RESUMEN
Bioavailability of potentially toxic elements (PTEs) from the Earth's crust in the soil, e.g., As, Hg, Tl, and Pb, can pose a potential environmental and health risk because of human activities, especially related to mining extraction. The biomonitoring allows to detect PTE contamination through their measurement in living organisms as trees. However, the choice of which plant species and tissue to analyse is a key point to be evaluated in relation to PTE absorption and translocation. The aim of this work was to assess the As, Hg, Tl, and Pb distribution in Castanea sativa Mill. plant tissues, given its importance for both biomass and food production. The study identified two sites in the Alpi Apuane (Italy), with similar environmental conditions (e.g., elevation, exposure, forest type, and tree species) but different soil PTE levels. The topsoil was characterized, and the PTE fractions with different bioavailability were measured. The PTE concentrations were also analysed in chestnut plant tissues (leaves, bark, wood, nuts, and shells) in parallel with and evaluation of plant health status through the determination of micro and macronutrient concentrations and the leaf C and N isotope composition (δ13C or δ15N). Chestnut trees showed a good health status highlighting its suitability for Tl, As, Hg, and Pb biomonitoring, displaying a tissue-specific PTE allocation. Thallium and Hg were detected in all plant tissues at similar concentrations, As was found in leaves, wood, and nuts while Pb only in the bark. The δ15N negatively correlated with leaf Mn and Tl concentrations, suggesting possible changes in N source and/or plant metabolism due to the high contamination level and acid soil pH. Thallium in La Culla site trees was associated with its presence in the carbonate rocks but not in the topsoil, highlighting the potentiality of chestnut in providing valuable information for geochemical surveying.
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Monitoreo del Ambiente , Fagaceae , Plomo , Minería , Contaminantes del Suelo , Contaminantes del Suelo/análisis , Monitoreo del Ambiente/métodos , Italia , Plomo/análisis , Plomo/metabolismo , Mercurio/análisis , Mercurio/metabolismo , Arsénico/análisis , Arsénico/metabolismo , Talio/análisis , Monitoreo Biológico/métodosRESUMEN
The integration of the ORION digital signal processing-based MCA system coupled with a 3â³ × 3â³ NaI(Tl) detector assembly with a GM detector for counting beta (ß) has eliminated the need for a standalone ß-γ method in which U3O8 is determined by gross ß and gross γ counting. Uraniferous and mixed U-Th samples were taken up for study and compared with the results obtained from Canberra p-type coaxial high resolution gamma ray spectrometry detector. In uraniferous samples, U3O8 values obtained are within ±10%, whereas in the case of mixed U-Th samples, U3O8 values are within ±15%. Regression graphs drawn between the outcomes from the two analytical systems indicate R2 > 0.95 for Ra(eU3O8) and ThO2. In uraniferous samples, the R2 value for U3O8 was found to be > 0.99, but in mixed U-Th samples, it is 0.92. The closeness of agreement between the results obtained from two methods at various concentrations over the analytical range shows that the integrated system is suitable for the quantitative determination of eU3O8, U3O8, Ra(eU3O8), ThO2 and K in geological rock samples.
