Search Results (1,054)

The Wadi Al-Ahsaba watershed is an arid to semi-arid catchment situated in southwestern Saudi Arabia, characterized by intermittent surface flow, high evaporation and low rainfall, and a dam reservoir built for flood control. The work aims to assess hydrological and anthropogenic controls on surface and groundwater quality, pollution status, and human health risks using an integrated approach of hydrogeochemical analysis, multivariable statistics, and water quality and contamination indices. A total of 21 water samples (15 surface water, 6 groundwater) were analyzed for general chemistry, major ions, and trace elements. Hydrogeochemical analysis and principal component analysis (PCA) were implemented to differentiate the geogenic from anthropogenic control on water quality. The pollution status and associated risk were evaluated using water quality index (WQI), contamination degree (Cd), Hazard Quotient (HQ), and Hazard Index (HI). Results suggest limited surface–groundwater interaction, with surface water dominated by Ca–Mg–HCO₃ facies, indicating recent recharge and limited water–rock interaction, whereas groundwater exhibits mixed Ca–Mg–Cl and Ca–Na–Cl–SO₄ types, revealing longer residence time and water–rock interaction. Nitrate (9.5–109 mg/L) and TDS (522–1003 mg/L) exceeded drinking water standards in 90% and 95% of tested samples, respectively, and WQI ranged from 43 to 134, reflecting excellent to poor water. High non-carcinogenic risk from nitrate was observed, especially for infants. The study concluded that the geogenic processes (water–rock interaction, evaporation, and mineral dissolution) control the general chemistry of tested water, while anthropogenic input from wastewater and agriculture input are likely contributors to nitrate contamination. The study contributes to the understanding of arid wadi-dam systems by revealing how limited recharge, hydrological connectivity, and episodic flow control contaminant transport and persistence, underscoring the critical role of integrated hydrological analysis and land use management in safeguarding freshwater resources in arid environments. Full article

Petroleum exploitation in the Niger Delta has caused widespread contamination of mangrove ecosystems, yet studies that integrate total petroleum hydrocarbons (TPH) and metals in mangrove water are still very limited. This study presents the first dual-pollutant baseline assessment of TPH and five priority metals (Cd, Cr, Pb, Ni, Zn) in Bille mangrove water, a severely oil-impacted system supporting about 50,000 residents. Water samples were collected from six sites along a contamination gradient (flow station, pipeline passage, old bunkering site) and analyzed for TPH (C8–C40) and metals. All concentrations are reported in mg/L for direct comparability with World Health Organization (WHO) drinking-water guidelines and United States Environmental Protection Agency (USEPA) thresholds. TPH concentrations ranged from 0.18 to 57.66 mg/L, with Site 3 (pipeline passage) showing levels about 320-fold higher than reference sites and exceeding the WHO drinking-water guideline (0.05 mg/L) by up to 1153-fold. Cadmium (0.040–0.350 mg/L) and nickel (0.055–0.561 mg/L) exceeded WHO drinking-water guidelines (Cd 0.003 mg/L; Ni 0.07 mg/L) by 13–117- and up to 8-fold, respectively. Health risk assessment, using USEPA Risk Assessment Guidance for Superfund (RAGS) protocols, revealed a total cancer risk of 4.15 × 10⁻³ at Site 3, 41-fold above the USEPA acceptable threshold of 1 × 10⁻⁴, and extreme non-carcinogenic risk (Hazard Index = 20.03–25.51) at petroleum-infrastructure sites; cadmium contributed 86–88% of both carcinogenic and non-carcinogenic effects. Ecological risk indices classified Site 3 as extreme (Potential Ecological Risk Index = 722, against the Håkanson PERI = 600 “very-high-risk” threshold), mainly driven by cadmium (Er = 310–350) and nickel (Er = 140–150). Source apportionment using the Carbon Preference Index, enrichment factors, and strong TPH–metal correlations (r > 0.88, p < 0.01) clearly identified petroleum operations as the dominant contamination source. This work demonstrates the critical importance of integrated multi-pollutant assessments in petroleum-degraded mangrove water for guiding environmental protection and public-health interventions. Full article

