Search Results (4,338)

This study aimed to characterize the reproductive performance of the local Algerian population (LAP) compared with the New Zealand White (NZW) rabbits, by evaluating sexual behavior, semen characteristics, and their modulation by environmental factors, namely photoperiod and temperature-humidity index (THI). Mature bucks (n = 14/breed) were monitored from January to April, with two successive ejaculates collected weekly. Sexual behavior, macroscopic and microscopic semen parameters, and testosterone concentrations were assessed. The effects of breed, ejaculate order, environmental factors, and their interactions were analyzed using Generalized Linear Mixed models. LAP and NZW bucks exhibited similar sexual behavior and blood testosterone levels (p > 0.05). Collection failures and ejaculate rejection causes were mainly clustered within specific individuals rather than being breed-dependent. However, LAP bucks showed higher sperm concentration (p = 0.01), viability (p = 0.02), and membrane integrity (p = 0.04) than NZW bucks, whereas most motility and quantitative semen traits remained comparable between breeds. Increasing photoperiod significantly improved reproductive performance (p < 0.05). Conversely, within the investigated range, THI mainly affected semen collection efficiency through increased urine contamination (p < 0.001), with limited effects on intrinsic sperm quality. Significant breed × environment interactions for sperm concentration (p = 0.03) suggested differential responsiveness between breeds, with LAP bucks showing a stronger positive response to increasing photoperiod and less pronounced variation under THI fluctuations. Overall, LAP bucks exhibited a more favorable seminal profile under the conditions of the present study, supporting the valorization of this local genetic resource for artificial insemination programs under Algerian conditions. Further studies are required to confirm these patterns under summer heat-stress conditions and evaluate their impact on fertility outcomes. Full article

At subsurface waste disposal sites, degradation of containment materials can cause leaks of chlorinated volatile organic compounds (Cl-VOCs) in the vadose zone. Material Disposal Area L (MDA L) is a heavily monitored waste site at Los Alamos National Laboratory in Northern New Mexico where a sharp increase in contaminant concentrations was measured in February 2019. Subsequently, soil vapor extraction (SVE) was performed as part of an ongoing interim measure. Here, we demonstrate a new method to introduce possible leakage within an existing numerical framework to bound possible leakage related to concentration increases seen in site monitoring data. A previously calibrated three-dimensional (3-D) model for SVE at MDA L is used to simulate the three conceptual stages from June 2017 to July 2024. The three conceptual stages based on the observed events are: leakage, passive diffusion, and soil vapor extraction. We use a 3-D multiphase flow simulator to introduce a simulated leak and attempt to approximately match monitoring data collected in February 2019, May 2024, and July 2024. After approximately matching the observed leak, outputs from the 3-D simulations were used to quantify the simulated mass of Cl-VOC leaked. Simulated results for a leak on the order of 40 kg of Cl-VOC showed general agreement with the monitoring data. Although the solution is non-unique, this paper presents a proof-of-concept addition to an existing case study, to show that a suspected subsurface container failure could create a signal consistent with the measured data and sets the stage for further analysis of future potential leak signals at the site. The work can also be adapted at other sites where changing subsurface conditions can require innovative modeling techniques to answer regulatory questions. Full article