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Monitoreo de Radiación , Espectrometría gamma , Monitoreo de Radiación/métodos , Monitoreo de Radiación/instrumentación , Espectrometría gamma/métodos , Espectrometría gamma/instrumentación , Partículas beta , Uranio/análisis , Europio/química , Europio/análisis , Dosimetría Termoluminiscente/instrumentación , Dosimetría Termoluminiscente/métodos , Procesamiento de Señales Asistido por Computador , Talio/análisis , Torio/análisis , Yoduro de SodioRESUMEN
The initial rise of molecular oxygen (O2) shortly after the Archaean-Proterozoic transition 2.5 billion years ago was more complex than the single step-change once envisioned. Sulfur mass-independent fractionation records suggest that the rise of atmospheric O2 was oscillatory, with multiple returns to an anoxic state until perhaps 2.2 billion years ago1-3. Yet few constraints exist for contemporaneous marine oxygenation dynamics, precluding a holistic understanding of planetary oxygenation. Here we report thallium (Tl) isotope ratio and redox-sensitive element data for marine shales from the Transvaal Supergroup, South Africa. Synchronous with sulfur isotope evidence of atmospheric oxygenation in the same shales3, we found lower authigenic 205Tl/203Tl ratios indicative of widespread manganese oxide burial on an oxygenated seafloor and higher redox-sensitive element abundances consistent with expanded oxygenated waters. Both signatures disappear when the sulfur isotope data indicate a brief return to an anoxic atmospheric state. Our data connect recently identified atmospheric O2 dynamics on early Earth with the marine realm, marking an important turning point in Earth's redox history away from heterogeneous and highly localized 'oasis'-style oxygenation.
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Atmósfera , Planeta Tierra , Oxígeno , Agua de Mar , Atmósfera/química , Sedimentos Geológicos/química , Historia Antigua , Océanos y Mares , Oxidación-Reducción , Oxígeno/análisis , Oxígeno/historia , Oxígeno/metabolismo , Agua de Mar/química , Sudáfrica , Isótopos de Azufre/análisis , Talio/análisis , Talio/químicaRESUMEN
Dietary supplements are drastically growing as a category of consumer products all over the world. The abuse of supplements marketed for slimming purposes and physical fitness has been observed worldwide in recent years, which raises concerns in terms of public health. In this study, different types of dietary supplements marketed and delivered through the e-commerce were studied for the determination of thallium as a hazardous inorganic contaminant. The total content of thallium was determined by a sensitive voltammetric method after a microwave-assisted oxidative digestion of the sample. In addition, a comparative spectrometric method was applied for validation of the results in the samples. The maximum concentration found for thallium was found to be 2.89 mg kg-1, which well agree with the comparative measurement. Considering the 32 studied formulations, it can be pointed out that â¼24% of the of dietary supplements presented Tl concentrations at concentrations higher than 1 mg kg-1. The results permitted the assessment of the health risk related to thallium from contaminated samples, based on the calculation of the estimated daily intake (EDI) and the risk quotient (HQ). The highest daily intake of thallium was calculated as 82.0 µg day-1 in a protein-based supplement, which is equivalent to an EDI of 1.17 µg kg-1 day-1. This work highlights the need to develop regulations on the limits of toxic elements such as thallium in widely consumed dietary supplements, as well as an in-depth look at the adverse effects caused by this element in the human body.
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Suplementos Dietéticos , Contaminación de Alimentos , Talio , Pérdida de Peso , Talio/análisis , Suplementos Dietéticos/análisis , Humanos , Contaminación de Alimentos/análisisRESUMEN
Thallium (Tl) is a potential toxicity element that poses significant ecological and environmental risks. Recently, a substantial amount of Tl has been released into the environment through natural and human activities, which attracts increasing attention. The determination of this hazardous and trace element is crucial for controlling its pollution. This article summarizes the advancement and progress in optimizing Tl detection techniques, including atomic absorption spectroscopy (AAS), voltammetry, inductively coupled plasma (ICP)-based methods, spectrophotometry, and X-ray-based methods. Additionally, it introduces sampling and pretreatment methods such as diffusive gradients in thin films (DGT), liquid-liquid extraction, solid phase extraction, and cloud point extraction. Among these techniques, ICP-mass spectrometry (MS) is the preferred choice for Tl detection due to its high precision in determining Tl as well as its species and isotopic composition. Meanwhile, some new materials and agents are employed in detection. The application of novel work electrode materials and chromogenic agents is discussed. Emphasis is placed on reducing solvent consumption and utilizing pretreatment techniques such as ultrasound-assisted processes and functionalized magnetic particles. Most detection is performed in aqueous matrices, while X-ray-based methods applied to solid phases are summarized which provide non-destructive analysis. This work improves the understanding of Tl determination technology while serving as a valuable resource for researchers seeking appropriate analytical techniques.
