Microplastic contamination in urban water systems poses emerging risks to human health, yet integrated frameworks linking sources, exposure pathways, and health outcomes remain limited. This study develops an integrated machine learning-Bayesian-structural equation modeling framework to quantify and predict microplastic-driven health risks across urban water systems. A systematic literature review screened 1,742 records, of which 47 studies met the predefined eligibility criteria and were included in the final analysis. Here, we integrate machine learning, Bayesian inference, and structural equation modeling (SEM) to resolve microplastic contamination dynamics and associated health impacts across urban water systems. The synthesized dataset incorporated environmental source characteristics, contamination indicators, exposure metrics, biological response proxies, and health-related outcomes to support integrated modeling and risk prediction. Random Forest clustering identified six distinct contamination-health regimes (R2 = 0.73), including industrial discharge-dominated, wastewater-associated, stormwater-influenced, mixed urban residential, landfill/leachate-associated, and low-contamination background conditions. Random Forest regression predicted health impairment with high accuracy (R2 = 0.84; RMSE = 3.77). Additionally, microplastic health risk is governed by coupled environmental pressures, exposure pathways, and biological responses rather than isolated factors. Binary classification achieved 80% accuracy for detecting regulatory exceedance risk. Bayesian correlation revealed strong coupling between microplastics and exposure, oxidative stress, and inflammation. Structural equation modeling demonstrated that land-use intensity impacts health both directly and indirectly through wastewater loading and biological stress pathways, explaining 89.9% of health variance. This study integrates systematic evidence synthesis, machine learning, Bayesian inference, within a unified predictive framework, providing a novel approach for quantifying contamination-health relationships and supporting evidence-based urban water management. These findings establish a data-driven framework for predicting microplastic risks and optimizing mitigation strategies in urban water cycles.
Artisanal brick kilns (ABKs) in Mexico operate predominantly under conditions of informality, poverty, and limited regulatory oversight. This narrative review integrates scientific literature, institutional reports, and regulatory documents to examine the socio-environmental impacts, health effects, and regulatory challenges associated with ABKs in Mexico, complemented by a state-level descriptive ecological analysis linking social deprivation and the territorial distribution of brick-kilns units. Evidence indicates that artisanal brick production is spatially and socially embedded in marginalized communities, where proximity of kilns to residential areas, family-based labor organization, and restricted access to cleaner fuels amplify exposure for workers and nearby populations alike. The combustion of low-cost and often waste-derived fuels, rather than the clay composition itself, is the primary driver of complex emissions including fine particulate matter, black carbon, polycyclic aromatic hydrocarbons, metals, and persistent organic pollutants, with contamination extending to soil, settled dust, and water. Health studies, though limited in number and geographically concentrated, document a burden of internal exposure to pollutant mixtures together with subclinical respiratory, renal, cardiometabolic, hematologic, genotoxic, and epigenetic alterations in children, adolescents, and workers. Within the international literature, Mexico stands out for the breadth of its multi-organ biomonitoring evidence. The current regulatory framework is structurally misaligned with the operational realities of the sector, with ambient and emission standards that are difficult to enforce in informal settings and an absence of occupational health protections for most brick kiln workers. Addressing these challenges will require regulatory instruments designed specifically for ABKs, expanded health surveillance, and governance arrangements compatible with the socioeconomic conditions of brick-making communities.
