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1.
Artigo em Inglês | MEDLINE | ID: mdl-38625450

RESUMO

PURPOSE: Cancer patients are at heightened risk for invasive aspergillosis (IA), a condition associated with elevated mortality risk. The JF5-based Aspergillus Galactomannoprotein Lateral Flow Device (AspLFD) offers rapid point-of-care testing (POCT) for IA. This study evaluated the diagnostic performance of AspLFD in cancer populations. METHODS: This retrospective study examined cancer patient bronchoalveolar lavage fluid (BALF) and serum samples collected between September 2021 and January 2023. Both AspLFD and galactomannan (GM) assays were conducted, and the results were analysed by two independent researchers. RESULTS: This study included 242 samples from 218 cancer patients, with 58 BALF and 184 serum samples. The overall agreement between AspLFD and GM assay results was 92.1%, with a kappa value of 0.552. AspLFD diagnosed proven/probable IA with a sensitivity and specificity of 91.7% and 95.3%, respectively, whereas GM exhibited sensitivity and specificity values of 83.3% and 93.7%, respectively. There were no statistical differences in the sensitivity and specificity between the two methods (P > 0.05). For serum analyses, AspLFD and GM exhibited similar sensitivity (66.7% vs. 66.7%, P > 0.05) and specificity (98.6% vs. 96.6%, P > 0.05) values. However, the sensitivity of the AspLFD was superior to the GM assay (100% vs. 88.9%) in BALF analyses but the difference was not statistically significant (P > 0.05), with no difference in specificity (83.7% vs. 83.7%, P > 0.05). In the solid-tumour cohort, both the AspLFD and GM assay exhibited high sensitivity (100% for both) and specificity (94.2% vs. 92.8%, P > 0.05). CONCLUSION: The AspLFD demonstrated good performance in diagnosing IA in cancer patients, especially those with solid tumours. The AspLFD is thus an alternative POCT, particularly when GM evaluations are not readily available.

2.
Sci Total Environ ; 919: 170694, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38325477

RESUMO

The uranium (U) containing leachate from uranium tailings dam into the natural settings, may greatly affect the downstream environment. To reveal such relationship between uranium contamination and microbial communities in the most affected downstream environment under drought stress, a 180 cm downstream artificial reservoir depth sediment profile was collected, and the microbial communities and related genes were analyzed by 16S rDNA and metagenomics. Besides, the sequential extraction scheme was employed to shed light on the distinct role of U geochemical speciations in shaping microbial community structures. The results showed that U content ranged from 28.1 to 70.1 mg/kg, with an average content of 44.9 mg/kg, significantly exceeding the value of background sediments. Further, U in all the studied sediments was related to remarkably high portions of mobile fractions, and U was likely deposited layer by layer depending on the discharge/leachate inputs from uranium-involving anthoropogenic facilities/activities upstream. The nexus between U speciation, physico-chemical indicators and microbial composition showed that Fe, S, and N metabolism played a vital role in microbial adaptation to U-enriched environment; meanwhile, the fraction of Ureducible and the Fe and S contents had the most significant effects on microbial community composition in the sediments under drought stress.


Assuntos
Urânio , Urânio/análise , Secas , Poluição Ambiental , Sedimentos Geológicos/química
3.
J Ethnopharmacol ; 325: 117810, 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38266948