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Monitoreo del Ambiente , Talio , Talio/análisis , Monitoreo del Ambiente/métodos , Contaminantes Ambientales/análisis , Espectrofotometría Atómica , Extracción en Fase Sólida/métodos , Espectrometría de Masas/métodos , Extracción Líquido-Líquido/métodosRESUMEN
OBJECTIVE: To establish an analytical method for determining the migration of 24 elements in Yixing clay pottery in 4% acetic acid simulated solution by inductively coupled plasma mass spectrometry. METHODS: Four types of Yixing clay pottery, including Yixing clay teapot, Yixing clay kettle, Yixing clay pot, and Yixing clay electric stew pot, were immersed in 4% acetic acid as a food simulant for testing. The migration amount of 24 elements in the migration solution was determined using inductively coupled plasma mass spectrometry. RESULTS: Lithium, magnesium, aluminum, iron, and barium elements with a mass concentration of 1000 µg/L; Lead, cadmium, total arsenic, chromium, nickel, copper, vanadium, manganese, antimony, tin, zinc, cobalt, molybdenum, silver, beryllium, thallium, titanium, and strontium elements within 100 µg/L there was a linear relationship within, the r value was between 0.998 739 and 0.999 989. Total mercury at 5.0 µg/L, there was a linear relationship within, the r value of 0.995 056. The detection limit of the elements measured by this method was between 0.5 and 45.0 µg/L, the recovery rate was 80.6%-108.9%, and the relative standard deviation was 1.0%-4.8%(n=6). A total of 32 samples of four types of Yixing clay pottery sold on the market, including teapots, boiling kettles, casseroles, and electric stewing pots, were tested. It was found that the migration of 16 elements, including beryllium, titanium, chromium, nickel, cobalt, zinc, silver, cadmium, antimony, total mercury, thallium, tin, copper, total arsenic, molybdenum, and lead, were lower than the quantitative limit. The element with the highest migration volume teapot was aluminum, magnesium, and barium; The kettle was aluminum and magnesium; Casserole was aluminum, magnesium, and lithium; The electric stew pot was aluminum. CONCLUSION: This method is easy to operate and has high accuracy, providing an effective and feasible detection method for the determination and evaluation of element migration in Yixing clay pottery.
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Arsénico , Mercurio , Oligoelementos , Acetatos , Aluminio/análisis , Antimonio/análisis , Arsénico/análisis , Bario/análisis , Berilio/análisis , Cadmio/análisis , Cromo , Arcilla , Cobalto/análisis , Cobre , Litio/análisis , Magnesio , Espectrometría de Masas , Mercurio/análisis , Molibdeno/análisis , Níquel , Plata/análisis , Talio/análisis , Estaño/análisis , Titanio/análisis , Oligoelementos/análisis , Zinc , ChinaRESUMEN
BACKGROUND: An interlaboratory study was conducted at the U.S. Food and Drug Administration's (FDA) Northeast Food and Feed Laboratory (NFFL) and the Center for Food Safety and Applied Nutrition (CFSAN) with the purpose to expand FDA Elemental Analysis Manual (EAM) method 4.7 (Inductively Coupled Plasma-Mass Spectrometric Determination of Arsenic, Cadmium, Chromium, Lead, Mercury, and Other Elements in Food Using Microwave Assisted Digestion) to include new analytes. OBJECTIVE: The goal of the study was to demonstrate the performance of FDA EAM method 4.7 when analyzing new analytes cobalt (Co), strontium (Sr), thallium (Tl), tin (Sn), uranium (U), and vanadium (V). This analyte extension method validation of EAM 4.7 for six additional elements, Co, Sr, Tl, Sn, U, and V, followed all guidelines for a Level 2 or single-laboratory validation and met all acceptance criteria for analyte extensions as per the Guidelines for the Validation of Chemical Methods. METHOD: As per EAM 4.7, this study followed the procedures and used specified equipment operated under recommended conditions. The analyte extension method validation was performed in accordance with protocol and with no deviations. RESULTS: All quality control (QC) requirements for this analyte extension method validation of EAM 4.7 passed as evidenced by the analytical data. The results presented demonstrate accuracy, linearity, and precision by successful analyses of method blanks, matrix spikes, unfortified test samples, and reference materials. The data analyzed met each of the validation requirements for each analyte in all representative matrixes. CONCLUSIONS: The study showed that the new analytes performed satisfactorily using EAM 4.7 for total acidic extractable elemental analysis of food according to FDA's guidelines. HIGHLIGHTS: The method met or exceeded the performance criteria.