Groundwater is a major source of domestic water in coastal Ghana, but its quality is increasingly threatened by salinisation, nutrient enrichment, geogenic mineralisation, and localised anthropogenic contamination. In addition to hydrochemical indices and multivariate statistics that have been used over the years to assess coastal water quality, this study has incorporated nonlinear machine learning and probabilistic risk assessment to enhance source discrimination and uncertainty-based health risk characterisation of groundwater along central coastal zone of Ghana. This study aimed to evaluate groundwater quality, understand the predominant hydrogeochemical and anthropogenic controls on it, and assess the non-carcinogenic health risks to adults, children, and infants. This has become necessary as more indigens are now relying on groundwater for their domestic use due to fluctuations in the national water delivery. 432 groundwater samples from wells were examined for physicochemical parameters, major ions, nutrients and trace metals. Hydrochemical indices, Principal Component Analysis, Self-Organising Maps and probabilistic Human Health Risk Assessment with Monte Carlo simulation were employed. The results revealed high hydrochemical variability in EC (94.6-52,700 µS/cm), TDS (5-53,925 mg/l), and chloride concentration (1-22,433 mg/l) among samples collected from the study area, indicating that hydrochemical salinisation and mineralisation are very pronounced. Some sites had nitrate and fluoride above the WHO drinking-water guidelines. The Weighted Average Water Quality Index classified 73.49% of samples as excellent to good, while the Comprehensive Pollution Index indicated that 76.10% of the samples were slightly to heavily polluted. The Water Nutrient Pollution Index classified 70.48% of samples as considerably to extremely polluted. In contrast, the Heavy Metal Evaluation Index classified 91.37% of the samples as having low heavy metal contamination. Five components were extracted by PCA, explaining 64.25% of the total variance; salinity and mineralisation explained 32.51%. SOM recognised two hydrogeochemical clusters, reflecting the major water-rock interaction and the minor anthropogenic and redox effects. The probabilistic health risk assessment indicated low non-carcinogenic risk for adults (mean HI = 0.38, 3.05% exceedance) and high risk for children (mean HI = 1.04, 32.11% exceedance) and infants (mean HI = 1.10, 36.49% exceedance). The most important factor in risk variability was fluoride. Results indicate that groundwater quality is primarily affected by geogenic mineralisation, coastal salinisation, and increasing anthropogenic nutrient inputs, and that the risk to groundwater is higher for vulnerable populations. In high-risk communities, groundwater should be monitored routinely, nutrient-source control measures should be implemented, wellhead protection measures should be applied, and targeted defluoridation measures should be implemented.
This study evaluated Hg contamination and geochemical fractionation in soils from a historical cinnabar mining site located in south-eastern Spain. Four representative environmental compartments were investigated: a furnace slag heap, the mine interior, the mine exterior and the Tía Anica la Ciega cave. Composite soil samples were obtained from 260 sampling points and analysed for total mercury (THg) using direct mercury analysis (DMA-80). Mercury fractionation was assessed through a sequential extraction procedure, and contamination and ecological risk indices were calculated as preliminary screening tools. THg concentrations showed a marked contrast among environmental compartments. The highest concentrations were recorded in the furnace slag heap and the mine interior (128 and 132 mg kg⁻1, respectively), whereas substantially lower concentrations were found outside the mine (1.356 mg kg⁻1) and in the cave environment (5.028 mg kg⁻1). Mercury fractionation revealed a remarkably consistent distribution pattern across all compartments. The mercury sulfide fraction (HgS) was dominant, accounting for approximately 72-75% of THg, whereas the residual fraction represented 28-30%. Organic mercury and strongly bound species were only present in trace amounts. The results indicate that historical mining and ore-processing activities remain the principal source of Hg contamination within the study area. Although contamination levels are extremely high in the furnace slag heap and mine interior, the predominance of HgS and residual fractions suggests relatively low current mobility under existing environmental conditions. The severe contamination is located in the slag heap and inside the mine. The external areas are within the limits established by the relevant legislation for forest use and do not require an immediate intervention. This spatial pattern constitutes one of the principal findings. Nevertheless, the elevated Hg concentrations identified in mining hotspots highlight the need for continued environmental monitoring and further studies addressing mineralogical characterisation, mercury bioaccessibility and long-term remobilisation processes. This study provides new evidence on mercury distribution and geochemical stability in a poorly documented legacy mining district and contributes to the environmental assessment of abandoned cinnabar mining sites.