RESUMO

ETHNOPHARMACOLOGICAL RELEVANCE: Vine Tea (VT, Ampelopsis grossedentata), boasts a venerable tradition in China, with a recorded consumption history exceeding 1200 years. Predominantly utilized by ethnic groups in southwest China, this herbal tea is celebrated for its multifaceted therapeutic attributes. Traditionally, VT has been employed to alleviate heat and remove toxins, exhibit anti-inflammatory properties, soothe sore throats, lower blood pressure, and fortify bones and muscles. In the realm of functional foods derived from plant resources, VT has garnered attention for its potential in crafting anti-fatigue beverages or foods, attributed to its promising efficacy and minimal side effects. Currently, in accordance with the Food Safety Standards set forth by the Monitoring and Evaluation Department of the National Health and Family Planning Commission in China, VT serves as a raw material in various beverages. AIM OF THE STUDY: VT has an anti-fatigue or similar effect in folk. However, the underlying molecular mechanisms contributing to VT's anti-fatigue effects remain elusive. This study endeavors to investigate the influence of Vine Tea Aqueous Extract (VTE) on fatigue mitigation and to elucidate its operative mechanisms, with the objective of developing VTE as a functional beverage. MATERIALS AND METHODS: The preparation of VTE involved heat extraction and freeze-drying processes, followed by the identification of its metabolites using UPLC-QTOF-MS to ascertain the chemical composition of VTE. A fatigue model was established using a forced swimming test in mice. Potential molecular targets were identified through network pharmacology, transcriptome analysis, and molecular docking. Furthermore, RT-PCR and Western blot techniques were employed to assess mRNA and protein expressions related to the AMPK and FoxO pathways. RESULTS: VTE significantly prolonged the duration of swimming time in an exhaustive swimming test in a dose-dependent manner, while simultaneously reducing the concentrations of blood lactic acid (LA), lactate dehydrogenase (LDH), serum urea nitrogen (SUN), and creatine kinase (CK). Notably, the performance of the high-dose VTE group surpassed that of the well-recognized ginsenoside. VTE demonstrated a regulatory effect akin to ginsenoside on the AMPK energy metabolism pathway and induced downregulation in the expression of Gadd45α, Cdkn1a, FOXO1, and Fbxo32 genes, suggesting an enhancement in skeletal muscle mass. These findings indicate that VTE can improve energy metabolism and muscle mass concurrently. CONCLUSIONS: VTE exhibits significant anti-fatigue effects, and its mechanism is intricately linked to the modulation of the AMPK and FoxO pathways. Crucially, no caffeine or other addictive substances with known side effects were detected in VTE. Consequently, vine tea shows substantial promise as a natural resource for the development of anti-fatigue beverages within the food industry.


Assuntos
Ampelopsis , Ginsenosídeos , Camundongos , Animais , Ampelopsis/química , Ampelopsis/metabolismo , Proteínas Quinases Ativadas por AMP/metabolismo , Ginsenosídeos/uso terapêutico , Simulação de Acoplamento Molecular , Fadiga/tratamento farmacológico , Chá , Músculos
4.
Sci Total Environ ; 912: 168939, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38029978

RESUMO

The mobilization of arsenic (As) at the sediment-water interface (SWI) is crucial for determining the accumulation of dissolved As to potentially toxic levels. However, the specific impacts of redox processes involving iron (Fe) and sulfur (S), as well as microbial activities occurring in sediments, on As mobilization at the marine SWI remain poorly understood. In this study, we investigated As mobilization at the SWI in the Changjiang Estuary during three different seasons with different benthic redox conditions. The preferential reduction of arsenate (As(V)) to arsenite (As(III)) and subsequent re-adsorption onto newly formed crystalline Fe oxides restricted As release in the As(V) reduction layer. Enhanced Fe(III) reduction in the Fe(III) reduction layer contributed to As release, while the presence of low As-high Fe-high SO42- levels resulted in As removal through adsorption onto pyrite in the sulfate reduction layer. Analysis of functional genes indicated that As(V) in sediments was released into porewater through the reductive dissolution of As(V)-bearing Fe(III) oxides by Geobacter species, followed by microbial reduction of the liberated As(V) to As(III) by microbes carrying the arrA gene. The dominant pathway governing As mobilization at the SWI in the Changjiang Estuary shifted from microbial reduction control during the hypoxic summer to Fe redox control during the aerobic autumn and winter. These findings provide valuable insights into the complex mechanisms driving As mobilization and highlight the importance of considering seasonal variations in understanding As dynamics at the marine SWI.