Despite their size, small wetlands play a vital role in maintaining ecosystem stability. To clarify the pollution levels as well as potential ecological and health risks of potentially toxic elements (PTEs) in small wetlands, 85 water samples were collected from small wetlands in the Baghrash Lake Basin (BLB) of China, and six PTEs (As, Cd, Cu, Hg, Pb, and Zn) were determined for their contents. The Nemerow integrated pollution index (NPI) was adopted to evaluate PTE pollution levels. The ecological risk index (RI) and USEPA health risk assessment model were further applied to quantify potential ecological and health risks of PTEs, respectively. The results revealed that PTEs in small wetlands showed a slight pollution level, with an average NPI value of 0.73. Meanwhile, the integrated ecological risk index of PTEs showed a low ecological risk level, with an average RI value of 23.041. Health risk assessment results demonstrated that the non-carcinogenic risk of PTEs in small wetlands remained at a negligible level, while the carcinogenic risk stayed within acceptable limits for both local population groups: children and adults. Among all detected PTEs, Hg was identified as the primary pollutant and major ecological risk factor, while As posed the highest relative potential health risk while overall risks remained acceptable. The findings of this study can provide a scientific basis for the environmental protection of small wetlands in the BLB. Full article

Polycyclic aromatic hydrocarbons (PAHs) represent a major class of ubiquitous environmental pollutants, posing significant risks to ecosystems and human health due to their persistence, toxicity, and potential for bioaccumulation. This review provides a comprehensive synthesis of current scientific knowledge on PAHs, integrating insights from chemical kinetics, environmental fate, and toxicological mechanisms. The fundamental structural chemistry of PAHs and its direct influence on their physicochemical properties and environmental properties are discussed. The major anthropogenic and natural sources of PAHs are detailed, alongside the chemical kinetics behind their formation during incomplete combustion and their transformation in environmental media. Unlike previous reviews that address PAH sources, remediation, or health effects as separate topics, this review uniquely traces the mechanistic continuum from molecular formation kinetics through physicochemical partitioning and environmental transport to toxicological endpoints, providing a causally linked framework for understanding how structural properties ultimately determine biological outcomes. A central focus is placed on the environmental fate and transport of PAHs across atmospheric, aquatic, and terrestrial compartments, highlighting processes such as gas–particle partitioning, sediment accumulation, and long-range transport. The review further elucidates the complex toxicological pathways of PAHs, including metabolic activation to reactive intermediates, DNA adduct formation, oxidative stress, and their roles in carcinogenesis and other systemic health effects. The analysis reveals strong scientific consensus on the carcinogenic mechanism of parent PAHs via CYP450-mediated metabolic activation to diol-epoxide intermediates while identifying critical areas of uncertainty: the current regulatory framework based on 16 priority PAHs underestimates total carcinogenic risk by a factor of 2–5, mixture toxicology remains poorly characterized, and dose–response relationships for non-cancer endpoints (cardiovascular, neurodevelopmental, immunotoxic) lack the quantitative data needed for robust risk assessment. Finally, human exposure pathways and health risk characterization approaches are discussed, highlighting the need for cumulative, mixture-based assessment frameworks. Full article

Slaughterhouse wastewater introduces potentially toxic elements into aquatic ecosystems, yet bioaccumulation patterns in commercial fish species and associated human health risks remain underexplored in West Africa. This study quantified zinc (Zn), lead (Pb), iron (Fe), magnesium (Mg), chromium (Cr), and cadmium (Cd) in three ecologically distinct fish species—Oreochromis niloticus (Nile tilapia), Clarias gariepinus (African sharptooth catfish), and Mugil cephalus (Flathead grey mullet)—from two slaughterhouse-impacted rivers (Transamadi and Mgbuosimini) and a control site (Iwofe) in Rivers State, Nigeria. Metal concentrations were measured using atomic absorption spectrophotometry. Two-way ANOVA assessed species and location effects. Principal component analysis (PCA) was performed, with Mg used as a potential geogenic tracer, as its loading pattern was independent of Pb and Cd and consistent with the natural background. A Water Quality Index (WQI) classified Mgboshimini and Iwofe as having poor water quality (WQI > 75), while Transamadi had medium quality. Health risks were evaluated using estimated daily intake (EDI), target hazard quotients (THQ), and hazard indices (HI) following USEPA guidelines. Metal levels varied significantly by species and location (p < 0.001). Flathead grey mullet from Mgbuosimini had the highest Pb (1.50 ± 0.05 mg/kg) and Cd (0.41 ± 0.02 mg/kg), exceeding EU maximum levels for fish muscle (Pb 0.30 mg/kg, Cd 0.05 mg/kg) by 500% and 800%, respectively. PCA explained 77.5% of the variance, with Pb and Cd clustering as anthropogenic sources, while Mg loaded independently. THQ for Pb approached unity in Flathead grey mullet (0.88), and THQ for Cd reached 0.97. HI exceeded 1.0 in all species from Mgbuosimini, peaking at 2.07 in Flathead grey mullet. Uncertainty analysis (using ±SD) gave a HI range of 1.89–2.25 for this species, all above the safety threshold. Carcinogenic risk for Flathead grey mullet (3.97 × 10⁻⁴) approached the upper acceptable limit. Slaughterhouse effluent appears to elevate Pb and Cd burdens in fish, with detritivorous Flathead grey mullet posing the highest health risk. Exceedance of safety thresholds and HI > 1.0 indicate potential non-carcinogenic and carcinogenic risks. We recommend improved wastewater treatment and species-specific consumption advisories. Full article

