Environmental Geochemistry and Health最新文献

In recent years, global attention has increasingly focused on soil heavy metal (HM) contamination. However, there remains a paucity of studies examining the interaction effects of agricultural wastes as amendments in HMs contaminated soil, particularly concerning the utilization of economic crops for soil remediation. This study investigates the impacts of various agricultural wastes (soybean meal, peanut bran, oak leaves, and coffee grounds) on soil properties, plant growth, and HMs accumulation in economic crops (sugarcane and cassava) through pot experiments. The application of these amendments resulted in significant increases in soil pH, soil organic matter (SOM), and cation exchange capacity (CEC) content. Moreover, catalase and urease activities in sugarcane planting soil were enhanced by 2.73-32.53% and 84.07-132.74%, respectively, with differing effects observed in cassava planting soil. Applications of oak leaves and coffee grounds inhibited soil invertase activity (by 28.78-61.95%), whereas soybean meal and peanut bran stimulated invertase activity (by 28.18-122.05%). Overall, these amendments reduced the bioavailability of HMs in the soil, with soybean meal demonstrating the most significant reduction in the effective state HMs content in sugarcane planting soil. The pot experiment results demonstrated that soybean meal and peanut bran, as soil amendments, improved soil quality, and promoted the growth of sugarcane and cassava. Additionally, they also increased the accumulation amount of Cd, Pb, and Zn in the plants, thereby enhancing the effectiveness of phytoremediation in HM-contaminated soils. Consequently, this study provides practical insights for soil safety and cleaner production in HMs contaminated karst farmland.

Biochar has widely used to immobilize soil heavy metals in recent years, while the properties of biochar varied with environmental conditions. The influence of biochar aging on fixation and speciation transformation of Cd in soil remains unclear. This study explores how biochar aging affects the fixation and speciation transformation of Cd in soil. Rice straw biochar (RBC) prepared at different pyrolysis temperatures (300 °C, 500 °C, and 700 °C) was aged under three treatments (drying and watering cycle (DW), H₂O₂ oxidation (HO), and citric acid acidification (CA)) to investigate the effects of the aging process on the adsorption and passivation capacity for Cd. Results showed that the aging treatment increased Cd adsorption on RBC300 by 73.69% to 216.15%, while adsorption on RBC500 and RBC700 decreased by 11.52% to 74.56% and 7.40% to 75.89%, respectively. The addition of both fresh and aged RBC raised pH, DOC, and TOC in Cd-contaminated soil, aiding in Cd fixation. Either fresh or aged RBC addition enhance the stability of Cd in soil. Compared to CK treatment, residual Cd content rose by 28.63% to 43.71%, while both acid-extractable and reducible Cd contents decreased by 9.144% to 10.95%. Furthermore, the available Cd content in the soil saw a reduction of 10.45% to 30.77%, and high-temperature pyrolytic RBC exhibited a stronger capacity for Cd passivation in the soil. Both fresh and aged RBC indirectly reduced Cd bioavailability by affecting soil pH, DOC, and TOC, and the nature aging process (DW) did not weaken the effect of biochar on Cd-contaminated soil remediation. Thus, biochar has a long-term potential for mitigating Cd pollution in farmland.