Assuntos
Arsênio , Arsênio/análise , Compostos Férricos/química , Estações do Ano , Água/análise , Oxirredução , Sedimentos Geológicos , Óxidos
5.
Front Neurosci ; 17: 1251685, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37849890

RESUMO

Eco-friendly consumption is important for solving climate crisis and moving humanity toward a better future. However, few consumers are willing to pay premiums for eco-friendly products. We investigated the psychological and neural factors that can increase eco-friendly consumption. We propose an experience of awe, in which the individual self is temporarily attenuated as the importance of beings other than oneself increases. Behavioral (Study 1) and functional magnetic resonance imaging (fMRI; Study 2) experiments were conducted to explore the awe mechanisms through which climate crisis messages lead to eco-friendly consumption. In Study 1, we found participants felt awe when exposed to climate crisis messages, and their choice of eco-friendly consumption increased. In Study 2, we found that when individuals were exposed to messages depicting the climate crisis (as opposed to a control stimulus), their brains exhibited a lower level of activation in the self-awareness processing and a higher level of activation in external attention processing areas. These results suggest that the awe experience plays an important role in promoting eco-friendly consumption. Marketing must evolve from satisfying basic individual needs to a high level for the well-being of humanity, the planet, and the biosphere. This study sheds light on our understanding of human perceptions of the climate crisis and suggests an effective communication strategy to increase individuals' eco-friendly actions.

6.
Front Psychol ; 14: 1094652, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37138978

RESUMO

Loneliness is a major risk factor for morbidity and mortality. However, the effect of loneliness on subsequent prosocial behavior is not well known. Understanding the neurobiological mechanisms underlying loneliness is necessary to address this research gap. We investigate the mechanism using a modified public goods game (PGG) wherein participants can choose to act for a collective or selfish interest after being exposed to loneliness cues. Both behavioral (Study 1) and event-related potential (ERP) (Study 2) measures were used to explore this relationship. In Study 1 (N = 131), we found that participants exhibited decreased prosocial actions under the loneliness priming condition as opposed to the control condition. In Study 2 (N = 17), frontal N400 and posterior P300 components were identified under the loneliness priming condition as opposed to the control condition. Increased (decreased) frontal N400 and posterior P300 lead to selfish (prosocial) choices. These results indicate that humans instinctively perceive loneliness as inconsistency with their desired social-relational life, which in turn stimulates coping strategies for self-preservation. This study contributes to our understanding of the neurobiological basis of loneliness associated with prosocial behavior.

7.
Microbiol Res ; 261: 127057, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35569319

RESUMO

Acinetobacter baumannii (A. baumannii) is an opportunistic pathogen and leading cause of health care-associated infections. Several known pathogenic factors, including lipopolysaccharide, capsular polysaccharides, phospholipase, protein secretion systems, two component efflux pumps and biofilm formation, are associated with the bacteria. However, owing to the new biological characteristics rapidly developed under the external stress, the pathogenesis becomes complicated. The formation of mucoid phenotype is a major adaptive defense response for A. baumannii. The mucus is mainly comprised of capsular polysaccharide, which forms a barrier around the bacterial cell wall, and provides protection from environmental pressures and host immune responses. Importantly, mucoid formation has been shown to confer changes in the pathogenicity and pathogenesis of A. baumannii. Thus, this review aims to highlight the biological characteristics, virulence and underlying pathogenic mechanisms of mucoid A. baumannii. We primarily provide profound insight into the structure, function and detecting methods of the mucus in mucoid A. baumannii. Then we mainly illustrate the current studies on mucoid A. baumannii. Finally, the unsolved areas associated with mucoid A. baumannii are summarized. In summary, this review will critically offer a comprehensive understanding of mucoid A. baumannii and provide novel insight into the diagnosis and intervention strategies for the increasingly deadly human pathogen.


Assuntos
Infecções por Acinetobacter , Acinetobacter baumannii , Infecção Hospitalar , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/genética , Biofilmes , Infecção Hospitalar/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Humanos , Virulência/genética
9.
J Hazard Mater ; 423(Pt A): 127080, 2022 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-34523503