Estuarine wetlands are critical coastal ecosystems increasingly threatened by anthropogenic pollution. This study investigates potentially toxic elements (PTEs) in surface sediments of the Ashtamudi Wetland System (AWS), a Ramsar site in Kerala, India, using samples collected during the monsoon (September 2020) and non-monsoon (April 2021) times during the COVID-19 pandemic period. Sediment texture, organic matter, physicochemical properties, and elemental composition were determined using standard analytical techniques, including Particle Size Analyser (PSA) and Wavelength Dispersive X-Ray Fluorescence (WD-XRF), while pollution indices were applied to evaluate sediment quality and metal enrichment. Trace element abundance followed the order Zr > V > Cr > Sr > Zn > Ni > Rb > La > Cu > Ga > Y, while major elements followed Si > Al > Fe > K > Mg > Ti > Ca > Na > P > Mn. Concentrations of Si (22.47%), Ti (0.75%), Cr (177.43 ppm), Cu (42.79 ppm), Zn (81.27 ppm), Zr (477.83 ppm), and La (45.73 ppm) exceeded local background values. Over 50% of sites exhibited pollution based on the pollution load index, with low-to-moderate contamination degrees. Chemical Index of Alteration values (CIA: 88.68, monsoon; 88.00, non-monsoon) and A-CN-K plots indicated moderate to high chemical weathering. TOC/TN ratios (1.85-15.76) reflected mixed terrestrial and marine organic matter inputs. Correlation and PCA analyses attributed Si, Al, Fe, Mg, and Ca to geogenic sources, while Cr, Cu, Zn, V, and Ni to anthropogenic sources. Human health risk assessment revealed higher non-carcinogenic and carcinogenic risks in children than adults, with ingestion as the dominant pathway. Notably, reduced metal concentrations during COVID-19 lockdown indicate diminished anthropogenic inputs. Continuous monitoring and sustainable management are essential to safeguard these ecosystems and advance United Nations Sustainable Development Goals.
Groundwater is the primary source of drinking water for private well users. Traditional safety assessments and the classification of groundwater bodies (GWBs) typically rely on regulatory standards for individual contaminants, thereby overlooking mixture toxicity. This study aims to conduct a comprehensive health risk assessment (HRA) and evaluate existing regulatory standards within the framework of the "silent risk" phenomenon. Monitoring data spanning 2010, 2016, and 2022 for 174 GWBs in Poland were analysed. Non-carcinogenic (hazard index, HI) and carcinogenic risks (total cancer risk, TCR) were evaluated for both adults and children using deterministic and probabilistic (Monte Carlo simulation) approaches. The carcinogenic risk assessment conservatively assumed that all measured total chromium occurred in the form of Cr(VI).The results were compared against Polish, European Union (EU), and World Health Organization (WHO) standards. Although manganese exceeded regulatory limits in over 60% of monitoring points due to the geogenic background, it was not the primary driver of health risk. Instead, extreme hazards (HI > > 1) were driven by localized, anthropogenic spikes in nitrate and boron concentrations. Notably, children faced health risks more than twice as high as adults. Crucially, the study identified conservative, model-derived a "silent risk" phenomenon, where water fully compliant with regulatory standards for individual contaminants still posed a screening-level warning of unacceptable cumulative health risks (HI > 1) due to the additive effects of chemical mixtures. Furthermore, aggregate GWB classifications masked localized hotspots of critical health hazards. These findings indicate that, within the limits of our conservative modeling assumptions, selected contaminants and ingestion-only exposure framework for the selected contaminants, regulatory compliance does not inherently ensure chemical safety. This screening-level silent risk highlights how current frameworks fail to account for mixture toxicity and the heightened vulnerability of children. Consequently, HRA should be integrated into routine monitoring programs, and GWB status assessments must incorporate consumption-based metrics to effectively safeguard the health of private well users.
Globally, there is a lot of concern about the quality of freshwater resources found in surface and subsurface water systems. The rapid growth of urban areas, industrial and agricultural sectors and over exploitation of groundwater resources in India put the freshwater water resources at a critical place. Saraikela-Kharsawan, a part of one of the largest industrial clusters of India, has been explored in the present study in terms of hydrochemical characteristics with the implications of major ions chemistry, contaminants source apportionment, geochemical evolution and non-cancer risk assessment. A total of 120 water samples were collected and analysed for the selected physicochemical parameters including electrical conductivity, pH, total hardness, total dissolved solid, major ions (HCO3-, SO42-, NO3-, Cl-, F-, Ca2+, Na+, Mg2+ and K+), and heavy metals following the American Public Health Association (APHA) specified methods. The geochemical evaluation deciphered that weathering of silicate and carbonate minerals along with ion exchange mechanisms and anthropogenic activities together governed the water chemistry of the area. The identified mineral phases of fluorite and carbonates like calcite, dolomite and aragonite symbolized precipitation tendency, while halite showed under-saturation status. The geospatial technique demonstrated zoning of non-hazardous to more hazardous spots based on the hazard index (HI) values in context to adult and child populations. The central and southern parts of the area have been found to be more susceptible to non-cancer human health risks due to increased levels of F- and NO3- in the studied water, attributed to geogenic and anthropogenic processes. Hazard index values of the studied groundwater indicated that adult population to be more susceptible to health risks. Higher levels of Mn, As and Co metals raised the HI values of the studied waters contributing non-cancer risks to the human community in the area.
