Environmental Geochemistry and Health最新文献

Although the use of biochar as an adsorbent for the removal of various pollutants from wastewater is well established, the use of biochar/modified biochar for the scavenging of antibiotics from aqueous media in the Fenton-like system receives less attention. The highest kasugamycin (KSM) adsorption capacity (5.0 mg g^-1) was obtained from the pristine biochar at the lowest initial pH of 3 in Fenton-like system. The Fenton-like system improved the KSM adsorption capacity of pristine biochar by 222.2%, 169.9%, and 159.9% at 25 °C, 35 °C, and 45 °C comparing to control, respectively, and it also increased adsorption capacity by 97.4%, 63.8%, and 56.8% comparing to modified biochar. The amounts of biochar applied and the Fenton-like system affected KSM mineralization and degradation. The KSM degradation products had a significant amount of small molecular organic matter (m/z 384) and a tetrahydropyran structure that was difficult to degrade. The highly efficient degradation of KSM in Fenton-like system can be attributed to the generation of large amounts of hydroxyl radical (·OH) and functional groups (C=C, C=O, etc.).

Coal mining in India, especially open-cast mining, substantially strengthens the economy while concurrently causing environmental deterioration, such as soil pollution with toxic chemicals and heavy metals. This study sought to examine the efficacy of vermicompost as a remediation technique for Mine Tailing Soil (MTS) in the Ledo Coal Fields. During a 120-day duration, different concentrations of vermicompost (20%, 30%, and 40%) were administered to MTS, and the impacts on soil physicochemical parameters, fertility, and plant growth were evaluated. The findings indicated substantial enhancements in soil fertility, encompassing increased nutrient availability, improved water retention, and diminished bulk density. Plant species, including Abelmoschus esculentus, Solanum lycopersicum, and Delonix regia, showed substantial growth when subjected to 20% and 30% vermicompost amendments, with the 30% treatment producing the most remarkable outcomes. Furthermore, Risk Assessment Code values for soils amended with 20%, 30%, and 40% vermicompost were markedly diminished, reducing the bioavailability and mobility of heavy metals. The data indicate that vermicompost is an efficient and sustainable method for remediating MTS, alleviating heavy metal contamination, and enhancing plant development, thus addressing the environmental hazards of coal mining.

Rare earth elements (REEs) are a critical global focus due to their increasing use, raising concerns about their environmental distribution and human exposure, both vital to food safety and human health. Surface soil (0-30 cm) and corresponding rice grain samples (n = 85) were collected from paddy fields in Taiwan. This study investigated the total REE contents in soil through aqua regia digestion, as well as their labile forms extracted using 0.05 M ethylenediaminetetraacetic acid (EDTA), 0.10 M hydrogen chloride (HCl), and 0.01 M calcium chloride (CaCl₂). The REE concentrations in the rice grains (Oryza sativa L.) were also analyzed. The estimated daily intake (EDI) of REEs through rice consumption for males was 1.3 times higher than that for females. Children under 12 years of age, regardless of gender, had the highest EDI of REEs compared to other age groups. High rice consumption and a high proportion of children are potentially at higher risk for elevated REE exposure. The transport of REEs from soil to rice demonstrated their shift of fractionation by the lower ratio of light REEs and heavy REEs in rice grain compared to soil and their upper continental crust (UCC)-normalized patterns. Empirical equations were developed to estimate the concentrations of REEs in rice grains based on soil pH, clay content, organic carbon, cation exchange capacity, dithionite-citrate-bicarbonate extractable iron, and labile REEs. This study provides critical insights into the health risks of REEs, clarifying their human exposure and the bioavailability from paddy soil to rice.

Studies regarding geochemical partitioning and leaching behavior of Hofmeister ions, which is considered as a risk/causative factor for chronic kidney disease of unknown etiology (CKDu), are scarce. Therefore, Hofmeister ions' leaching behavior of partially weathered rocks from CKDu endemic (Girandurukotte) and non-endemic (Sewanagala) areas, Sri Lanka were compared. Rock mineralogy was analyzed using X-ray Diffraction, and total ion contents were determined using alkaline and acid digestions. Leaching experiments were conducted for powdered rocks using HCO₃^- rich water and deionized water (DI) to determine the kinetics of Hofmeister ion release into groundwater. Fluoride fractionation in rocks was determined through a sequential extraction. The most abundant ions in both rocks from CKDu endemic and non-endemic areas were Cl^-; possibly due to carbonate and silicate minerals and Mg²⁺; possibly due to biotite minerals. Maximum leaching capacities of Hofmeister ions; F^-, Cl^-, SO₄^2-, K⁺, Mg²⁺, Ca²⁺ were higher with HCO₃^- rich water compared to deionized water in both rocks from Girandurukotte (F^-_HCO3: 5.51 mg/kg > F^-_DI: 2.62 mg/kg) and Sewanagala (F^-_HCO3: 6.24 mg/kg > F^-_DI: 3.78 mg/kg). This F^- variation might be due to the higher exchangeable fraction in the rock from Sewanagala (2.027 mg/kg) compared to Girandurukotte (0.963 mg/kg). Although, the organic matter bound F^- fraction in the rock from Girandurukotte (47.62 mg/kg) was higher than that of Sewanagala (31.66 mg/kg). However, the cumulative effect of exchangeable, carbonate bound, Fe-Mn oxide bound, and organic matter bound F^- fraction in the rock from Girandurukotte was higher (52.6%) compared to Sewanagala, making F^- a possible risk factor for CKDu.