RESUMO

Thallium (Tl) is a trace metal with high toxicity. Comprehensive investigation of spatial distribution of Tl and microorganism is still limited in soils from mining area. In this study, 16S rRNA sequencing and network analysis were used for deciphering the co-occurrence patterns of bacterial communities in two different types of soil profiles around a typical Tl-bearing pyrite mine. The results showed that geochemical parameters (such as pH, S, Tl, Fe and TOM) were the driving forces for shaping the vertical distribution of microbial community. According to network analysis, a wide diversity of microbial modules were present in both soil profiles and affected by depth, significantly associated with variations in Tl geochemical fractionation. Phylogenetic information further unveiled that the microbial modules were mainly dominated by Fe reducing bacteria (FeRB), Fe oxidizing bacteria (FeOB), S oxidizing bacteria and Mn reducing bacteria. The results of metagenome indicated that Fe, Mn and S cycle in soil are closely involved in the biogeochemical cycle of Tl. The findings of co-occurrence patterns in the bacterial network and correlation between microorganisms and different geochemical fractions of Tl may benefit the strategy of bioremediation of Tl-contaminated soils with indigenous microbes.


Assuntos
Poluentes do Solo , Tálio , Filogenia , RNA Ribossômico 16S/genética , Solo , Poluentes do Solo/análise , Tálio/análise
10.
J Hazard Mater ; 416: 126153, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492934

RESUMO

Uranium mill tailings (UMTs) are one critical source of environmental U pollution. Leaching test has been extensively used to reveal U release capacity and mechanism from UMTs, while little attention has been paid to the effects of re-adsorption process on U release. In this study, the role of U re-adsorption behaviors during leaching test with UMTs was comprehensively investigated. Through paired data on mineralogical composition and aqueous U speciation, the influence of environmentally relevant factors on U re-absorption capacity and mechanism on UMTs with different particle sizes was revealed. Significant amounts of U re-adsorption were observed and primarily attributed to the adsorption on chlorite, albite and muscovite as well as combined reduction-sequestration by muscovite. Uranium re-adsorption predominantly occurred via inner-sphere complexation and surface precipitation depending on leachant pH. Coexisting sulfate or phosphate could further enhance U re-adsorption. The enhanced re-adsorption from sulfate occurred when inner-sphere complexation governed the re-adsorption process. These findings suggest that the environmental hazards and ecological risks of the U containing (waste) solids might have been underestimated due to the ignorance of the re-adsorption process, since the re-adsorbed U could be easily re-mobilized. The insights from this study are also helpful in developing effective in-situ remediation strategies.


Assuntos
Poluentes Radioativos do Solo , Urânio , Poluentes Radioativos da Água , Adsorção , Tamanho da Partícula , Urânio/análise , Poluentes Radioativos da Água/análise
11.
Huan Jing Ke Xue ; 42(3): 1343-1353, 2021 Mar 08.
Artigo em Chinês | MEDLINE | ID: mdl-33742931

RESUMO

Bacteriohopanepolyols (BHPs), as a novel bacterial biomarker, show clear potential for tracking organic matter sources and environmental change. To evaluate BHPs as indicators of seasonal hypoxia in the Yangtze Estuary and its adjacent areas, the composition, distribution, and source of BHPs in surface sediments were analyzed using high-performance liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (HPLC-APCI-MS). A total of 12 BHPs were detected with a normalized TOC concentration of 3.79-269 µg·g-1. The BHPs present in the surface sediments were dominated by bacteriohopanetetrol (BHT), 2-methyl-BHT, amino-BHPs, and adenosylhopane and its homologues, accounting for 40%, 22%, 12%, and 4% of the total BHPs, respectively. Each of these components and their corresponding indices show clear spatial trends. Specifically, BHT showed an "offshore increase" trend, which was mainly attributed to marine autochthonous inputs; and soil marker BHPs including adenosylhopane, which were dominated by terrestrial sources, showed an "offshore decrease" trend. The Rsoil index indicated a similar spatial pattern to the soil marker BHPs, with the relative contribution of terrestrial organic matter decreasing from 61.5% in coastal waters to 1.66% in the open ocean. This suggests that the organic matter in the coastal waters was mainly derived from terrestrial sources while marine sources were dominant in the open ocean. BHT-Ⅱ, the BHT stereoisomer, was derived from anaerobic ammonium oxidizing bacteria. High BHT-Ⅱ ratios were consistent with seasonal hypoxic zones in the Yangtze Estuary and, furthermore, these ratios were significantly negatively correlated with dissolved oxygen (DO) concentrations in the bottom waters. These observations indicate that hypoxic environments are beneficial to BHT-Ⅱ production, implying that BHT-Ⅱ can be used as an indicator of marine hypoxia.