Plants, as sessile organisms, have evolved highly integrated molecular, biochemical, and physiological networks that enable them to detect, interpret, and adapt to changing environmental stresses, including drought, salinity, heat, heavy metals, and pathogen attack. Increasing evidence indicates that these adaptive plant responses extend beyond immediate stress acclimation, enabling plants to retain a form of biological memory that enhances their capacity to respond more efficiently and rapidly upon re-exposure. Stress memory is established through the coordinated action of action of multiple regulatory layers, including epigenetic modifications, chromatin remodelling, small RNA-mediated regulation, redox signaling, physiological adjustments, metabolic adjustment and hormonal reprogramming. Stable molecular signatures, such as stress-induced DNA methylation patterns (particularly CHH methylation mediated through the RNA-directed DNA methylation (RdDM) pathway), histone modifications, Persistent changes in chromatin accessibility stress-responsive small RNAs, ROS dynamics, and long-lasting alterations in primary and secondary metabolism collectively contribute to memory formation. When these molecular changes mechanistically linked to enhanced re-stress responses, regarded as reliable biomarkers of stress memory. The effect of stress memory extends beyond molecular regulation to influence plant physiology and development. Traits such as enhanced root architecture, stomatal regulation, improved photosynthetic recovery and accelerated post growth recovery represent the functional outcomes of these underlying molecular and biochemical processes. In certain cases, epigenetic marks and small RNA signatures may persist through meiosis, enabling stress adaptive traits to be transmitted to the next generation and contributing to transgenerational stress memory. A comprehensive understanding of these interconnected biomarkers offers valuable opportunities for predicting plant resilience under adverse environmental condition. Such knowledge can facilitate the development of epigenetic-assisted crop breeding, stress priming interventions, improved phytoremediation approaches, and biomarker based early warning systems for climate resilient agriculture. Future research should prioritize on rigorous biomarker validation of candidate biomarkers, multi-omics integration, AI-based predictive modelling, and evaluation of ecological and evolutionary consequences associated with stress memory. Overall, stress-responsive biomarkers provide an essential mechanistic link between environmental perception with and long-term adaptive responses, offering practical tools for enhancing crop productivity and plant performance under variable and challenging environmental conditions.
Accurately identifying the sources of heavy metals in agricultural soils with geogenic high background is crucial for distinguishing natural enrichment from anthropogenic pollution and for safeguarding agricultural production. Traditional multivariate methods have limitations with high-dimensional, nonlinear environmental data, whereas the Self-Organizing Map (SOM) framework offers a new approach. This study focuses on Changning County, southern Sichuan, China, where Permian-Triassic Emeishan basalts, carbonate-bearing sedimentary strata, and pure carbonate rocks are superimposed within a single small agricultural county. Based on 2935 grid samples collected in 2013-2014, the concentrations and spatial distribution of As, Cd, Cr, Cu, Ni, Pb and Zn were analyzed; pollution was assessed by the Geo-accumulation Index (Igeo) and Potential Ecological Risk Index (RI); health risks were evaluated by Monte Carlo simulation; and the SOM-K-means model was used for source apportionment. The average Cd concentration (0.42 mg/kg) was 5.3 times the Sichuan background, with 65.2% of points exceeding the risk screening threshold, making Cd the primary ecological risk. Cr was the dominant non-carcinogenic risk element (53.68% probability of exceeding standards for children), and the combined probabilistic carcinogenic risk for As, Cd, Cr and Ni reached 56.08% for adults and 58.14% for children. SOM distinguished three dominant source assemblages rather than fixed quantitative contributions: Cd associated with combined carbonate-rock weathering and anthropogenic activities; Cr, Cu and Ni inherited from Emeishan basalt and associated sedimentary strata; and As, Pb and Zn from human activities. This study establishes a transferable "lithology-source-risk" framework that decouples superimposed natural and anthropogenic signals, providing a scientific basis for differentiated soil management in carbonate-dominated high-background regions of Southwest China.