Plastic pollution in terrestrial and freshwater environments and its accumulation along food chains has been poorly studied in birds. In this paper we reported evidence of microplastic (MP) contamination in pellets collected in rural and urban sites for a set of species: common kestrel, Falco tinnunculus; great cormorant, Phalacrocorax carbo; barn owl, Tyto alba; little owl, Athene noctua; long-eared owl, Asio otus; Eurasian scops owl, Otus scops; European bee-eater, Merops apiaster; and little egret, Egretta garzetta. A total of 559 pellets were collected and analyzed; among them, 78 microplastics were found on 77 pellets (13.8% compared to the total number of pellets sampled). The following polymers were recorded: polyvinylchloride (PVC), polyethylene (PE), expanded polyester (EPS), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyester (PES), polymethyl acrylate (PMA), rubber, and starch-based biopolymer. We found significantly higher MP frequency in the most anthropized site. Pellets with the highest number of microplastics were those produced by Falco tinnunculus, Asio otus, and Tyto alba, with 30.0%, 29.6%, and 27.1%, respectively. Of a total sample of 78 MP items, 59.0% are represented by fibers, 23.1% by fragments and 17.9% by films. Among the microplastics, fragments of balloons (in a remote area) and biopolymer shopping bags were found. Our results suggest that pellet analysis may represent a cost-effective method for monitoring MP contamination along food chains in terrestrial ecosystems. Full article

Acid mine drainage (AMD) pollution from closed coal mines in karst regions represents a major environmental challenge in the global mining industry. The complexity of hydrogeological conditions in such regions leads to significant challenges in both predictability and controllability of pollution. Taking the Yudong River Basin in Guizhou Province, Southwest China, as the study area, and based on six years (2017–2023) of systematic remediation practices and monitoring data, this study systematically evaluates the effectiveness and applicable conditions of three types of treatment technologies: centralized treatment stations, source control combined with end-of-pipe treatment, and water-sealing ecological plugging. On this basis, governance models applicable to karst regions are distilled. The results show that after six years of remediation, the number of pollution points in the Yudong River Basin decreased from 27 to 12. At the outflow section, the total Fe reduction rate reached 88.3%, the total Mn reduction rate reached 62.3%, and the proportion of contaminated river length was reduced by 78.5%. Each of the three technologies has its own applicable conditions. Centralized treatment stations, characterized by mature technology but high operational costs, are suitable for emergency transition periods. Source control combined with end-of-pipe treatment addresses both symptoms and root causes, making it applicable to complex pollution points. Water-sealing ecological plugging, although cost-controllable, carries a risk of secondary pollution in karst-developed areas. The failure of water-sealing ecological plugging technology is mainly attributed to two mechanisms: bypass flow through karst conduits and overflow induced by water level rise. Based on the six-year remediation practice, this study proposes a source control model for karst conduits centered on the core concepts of “filling, isolating, plugging, intercepting, draining, and controlling”. The implementation process consists of four stages: detailed investigation, graded optimization, stepwise implementation, and long-term monitoring. The core innovation lies in the cross-disciplinary application of coal mine water control techniques to environmental remediation, achieving a shift from passive end-of-pipe treatment to active source control. This model can provide theoretical reference and practical guidance for karst mining areas in Southwest China and other regions with similar geological conditions. Full article

Landfill tire fires are complex environmental disasters generating toxic pollutants with severe health risks. This study quantified emission dynamics and toxicological consequences of a large-scale tire fire in an urban ecosystem. A comprehensive source-to-receptor approach was applied, integrating Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) atmospheric dispersion modeling with comparison against air quality monitoring data. Soil samples collected from the fireground and surrounding urban allotment gardens were analyzed for tire-specific tracers (Zn) and 16 priority polycyclic aromatic hydrocarbons (PAHs). Human health risks were assessed using Incremental Lifetime Cancer Risk (ILCR), Toxic Equivalency Quotient (TEQ), and Mutagenic Equivalency Quotient (MEQ) metrics. Fire emissions were dominated by particulate matter (PM₁₀: 1.34 t) and PAHs (17.7 kg). Soil at the fire site showed severe contamination (Σ PAHs: 148.9 mg/kg), with benzo[a]pyrene as the primary carcinogen. The cumulative ILCR for children reached 9.7 × 10⁻⁴, exceeding the commonly used upper regulatory benchmark of 10⁻⁴. Dermal contact was identified as the dominant exposure pathway for pyrogenic PAHs. Elevated risk levels persisted at distal residential sites (ILCR: 10⁻⁵–10⁻⁴), indicating long-term environmental contamination Ecological risk quotients (RQ) exceeded unity for PAHs across all fire-impacted locations and for Zn and Cu in the immediate vicinity of the fire scene. These findings demonstrate that acute tire fire events can evolve into persistent terrestrial health hazards, highlighting the critical role of dermal exposure in PAH uptake and the need for long-term environmental monitoring and adaptive land-use management strategies to mitigate chronic health risks in urban populations. Full article