Assuntos
Estuários , Poluentes Químicos da Água , Bactérias , China , Monitoramento Ambiental , Sedimentos Geológicos , Humanos , Hipóxia , Rios , Poluentes Químicos da Água/análise
12.
J Hazard Mater ; 414: 125466, 2021 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-33657470

RESUMO

Uranium (U) geochemistry and its isotopic compositions of reservoir sediments in U mine area were poorly understood. Herein, U and Th isotopic compositions were employed to investigate source apportionment and geochemical behavior of U in 41 reservoir sediments from a U mining area, Guangdong, China. The remarkably high contents of both total U (207.3-1117.7 mg/kg) and acid-leachable U (90.3-638.5 mg/kg) in the sediments exhibit a severe U contamination and mobilization-release risk. The U/Th activity ratios (ARs) indicate that all sediments have been contaminated apparently by U as a result of discharge of U containing wastewater, especially uranium mill tailings (UMT) leachate, while the variations of U/Th ARs are dominated by U geochemical behaviors (mainly redox process and adsorption). The U isotopic compositions (δ238U) showed a large variance through the sediment profile, varying from - 0.62 to - 0.04‰. The relation between δ238U and acid-leachable U fraction demonstrates that the U isotopic fractionation in sediments can be controlled by bedrock weathering (natural activity), UMT leachate (anthropogenic activity) and subsequent biogeochemical processes. The findings suggest that U-Th isotopes are a powerful tool to better understand U geochemical processes and enrichment mechanism in sediments that were affected by combined sources and driving forces.

13.
J Hazard Mater ; 411: 125015, 2021 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-33445048

RESUMO

Cadmium (Cd) is a toxic heavy metal pollutant. Various industrial activities, especially metal smelting, are the main sources of Cd pollution. Cd isotopes have exhibited the ability to be excellent source tracers and can be used to assess the pollution contributions from different sources. Herein, in a typical lead-zinc smelter, Shaoguan, China, significant Cd isotopic fractionation was found during the high temperature smelting process and followed a Rayleigh distillation model. The heavier Cd isotopes were concentrated in the slag, while the lighter Cd isotopes were concentrated in the dust. In the downstream sediment profile of the smelter, sediments have extremely high Cd concentrations that far exceed the Chinese background sediment, indicating severe pollution levels. The ε114/110Cd of the sediment core, ranged from - 0.62 ± 0.5-1.73 ± 0.5, are found between slag (ε114/110Cd=10.42) and dust (ε114/110Cd=-5.68). The binary mixture model suggests that 88-93% of the Cd in sediment profile was derived from the slag, and 7-12% from the deposition of dust. The findings demonstrate the great potential to apply Cd isotopes as a new geochemical tool to distinguish anthropogenic sources and quantify the contribution from various sources in the environment.

14.
Microbiol Res ; 246: 126702, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33465557

RESUMO

Mucoid phenotype is an important adaptive defense response for Acinetobacter baumannii (A. baumannii). The aim of this study was to analyze the impact of mucoid phenotype for the molecular characteristics and virulence of A. baumannii. We observed that the colonies of mucoid A. baumannii were moist, with an elevated surface, and the wire drawing result was positive. Transmission electron microscopy data showed that the outer wall of the mucoid colonies was not smooth, had protruding pseudopodia, and was surrounded by a layer of unknown material. Antibiotic susceptibility testing showed that the mucoid strains were multidrug resistant. Notably, the mucoid phenotype and antibiotic resistance were not correlated with the amount of biofilm produced by A. baumannii. MLST data demonstrated that the mucoid A. baumannii strains belonged to type ST2. Most (82.6 %, 38/46) of the multidrug-resistant nonmucoid strains also belonged to the molecular type ST2 and to other types, including ST129, ST158, ST195, ST80 and ST3. Moreover, mucoid A. baumannii strains were more virulent than nonmucoid isolates in a mouse model. The comparative transcriptomic data indicated that 15 genes, especially IX87_RS16955 (acnA), IX87_RS10800 (XanP), IX87_RS12875 (GlmM), IX87_RS00885 and IX87_RS12395 (bfr), were possibly associated with the phenotype and virulence of mucoid A. baumannii. In conclusions, the study comprehensively describes the molecular characteristics and virulence regulatory mechanism of mucoid A. baumannii, and provides novel insights for the prevention and treatment of infections associated with these strains.