In historic mining towns, where mining activities were abandoned many decades or even centuries ago, legacy contaminations can be remobilized and redispersed, representing a threat for the environment and human health. This study focuses on urban soils (n = 19) in the town of Jihlava, the Czech Republic, one of the medieval centers of silver mining in central Europe. The basic geochemical characterization of the soils was combined with mineralogical investigations to understand the solid speciation of the metal(loid) contaminants, oral bioaccessibility tests, and exposure assessment. The total concentrations of the metal(loid)s in the original soils were not excessively high (up to 45.8 mg As/kg, 19.2 mg Cd/kg; 205 mg Cr/kg; 91.8 mg Cu/kg, 163 mg Pb/kg, 253 mg V/kg, 262 mg Zn/kg), although, in some cases, they exceeded the regulatory guidelines for agricultural and/or residential soils. A substantial increase in the metal(loid)s contents was confirmed for the < 48-µm soil fraction that was later used for the bioaccessibility tests. Scanning electron microscopy and the electron microprobe showed that ore-derived primary sulfides were rare in the studied soils. Still, hydrous ferric oxides rich in Cu, Pb and Zn and fragments of metallurgical slags composed of metal-containing glass and silicates (olivine) were prone to dissolution during extraction in a simulated gastric fluid (SGF, glycine solution acidified to pH 1.5 by HCl). The maximum bioaccessible concentrations corresponded to 4.69 mg As/kg, 1.75 mg Cd/kg, 2.02 mg Cr/kg, 20.3 mg Cu/kg, 81.6 mg Pb/kg, 16.2 mg V/kg, and 233 mg Zn/kg. Exposure estimates were carried out for children (10 kg) as a target group and a conservative soil ingestion rate (100 mg/d). However, the daily intake of all the studied contaminants was far below the tolerable limits. Our results show that the human health risk based on incidental soil ingestion in the studied area seems limited.

People spend about 90% of their day indoors and are at increased risk of exposure to metal elements (MEs), water-soluble ions (WSIs) and polycyclic aromatic hydrocarbons (PAHs) contained in indoor PM_2.5. Therefore, firstly this study investigated indoor PM_2.5 pollution to explore the distribution characteristics of MEs, WSIs and PAHs. Secondly, the carcinogenic risk of MEs and PAH to the population was analyzed using health risk assessment models. Finally, the sources of MEs and PAHs were identified using statistical analyses. The results of the study show that PM_2.5 concentrations fluctuate between spring and winter, with the most significant fluctuations reaching around 100 µg/m³ in March and January. Concentrations of most MEs, WSIs and PAHs during the heating season are twice as high as during the non-heating season. The main sources of MEs and PAHs are industrial, coal-fired emission sources, vehicle exhaust and metallurgical chemical emission sources. The non-carcinogenic and carcinogenic risks of metallic elements to the population are mainly due to Co, which contribute up to 80% in both adults and children. The carcinogenicity risk indices of the six monomeric PAHs, BaP, DbA, Bbf, Bkf, Inp and BaA, were greater than 10^-6, indicating a potential carcinogenic risk.

Extensive agricultural regions commonly face issues of poor groundwater management, non-standard agricultural production practices, and unordered discharge of domestic pollution, leading to a continuous decline in groundwater quality and a sharp increase in risks. A comprehensive understanding of groundwater conditions and pollution is a crucial step in effectively addressing the water quality crisis. This study employs the Comprehensive Water Quality Index, Irrigation parameter, and Pollution Index to comprehensively investigate the groundwater quality in a typical agricultural area in Shandong, China, and assesses the suitability of groundwater for irrigation and the risks to human health. Furthermore, multivariate statistical analysis methods are utilized to analyze the relationship between groundwater quality and agricultural production and human activities. The results of the comprehensive quality evaluation indicate that the groundwater in the study area is primarily characterized as weakly alkaline hard freshwater and slightly brackish water, with a hydrochemical type of HCO₃-Ca. 42% of the groundwater is unsuitable for drinking, with the main pollutants being TDS, TH, F^-, and NO₃^-. The shallow groundwater level and high soil permeability provide favorable conditions for pollutant migration. Residual Sodium Carbonate (RSC) and Potential Salinity (PS) indicate that 37% of the water samples have excessive bicarbonate levels and 5% have excessive salinity, making them unsuitable for irrigation. Nitrate poses non-carcinogenic risks to all three age groups. Multivariate analysis results show that agricultural pollution dominates in the groundwater, with major pollutants including SO₄^2-, NO₃^-, COD, NH₄-N, F^-, etc. Domestic pollution mainly increases the concentrations of ions such as Ca²⁺, Na⁺, Mg²⁺, and also contributes to Cl^- and NO₃^-. The findings of this study contribute to enhancing the rational utilization of groundwater quality in agricultural areas, standardizing agricultural production activities, and promoting the sustainable development of green agriculture.