Rapid detection of heavy metals is vital for monitoring surface water contamination and preventing environmental and health risks. Traditional detection methods for metals such as lead and copper often require sophisticated, costly instrumentation, limiting their use in routine analyses. To address this challenge, we developed a cost-effective fluorescence-based approach using semiconductor quantum dots (QDs) as nanosensors for metal ion detection. The QDs were synthesized directly in aqueous medium through a reflux-assisted process employing cadmium precursors, selenium, thioglycolic acid (TGA), and branched polyethyleneimine (PEI, Mw ~25,000) as stabilizing agents. Structural analysis revealed nanoparticles with diameters below 5 nm, spherical morphology, and a zinc blende (face-centered cubic) crystalline structure. Optical characterization by UV–Vis, photoluminescence (PL), and FTIR spectroscopy confirmed effective surface functionalization and strong quantum confinement. PEI-capped QDs exhibited enhanced colloidal stability and showed pronounced fluorescence quenching in the presence of Pb²⁺ ions, indicating high sensitivity and selectivity toward lead. Both TGA- and PEI-capped QDs also demonstrated moderate responses to Co²⁺ but negligible interaction with Sn²⁺, confirming ion-specific detection. Overall, this study demonstrates that surface-engineered QDs constitute a simple, accessible platform for selective detection of toxic metals, with promising applications in environmental monitoring and water quality assessment. Full article

This scoping review examines how contaminants in drinking water influence children’s neurological development. Evidence across epidemiological, experimental, and mechanistic studies demonstrates that early-life exposure to lead, arsenic, fluoride, manganese, and PFAS is consistently associated with adverse cognitive, behavioral, and neurodevelopmental outcomes. These effects occur even at low exposure levels and involve pathways such as oxidative stress, endocrine disruption, and impaired neuronal signaling. In contrast, data on nitrates and microplastics remain limited, highlighting substantial research gaps. Overall, the findings underscore drinking water quality as a critical determinant of child neurodevelopment and emphasize the need for strengthened monitoring and public health protections. Full article

Groundwater level mapping is used in order to detect aquifer locations, flow paths, recharge zones, and contamination/pollution of groundwater. This is crucial for water management, environmental studies and resource planning focusing on landfills. This study involves the collection of monitoring well data and the mapping of the groundwater table at the Mavrorachi landfill site using Geographic Information Systems (GISs). The monitoring period spans from 2008 (startup) to 2025 (the current full year) for the 11 monitoring boreholes. Interpolation methods in GISs enabled us to map the groundwater level, while spatial analysis tools modeled the potential groundwater flow. The above process proved to be a valuable tool for modeling groundwater resources. The monitoring of groundwater level is essential to prevent the impact of leachate generated from landfill. Full article