Heavy metal (HM) pollution in dumpsite soils is a major environmental concern in developing countries due to rapid population growth, urbanization, and unmanaged municipal solid waste (MSW). This study employed portable X-ray fluorescence (PXRF) to assess HM contamination in surface soils from the Anandabazar landfill in Chattogram, Bangladesh. Spatial distribution, contamination indices (geo-accumulation index, Igeo; enrichment factor, EF; contamination factor, CF; and ecological risk, ER), and human health risks (non-carcinogenic and carcinogenic) were evaluated for agricultural (AG) soils surrounding the landfill and landfill slope (LS) soils. The LS soils exhibited substantially higher HM concentrations than AG soils; often the mean values (e.g., Mn = 471 mg kg-1; Zn = 675 mg kg-1, Cu = 278 mg kg-1, Pb = 313 mg kg-1, Cr = 180 mg kg-1, and As = 20 mg kg-1) exceeded local geological backgrounds, indicating anthropogenic enrichment. Elevated concentrations of most of the HMs were observed, with spatial heterogeneity across AG soils influenced by leachate migration and terrain. In contrast, Sn, Co, Sb, and Ag showed patterns suggesting geogenic origins. While most AG soils remained within permissible limits, some exceeded thresholds (V, Co, Sb). Contamination indices indicated minimal contamination in AG soils but strong contamination (Igeo > 3) in LS soils, particularly for Cu (3.95), Pb (3.93), and Zn (3.26). LS soils showed considerable risk (ER > 80) for Cu, Pb, and As, whereas AG soils showed lower risk. Health risk assessment revealed non-carcinogenic risks (hazard index, HI > 1) for both adults and children, with children more vulnerable. Lifetime carcinogenic risk was below the critical limit in AG soils; however, it was substantially higher in LS soils, especially for children. As a complementary test, some representative crops like spinach, mostly grown on the top of LS, were also screened by PXRF for HMs. Screening-level PXRF results suggested elevated HM concentrations in selected crop samples relative to food-safety guideline/reference values. Results indicated that landfill-derived HM contamination presents substantial risks warranting management intervention.
Constructed wetlands are widely recognized as nature-based solutions for improving water quality in systems receiving treated wastewater. However, their effectiveness depends primarily on hydrological connectivity, contaminant properties, and hydraulic residence time. In Mediterranean wetlands, where strong hydrological variability and seasonal water scarcity influence water quality dynamics, understanding attenuation processes under contrasting water-circulation scenarios is relevant for protecting sensitive downstream ecosystems. This study assessed the capacity of a semi-natural pond system i.e., a series of interconnected shallow ponds comprising both natural and managed water bodies that receive treated wastewater while retaining natural wetland characteristics, located upstream of the Fuente de Piedra Ramsar wetland main basin (southern Spain) to reduce nutrients and emerging contaminants under contrasting water-circulation scenarios. Across 26 sampling events, substantial reductions were observed when treated wastewater flowed through the semi-natural pond system before reaching the main wetland basin, including decreases of 75% in total nitrogen. Marked attenuation was detected for emerging contaminants with shorter environmental half-lives, such as trimethoprim, naproxen, caffeine and selected triazine metabolites showed removals exceeding 70-90%, whereas more persistent substances, including carbamazepine and gemfibrozil, exhibited limited reduction. In contrast, negligible changes occurred during a temporary bypass configuration put in place for restoration works, in which treated wastewater avoided most of the semi-natural ponds before reaching the main wetland basin. Dry-season conditions enhanced contaminant attenuation, largely reflecting lower flows and extended hydraulic residence times. Cumulative ecotoxicological risk, estimated using risk quotients (RQsample) based on measured environmental concentrations and the lowest predicted no-effect concentrations for freshwater organisms, declined downstream under the regular flow pathway, particularly for pesticides, but moderate risk persisted under the bypass scenario. Overall, the semi-natural pond system demonstrates a strong but hydrologically dependent capacity to mitigate nutrient and emerging contaminant loads entering a Mediterranean Ramsar wetland. Nevertheless, elevated phosphorus concentrations and the persistence of certain emerging contaminants highlight the limitations of natural attenuation alone and support the integration of complementary management and treatment strategies to ensure long-term ecosystem protection.