Groundwater arsenic (As), contamination is a significant issue worldwide including China and Pakistan, particularly in canal command areas. In this study, 131 groundwater samples were collected, and three machine learning models [Random Forest (RF), Logistic Regression (LR), and Artificial Neural Network (ANN)] were employed to predict As concentration. Descriptive statistics helped to conclude that all of the samples were inside the permitted limit of WHO for pH, Ca, Mg, Turbidity, Cl, K, Na, SO₄, NO₃, F and beyond limit of WHO for EC, HCO₃, TDS, and As. RF suggested a median drop in Gini node impurity across all tree divisions. This predicted As contamination in samples due to presence of TDS, EC, HCO₃^- and turbidity in upper end of graph which expressed significance of these factors in contaminating water with Arsenic. Moreover, these factors were found positively correlated with Ar contamination. LR model expressed about best fitness of model. ANN classified large data set into two classes i.e. (1) Inside limit of WHO and (2) and outside limit of WHO. Total dissolved solids (TDS), turbidity, sodium (Na) and electrical conductivity (EC) were positively correlated with Ar (Arsenic concentration) in the collected samples. pH and K were negatively associated with Arsenic concentration of the observed samples. Confusion matrices and ROC-AUC scores evaluated that RF, model outperforming than LR, and ANN, in accuracy and sensitivity. Key variables influencing As concentration in the groundwater resources of the study area were identified, such parameters include TDS, chloride (Cl), bicarbonate (HCO₃^-) and turbidity. The study provided the complete profile of the 131 water samples which can be used to make strategies for the minimization of ground Water contamination for Rohri canal command area. Moreover, the steps can be taken to control the discussed parameters inside the WHO limit.

Fusarium solani biomass plays a significant role in water pollution remediation due to its ability to sequester heavy metals, particularly cobalt (Co(II)) and cadmium (Cd(II)), which pose severe environmental and health risks. This study aimed to identify fungi from sewage-contaminated sites and evaluate their efficiency in absorbing and reducing Co(II) and Cd(II) ions. The biosorption potential of irradiated Fusarium solani biomass for removing Co(II) and Cd(II) ions from aqueous solutions was investigated. Six fungal isolates were screened, and the most promising isolate, identified as F. solani, was selected for further research. The biomass was exposed to different gamma irradiation doses (0, 1, 3, and 5 kGy), and its biosorption efficiency was assessed. The highest biosorption efficiencies were observed with the biomass exposed to 5 kGy (FS-5), achieving 37% for Co(II) and 90% for Cd(II) removal within 25 min. The surface area of the biosorbent increased from 13.12 m² g^-1 for unexposed biomass (FS-0) to 34.87 m² g^-1 for FS-5, enhancing the biosorption capacity. The adsorption kinetics followed a pseudo second order model with high correlation coefficients (R² > 0.993), indicating chemisorption as the rate-limiting step. Isotherm studies showed that the Langmuir model provided a better fit to the experimental data, with maximum adsorption capacities of 4.44 mg g^-1 for Co(II) and 21.00 mg g^-1. This study provides valuable insights into the effective removal of Cd and Co from polluted sites, underscoring the potential of developing eco-friendly and cost-effective bioremediation approaches.

Soil microplastics (MPs) pollution has garnered considerable attention in recent years. The use of biodegradable plastics for mulching has led to significant quantities of plastic entering agro-ecosystems. However, the effects of biodegradable polylactic acid (PLA) plastics on meadow soils remain underexplored. This study investigates the impacts of PLA-MPs of varying particle sizes and concentrations on soil physicochemical properties, enzyme activities, and microbial communities through a 60-day incubation experiment. PLA-MPs increased the pH, soil organic matter, total nitrogen (TN) and available potassium (AK) content, as well as enhanced the activities of superoxide dismutase (S-SOD), peroxidase (S-POD), soil catalase (S-CAT), β-glucosidase (S-β-GC) and urease (S-UE) activities. Conversely, a decrease in alkaline phosphatase (S-ALP) activity was observed. The influence of PLA-MPs on soil physicochemical properties was more pronounced with larger particle sizes, whereas smaller particles had a greater effect on enzyme activities. Additionally, PLA-MPs led to an increase in the abundance of Acidobacteriota, Chloroflexi, and Gemmatimonadota, while the abundance of Proteobacteria, Actinobacteriota, and Patescibacteria declined. Mantel test analysis showed that changes in microbial community composition affected soil properties such as pH, AK, S-UE and S-β-GC. Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt2) analysis demonstrated that PLA-MPs modify bacterial metabolic pathways. Our results suggest that particle size and concentration of PLA-MPs differentially affect soil nutrients and microbial community structure and function, with more significant effects observed at larger particle sizes and higher concentrations.