The Baleysky gold deposit in Eastern Transbaikalia is a classic example of the long-term environmental legacy of gold mining. The cessation of industrial wastewater discharge in 1995 led to the accumulation of more than 3 million m³ of acidic water with high concentrations of heavy metals and metalloids. These waters contain concentrations many times higher than the maximum permissible levels for fishery waters (Mn up to 6594, Al—1473, Zn—486, and Cu—414), posing a significant threat to the ecosystem of the Unda River and the health of the local population. The aim of this study was to evaluate the effectiveness of the artificial geochemical barrier method for treating such waters under laboratory conditions. Column experiments were conducted using local soil and the commercial carbonate sorbent taurite at a sorbent-to-filtrate ratio of 1:5. Taurite demonstrated a significantly higher sorption capacity than soil, substantially reducing the concentrations of As, Cd, Pb, Al, Mn, Fe, Zn, and Cu and raising the pH from 2.90 to 7.96–8.03. Although health risks associated with both carcinogenic (CR) and non-carcinogenic effects (HI) decreased significantly after treatment with taurite, residual risk levels remained unacceptably high (CR ≈ 10⁻³, HI > 1). The results show that engineered geochemical barriers have great potential for reducing anthropogenic contamination at abandoned mining sites, although further optimization of this technology is necessary to achieve compliance with regulatory requirements. 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

Oral squamous cell carcinoma (OSCC) frequently develops within chronically injured oral mucosa and may be preceded by clinically recognizable oral potentially malignant disorders (OPMDs), which provide an important window for cancer interception. This review examines how etiological exposures, persistent inflammation, and lesion-specific epithelial–stromal–immune interactions cooperate during the transition from mucosal injury to dysplasia, carcinoma in situ, and invasive OSCC. Major carcinogenic exposures, including tobacco, alcohol, and areca nut, are considered together with context-dependent contributors such as microbial dysbiosis, viral infection, and immune-mediated epithelial injury. At the molecular level, inflammation-driven oral carcinogenesis involves cytokine and chemokine amplification, oxidative and nitrosative stress, NF-κB and STAT3 activation, the COX-2/PGE₂ axis, genomic instability, field cancerization, epithelial–stromal crosstalk, angiogenesis, immune dysregulation, and epigenetic and non-coding RNA-mediated reprogramming. Emerging tools such as molecular risk assessment, liquid biopsy, optical imaging, spatially resolved profiling, and artificial intelligence-assisted models may improve identification of high-risk lesions, although most biomarkers require further prospective validation. Prevention should therefore integrate exposure control, biopsy-based diagnosis, local treatment when indicated, long-term surveillance, and trial-based precision strategies according to lesion risk, intervention window, and safety profile. This review supports a shift from lesion-centered management toward risk-adapted precision prevention in inflammation-driven oral carcinogenesis. Full article