Assuntos
Acinetobacter baumannii/genética , Acinetobacter baumannii/patogenicidade , Antibacterianos/farmacologia , Fatores de Virulência/genética , Virulência , Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/ultraestrutura , Animais , Biofilmes/crescimento & desenvolvimento , Farmacorresistência Bacteriana Múltipla , Feminino , Perfilação da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Tipagem de Sequências Multilocus , Fenótipo
15.
Sci Total Environ ; 769: 145269, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33493908

RESUMO

The dynamics of As at the sediment-water interface (SWI) is an important link in driving As release into the upper water column to affect biological activities. At present, it is unclear about the As cycling at the SWI, especially under the influence of seasonal hypoxia in the Changjiang Estuary. In this study, the profile variations of As in porewater and solid phases from the Changjiang Estuary were studied. Results suggested that As profiles presented the "removal-release-removal" pattern with depth. Arsenic profiles were typically characterized by subsurface maxima in porewater and surficial enrichment in solid phase, which were closely related to Fe and S cycling. The occurrence of porewater As peaks and its obvious speciation transition at subsurface layers, companied by the conversion of dominant phases of solid As from reductive to oxidative fractions at the same layers indicated the reductive release of As at redoxcline. Arsenic species, saturation indexes (SI) and net reaction rates (RnetAs) suggested that the removal of As at surface and deep layers were attributed to the adsorption of As(V) by Fe oxides and the formation of orpiment and/or adsorption by Fe sulfides, respectively. The benthic hypoxic environment in late-summer was more favorable for upward migration and diffusion of As. This process was considered as an important contribution to the elevated aquatic As in the Changjiang Estuary.

16.
J Hazard Mater ; 401: 123311, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-32652417

RESUMO

Thallium (Tl), is a highly toxic trace metal in the natural environment. Emerging Tl pollution in waters has gradually become a global concern. However, limited removal technologies are available for Tl-containing wastewater. Herein, MnFe2O4-biochar composite (MFBC) was successfully fabricated via coprecipitation method as a novel and efficient adsorbent for treating Tl(I)-contaminated wastewater. It was found that the MFBC, with a specific surface area of 187.03 m2/g, exhibited high performance across a wide pH range of 4-11, with the superior Tl(I) removal capacity (170.55 mg/g) based on Langmuir model (pH 6.0, a dosage of 1 g/L). The removal mechanisms included physical and chemical adsorption, ion exchange, surface complexation, and oxidation. This investigation revealed that MFBC is a promising and environmentally friendly adsorbent with a low cost, large specific surface area, magnetic properties, and high efficiency for the removal of Tl(I) from wastewater.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Cinética , Tálio/análise , Poluentes Químicos da Água/análise
17.
J Hazard Mater ; 407: 124402, 2021 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-33189469

RESUMO

Thallium (Tl) pollution caused by the exploitation of uranium (U) mines has long been neglected due to its low crustal abundance. However, Tl may be enriched in minerals of U ore because Tl has both sulfurophile and lithophile properties. Herein, a semi-dynamic leaching experiment combined with statistical analysis, geochemical speciation and multi-characterization provided novel insight into the distinct features and mechanisms of Tl release from uranium mill tailings (UMT). The results showed that particle size effects prevail over the pH on Tl release, and surface dissolution is the pivotal mechanism controlling Tl release based on Fick's diffusion model. The study revealed that long-term leaching and weathering can lead to the increased acid-extractable and oxidizable fractions of Tl in UMT, and that the exposure and dissolution of Tl-containing sulfides would largely enhance the flux of Tl release. The findings indicate that UMT containing (abundant) pyrite should be paid particular attention due to Tl exposure. Besides, critical concern over the potential Tl pollution in universal U mining and hydrometallurgical areas likewise may need to be seriously reconsidered.