Mercury (Hg) from artisanal and small-scale gold mining (ASGM) poses significant environmental and public health risks, particularly in tropical agricultural systems. This study investigated the spatial, seasonal, and vertical distribution of Hg in paddy soils surrounding ASGM activities in Tasikmalaya Regency, Indonesia, and evaluated the associated ecological and human health risks. Soil samples were collected along a topographic gradient from an uphill area to downstream lowlands at multiple depths during the wet and dry seasons. Hg concentrations were determined using ICP-OES and a mercury analyzer with analytical validation following Eurachem guidelines. Ecological risks were assessed using the Geoaccumulation Index ( I geo ) and Potential Ecological Risk Index (PERI), while non-carcinogenic human health risks were evaluated using the Hazard Index (HI). Results showed that Hg concentrations were highest near the ASGM hotspot and decreased with increasing distance from the source in both seasons. Kruskal-Wallis analysis revealed significant spatial differences in Hg concentrations among sampling locations but no significant differences across soil depths. Hg concentrations in ASGM-affected areas generally exceeded the Australian soil quality guideline value (1 mg kg-1), whereas those in non-ASGM areas remained below this threshold. I geo ranged from unpolluted to extremely polluted, while PERI ranged from low to very high ecological risk, reaching a maximum value of 5941.2. HI indicated higher non-carcinogenic health risks for children than adults, with values exceeding 1 at sampling locations nearest the ASGM hotspot. These findings demonstrate the dominant influence of ASGM on Hg distribution and risk, supporting effective mercury management in ASGM-affected regions.
Groundwater is the primary source of drinking water through which fluoride enters the human body. Excessive intake of fluoride-contaminated water poses serious health risks. The study aims to collect groundwater samples from various sources, investigate their spatial distribution, and assess non-carcinogenic health risks. 147 samples have been collected from various groundwater sources, including borewells, dug wells, tube wells, and hand pumps, across the Jaisalmer district, Rajasthan, during the post-monsoon season in November 2025, and analysed using an Ion Selective Electrode (ISE). The results indicate that the fluoride concentration range is 0.1 to 11.8 mg L-1, with 42 samples (29%) exceeding the World Health Organisation (WHO) permissible limit of 1.5 mg L-1. Spatial distribution mapping via ordinary kriging reveals that the highest fluoride contamination is localised in the Mohangarh block (maximum 11.8 mg L-1). Statistical evaluations were performed using the Shapiro-Wilk test for normality, followed by the nonparametric Kruskal-Wallis test. Block-wise non-carcinogenic health risk assessments calculating chronic daily intake (CDI) and hazard quotient (HQ) show a maximum mean HQ value of 4.04 for children and 1.73 for adults in the Mohangarh block, followed by 3.36 for children and 1.44 for adults in the Nachana block, indicating that approximately 70% of children across the study area are at a high risk of fluorosis. These findings highlight that the region is a high-risk zone for fluoride-related health issues and requires urgent mitigation strategies, such as implementing defluoridation techniques and providing alternative safe drinking water, to protect public health.
Groundwater is a principal drinking-water source in Mainpur Block, a tribal region of Gariaband District, Chhattisgarh, India, where evidence on heavy-metal exposure and health risks remains limited. Groundwater samples collected from community drinking-water sources during 2023-2025 were analysed for Zn, Fe, Pb, Cr, Mn, and Cd using atomic absorption spectrophotometry. The contamination was evaluated using Heavy Metal Pollution Index, Heavy Metal Evaluation Index, Degree of Contamination, and Metal Index, while health risks for adults and children were estimated, and spatial interpolation was used to identify priority hotspots. Pb and Cd were the major contaminants, with 79% and 86% of 2023 samples, respectively, exceeding the permissible limits prescribed by BIS IS 10500:2012, with maximum concentrations 33 and 9 times the respective limits. The average Heavy Metal Pollution Index was 486, and 83% of the sites were highly polluted. Mean hazard indices were 2.58 for adults and 6.71 for children; 62 of 63 scenarios of child exposure exceeded the safety threshold (HI > 1). Screening-level lifetime carcinogenic risk exceeded the de minimis benchmark (10-4) at 95% of locations. Principal component analysis associated Pb-Cd-Mn with anthropogenic influences and Fe-Cr with possible geogenic controls. Eighteen composite hotspots were identified for priority intervention. These findings support targeted groundwater monitoring, drinking-water safety planning, and mitigation in groundwater-dependent tribal communities.