A comprehensive hydrogeochemical analysis of 156 groundwater samples (106 shallow and 50 deep) was conducted in the Kathmandu Valley, Nepal. This study addresses a significant research gap by focusing on the hydro-geochemical composition and contamination of groundwater in the Kathmandu Valley, an area with limited detailed assessments. The novelty of this work lies in its comprehensive analysis of both shallow and deep groundwater, particularly concerning the high concentration of contaminants like arsenic, microbial pathogens, and ammonium, which are critical for public health. The results indicate that the mean concentration of turbidity, iron (Fe), and total coliform (TC) was exceeded the permissible range by National Drinking Water Quality Standards (NDWQS). Hydro-geochemical analysis using the Piper and Chadha diagrams showed the Ca²⁺-Mg²⁺-HCO₃ dominance, suggesting carbonate rock weathering and ion exchange as primary processes. Gibbs and mixing diagrams further supported these findings. The Water Quality Index ranged from 3.93 to 442.11 (mean: 66.87) for shallow water while 8.07 to 252.87 (mean: 79.24) with turbidity, iron, and ammonia significantly contributing to the overall index. Salinity hazard assessment considering total dissolved solids, sodium adsorption ratio, sodium percentage, magnesium adsorption ratio, and Kelly ratios, indicated that shallow and deep groundwater samples are suitable for irrigation, as confirmed by Wilcox diagrams. This study provides valuable insights into the groundwater quality of Kathmandu Valley and highlights the need for effective management strategies to ensure sustainable use of this vital resource, providing a nuanced understanding of groundwater quality and its implications for water management in the region. The findings can inform water treatment practices, policy-making, and future research, ultimately aiding in the development of safer and more sustainable groundwater management practices for the region.

Three fish species (common carp, Wels catfish, and silver carp) were collected from three locations along the Danube River in Serbia, and fish meat was analyzed for the content of toxic elements, micro- and macrominerals. Silver carp had the highest lead (Pb), arsenic (As), and cadmium (Cd) content, while Wels catfish had the highest level of mercury (Hg). Moreover, metal pollution index (MPI) ranged from 0.1096 to 0.275 and among the fish, the silver carp had the highest MPI (from 0.21 to 0.28), indicating that it could be reliable bioindicator of river pollution. Maximum determined levels of As (0.1968 mg/kg of w.w.), Hg (0.175 mg/kg of w.w.), and Pb (0.0315 mg/kg of w.w.) did not exceed values prescribed by the European Commission Regulation, Codex Alimentarius Commission, Food and Agriculture Organization (FAO), and national regulations, but Cd in silver carp was at levels higher than prescribed (0.0808 mg/kg of w.w.). Furthermore, our study's results showed that the target hazard quotient (THQ) of each analyzed element and hazard index (HI) were < 1, indicating that consumers would not be exposed to adverse health effects after consuming these fish species from the Danube River. Regarding target cancer risk (TR), for Pb this was below 10^-6, which was regarded as negligible, while TRs for As and Cr were between 10^-4 and 10^-6, which was regarded as acceptable. Moreover, since the studied fish had low values of health risk indexes, it could be concluded that fish meat did not pose a significant risk to human health.

