Environmental Geochemistry and Health最新文献

This study evaluated the Air Pollution Prevention and Control Action Plan (APPCAP) in China using 2000-2023 data. The average annual PM_2.5 concentration dropped from 46.11 ± 16.18 µg/m³ to 31.75 ± 14.22 µg/m³ (P < 0.05) after APPCAP, with components showing a similar decline. Temporal analysis via Mann-Kendall test indicated a decreasing trend (Z < 0, P < 0.05), seasonally peaking in winter and lowest in summer. Spatially, APPCAP reduced concentration distribution, with key regions improving but areas like Shandong and Henan still facing severe pollution. The main PM_2.5 driver shifted from human (e.g., population density) to meteorological (e.g., temperature) factors post-APPCAP, and anthropogenic influence varied across regions. In summary, APPCAP has curbed PM_2.5 pollution, yet SO₄^2-, NO₃^-, and NH₄⁺ remain relatively high, and the increasing human impact in central and southeastern China demands attention in future policies.

Heavy metal (HM) pollution in agricultural areas seriously threatens food security and ecological health. In this study, based on different soil parent materials, the HMs enrichment in the soil-crop systems of two typical eastern Chinese agricultural lands was compared and analyzed. Multivariate linear stepwise regression analysis, influence index of comprehensive quality and HHRA model were used to understand the bioaccumulation and to evaluate the soil-crop-human system. The study showed that HMs exhibited different enrichment characteristics in the two soil parent material areas. Cd faced a higher risk control rate and was a priority pollutant in the soil environment. The acidification soils in the granitic parent material area led to more widespread Ni pollution in wheat grains. The HM absorption model clarifies that driving factors such as the HM content, physicochemical properties and the distance to the river can well explain the enrichment ability of HMs in wheat grains. The synergistic evaluation revealed that only 13.04% of soil and crops were at a clean level. Soil contamination is more prevalent in the metamorphic rocks area, while crop contamination is more severe in the granitic parent material area. Probabilistic health risk assessment indicated that HMs primarily impact health through the ingestion of contaminated wheat, so residents of the granitic parent material area face a slightly higher HI. This information will be crucial for understanding the translocation and accumulation of HMs within soil-crop-human health systems of agricultural land in different soil parent material areas and for developing effective pollution prevention and control programs.

In households and greenhouses, fuel combustion generates ashes that are sometimes deposited on the of soil surface. The consequences of the deposition of such wastes on soil properties are not well known. Therefore, this study determines these geochemical processes (effects of the deposition of household and greenhouse ashes on buried sandy soils) and soil-forming processes. The study reveals that the deposition of household ashes increases the pH of buried Arenosols, while greenhouse ashes do not raise the pH of buried soil. The increased pH of buried soils caused by household ashes arises from calcite dissolution, Ca and K mobilisation, and Ca and K trapping by coatings on quartz grains. In turn, pozzolanic reactions and the crystallisation of gypsum (or a mixture of calcite and gypsum) on the surface of coke in greenhouse ashes limit Ca leaching downwards in the soil profile. Soil horizons with household and greenhouse ashes are characterised by relatively high contents of metal(loid)s. Furthermore, the mobilisation of metal(loid)s is evidenced from horizons containing both types of combustion wastes downwards in the soil profiles. The contents of Mn, Ti, Zn, Cd, Sr, As, Cr, V, and Ba in sandy horizons buried by household ashes are higher than the contents of these elements in soils, reflecting the local geochemical background. For sandy horizons buried by greenhouse ashes, the enrichment of Cd, Sr, As, Cr, and Ba is noted as being relative to soils from a local geochemical background. Therefore, this study demonstrates that household and greenhouse ashes need special attention because of their potential negative environmental effects. The incineration of household ashes (and greenhouse ashes) with municipal wastes, and metal(loid)s recovery from the resulting ashes is a promising management strategy for these types of combustion wastes instead of storing them around households.

Soil contamination due to heavy metals, especially cadmium (Cd), poses a growing concern. This study seeks to develop an economical and non-polluting sustainable remediation program for Cd-contaminated soil to address this issue. This study pioneered the exploration of Cd accumulation patterns in three forage species: Lolium multiflorum Lamk (LMJS), Sorghum bicolor × sudanense (SSBJ), and Sorghum sudanense (Piper) Stapf (SUJS) to identify their optimal harvest periods in Cd-contaminated soils. Additionally, a consortium of beneficial microorganisms (combinations of C, F, and H; C: 10% Bacillus subtilis; F: 20% Bacillus subtilis + 10% Bacillus cereus + 20% Citrobacter; H: 20% Deinococcus radiodurans + 10% Bacillus cereus) was implemented, with a focus on developing an efficient forage-microbial co-remediation system. Subsequently, agronomic strategies (mowing or chelating agents) were employed to improve the Cd enrichment capacity of the combined forage-microbe remediation system, offering sustainable field remediation strategies. The results indicate that the SSBJ + F combined remediation system was mowed on the 60th day (stubble left at 35 cm, light mowing) and harvested on the 120th day as the optimal choice. The bioaccumulation quantity (BCQ) unit accumulation in Cd-contaminated soil at a concentration of 10 mg/kg reached 0.397 mg/kg, and the annual Cd removal rate was 9.23%, representing a 29.63% increase compared to the control group. The results of this study provide valuable insights into the development of practical, field-applicable remedial measures for cadmium-contaminated soils while minimizing environmental impacts.

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.