without the use of herbicides, demonstrating both agronomic and ecological advantages. Economic evaluation revealed that F2 generated the highest cumulative profit (€142,164.5) compared to the control (€65,555.3). Despite higher initial investment, F2 had the most favorable cost–benefit ratio in the long term. This study highlights the crucial influence of mulching and planting density on optimizing lemon balm production across diverse climatic and soil conditions, while also underscoring the importance of sustainable, non-chemical weed management strategies in lemon balm cultivation. Full article

This study used Jilin-1 satellite data and unmanned aerial vehicle (UAV)-collected visible-thermal infrared imagery to calculate twelve spectral indices and evaluate their effectiveness in distinguishing post-fire forest areas and identifying human-altered land-cover changes in Jinyun Mountain, Chongqing. The research goals included mapping wildfire impacts with M-statistic separability, measuring land-cover distinguishability through Jeffries–Matusita (JM) distance analysis, classifying land-cover types using the random forest (RF) algorithm, and verifying classification accuracy. Cumulative human disturbances—such as land clearing, replanting, and road construction—significantly blocked the natural recovery of burn scars, and during long-term human-assisted recovery periods over one year, the Red Green Blue Index (RGBI), Green Leaf Index (GLI), and Excess Green Index (EXG) showed high classification accuracy for six land-cover types: road, bare soil, deadwood, bamboo, broadleaf, and grass. Key accuracy measures showed producer accuracy (PA) > 0.8, user accuracy (UA) > 0.8, overall accuracy (OA) > 90%, and a kappa coefficient > 0.85. Validation results confirmed that visible-spectrum indices are good at distinguishing photosynthetic vegetation, thermal bands help identify artificial surfaces, and combined thermal-visible indices solve spectral confusion in deadwood recognition. Spectral indices provide high-precision quantitative evidence for monitoring post-fire land-cover changes, especially under human intervention, thus offering important data support for time-based modeling of post-fire forest recovery and improvement of ecological restoration plans. Full article

Understanding the dynamic behavior of the grazing land footprint (GLF) is critical for sustainable land management. This study examines the GLF in 92 countries to determine if the series is stationary, a statistical property indicating that shocks have transitory effects, or non-stationary, which implies that shocks have permanent, cumulative impacts (a phenomenon known as persistence). We employ a novel machine learning framework that uses an XGBoost algorithm to synthesize information from multiple conventional tests and time-series characteristics, enhancing analytical robustness. The results reveal significant cross-country heterogeneity. The GLF exhibits stationary behavior in a subset of nations, including China, India, and Norway, suggesting that their ecosystems can absorb shocks. However, for most countries, the GLF is non-stationary, indicating that ecological disruptions have lasting and cumulative impacts. These findings underscore that a one-size-fits-all policy approach is inadequate. Nations with a stationary GLF may find short-term interventions effective, whereas those with non-stationary series require profound structural reforms to mitigate long-term degradation. This highlights the critical role of advanced methodologies in shaping evidence-based environmental policy. Full article