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Cobalto , Estroncio , Talio , Estaño , Uranio , Cobalto/análisis , Talio/análisis , Uranio/análisis , Estaño/análisis , Estroncio/análisis , Vanadio/análisis , Análisis de los Alimentos/métodos , Espectrometría de Masas/métodos , Estados Unidos , United States Food and Drug AdministrationRESUMEN
The current review highlights the complex behavior of thallium (Tl) in soil and plant systems, offering insight into its hazardous characteristics and far-reaching implications. The research investigates the many sources of Tl, from its natural existence in the earth crust to its increased release through anthropogenic activities such as industrial operations and mining. Soil emerges as a significant reservoir of Tl, with diverse physicochemical variables influencing bioavailability and entrance into the food chain, notably in Brassicaceae family members. Additionally, the study highlights a critical knowledge gap concerning Tl influence on legumes (e.g., soybean), underlining the pressing demand for additional studies in this crucial sector. Despite the importance of leguminous crops in the world food supply and soil fertility, the possible impacts of Tl on these crops have received little attention. As we traverse the ecological complexity of Tl, this review advocates the collaborative research efforts to eliminate crucial gaps and provide solutions for reducing Tl detrimental impacts on soil and plant systems. This effort intends to pave the path for sustainable agricultural practices by emphasizing the creation of Tl-tolerant legume varieties and revealing the complicated dynamics of Tl-plant interactions, assuring the long-term durability of our food systems against the danger of Tl toxicity.
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Contaminantes del Suelo , Suelo , Talio , Talio/análisis , Suelo/química , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismo , Productos Agrícolas/metabolismo , Agricultura , Plantas/metabolismo , Monitoreo del Ambiente , Fabaceae/metabolismo , Fabaceae/crecimiento & desarrolloRESUMEN
Most nonoccupational human exposure to thallium (Tl) occurs via consumption of contaminated food crops. Brassica cultivars are common crops that can accumulate more than 500 µg Tl g-1. Knowledge of Tl uptake and translocation mechanisms in Brassica cultivars is fundamental to developing methods to inhibit Tl uptake or conversely for potential use in phytoremediation of polluted soils. Brassica cultivars (25 in total) were subjected to Tl dosing to screen for Tl accumulation. Seven high Tl-accumulating varieties were selected for follow-up Tl dosing experiments. The highest Tl accumulating Brassica cultivars were analyzed by synchrotron-based micro-X-ray fluorescence to investigate the Tl distribution and synchrotron-based X-ray absorption near-edge structure spectroscopy (XANES) to unravel Tl chemical speciation. The cultivars exhibited different Tl tolerance and accumulation patterns with some reaching up to 8300 µg Tl g-1. The translocation factors for all the cultivars were >1 with Brassica oleracea var. acephala (kale) having the highest translocation factor of 167. In this cultivar, Tl is preferentially localized in the venules toward the apex and along the foliar margins and in minute hot spots in the leaf blade. This study revealed through scanning electron microscopy and X-ray fluorescence analysis that highly Tl-enriched crystals occur in the stoma openings of the leaves. The finding is further validated by XANES spectra that show that Tl(I) dominates in the aqueous as well as in the solid form. The high accumulation of Tl in these Brassica crops has important implications for food safety and results of this study help to understand the mechanisms of Tl uptake and translocation in these crops.