Heavy metal(loid) pollution in watersheds surrounding mining areas originates from multiple and complex sources, posing persistent threats to terrestrial–aquatic ecosystems and human dietary safety. This study systematically investigated the pollution characteristics, spatial distribution, ecological risks and human health hazards of seven typical heavy metal(loid)s (As, Pb, Cr, Cd, Cu, Zn, and Ni) in the integrated water–soil–vegetable continuum of a mining-affected watershed in Southwest China. Field sampling was carried out in three functional zones with different mining disturbance intensities, and inductively coupled plasma mass spectrometry (ICP-MS) was used to detect heavy metal(loid) concentrations in all samples. Multiple pollution evaluation indices and the USEPA human health risk assessment model were adopted for comprehensive quantitative analysis. The results showed that 44.0% of surface water samples exceeded national permissible limits, with high-pollution areas concentrated in intensive mining zones, presenting moderate overall aquatic heavy metal(loid) pollution. Although the average concentrations of seven heavy metal(loid)s in riparian soils complied with Chinese agricultural soil screening standards, localized significant enrichment was observed for As (1.98 times), Cd (4.62 times), Cu (1.81 times), and Zn (2.72 times) compared with regional background values, causing mild comprehensive soil pollution. Farmland soils exhibited prominent Cu and Zn accumulation, and leafy vegetables in the study area suffered severe Pb and Cd pollution, with potential dietary exposure risks. Health risk assessment indicated that children face higher non-carcinogenic and carcinogenic risks than adults via soil hand-to-mouth exposure; dietary intake of vegetables leads to moderate carcinogenic risks for children caused by As and Ni exposure. Overall, this study clarifies the migration and enrichment rules of heavy metal(loid)s in the water–soil–vegetable system of mining watersheds, confirms the prominent ecological and human health risks of Cd, As and Pb in the study area, and provides targeted basic data for regional heavy metal(loid) pollution prevention and food safety management. 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

Atmospheric wet deposition represents a major pathway for the transfer of organic micropollutants into terrestrial and aquatic ecosystems. This study investigates the occurrence and spatial distribution of polycyclic aromatic hydrocarbons (PAHs), phthalate esters (PAEs), and BTEX compounds in rainwater across Northern Serbia (Vojvodina region). Rainwater samples were collected during the 2025–2026 heating season at three locations: a petrochemical site in Kikinda, a traffic- and residentially influenced site in Sremska Mitrovica, and an urban background site in Sombor. Total concentrations showed pronounced spatial variability, with the highest ΣBTEX and ΣPAE levels recorded in Kikinda (∑BTEX = 2.818 μg L^∑1; ∑PAE = 0.930 μg L^∑1). Diagnostic ratios identified a dominant petrogenic signature in Kikinda (LMW/HMW > 1), while pyrogenic sources prevailed in Sremska Mitrovica and Sombor ((Fla/Fla + Pyr) > 0.5). BTEX profiles across all sites were characterised by the absence of benzene and elevated toluene and xylene levels (B/T ≈ 0; T/X > 1). Health risk assessment indicated an acceptable but non-negligible carcinogenic risk from PAHs, particularly for children in industrial areas. These findings highlight the role of precipitation as an efficient scavenger of organic pollutants and emphasise the need for integrated atmospheric–hydrological monitoring frameworks in industrialised regions. Full article

Excessive fluoride intake from drinking water remains a public health concern in geogenic high-fluoride regions, yet direct evidence linking environmental fluoride levels to internal exposure in remote high-altitude areas is limited. This study integrated environmental monitoring with human biomonitoring to assess fluoride exposure and health risks in the Taruo Lake region of the Tibetan Plateau. Surface water (n = 45 for Taruo Lake; n = 8 for its tributaries) and groundwater samples (n = 4) were collected and analyzed for fluoride concentrations, and blood ionic fluoride (BIF) levels were measured in 122 local residents (47 adults, 75 children). The results showed that fluoride concentrations in most surface water tributaries of Taruo Lake and groundwater sources were below China’s drinking water standard, whereas those in Taruo Lake exceeded this limit (routine monitoring mean 2.54 mg/L; multi-site mean 2.79 mg/L). BIF levels were significantly higher in adults (0.126 ± 0.041 mg/L) than in children (0.075 ± 0.032 mg/L) and showed a positive correlation with age (r = 0.533, p < 0.001). Notably, 23.4% of adults and 1.3% of children exceeded 0.15 mg/L, an empirical threshold typical for healthy populations in non-endemic areas. Based on the hazard quotient (HQ) model recommended by the US EPA, most drinking water sources posed acceptable non-carcinogenic risks (HQ < 1). In contrast, Taruo Lake water presented an elevated risk (HQ > 1) in 2024 primarily due to the regional geological background, and although not used for daily drinking, this finding offers an indicative reference for local water management and risk prevention. This preliminary monitoring and biomonitoring assessment provides baseline data for future studies and underscores the necessity of continuous surveillance and evaluation of total dietary fluoride intake to protect the health of this vulnerable high-altitude population. Full article