The widespread application of PFAS in textile industry has triggered serious human health risks worldwide, leading to typical adverse health outcomes such as thyroid dysfunction, neurodevelopmental disorders in children and reproductive damage. This paper reviews per- and polyfluoroalkyl substances (PFAS) in textiles, focusing on their overlooked release mechanisms across the lifecycle (production, usage, disposal). It summarizes post-release detection, regulation, environmental distribution, exposure characteristics and health-related toxicity, and mitigation strategies. PFAS enter the environment mainly through industrial emissions during manufacturing, oxidative degradation in use,and improper disposal. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is the most widely used and reliable method for PFAS detection, with emerging ion chromatography-tandem mass spectrometry (IC-MS) offering cost-effective, low-interference analysis for trace health-risk PFAS monitoring. PFAS undergo atmospheric deposition, aquatic transport, soil accumulation, and bioaccumulation; toxicity assessment increasingly uses computational modeling to reveal chain-length-dependent toxic differences of textile PFAS. Mitigation includes adsorption (activated carbon, biochar) and degradation (advanced oxidation, microbial degradation), optimized by computational simulations to achieve health risk reduction. Future research shall focus on clarifying long-term health hazards of emerging PFAS alternatives, exploring combined toxic effects from multi-pathway human exposure, and establishing health risk-oriented lifecycle prevention and control systems to reduce public health threats posed by textile-derived PFAS.
Plastic particles less than 5 mm, known as microplastics (MPs), are emerging as major contaminants in the marine environment. Microplastic (MP) pollution significantly impacts sea cucumbers (Class: Holothuroidea) due to their deposit-feeding activity, which involves ingesting organic contaminants and sediment. The distribution, abundance, morphological characteristics, and polymer composition of MPs in sea cucumbers are all extensively assessed in this review, which is based on a systematic review of 41 peer-reviewed studies evaluating patterns in MP contamination. Fibers (33%), fragments (27%), and films (14%) make up most of the MP particles found in these types of organisms. The most common sizes are between 100 and 500 µm, while the most common colours are blue (22%) and black (23%). Polyethylene (PE) (25%), polypropylene (PP) (17%), and polyester (PES) (14%) are the most frequent types of polymers. Geographical location, environmental pollution levels, and species-specific feeding habits all have a major impact on reported abundances. Consuming microplastic particles (MP) may lead to tissue damage, physiological stress, and contamination of the marine food web. Additionally, since sea cucumbers are important seafood commodities in several regions, the existence of MPs is about possible dietary exposure to humans. This study addresses the environmental effects of MP contamination in sea cucumbers and highlights the necessity of integrated environmental risk assessments, long-term monitoring programs, and standardized methodology.
To reveal the pollution characteristics, sources, and ecological risks of polycyclic aromatic hydrocarbons (PAHs) in soils under different land use patterns in Yangxin County, southeastern Hubei Province, surface soil samples (0-20 cm) were collected from tea garden, camphor forest, rapeseed field, wasteland, and peach grove, and 16 priority PAHs were analyzed. The Σ16PAH concentration ranged from 8.29 to 194.39 ng/g, with a mean of 94.58 ng/g, indicating a relatively low contamination level compared with previously reported national soil PAH levels. Relatively high PAH concentrations were observed in the tea garden soils and in the single wasteland area-integrated composite sample, whereas generally lower concentrations occurred in camphor forest, rapeseed field, and peach grove soils. High molecular weight PAHs (5-6 ring) accounted for 53.7%, dominating the composition and suggesting high-temperature combustion sources. Exploratory source analysis (diagnostic ratios and principal component analysis) provided exploratory evidence that PAHs mainly originated from mixed combustion sources (coal, biomass burning, and vehicle exhaust), with a minor petroleum contribution. The mean toxic equivalent (TEQ) was 12.161 ng/g, with DahA and BaP accounting for approximately 70% of the total BaP-equivalent concentration (TEQBaP) Ecological risk assessment based on ERL/ERM benchmarks showed that all PAH concentrations were below ERM values. However, concentrations of phenanthrene (Phe), indeno[1,2,3-cd]pyrene (IcdP), benzo[b]fluoranthene (BbF), and benzo[ghi]perylene (BghiP) in some tea garden samples and in the wasteland composite sample fell between the ERL and ERM, indicating potential ecological risks. Cumulative ILCR differed among land-use types, and female values were consistently slightly higher than male values. Although the mean cumulative ILCR values for all land-use types were below the screening level of 1 × 10-6, the upper range in the tea garden exceeded this threshold, indicating that some sampling points may pose relatively higher carcinogenic risks. This study provides baseline information for PAH pollution control and ecological risk management in tea garden soils.