This study develops exact analytical solutions for transient elliptical groundwater flow toward an extended well in an anisotropic fractured confined aquifer and then discusses how the resulting hydraulic response can support groundwater-head interpretation in shale-gas development areas. The environmental connection is made at the aquifer-protection scale: the model is not a shale-gas reservoir production model, and it does not solve contaminant transport directly. Instead, it provides a hydraulic interpretation framework for estimating anisotropy, equivalent fracture length, wellbore-storage effects, and the preferential direction of head propagation around possible leakage points, old wells, fractures, or monitoring wells. Based on Mathieu-function theory and the separation-of-variables method, constant-rate and constant-head solutions are derived in Laplace space and inverted to the time domain with the Stehfest algorithm. The analytical results are validated against COMSOL5.2 finite-element simulations, and the effects of anisotropy coefficient and wellbore storage are analyzed through drawdown and flow-rate type curves. A synthetic but field-style water-head example is included to demonstrate how monitoring records can be converted to drawdown, fitted to the elliptical-flow solution, and used to delineate a preliminary hydraulic response zone. The results show that anisotropy mainly controls early-to-middle time response, whereas wellbore storage may obscure early head changes and delay the recognition of fracture connectivity. Therefore, the solution is best regarded as a rapid hydraulic-screening and monitoring-design tool that can precede, but not replace, site-specific contaminant-transport modeling in shale-gas groundwater-protection studies. The relevant technical issues are possible head disturbances and preferential groundwater pathways associated with surface spills, flowback-water handling, old wells, faults, and fracture-connected water-bearing zones. Because verified local field-monitoring records were not available for us, the application example is explicitly described as a synthetic field-style demonstration; it is used to show the workflow and its limitations, not to claim site-specific prediction of contaminant concentration. Full article

Background: Access to safe drinking water remains a critical public health concern in rural Ghana, particularly in climatically vulnerable and underserved settings. This study assessed the microbiological and chemical quality of drinking water and evaluated nitrate-related health risks in the North Gonja and North-East Gonja Districts of the Savannah Region. Methods: A cross-sectional study was conducted between January and March 2025. A total of 460 water samples were collected from groundwater sources and household storage containers. Microbial analyses targeted total coliforms and Escherichia coli. Physicochemical and chemical parameters included nitrate-nitrogen, pH, residual chlorine, major ions, and trace metals. Data was analyzed using descriptive statistics, chi-square tests, spatial interpolation, and non-carcinogenic health risk assessment based on the hazard quotient (HQ) approach. Results: Widespread microbial contamination was observed, with 91.5% of household water samples positive for total coliforms and 46.6% for E. coli. Contamination of source water was significantly higher in North Gonja than in North-East Gonja. Overall, 49.1% (n = 55) of groundwater sources exceeded the World Health Organization guideline value for nitrate-nitrogen, with exceedances predominantly occurring in North Gonja. Additionally, 67.0% (n = 75) of samples were outside the acceptable pH range (6.5–8.5), including 74 samples below 6.5 and one above 8.5. Residual chlorine was not detected in any of the samples. Health risk assessment indicated potential non-carcinogenic risks associated with nitrate exposure, particularly among infants and children. Conclusions: The study demonstrates significant microbial contamination and nitrate-related health risks in the study area, particularly in North Gonja. Interventions such as improved source protection, routine water quality monitoring, chlorination, household water treatment, and implementation of Water Safety Plans are recommended to enhance drinking water safety and reduce associated public health risks. Full article

An Aspergillus flavus outbreak strain dominated the indoor environment in a Danish hospital ward for eight years and subsequently multiple isogenic infections occurred. We investigated whether strain-specific traits were present to understand its prevalence and persistence. The outbreak strain was studied alongside comparator A. flavus isolates with respect to altered virulence that could enhance its pathogenic potential and secondary metabolism that could influence environmental persistence. Twenty-four isolates were examined for growth patterns on ten media and by secondary metabolite profiling using high-performance liquid chromatography with diode-array detection. Strain-specific virulence and other phenotypic traits were studied in vivo using Galleria mellonella and in vitro by culturing on specialised media. No indication of virulence alterations was observed in larvae. However, the outbreak strain exhibited a reproducible fingerprint phenotype with distinct morphological features and secondary metabolites. These included mycotoxins known to be harmful to humans and animals. Although this study found no evidence of increased virulence, identification of a distinct phenotypic profile could indicate adaptation or an intrinsic ecological background of the outbreak strain and possibly competitive traits via potentially bioactive secondary metabolites. Moreover, the production of several mycotoxins by this A. flavus strain raises concerns for both patients and staff. Further analyses of the strain’s ecology, toxic potential, virulence, and phylogeny in a global context could be studied in future experiments. Full article

