Environmental Geochemistry and Health最新文献

Environmental pollution by heavy metals (HMs) in mining areas is a major concern worldwide since it pollutes the surrounding surface water, groundwater, and farmland soils. Once in the food chain, HMs can cause mild to life-threatening side effects thereby negatively affecting the environment and human health. To remedy this situation, cost-effective and environmentally friendly remediation approaches are needed to ensure food safety. Phytoremediation is a remediation technique that meets these criteria; however, it is still unclear whether co-cultivation of food crops during phytoremediation can produce crops that meet the required safety standards. In this study, we investigate the effectiveness of phytoremediation and food crop co-cultivation to produce "HM-free" crops from farmland soils in Sidi village in Xingping Town of Guangxi Zhuang Autonomous Region in China, contaminated by HMs from a lead-zinc mine. Our results show that (1) After 19 months of phytoremediation, the redistribution of HMs (cadmium, lead, and arsenic) from acidic to slightly acidic, neutral, and mostly weakly alkaline soils was promoted. This resulted in a reduction in HMs availability and consequently the amount absorbed by food crops. (2) The concentrations of important nutrients including nitrogen, phosphorus, and potassium were significantly increased during phytoremediation. This translated to increased plant biomass in Celosia Argentea L. (26.09%), Sedum erythrostictum Migo (18.52%), and Amaranthus cruentus L. (21.67, 33.33, and 66.67%, for consecutive harvests). (3) Co-cultivation of maize crops with low HM accumulator plants in slightly and moderately polluted sites or a rotation of rapeseed-sunflower plants with hyperaccumulator plants in the highly polluted site ensured 100% compliance with the food crop and feed safety standards. Our findings can provide an important reference for studies aimed at managing polluted sites and ensuring food safety.

Rhizomatous traditional Chinese medicines (RTCMs) are widely crushed into powder and swallowed directly as medicine and food or health products to treat various diseases; however, they may contain toxic microplastics (MPs) and heavy metals. Currently, there are no reports on the detection of MPs and MP-heavy metal synergies in RTCMs. In this study, we selected eight representative RTCMs to investigate the abundance, types, sizes, and polymers of MP and heavy metals and to assess the level of contamination of MPs and synergies between MPs and heavy metals in RTCMs. The abundance of MPs in different RTCM ranged from 20.83 to 43.65 items/g. The dominant type was fragment (95.43%), and the dominant particle size was < 0.5 mm (73.72%) in MPs. Polyurethane (PU) (29.21%) and acrylics (ACR 13.53%) were the dominant polymers of MP. MP polymers showed obvious correlations with type and particle size: PU was enriched in 0-50-mm and 100-300-mm fragments, whereas ethylene vinyl acetate and ACR were enriched in 0-30-mm fibers. The heavy metals arsenic (As), lead (Pb), and chromium (Cr) were found to be more susceptible to synergistic contamination with MPs in RTCMs compared to other heavy metals. The estimated daily intake (EDI) of the MPs and heavy metals for RG (Rehmannia glutinosa) and RAY (Rhizoma atractylodis) were higher than others. The results showed that MP pollution is common in RTCMs and carries the potential risk of heavy metal or MP poisoning in humans who consume RTCMs.

The physicochemical analysis of 292 groundwater samples from the Sarakhs Plain revealed significant variations in water quality, influenced by natural factors. The pH values ranged from 6.4 to 8.6, with an average of 7.97, indicating that most of the samples (98.97%) meet WHO drinking water standards. However, electrical conductivity (EC) levels were alarmingly high, ranging from 1020 to 37,500 μS cm^-1, making all samples unsuitable for drinking. Ca²⁺ and Mg²⁺ concentrations were within acceptable limits for approximately 88.39% and 61.09% of the samples, respectively. Spatial distribution analysis showed that higher salinity levels were concentrated in the western and central regions, while the eastern areas benefited from fresher water due to the influence of the Harirud River, which enhances groundwater quality through natural dilution processes. Hydrogeochemical assessments indicated a predominance of mixed-type water, with significant intrusion processes affecting chemical composition. The Gibbs diagram highlighted evaporation as a major factor influencing water chemistry. Groundwater quality index (GWQI) indicated that nearly half of the samples were classified as unsuitable for drinking, while agricultural suitability varied significantly. Although salinity was a critical concern, many samples were deemed suitable for irrigation based on specific ion concentrations. Overall, this study addressed the necessity for sustainable groundwater management practices in the Sarakhs Plain to mitigate salinity issues and enhance water quality for both human consumption and agricultural use.