Assuntos
Poluentes Radioativos do Solo , Urânio , Poluentes Radioativos da Água , Mineração , Tálio/análise , Urânio/análise , Poluentes Radioativos da Água/análise
18.
Environ Int ; 146: 106207, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33197789

RESUMO

Industrial activities tend to deteriorate adjacent agricultural lands due to accumulation of potentially toxic elements in soils and crops. However, better understanding of their distinctive source partitions and transfer process remains insufficient in steel-making area. The paper focuses on the pollution levels, health risks, and provenance identification of Tl, As, Pb, Cu, Ni, Co, Sb, Cd, Zn, Be, Cr, Fe, Mn, Mo, Sn, and V in common vegetables from different farmlands near a steel-making plant. The results showed that the Tl, As, Pb, Cd, Cr, Cu and Mn were of high-level contamination in soils and generally above the maximum permissible level (MPL). Calculation using hazard quotients (HQ) exhibited that consumption of the studied vegetables may entail significant health risks to residents, especially for children, resulting from the elevated contents of Tl, As and associated toxic elements. Calculation by binary mixing model using Pb isotopic compositions suggested that steel-making activities contributed to 35-80% of the contamination of Pb and As in vegetables. It is necessary to adopt appropriate remediation measures to mitigate the farmland contamination and ensure the food safety of the agricultural products.


Assuntos
Metais Pesados , Poluentes do Solo , Criança , China , Monitoramento Ambiental , Humanos , Metais Pesados/análise , Medição de Risco , Solo , Poluentes do Solo/análise , Aço , Verduras
19.
Sci Total Environ ; 742: 140321, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-32721712

RESUMO

Metal(loid) contamination caused by industrial activities in agricultural soils has become a universal environmental and food safety concern. This study revealed the contamination, pathway, and source contribution of metal(loid)s such as lead (Pb), zinc (Zn) and cadmium (Cd) in maize and soils in different residential areas impacted by long-term historical artisanal zinc smelting activities from Southwest China. Results revealed that the soils were contaminated heavily by metals like Pb, Zn and Cd, with contents of 40-14,280, 150-47,020 and 1.28-61.7 mg/kg, respectively. Hazard quotients of food uptake for Pb, Cd and Cr in maize grains were extremely high for residents, in particular for the children. To trace the sources of metal health risk, lead isotope fingerprinting and binary mixing modeling were applied. It indicated that the anthropogenic activities contributed over 80% to the Pb contamination in maize grains. The findings highlighted warning levels of health risks to the residents in consuming maize grains in the historical artisanal PbZn smelting area. Therefore, an effective strategy including pollution source control and remediation measures must be taken to improve the soil quality and guarantee food safety around the historical smelting areas likewise.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Criança , China , Monitoramento Ambiental , Humanos , Isótopos , Chumbo , Medição de Risco , Solo , Zea mays , Zinco/análise
20.
Ecotoxicol Environ Saf ; 202: 110874, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32619890

RESUMO

The adverse impacts of detrimental thallium (Tl) contamination are of increasing concerns to sustainable development. Herein, the contents, distributions and sources of Tl and potential toxic elements (PTEs) (Pb, As, Cr, Cu, Ni, Co, Sb, Cd and U) were investigated in sediments collected in Gaofeng River, which has been contaminated by long-term mining activities, located in Yunfu City, Southern China. Results indicated that excessive Tl levels were found in sediments (1.80-16.70 mg/kg). Sequential extraction procedure indicated that despite a large amount of Tl entrapped in residual fraction, a significant level of Tl (0.28-2.34 mg/kg) still exhibited in geochemically labile fractions, which was easy for Tl mobilization and availability. Pb isotope tracing method further confirmed that the pyrite exploitations may be the prime contaminated contributor (47-76%) to these sediments. These findings highlight that it is essential to establish more effective measures for Tl contamination control and call for engineered remediation countermeasures towards polluted river sediments.


Assuntos
Monitoramento Ambiental , Tálio/análise , Poluentes Químicos da Água/análise , China , Cidades , Poluição Ambiental , Sedimentos Geológicos/química , Ferro , Isótopos , Metais Pesados/análise , Mineração , Rios/química , Sulfetos
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