Areas where mining activities overlap with agricultural production may promote the mobilization of potentially toxic elements (PTEs) into soils and water resources, thereby creating exposure pathways for populations living or working in these environments. This study analyzes the concentration of PTEs in agricultural soils and irrigation water from Santa Rosa, southern Ecuador, and assesses the associated health risks for exposed agricultural workers. For this purpose, 35 soil samples were collected from farms and 12 water samples from the irrigation canal during the dry season of 2025. The concentration of PTEs in soil and water was determined using X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS), respectively. The PTE concentration in both matrices was compared with the maximum permissible limits (MPL) established by Ecuadorian regulations. Non-carcinogenic hazard indices ($\mathrm{H}\mathrm{I}$) and carcinogenic risk ($\mathrm{T}\mathrm{C}\mathrm{R}$) were estimated following the U.S. EPA methodology. In soil, As and Cr were the PTEs of greatest concern, exceeding the MPL in 93% of the samples and by up to 4.4 and 2.4 times, respectively, while in water, all PTEs were below the MPL. Non-carcinogenic risk was below the recommended limit for soil and water ($\mathrm{H}{\mathrm{I}}_{\mathrm{s}\mathrm{o}\mathrm{i}\mathrm{l}}$ = 3.00 × 10⁻² and $\mathrm{H}{\mathrm{I}}_{\mathrm{w}\mathrm{a}\mathrm{t}\mathrm{e}\mathrm{r}}$ = 2.00 × 10⁻³), with As as the dominant contributor. Cancer risk was tolerable in soil ($\mathrm{T}\mathrm{C}{\mathrm{R}}_{\mathrm{s}\mathrm{o}\mathrm{i}\mathrm{l}}$ = 4.34 × 10⁻⁵), while in water it remained at a low level ($\mathrm{T}\mathrm{C}{\mathrm{R}}_{\mathrm{w}\mathrm{a}\mathrm{t}\mathrm{e}\mathrm{r}}$ = 1.65 × 10⁻⁶). These findings identify As and Cr as priority contaminants and support targeted monitoring and source-control measures in mining-influenced agricultural areas. Overall, by integrating agricultural soil and irrigation water quality with an occupational health risk assessment in Santa Rosa, this study contributes evidence to support future research in mining–agriculture coexistence areas. Full article

Introduction: Aquatic chemical pollution is among the most worrying threats to ecosystem health. There is an ever-increasing variety of pollutant substances detected across the source-to-sea continuum, causing loss of biodiversity and ecological disequilibrium. Achieving cleaner and healthier systems relies on carrying out sustained, cost-effective, diagnosis and aquatic effects monitoring, within the adaptive management cycle. The available methods are, however, cumbersome, which creates a clear need for innovative expeditious approaches for low-cost surveillance monitoring. In the last decade, Raman Spectroscopy (RS) has gained wide recognition for application to biological questions, for its ability to uncover the complexity of molecules and their interactions. Various fields, from pharmacology to disease diagnosis and prognosis, have suffered an innovation revolution through the application of RS. In this technique inelastic light scattering of a small part of photons of an incident electromagnetic monochromatic light beam (ranging from near-infrared to visible or ultraviolet) is caused by the molecular vibration of chemical bonds. This results in shifts in energy, which indicate discrete vibrational modes of polarisable molecules, providing qualitative and quantitative assessments of the chemical composition and molecular structure of the sample. The technique shows high sensitivity, no need for sample preparation and the possibility of use in non-invasive and label-free analysis. Objective: The aim of this work is to present and discuss evidence about the application of Raman Spectroscopy (RS) to environmental diagnosis and aquatic effect monitoring of pollution. Methodology: The technique was applied to different biological models, i.e., diatoms, zebrafish embryos and larvae and freshwater snails. Quality assessments with diatoms were tested in environmental monitoring, while assessments with other models were done upon exposure to metals and organic contaminants. Results and conclusions: The Raman spectra obtained from the samples analysed comprised bands detected within the 800 to 2000 cm⁻¹ wavenumber range. These were related to bond vibrations of carbohydrates, DNA phosphate groups, proteins or CH, NH and OH stretching in lipids and proteins. Data analysis using chemometric methods clearly distinguished pollutant exposure from control sites or treatments, pointing out the potential for surveyance monitoring. The next steps include the comparison with other sensitive methods (e.g., locomotion and avoidance behaviours, omics methods) to assess efficiency and bring further mechanistic understanding. Full article