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Brassica , Contaminantes del Suelo , Humanos , Brassica/química , Talio/análisis , Verduras , Rayos X , Fluorescencia , Biodegradación Ambiental , Productos AgrícolasRESUMEN
The prevalence of toxic element thallium (Tl) in soils is of increasing concern as a hidden hazard in agricultural systems and food chains. In the present work, pure biochar (as a comparison) and jacobsite (MnFe2O4)-biochar composite (MFBC) were evaluated for their immobilization effects in Tl-polluted agricultural soils (Tl: â¼10 mg/kg). Overall, MFBC exhibited an efficient effect on Tl immobilization, and the effect was strengthened with the increase of amendment ratio. After being amended by MFBC for 15 and 30 days, the labile fraction of Tl in soil decreased from 1.55 to 0.97 mg/kg, and from 1.51 to 0.88 mg/kg, respectively. In addition, pH (3.05) of the highly acidic soil increased to a maximum of 3.97 after the immobilization process. Since the weak acid extractable and oxidizable Tl were the preponderantly mitigated fractions and displayed a negative correlation with pH, it can be inferred that pH may serve as one of the most critical factors in regulating the Tl immobilization process in MFBC-amended acidic soils. This study indicated a great potential of jacobsite-biochar amendment in stabilization and immobilization of Tl in highly acidic and Tl-polluted agricultural soils; and it would bring considerable environmental benefit to these Tl-contaminated sites whose occurrence has significantly increased in recent decades near the pyrite or other sulfide ore mining and smelting area elsewhere.
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Contaminantes del Suelo , Talio , Talio/análisis , Suelo , Sulfuros , Contaminantes del Suelo/análisisRESUMEN
Multiple patient doses of [201Tl]TlCl has been produced using electrodeposited enriched 203Tl in 30 MeV cyclotron (Cyclone-30) with 28 MeV proton energy at 50 µA beam current for 8 h. Ion Exchange Column Chromatography (IECC) and liquid-liquid extraction has been employed for semi-automated radiochemical separation and purification of produced [201Tl]TlCl. The produced [201Tl]TlCl was used in coronary artery disease (CAD) patients.
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Ciclotrones , Talio , Preparaciones Farmacéuticas , Talio/análisisRESUMEN
Thallium (Tl) is a highly toxic trace metal, included in the US EPA list of priority pollutants. Even though its toxicity is potentially higher or comparable to Cd or Hg, its environmental impact is largely unknown. Despite its toxicity, only a few recent studies are mapping the impact of recently introduced Tl on soil microbial communities, namely in agricultural systems but no studies focus on its long term effect. To complement the understanding of the impact of Tl on soil, this study aims to describe the influence of extremely high naturally occurring Tl concentration (50 mg/kg of potentially bioavailable Tl) on soil microbial communities. Our investigation concentrated on samples collected at Buus (Erzmatt, Swiss Jura, Switzerland), encompassing forest and meadow soil profiles of the local soil formed on hydrothermally mineralized dolomite rock, which is naturally rich in Tl. The soil profiles showed a significant proportion of potentially bioavailable Tl. Yet, even this high concentration of Tl has a limited impact on the richness of the soil bacterial community. Only the meadow soil samples show a reduced richness compared to control samples. Furthermore, our analysis of geogenic Tl contamination in the region unveiled a surprising finding: compared to other soils of Switzerland and in stark contrast to soils affected by recent mining activities, the structure of the bacterial community in Buus remained relatively unaffected. This observation highlights the unique ability of soil microbial communities to withstand extreme Tl contamination. Our study advances the understanding of Tl's environmental impact and underscores the resilience of soil microbes in the face of severe long-term contamination.