The accumulation pattern of some inorganic pollutants in quarry sites around Ogun State was modeled using a Fuzzy comprehensive assessment (FCA). Potentially toxic elements (PTEs) and naturally occurring radionuclides materials (NORMs) were assessed from soil samples collected from ten quarry sites in three districts (Odeda, Ajebo, and Ijebu Ode) in Ogun State. Three (3) NORMs (⁴⁰ K, ²³⁸U, ^{and 232}Th) were assessed using gamma spectrometer with a NaI detector while ten (10) PTEs (As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were determined by digestion method using Inductively coupled plasma optical emission spectrophotometer. The FCA was used to evaluate soil contamination, and SPSS version 21.0 was used for statistical analysis. Concentration range of PTEs(mg/kg) and NORMs(Bq/kg) in all the site are: As (5.62 ± 0.85 - 15.93 ± 2.40), Cd (BDL-1.26 ± 0.60), Co (5.56 ± 1.34 - 27.25 ± 1.14), Cr (18.68 ± 1.54 -61.43 ± 6.33), Cu (12.40 ± 1.31-82.43 ± 7.94), Fe (15,035.00 ± 81.12 - 36,520.00 ± 292.20), Mn (168.97 ± 5.93 - 353.30 ± 20.84), Ni (5.63 ± 1.99- 25.54 ± 2.50),),Pb (4.44 ± 0.8 - 17.87 ± 2.80) and Zn (42.97 ± 413 - 147.00 ± 7.50); ⁴⁰ K (76.78 ± 44.76-2647.88 ± 179.44), ²³⁸U (3.24 ± 1.82-55.42 ± 24.88),and ²³²Th (5.24 ± 3.90-244.36 ± 89.84). The results were modeled into a membership function matrix of three pollution classes. The FCA of NORMs revealed that 30, 10, and 60% of the sites were pristine, moderately polluted, and heavily polluted.In comparison, the FCA of PTEs confirmed 100% of the sites to be heavily polluted due to the accumulative effect of the PTEs. A high percentage of membership in the extremely impacted class is linked to a high concentration of Fe in all the sites due to the soil's geological structure and natural activities. At the same time, ⁴⁰ K and ²³⁸U have high-impact membership in all the quarry sites. Based on the findings, there is a need for stringent pollution control measures, targeted monitoring of PTEs and NORMs and the development of region-specific environmental regulations to protect both public health and ecosystems.

Polychlorinated biphenyls (PCBs) are persistent organic pollutants emitted during e-waste activities. Upon release into the environment, PCBs can pose harmful effects to the humans and environment. The present review focused on the effects of PCBs on cell proliferation, apoptosis, functional and developmental toxicity and potential possible molecular mechanisms upon cells and stem cells. The review also highlights the effects of low- and high-chlorinated, and dioxin and non-dioxin PCBs. The review suggested that high chlorinated and dioxin like PCBs at higher concentrations posed more toxic effects to cells and stem cells. PCBs at higher levels induced hepatotoxicity, carcinogenicity, reproductive toxicity, neurotoxicity and lung cell toxicity. PCBs triggered reactive oxygen species which actives mitogen activated pathways, nuclear factor and cytochrome pathway for cell proliferation and apoptosis. Further, review highlights PCBs induced toxicity in stem cells with the focus on developmental and functional toxicity. The review could be useful to understand the PCBs toxicities and mechanisms and will guide to policy makers to design policies for e-waste pollutant.

As a typical ecologically fragile area, the Wudong Coal Mine region in Xinjiang generates large accumulations of coal gangue each year, which, in the alkaline soil environment, can easily lead to significant leaching and accumulation of As. This study developed a stabilizer (CFD) using cement, fly ash, and desulfurized gypsum to modify in-situ soil in the Xinjiang mining area, resulting in a modified solidified soil with excellent geotechnical performance and As stabilization capability. The study results showed that when CFD content exceeded 14.5% (H8), the unconfined compressive strength was above 350 kPa. The adsorption capacity of the solidified soil for As could exceed 90%. Leaching experiments revealed that the As leaching amount from solidified soil-coal gangue was below 0.01 mg/L, meeting China's Class III groundwater standard, thereby effectively reducing ecological and environmental risks. The modified solidified soil prepared in this study expanded the application scenarios for cement, providing a technical basis for the large-scale in-situ disposal of coal gangue in Xinjiang mining areas. It reduced the disposal costs of coal gangue and offered insights into its resource utilization and harmless use.