The Chishui River Basin, a core production area for Chinese sauce-aroma Baijiu (exemplified by Moutai), supports sorghum cultivation critical to the liquor’s distinctive quality. The soil environment quality within this region, therefore, directly impacts the safety and quality of both raw material and the final distilled spirit. To underpin the safe production and sustainable development of this iconic beverage, it is essential to assess soil heavy metal contamination in the soils and quantify the contributions from various sources. In this study, 172 surface soil samples were collected from typical sorghum planting bases in the Renhuai area. Concentrations of eight heavy metals (loids) (As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn) were determined. The contamination status was evaluated using the geostatistical inverse distance weighting interpolation, the Nemerow pollution index (P_N), and the potential ecological risk index (RI). Source identification and quantification were performed using the positive matrix factorization receptor model (PMF). Results revealed significant enrichment of Cd and Hg in the soil, with mean concentrations 2.07 times and 2.54 times the soil background values for Guizhou Province, respectively. Pollution index results (P_i, P_N) indicated that soil Cd contamination is relatively severe, whereas contamination from other elements is minimal. Overall, approximately 86.5% of the study area was classified as clean or only slightly polluted. Cd poses a moderate ecological risk and was the primary contributor to the total ecological hazard. Other elements exhibited lower risk, resulting in a slight overall potential ecological risk. The soil environmental quality in certified organic sorghum bases was generally favorable. PMF analysis identified three principal sources: historic industrial emissions and traffic-related sources (contributing 46%), weathering of carbonate rocks combined with agricultural activities (37%), and natural background coupled with organic fertilizer application (17%). In conclusion, while the overall soil heavy metal pollution level in the sorghum planting areas is low, the notable enrichment and higher ecological risk of Cd necessitate enhanced dynamic monitoring and targeted risk control measures to ensure long-term soil health and product safety. Full article

Agricultural intensification in Eastern Africa has raised concerns about the transport of pesticides and nutrients from farmland into surface waters, posing risks to ecosystems and human health. This study systematically reviews the peer-reviewed literature published between 2010 and 2024 to assess the extent, patterns, and drivers of agrochemical contamination in rivers, lakes, and reservoirs across the region. Reported pesticide concentrations ranged from <0.01 to 0.55 μg L⁻¹, with several studies indicating exceedances of drinking-water or environmental guideline values, particularly for organophosphate and carbamate compounds. Nutrient enrichment was widespread, with nitrate concentrations of 0.99–5.6 mg L⁻¹ and phosphate levels of 0.16–2.0 mg L⁻¹, frequently linked to eutrophication. Many studies showed strong seasonal variability, with higher concentrations during rainy periods due to increased runoff and erosion. Variability among findings reflected differences in land use, catchment characteristics, sampling design, and analytical approaches. Where evaluated, mitigation measures such as vegetated buffer strips, cover cropping, and improved nutrient management were associated with reductions in agrochemical runoff of approximately 50–80%. Overall, agrochemical contamination is widespread across Eastern African basins and influenced by agricultural practices and hydrological dynamics, highlighting the need for strengthened monitoring, improved stewardship, and broader adoption of mitigation strategies. Full article