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Mercurio , Contaminantes del Suelo , Oligoelementos , Talio/análisis , Suelo/química , Bacterias , Mercurio/análisis , Oligoelementos/análisis , Contaminantes del Suelo/análisis , Monitoreo del Ambiente , ChinaRESUMEN
Soil thallium (Tl) pollution is a serious environmental problem, and vegetables are the primary pathway for human exposure to Tl. Therefore, it is important to investigate the characteristics of soil Tl uptake by vegetables. In this study, the meta-analysis approach was first applied to explore the relationship between Tl content in vegetables and soil environment, as well as key factors influencing soil physical-chemical properties, and to derive soil thresholds for Tl. The results indicated that various types of vegetables have different capabilities for Tl accumulation. Vegetables from contaminated areas showed high Tl accumulation, and the geomean Tl content in different types of vegetables was in the following order: leafy > root-stalk > solanaceous vegetables. Taro and kale had significantly higher capability to accumulate soil Tl among the 35 species studied, with Tl bioconcentration factor values of 0.060 and 0.133, respectively. Pearson correlation analysis and meta-analysis revealed that the Tl content in vegetables was significantly correlated with soil pH and Tl content in soil. The linear predictive model for Tl accumulation in vegetables based on soil Tl content described the data well, and the fitting coefficient R2 increased with soil pH value. According to potential dietary toxicity, the derived soil Tl thresholds for all, leafy and root-stalk vegetables increased with an increase in soil pH, and were in the range of 1.46-6.72, 1.74-5.26 and 0.92-6.06 mg/kg, respectively. The soil Tl thresholds for kale, lettuce and carrot were in the range of 0.24-4.89, 2.94-3.32 and 3.77-14.43 mg/kg, respectively. Ingestion of kale, beet, sweet potato, potato, taro, pepper, turnip, Chinese cabbage, eggplant and carrot poses potential health risks. The study provides scientific guidance for vegetable production in Tl-contaminated areas and can help with the selection of vegetable species suitable for avoiding the absorption of Tl from contaminated soil.
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Brassica , Contaminantes del Suelo , Humanos , Verduras/química , Talio/análisis , Suelo/química , Contaminantes del Suelo/análisis , Brassica/química , ChinaAsunto(s)
Litio , Talio , Talio/análisis , Contaminación Ambiental , Suministros de Energía EléctricaRESUMEN
The abandoned Allchar Mine in the Republic of North Macedonia is a globally unique deposit with the highest known grades of thallium (Tl) and arsenic (As) mineralization. We aimed to determine the distribution of As and Tl in whole dehydrated shoots of the three Viola taxa using synchrotron micro-X-ray fluorescence analysis. Additionally, soil and plant organ samples were collected from all three Viola taxa at the Allchar site and analysed using inductively coupled plasma-atomic emission spectrometry. Concentrations of Tl were extremely high in all three Viola taxa (up to 58 900 mg kg-1), but concentrations of As were highly variable with V. tricolor subsp. macedonica and V. allchariensis having low As (up to 20.2 and 26.3 mg kg-1, respectively) and V. arsenica having the highest concentrations (up to 381 mg kg-1). The extremely high Tl in all three species is endogenous and not a result of contamination. Arsenic in V. tricolor subsp. macedonica and V. allcharensis is strongly affected by contamination, but not in V. arsenica where it appears to be endogenous. The pattern of As enrichment in V. arsenica is very unusual and coincides with Ca-oxalate deposits and Br hotspots. The results of this study could form the basis for more detailed investigations under controlled conditions, including plant dosing experiments.