Urban environments are heavily influenced by various activities, leading to contamination of water sources by emerging contaminants (ECs). Among these, caffeine (CAF) and N, N-diethyl-meta-toluamide (DEET) are notable ECs frequently found in domestic sewage due to human activities. Despite extensive research on emerging contaminants, limited studies have focused on the seasonal variations, human health and ecological risks of CAF and DEET in urban groundwater, particularly in Indian cities. This study aimed to analyze the occurrence, spatial distribution, ecological and health risks of CAF and DEET in groundwater in Vellore city, Tamil Nadu, India. A total of 96 groundwater samples were collected across four seasons in 2022 and analyzed using Hichrom HPLC in an 844 UV/VIS compact Ion Chromatography system. CAF and DEET were detected in 95% and 96% of samples, with mean concentrations of 34 μg/L and 30 μg/L, respectively. Contamination levels were higher during the Southwest Monsoon (SWM) and Northeast Monsoon (NEM) seasons. Health risk assessments for children, women, and men showed that CAF posed significant risks, particularly to children during the NEM season, followed by women and men. Although DEET exhibited lower health risks overall, children remained the most vulnerable group. Statistical analysis confirmed significant differences in exposure levels, with children showing the highest variations. Ecological risk assessment revealed that 96.88% of samples containing CAF posed moderate ecological risks, while 6.25% of DEET samples fell into the same category. This study highlights the widespread presence of CAF and DEET in urban groundwater and their associated health and ecological risks. The findings emphasize the need for effective strategies to monitor and mitigate EC contamination in urban water systems.

Long-term intake of high-fluoride water can cause fluorosis in bones and teeth or damage to organs. Fluoride in groundwater is primarily derived from reactions with rocks containing fluorine-related minerals, and fluoride concentrations are elevated in groundwater that has been reacting with these rocks for a long time. The purpose of this study is to investigate the origin and distribution of fluoride in groundwater and to assess the influence of various factors, including geology, on fluoride concentrations in groundwater. The Eumseong basin and surrounding areas were selected as the study area due to the diversity of geologic factors. 139 groundwater samples and 14 rock samples were collected, with groundwater samples subjected to field water quality measurements, chemical analysis, and statistical analysis, and rock samples subjected to microscopic observation and chemical analysis. Fluoride concentration in groundwater increased with well depth, and was highest in groundwater associated with granitic rocks rich in biotite. The fluoride concentration in groundwater showed a negative correlation with the distance to the fault, suggesting that deep groundwater may preferentially flow along fault zones in certain areas. In addition, high-fluoride groundwater had depleted water-stable isotope values, which is likely to be resulted from higher degree of water-rock interaction in groundwater recharged at higher elevations. Calcite precipitation in most groundwater appears to weaken fluorite solubility control on fluoride concentration. Multivariate statistical analysis revealed that water-rock interactions generally governed fluoride and major element concentrations, with high-fluoride groundwater clearly distinguished. These findings can aid in assessing fluoride occurrence in groundwater and managing water quality in areas with similar geological characteristics.

It remains unclear whether phthalates are associated with gallstones and whether the associations of phthalate alternatives with gallstones are different from traditional phthalates. In this study, 1735 participants from the NHANES 2017-2018 were included and their urine was used to detect phthalate metabolites. We used logistic and restricted cubic spline regressions to assess individual associations and dose-response relationships between phthalate metabolites and gallstones, quantile g-computation and Bayesian kernel machine regression to assess mixed associations of phthalate metabolites with gallstones, and subgroup analyses to explore potential effect modifiers. We observed that individual associations of cyclohexane-1,2-dicarboxylic acid-mono(carboxyoctyl) ester phthalate (MCOCHP) (OR: 1.423, 95% CI: 1.098-1.844) and cyclohexane 1,2-dicarboxylic acid monohydroxy isononyl ester (MHNCH) (OR: 1.380, 95% CI: 1.080-1.763) with gallstones were linearly positive, mixed association of phthalate metabolites (OR: 2.453, 95% CI: 1.054-5.708) with gallstones was also positive, and MCOCHP and MHNCH had positive weights. The associations of phthalate metabolites with gallstones were higher in the males and participants with age ≥ 60 years, BMI ≥ 30 kg/m², hypertension, and diabetes. MCOCHP and MHNCH had the highest groupPIP (groupPIP: 0.941), mono(2-ethyl-5-carboxypentyl) terephthalate (MECPTP) had the highest condPIP (condPIP: 0.721), and mono(2-ethyl-5-carboxypentyl) phthalate (MECPP), MCOCHP, and mono-isobutyl phthalate (MiBP) also had high condPIPs (condPIP > 0.5). The trend in mixed associations of phthalate metabolites with gallstones was positive. Our study suggests that traditional phthalates and phthalate alternatives are associated with gallstones, especially in the elderly, men, obese, hypertensive populations, and diabetic populations, and phthalate alternatives are associated with a higher risk of gallstones.