After elevated levels of lead (Pb) were found in the blood of children living near the antimony (Sb) mine and battery smelter in Zajača, Republic Serbia, studies were carried out to determine the health risk assessment (HRA) effects of the soil. In this study, for the first time a combination of Network Analysis, CoDA (Compositional Data Analysis) and receptor modelling was used to determine the geopedological and atmospheric origin of PTEs in soil and their historical significance. It was found that arsenic (As) and Pb are the main pollutants in the area. The largest contribution to the environmental risk (Er) was made by Pb. In addition to perception methods Network Analysis (NA) was used to determine the source of pollution and, for the first time, the strength of the positive and negative connections of the network nodes of the mutual influence of PTE. Lead pollution was found to originate from two sources: historical and present, and As was found to originate from a wider area. For the child population, an unacceptable risk for the occurrence of chronic diseases with a probability of 95% was found, with As and Pb accounting for the highest percentage. Similarly, As has the greatest impact on occurrence of cancer at the unacceptable risk level, while Pb is at the notable risk level. The historical exposure to Pb is slightly lower and the difference is slightly more pronounced for total pollution for HRA.

Particulate matter (PM) poses significant health risks due to its ability to generate reactive oxygen species (ROS) and transport toxic metal(loid)s into the human body. In this study, an in vitro physiologically based extraction test (PBET) method, allowing the simulation of the gastric phase (GPh) and intestinal phase (IPh) of human digestion, was applied to evaluate bioaccessibility of eleven potentially toxic elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) in airborne particulate matter (APM) samples collected from an urban-residential area in Chhattisgarh, India. Additionally, oxidative potential (OP) was assessed using the dithiothreitol (DTT) assay for a comprehensive understanding of PM toxicity. The bioaccessibility of metal(loid)s varied significantly across phases, with gastric phase solubility upto ~ 75%, attributed to its lower pH enhancing metal dissolution. Elevated DTT responses were recorded for PM₁₀ and PM_2.5, driven primarily by Fe, Zn, and Pb, underlining their pivotal role in oxidative stress generation. Correlation analyses demonstrated strong associations between bioaccessible fractions and OP, especially in the GPh. The findings advance understanding by linking bioaccessibility with ROS generation and highlight the importance of particle size and solubility in assessing the health risks posed by PM. These insights provide a foundation for improved risk assessments and mitigation strategies targeting emissions from high-temperature processing industries, and vehicular activities, on a global scale.

Asia's largest opencast lignite mines, located in Neyveli, Tamil Nadu, India, were studied to evaluate the organic and inorganic characteristics and reconstruct the paleo-depositional environment of the lignite deposits. The investigation involved advanced geochemical and analytical techniques, including X-ray fluorescence, field emission scanning electron microscopy (FE-SEM), as well as proximate and ultimate analyses. The physical properties of the lignite revealed a moisture content ranging from a minimum of 7.5% to a maximum of 25%, with an average of 14.4%. The ash content varied between 2.6 and 19%, with an average of 6.6%, suggesting the low mineral impurity levels in the lignite deposits. Volatile matter ranged from 38.2 to 48.9%, while fixed carbon content was observed between 31.4 and 40.3%. The ultimate analysis identified carbon content ranging from 51.93 to 78.58%, with moderate levels of hydrogen (< 5%), nitrogen (< 5%), and sulfur (< 1%). Variations in the Gross Calorific Value (4608-5882 kcal/kg) reflect the heterogeneous nature of the lignite, emphasizing the necessity of utilization strategies based on energy density. Major oxide analysis demonstrated strong correlations among SiO₂, Al₂O₃, and TiO₂ with ash yield, suggesting a shared origin and close association with the inorganic constituents of the lignite. Trace elements revealed significant associations among elements such as Zr, V, Sr, Nb, Ga, and Cr, providing the geochemical composition of Neyveli lignite. Microstructural investigation via FE-SEM revealed a fine-grained morphology, distinct mineral phases, and porosity characteristics. Weathering indices and alteration studies pointed to a felsic to intermediate igneous provenance for the inorganic components. The study situates the Neyveli lignite deposits within a deltaic depositional system formed during the late Cretaceous to early Tertiary periods. This paleoenvironment was characterized by dynamic hydrological regimes, as evidenced by sedimentary structures and interbedded lignite layers.

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.