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Arsénico , Contaminantes del Suelo , Talio/análisis , Arsénico/análisis , República de Macedonia del Norte , Sincrotrones , Plantas , Contaminantes del Suelo/análisis , Monitoreo del Ambiente/métodos , Suelo/químicaRESUMEN
Mercury-thallium mining waste slag has the characteristics of extremely acidic, low fertility and highly toxic polymetallic composite pollution, making it difficult to be treated. We use nitrogen- and phosphorus-rich natural organic matter (fish manure) and calcium- and phosphorus-rich natural minerals (carbonate and phosphate tailings) individually or in combination to amend the slag, analyze their effects on the migration and transformation of potentially toxic elements (Tl and As) in the waste slag. We set up sterile and non-sterile treatments specifically to further investigate the direct or indirect effect of microorganisms attached to added organic matter on Tl and As. The results showed that addition of fish manure and natural minerals to the non-sterile treatments promoted the release of As and Tl, resulting in an increase in As and Tl concentrations in the tailing lixiviums from 0.57 to 2.38-6.37 µg/L and from 69.92 to 107.51-157.21 µg/L, respectively. Sterile treatments promoted the release of As (from 0.28 to 49.88-104.18 µg/L) and inhibited the release of Tl (from 94.53 to 27.60-34.50 µg/L). Use of fish manure and natural minerals alone or in combination significantly reduced the biotoxicity of the mining waste slag, in which the combination was more efficient. XRD analysis showed that microorganisms in the medium promoted the dissolution of jarosite and other minerals, which indicated that the release and migration of As and Tl in Hg-Tl mining waste slag were closely related to microbial activities. Furthermore, metagenomic sequencing revealed that microorganisms such as Prevotella, Bacteroides, Geobacter, and Azospira, which were abundant in the non-sterile treatments, had remarkable resistance to a variety of highly toxic heavy metals and could affect the dissolution of minerals and the release and migration of heavy metals through redox reactions. Our results may aid in the rapid soilless ecological restoration of related large multi-metal waste slag dumps.
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Mercurio , Metales Pesados , Talio/análisis , Estiércol , Metales Pesados/análisis , Minerales/análisis , FósforoRESUMEN
We sought to explore the association between heavy metal exposure and coronary heart disease (CHD) based on data from the US National Health and Nutrition Examination Survey (NHANES, 2003-2018). In the analyses, participants were all aged > 20 and had participated in heavy metal sub-tests with valid CHD status. The Mann-Kendall test was employed to assess the trends in heavy metals' exposure and the trends in CHD prevalence over 16 years. Spearman's rank correlation coefficient and a logistics regression (LR) model were used to estimate the association between heavy metals and CHD prevalence. 42,749 participants were included in our analyses, 1802 of whom had a CHD diagnosis. Total arsenic, dimethylarsonic acid, monomethylarsonic acid, barium, cadmium, lead, and antimony in urine, and cadmium, lead, and total mercury in blood all showed a substantial decreasing exposure level tendency over the 16 years (all Pfor trend < 0.05). CHD prevalence varied from 3.53 to 5.23% between 2003 and 2018. The correlation between 15 heavy metals and CHD ranges from - 0.238 to 0.910. There was also a significant positive correlation between total arsenic, monomethylarsonic acid, and thallium in urine and CHD by data release cycles (all P < 0.05). The cesium in urine showed a negative correlation with CHD (P < 0.05). We found that exposure trends of total arsenic, dimethylarsonic acid, monomethylarsonic acid, barium, cadmium, lead, and antimony in urine and blood decreased. CHD prevalence fluctuated, however. Moreover, total arsenic, monomethylarsonic acid, and thallium in urine all showed positive relationships with CHD, while cesium in urine showed a negative relationship with CHD.