Clarifying surface water (SW)-groundwater (GW) interactions and their effects on material fluxes is essential for water-resource protection and ecosystem stability. This study integrated hydrochemical data, stable isotopes (δD and δ18O), a 222Rn mass balance model, riverbed vertical permeability coefficients, and land use types to investigate the spatial variability and controlling factors of SW-GW interactions and material fluxes in the Xiliugou watershed, Ordos Plateau. Results showed that both SW and GW were dominated by the Ca-Na-HCO₃ hydrochemical type, while overlapping δD and δ18O values suggested similar recharge sources. Spatial variations in total dissolved solids (TDS), δ18O, and 222Rn concentrations revealed that the upstream reach was dominated by SW recharge, the midstream by GW discharge, and the downstream by anthropogenic regulation. These patterns were corroborated by hydraulic head and a 222Rn mass balance model. Combined with land use data, the results revealed a spatial decoupling between hydrological exchange and material fluxes. In the upstream reach, intensive agricultural activities maintained high groundwater TN concentrations and TN fluxes despite relatively low SW recharge fluxes. In the midstream reach, although GW discharge fluxes were relatively high, the dominance of barren land resulted in low TN concentrations and thus low TN fluxes. In the downstream reach, intensive agricultural activities also contributed to elevated groundwater TN concentrations, and although GW discharge fluxes were lower than those in the midstream, the resulting TN fluxes exceeded the midstream values. Based on these findings, SW-GW interactions and land use types should guide management.
Surface water quality in the Quadrilátero Ferrífero, a mining province in southeastern Brazil, was evaluated by combining water quality indices (WQI), land use and land cover (LULC), and population data to identify spatial and seasonal influences on river chemistry. We analyzed 835 (rainy) and 845 (dry) samples and calculated WQI scores using established methods from the literature. The methods for calculating the WQI detected broad signals of eutrophication and those related to sanitation but were less sensitive to inorganic and potentially toxic elements (PTE), whereas CCME, especially when including PTE variables, offered a more rigorous and adaptable assessment for mining-influenced areas. Microcatchments were classified into LULC groups based on the proportional dominance and co-occurrence of classes. Across methods and seasons, WQI values showed a clear degradation gradient aligned with increasing human activity. Catchments dominated by natural cover and low-intensity uses consistently exhibited the highest WQI values; notably, mining-influenced classes with substantial natural vegetation often clustered towards this higher-quality end. In contrast, catchments shaped by human occupation in urban and rural settings showed the lowest WQI scores and were statistically distinct from the low-intensity group in most pairwise comparisons, although overlaps occurred among the anthropogenic classes depending on method and season. Total population per micro-catchment was inversely related to WQI results by IGAM method in both seasons, highlighting the impact of urban expansion and infrastructure pressures on water-quality decline. Overall, the LULC-based microcatchment classification was crucial for understanding how dominant land use patterns influence water quality and for guiding targeted watershed management in mining regions.
The environmental behavior of potentially toxic elements (PTEs) in soils surrounding uranium mines depends heavily on the operational status of the facilities, yet longitudinal comparisons between active and decommissioned sites remain scarce. This study presents a three-year (2018-2020) comparative assessment of agricultural soils located around an active uranium mine (AUM) and a decommissioned uranium mine (DUM) in southern China. Soil samples were analyzed for pH and concentrations of As, Cd, Pb, Th, U, Mn, and Zn, integrating contamination indices (the Geo-accumulation Index and Potential Ecological Risk Index) and the USEPA health risk model (ingestion, skin contact, inhalation). As, Cd, and U are the main contaminants at both regions, with contrasting temporal dynamics. At the AUM, U and Pb increased significantly over time (average U: from 0.274 to 0.515 in non-carcinogenic contribution for children), while at the DUM, Th decreases and U remains consistently high. The hazard index (HI) for ingestion in children exceeds 1 at both regions (up to 2.46 at AUM in 2020). As accounts for > 98% of the total carcinogenic risk, with TCR values exceeding 10-4 (e.g., 1.01 × 10-3 at DUM, 2019). The oral route accounts for nearly 100% of the total risk. Contamination mechanisms evolve after the mine ceases operations: the active mine generates a steady increase in risks, while the DUM exhibits delayed release (peaking in 2019). Environmental management tailored to each operational status is necessary, targeting both active anthropogenic inputs and long-term weathering processes.