The Ghris watershed in southern Morocco is a significant ecological and agricultural area. However, due to the current impacts of climate change, farming activities, and pollution, data on its quality and biological importance need to be updated. Therefore, this study aimed to evaluate the physico-chemical and biological quality of surface water in the Ghris River. The Water Quality Index (WQI) and the Iberian Biological Monitoring Working Group (IBMWP) index were used to assess water quality along four sampling sites in 2024. The collected data were analyzed with descriptive and multivariate statistics. In total, 424 benthic macroinvertebrates belonging to seven orders were identified in the surface waters of the Ghris basin. These microfauna were significantly variable among the studied sites (p < 0.05). Station S4 is significantly rich in species, including seven orders and nine families of macroinvertebrates, followed by Station S2, with seven orders and eight families. Stations S3 and S1 showed less species diversity, with three orders and one family, respectively. The Insecta comprised 95.9% of the abundance, while the Crustacea constituted just 4.1%. The physico-chemical parameters significantly surpassed (p < 0.05) the specified norms of surface water in Morocco. This indicates a decline in the water quality of the studied sites. The findings of the principal component analysis (PCA) demonstrate that the top two axes explain 87% of the cumulative variation in the data. Stations 2 and 3 are closely associated with high concentrations of pollutants, notably Cl⁻, SO₄²⁻, NO₃⁻, and K⁺ ions. Dissolved oxygen (DO) showed a slight correlation with S2 and S3, while S4 was characterized by high COD and PO₄ concentrations, low levels of mineral components (except Cl⁻), and average temperature conditions. Bioindication scores for macroinvertebrate groups ranging from 1 to 10 enabled the assessment of pollution’s influence on aquatic biodiversity. The IBMWP biotic index indicated discrepancies in water quality across the sites. This study gives the first insight and updated data on the biological and chemical quality of surface water in the Ghris River and the entire aquatic ecosystem in southeast Morocco. These data are proposed as a reference for North African and Southern European rivers. However, more investigations are needed to evaluate the impacts of farming, mining, and urbanization on the surface and ground waters in the study zone. Similarly, it is vital to carry out additional research in arid and semi-arid zones since there is a paucity of understanding regarding taxonomic and functional diversity, as well as the physico-chemical factors impacting water quality. Full article

Acid rain alters soil chemistry significantly and is a key driver of heavy metal pollution. This study investigates the environmental impact of acid rain-induced heavy metal migration in the Siding Lead–Zinc mining area in south China. Tailings, surrounding soils, and riverbed sediments were examined through simulated acid rain soil column leaching experiments. Leachate parameters—including pH, redox potential (Eh), total dissolved solids (TDSs) and heavy metal concentrations—were used to develop machine learning models (Random Forest and Support Vector Machine) to quantify the influence of environmental factors on metal migration. The results showed that leachates were generally alkaline and reductive after leaching, with Cd, Pb, and Zn as the dominant migrating metals. Leachates from tailings and nearby soils exceeded safe drinking water standards, with significantly higher cumulative metal release than other samples. The RF model outperformed the SVM model in predicting heavy metal concentrations. Feature importance analysis revealed that, beyond sample characteristics, pH and Eh were critical factors driving metal migration. Zn and Cd showed strong sensitivity to these parameters, with pH and Eh contributing over 80% to their migration. The findings highlight that acid rain can enhance the solubility and migration of heavy metals, posing a serious threat to the quality of surrounding water and underscoring the requirement for effective mitigation strategies to protect the ecological environment in mining areas. Full article

Municipal wastewater effluent (MWWE) is a common source of nutrient enrichment and provides a route for emerging substances of concern (ESOCs) to enter aquatic systems. Community composition and abundance metrics of benthic macroinvertebrates are commonly utilized to assess ecological impacts associated with nutrient enrichment; however, the responses of these metrics in systems with diverse chemical mixtures from MWWE, are not well understood. This study specifically addresses the effects of cumulative loading of tertiary-treated MWWE through responses in benthic macroinvertebrate communities in experimental control and treatment streams. Treatment streams used source river water previously exposed to upstream wastewater treatment plants but with an additional 5% by volume tertiarily treated MWWE, while control streams used only source river water. Surbers and artificial substrate rock baskets were used to examine impacts on both established and colonizing benthic communities, respectively. No significant differences were observed between the control and treatment streams in any of the community metrics of well-established benthic communities. In contrast, significant decreases in colonizing taxon diversity and evenness were found between treatment and control streams. The dominant taxa (most abundant family, by percentage of sample) in the community, often filter feeders, significantly increased in percentage of the total community in treatment streams. This response was consistent with a nutrient enrichment effect, with no evidence of ESOC related toxicity. This study highlights the need for bioassessment programs to utilize approaches involving varied in-situ sampling methods and controlled exposure systems to gain a better understanding of how various stages of community-level development are impacted by urban pollutants such as MWWE. Full article