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Arsénico , Enfermedad Coronaria , Metales Pesados , Adulto , Humanos , Cadmio/análisis , Encuestas Nutricionales , Arsénico/toxicidad , Arsénico/análisis , Antimonio/análisis , Bario/análisis , Talio/análisis , Prevalencia , Exposición a Riesgos Ambientales/análisis , Metales Pesados/análisis , Cesio/análisis , Enfermedad Coronaria/inducido químicamente , Enfermedad Coronaria/epidemiologíaRESUMEN
Little attention has been paid to the in situ-generated biogenic manganese oxides (BMnOx) for practical implementation in continuous groundwater remediation systems. The enrichment effects of manganese oxidizing bacteria (MOB) in bioaugmentation columns and the in situ-generated BMnOx for continuous thallium(I) (Tl(I)) removal from groundwater were investigated. Results indicated that Pseudomonas Putida MnB1 (strain MnB1) attached on the groundwater sediments (GS) can achieve a maximum of 97.37 % Mn(II) oxidation and generate 29.6 mg/L BMnOx, which was superior than that of traditional quartz sand (QS). The in situ-generated BMnOx in MOB_GS column effectively removed 10-100 µg/L Tl(I) under the interference of high concentrations of Fe(II) and Mn(II) in groundwater. Distinctive microbial enrichment effects occurred in the bioaugmentation columns under the competition of indigenous microbes in groundwater. The release of Mn(II) from the BMnOx inhibited with the decrease in Tl(I) removal efficiency. XAFS analysis revealed Tl(I) was effectively adsorbed by BMnOx and Mn-O octahedra with Tl-O tetrahedral coordination existed in BMnOx. This study provides an in-depth understanding of the in situ-generated BMnOx for the Tl(I) removal and contributes to the application of BMnOx in groundwater remediation.
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Agua Subterránea , Manganeso , Manganeso/análisis , Talio/análisis , Óxidos/análisis , Compuestos de Manganeso , Oxidación-Reducción , Bacterias , Agua Subterránea/microbiologíaRESUMEN
Thallium (Tl) is widely used in various industries, which increases the risk of leakage into the environment. Since Tl is highly toxic, it can do a great harm to human health and ecosystem. In order to explore the response of freshwater sediment microorganisms to sudden Tl spill, metagenomic technique was used to elucidate the changes of microbial community composition and functional genes in river sediments. Tl pollution could have profound impacts on microbial community composition and function. Proteobacteria remained the dominance in contaminated szediments, indicating that it had a strong resistance to Tl contamination, and Cyanobacteria also showed a certain resistance. Tl pollution also had a certain screening effect on resistance genes and affected the abundance of resistance genes. Metal resistance genes (MRGs) and antibiotic resistance genes (ARGs) were enriched at the site near the spill site, where Tl concentration was relatively low among polluted sites. When Tl concentration was higher, the screening effect was not obvious and the resistance genes even became lower. Moreover, there was a significant correlation between MRGs and ARGs. In addition, co-occurrence network analysis showed that Sphingopyxis had the most links with resistance genes, indicating that it was the biggest potential host of resistance genes. This study provided new insight towards the shifts in the composition and function of microbial communities after sudden serious Tl contamination.
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Microbiota , Talio , Humanos , Talio/análisis , Ríos , Metales/análisis , Farmacorresistencia Microbiana/genética , Genes Bacterianos , AntibacterianosRESUMEN
Thallium contamination in water can cause great danger to the environment. In this study, we synthesized manganese oxide-coated sand (MOCS) and investigated the transport and retention behaviors of Tl(I) in MOCS under different conditions. Characterization methods combined with a two-site nonequilibrium transport model were applied to explore the retention mechanisms. The results showed that Tl(I) mobility was strongly inhibited in MOCS media, and the retention capacity calculated from the fitted model was 510.41 mg/g under neutral conditions. The retention process included adsorption and oxidative precipitation by the manganese oxides coated on the sand surface. Cotransport with the same concentration of Mn(II) led to halving Tl(I) retention due to competition for reactive sites. Enhanced Tl(I) retention was observed under alkaline conditions, as increasing pH promoted electronegativity on the media surface. Moreover, the competitive cation Ca2+ significantly weakened Tl(I) retention by occupying adsorption sites. These findings provide new insights into understanding Tl(I) transport behavior in water-saturated porous media and suggest that manganese oxide-coated sand can be a cost-effective filter media for treating Tl-contaminated water.