Per- and polyfluoroalkyl substances (PFASs) present a critical challenge to global public health and environmental integrity due to the exceptional stability of the carbon–fluorine (C–F) bond. This review synthesizes current knowledge on PFAS physicochemical properties, exposure pathways, and toxicological outcomes, while evaluating global regulatory efficacy. A central problem addressed in this review is the widening discrepancy between rigid, yet deeply fragmented, international regulatory frameworks and the increasingly complex, non-linear epidemiological data regarding PFAS health risks. While historical paradigms focused heavily on direct carcinogenicity, recent high-resolution data reveal significant heterogeneity and methodological inconsistencies in cancer links. Instead, robust evidence points to severe systemic toxicities—including hepatotoxicity, immunotoxicity, and maternal–fetal disruptions—frequently driven by mixture co-exposures and sex-specific metabolic dimorphisms. Furthermore, the industrial transition to short-chain substitutes has inadvertently compounded the crisis due to their high environmental mobility and resistance to conventional water treatment. By critically evaluating these toxicological and regulatory contradictions, this review demonstrates that current substance-by-substance legislative models fail to mitigate real-world pollution trends. Ultimately, we emphasize the urgent need to transition to holistic mixture modeling, implement unified class-based global regulations, and accelerate advanced destructive remediation technologies to mineralize the resilient C–F bond. Full article

Polycyclic aromatic hydrocarbons (PAHs) in farmland soils pose potential ecological and human health risks, yet their contamination characteristics and source-related risks in farmland soils across different river basins in China remain insufficiently understood. This present study analyzed 84 farmland soil samples from northeast (primarily the middle and lower reaches of the Songhua River and Liao River basin), central (primarily the middle reaches of the Yellow River basin and Dongting Lake system), northwest (primarily the middle and upper reaches of the Yellow River and Yarlung Zangbo River basin), and southern (primarily the upper reaches of the Pearl River and Yangtze River basin) China in order to assess the contamination characteristics, sources, ecological risks, and human health risks associated with 16 US EPA priority PAHs in the samples. The findings suggest that the 16 aggregate PAHs’ concentrations in Chinese farmland soils varied from 63.9 to 9637.7 μg/kg, with an average of 1919.3 μg/kg. A gradual decline was observed from north to south, with dibenz[a,h]anthracene (DahA) accounting for the highest proportion at 14.3%. Correlation analysis, principal component analysis, and positive matrix factorization jointly indicated that fossil fuel combustion, high-temperature combustion, and traffic-related emissions were the main PAH inputs to farmland soils. The results of the ecological risk assessment indicated that the northeastern region exhibited the highest PAH ecological risk, with 41.2% of sample plots demonstrating severe PAH contamination. Conversely, the southern region exhibited the lowest PAH ecological risk, with 73.9% of the sample plots demonstrating no ecological risk. The human health risk assessment found that non-carcinogenic risks for both children and adults were within safe limits, while carcinogenic risks for both groups were relatively high. DahA was identified as the primary carcinogen, accounting for 45.9% and 70.3% of the total carcinogenic risk for children and adults, respectively. Oral ingestion was the primary route of exposure. This study provides an integrated basin-scale assessment of PAH contamination and source-related risks in Chinese farmland soils, supporting targeted management of PAH inputs in agricultural environments. Full article

With the rapid urbanization of China, environmental risks posed by informal landfills, particularly those dominated by agricultural waste, are an urgent yet understudied concern. This study systematically monitored groundwater quality surrounding five typical informal agricultural waste landfills in a coastal Chinese city. Eight major pollutants were analyzed using pollution index evaluation, the health risk model and multivariate statistical methods. The results indicate one landfill as a high-priority concern, exhibiting a combined multi-index pollution pattern with an exceedance rate of 87.5%, where NO₃⁻-N, F⁻, COD_Mn, and total hardness are the dominant indicators. Another landfill showed high background levels and anthropogenic impacts. Total non-carcinogenic risk of all landfills is below 1 (negligible). Children face approximately twice the health risk of adults. The exposure risk through drinking water ingestion is three orders of magnitude higher than that from dermal contact, with NO₃⁻-N contributing >90% of the total risk. Groundwater deterioration is primarily affected by geological conditions and seawater intrusion (52.31%), followed by agricultural activities and soil characteristics. Given these findings, priority attention should be directed to nitrogen-driven landfill and multi-index composite pollution landfill, with reinforced source tracing and control of NO₃⁻-N, alongside long-term monitoring for regional groundwater protection. Full article