Marijuana legalization has been at the center of debate in the social and political realm of the United States. So far, thirty nine states and the District of Columbia have legalized marijuana either for recreational or medical purposes. States are taking a cautious approach to legalization in a policy context consisting of multi-layered sociopolitical systems. Strong arguments from advocacy groups supporting and opposing legalization highlight the significance of assessing the impact of marijuana use and its legalization on the well-being of the community and its members. Utilizing the social determinants of health and system perspectives, this study measures the cumulative effect of six socio-ecological and economic predictors, such as the state’s marijuana use prevalence and median household income, on the dependent variable of marijuana legality scores using discriminant analysis and One-way ANOVA. As hypothesized, the result shows a significant influence of the predictors on the state policy score of marijuana legality. Predicted associations between independent and dependent variables were also found. Findings suggest that without a supportive policy context comprising social, economic, and political factors, marijuana legalization might not have the desired impact on the community. Implications and recommendations for future research are provided. Full article

Diclofenac, a nonsteroidal anti-inflammatory drug widely used worldwide, has been detected in waterbodies at concentrations ranging from ng L⁻¹ to µg L⁻¹. Although diclofenac is not a persistent compound, aquatic organisms may be exposed to this drug for extended periods due to its incorporation into the environment by continuous release from hospitals and municipal discharges. This study aimed to evaluate the toxic effects of diclofenac on the microalga Pseudokirchneriella subcapitata, the cladoceran Daphnia curvirostris, and zebrafish embryos (Danio rerio). Toxicity bioassays for the microalga were performed according to the OECD 201 protocol with diclofenac concentrations of 0, 6.25, 12.5, 25, 50, 75, and 100 mg L⁻¹. For the determination of acute toxicity in the cladoceran (48 h), concentrations of 0, 10, 20, 30, 40, 50, and 60 mg L⁻¹ were tested; in subchronic bioassays, the effect of the drug on the reproductive parameters of D. curvirostris was determined for 21 days with sublethal concentrations of 10.3, 14.4, 17.2, and 21.3 mg L⁻¹. Toxicity bioassays on zebrafish embryos were performed according to the OECD 236 protocol, using concentrations of 0, 1, 2, 4, 6, 8, and 10 mg L⁻¹ of diclofenac. The results confirmed the toxic effects of the drug. The IC₅₀ for the microalga was 16.57 mg L⁻¹, while the LC₅₀ for D. curvirostris and D. rerio was 32.29 and 6.27 mg L⁻¹, respectively. In the microalga, chlorophyll-a and carotenoids increased at a concentration of 3.62 mg L⁻¹ of diclofenac; however, chlorophyll-b decreased at the highest drug concentration (13.51 mg L⁻¹). Protein and lipid concentrations in P. subcapitata exposed to all concentrations were higher than in the control. Chronic diclofenac exposure did not affect the survival of D. curvirostris; however, the cumulative progeny and number of clutches significantly decreased, and the age of first reproduction was delayed at all drug concentrations. Protein concentration in D. curvirostris hatchlings was higher at all diclofenac concentrations; in contrast, the amount of lipids and carbohydrates decreased significantly. In D. rerio, the hatching rate decreased by 40, 51.6, and 80% at concentrations of 6, 8, and 10 mg L⁻¹ diclofenac, respectively, and exposure to the drug caused lethal effects such as coagulation at 24 and 48 hpf; sublethal effects such as edema and curved tail were also observed at concentrations of 2 to 10 mg L⁻¹, and the effects increased with increasing concentration up to 144 hpf. The results demonstrate the vulnerability of aquatic organisms to the toxic effects of diclofenac, suggesting that discharging it into water bodies should be regulated to prevent potential ecological impacts on the various trophic levels of freshwater biota. Full article

Water, often described as the elixir of life, is a critical resource that sustains life on Earth. The acute water scarcity in the major basins of the Arabian Peninsula has been further aggravated by rapid population growth, urbanization, and the impacts of climate change. This situation underscores the urgent need for a comprehensive analysis of the region’s morphometric characteristics. Such an analysis is essential for informed decision-making in water resource management, infrastructure development, and conservation efforts. This study provides a foundational basis for implementing sustainable water management strategies and preserving ecological systems by deepening the understanding of the unique hydrological processes within the Arabian Peninsula. Additionally, this research offers valuable insights to policymakers for developing effective flood mitigation strategies by identifying vulnerable areas. The study focuses on an extensive investigation and assessment of morphometric parameters in the primary basins of the Arabian Peninsula, emphasizing their critical role in addressing water scarcity and promoting sustainable water management practices. The findings reveal that the Arabian Peninsula comprises 12 major basins, collectively forming a seventh-order drainage system and covering a total land area of 3.24 million km². Statistical analysis demonstrates a strong correlation between stream order and cumulative stream length, as well as a negative correlation between stream order and stream number (R² = 99%). Further analysis indicates that many of these basins exhibit a high bifurcation ratio, suggesting the presence of impermeable rocks and steep slopes. The hypsometric integral (HI) of the Peninsula is calculated to be 60%, with an erosion integral (EI) of 40%, indicating that the basin is in a mature stage of geomorphological development. Importantly, the region is characterized by a predominantly coarse drainage texture, limited infiltration, significant surface runoff, and steep slopes, all of which have critical implications for water resource management. Full article

Water–sediment evolution and attribution analysis in watersheds is one of the research focuses of hydrogeology. An in-depth investigation into the spatiotemporal variation of water and sediment at multiple spatial scales within the basin, along with a systematic assessment of the respective impacts of climate change and human activities, provides a scientific foundation for formulating effective soil and water conservation practices and integrated water resource management strategies. This research holds significant implications for the sustainable development and ecological management of the basin. In this study, the Mann–Kendall nonparametric test method, double cumulative curve method, cumulative anomaly method, and cumulative slope change rate analysis method were used to quantitatively study the effects of climate change and human activities on runoff and sediment load changes at different spatial scales in the Huangfuchuan River basin. The results show that (1) from 1966 to 2020, the annual runoff and annual sediment load discharge in the Huangfuchuan River basin showed a significant decreasing trend. Among them, the reduction in runoff and sediment in the control sub-basin of Shagedu Station in the upper reaches was more obvious than that in the whole basin. The mutation points of runoff and sediment load in the two basins were 1979 and 1998. The water–sediment relationship exhibits a power function pattern. (2) After the abrupt change, in the change period B (1980–1997), the contribution rates of climate change and human activities to runoff and sediment load reduction in the Huangfuchuan River basin were 24.12%, 75.88% and 20.05%, 79.95%, respectively. In the change period C (1998–2020), the contribution rates of the two factors to the runoff and sediment load reduction in the Huangfuchuan River basin were 18.91%, 81.09% and 15.61%, 84.39%, respectively. Among them, the influence of precipitation in the upper reaches of the Huangfuchuan River basin on the change in runoff and sediment load is higher than that of the whole basin, and the influence on the decrease of sediment load discharge is more significant before 1998. There are certain stage differences and spatial scale effects. (3) Human activities such as large-scale vegetation restoration and construction of silt dam engineering measures are the main reasons for the reduction in runoff and sediment load in the Huangfuchuan River basin and have played a greater role after 1998. Full article

The rapid increase in construction and demolition waste (C&DW) has emerged as a significant environmental challenge, particularly due to the hazardous substances embodied within the fine residues destined into landfills. The disposal of C&DW in landfills has been widely recognized as a source of leachate, containing toxic contaminants, which pose significant environmental risks. A controlled column leaching experiment was conducted using samples with varying proportions of C&DW, gypsum, and organic content to assess their impact on leachate chemistry. The results indicate that higher C&DW content leads to increased concentrations of heavy metals, such as Pb, Hg, As, Cr, Ni, Cu, Zn, and Co, as well as other metals like Al and Fe, with peak contamination occurring within the first 13–15 weeks. Gypsum presence exacerbates heavy metal solubility by reducing pH, increasing sulfate levels, and promoting metal-sulfate complex formation. Despite remaining within regulatory thresholds, the cumulative concentration of toxic metals over time highlights potential environmental risks, particularly in landfill settings. This study underscores the need for improved C&DW management practices, enhanced waste segregation, and sustainable alternatives to gypsum to mitigate long-term ecological impacts. These findings contribute to a deeper understanding of C&DW leachate dynamics and inform policy recommendations for sustainable waste management in the construction sector. Full article

Anthropogenic activities (represented by dams and land use change) and climate change have disrupted the delicate balance between natural and anthropogenic factors affecting riverine material transport, yet their effects across different river basins remain underexplored. This study investigated multi-decade (1980–2023) variations in sediment and particulate carbon (C), nitrogen (N), and phosphorus (P) exports from the Jinsha (JSR) and Jialing River (JLR) basins, two cascading developmental river systems in Southwestern China, and evaluated the cumulative impacts of land use change and dam construction. The results revealed significant decreases in particulate fluxes from both basins, despite stable water discharge. Particulate material fluxes declined by 90.9–99.6% in the JSR (last decade vs. 1980–1989, with an abrupt change occurring during 2002–2003) and by 54.0–79.3% in the JLR (with an abrupt change occurring in 1994). Over time, the influence of precipitation and water discharge on material transport has diminished, whereas land use change and dams have become increasingly dominant. Key drivers include forest expansion, increased impervious surfaces, reservoir construction, and reductions in grassland and farmland; however, there are spatial differences in the relative importance of these drivers. This study provides crucial insights for decision making on regional ecological conservation and cascading development. Full article

This study examines runoff variations and their drivers in the Buha and Shaliu Rivers of the Qinghai Lake Basin (1960–2016), a key ecological area in China. Abrupt changes were detected using the Mann–Kendall and cumulative anomaly methods, while the Budyko framework attributed runoff variations to dominant factors. Correlation and grey relational analyses assessed multicollinearity, and a lake water balance model with climate elasticity theory quantified the effects of climate and land surface changes on runoff components and lake levels. Results indicate that the Buha River experienced an abrupt runoff change in 2004, while the Shaliu River exhibited a change beginning in 2003. Based on the trends and abrupt change points of each factor, the study period was divided into four segments: 1960–1993, 1994–2016, 1960–2003, and 2004–2016. The correlation coefficients are significantly different in different periods. The climate elasticity coefficients were as follows: P (precipitation), 1.98; ET₀ (potential evapotranspiration), −0.98; Rn (net radiation), 0.66; T (average temperature), 0.02; U₂ (wind speed at 2 m height), 0.16; RHU (relative umidity), −0.56. The elasticity coefficient of runoff with respect to precipitation is significantly higher than that for other climate variables. Net radiation and relative humidity contribute equally to runoff, while wind speed and temperature have relatively smaller effects. In the Qinghai Lake Basin, runoff is sensitive to precipitation (0.38), potential evapotranspiration (−0.07), and the underlying surface parameter ω (−98.32). Specifically, a 1 mm increase in precipitation raises runoff by 0.38 mm, while a 1 mm rise in potential evapotranspiration reduces it by 0.07 mm. A one-unit increase in ω leads to a significant runoff decrease of 98.32 mm. According to the lake water balance model, climate contributes 88.43% to groundwater runoff, while land surface changes contribute −11.57%. Climate change and land surface changes contribute 93.02% and 6.98%, respectively, to lake water levels. This study quantitatively evaluates the impacts of climate and land surface changes on runoff, providing insights for sustainable hydrological and ecological management in the Qinghai Lake Basin. Full article

The ecological transformation of industrial enterprises is crucial for promoting sustainable development, improving energy efficiency, and boosting environmental quality. This study provides empirical insights into the relationship between digital commerce and the ecological transformation of manufacturing firms, using panel data from Chinese A-share-listed manufacturing businesses from 2011 to 2021. The findings demonstrate that digital commerce significantly accelerates the environmental transition of manufacturing firms, particularly within established organizations, competitive sectors, and non-renewable energy industries. Mechanism analysis reveals that advancements in digital commerce improve the breadth, quality, and sustainability of green technology innovation. Examining threshold effects identifies a distinct threshold in the cumulative impact of green technological improvements, beyond which digital commerce facilitates the ecological transition of industrial firms. Manufacturing enterprises need to optimize the use of digital tools and provide more efficient solutions around resource allocation, so as to gain an advantageous position in the green supply chain. Full article