Antimony Content Research Articles

Interactive association of metals and Life's Essential 8 with mortality in U.S. adults: a prospective cohort study from the NHANES dataset.

Life's Essential 8 (LE8) is a novel assessment of cardiovascular health (CVH) by evaluating lifestyle, and reports of the associations between LE8 and urinary metals on mortality have been very limited. This study aimed to conduct a prospective cohort study and investigate the combined effects of metals and LE8 on mortality in U.S. adults. This study enrolled participants with complete information on urinary metals, LE8, mortality status, and confounders from the National Health and Nutrition Examination Survey (2005-2018). The Cox regression model, adaptive lasso penalized regression, and restricted cubic spline were used to analyze the individual effects of metals and LE8 on all-cause mortality. The additive and multiplicative interaction scales and quantile g-computation were used to evaluate the interaction and combined effects. Stratified analyses were performed to clarify whether metals and LE8 interacted with other variables to influence all-cause mortality. A total of 8017 participants were included in this study. The concentrations of cadmium, cobalt, lead, antimony, and thorium were greater in the low CVH group than in the high CVH group [median (µg/L): 0.29 vs. 0.19, 0.36 vs. 0.35, 0.48 vs. 0.39, 0.05 vs. 0.04, and 0.07 vs. 0.06]. The interaction between cadmium and LE8 was statistically significant, with a synergy index of 1.169 (95% CI: 1.004, 1.361). The stratified analyses showed that the interaction between age and LE8 had an impact on all-cause mortality (P for interaction = 0.004). In this representative sample of the U.S. population, we found that the combined effect of cadmium, lead, thallium, and LE8 was positively associated with all-cause mortality. Furthermore, the interaction between cadmium and LE8 influenced all-cause mortality. So people should adopt healthy behaviors and reduce heavy metal exposure to minimize the risk of adverse health outcomes.

In-situ trace element and sulfur isotope compositions of Multi-Stage sulfides in the Buzhu orogenic gold (Antimony) Deposit, southern Tibet: Implications for the metallogenic process

The Buzhu gold (antimony) deposit, located within the gold-antimony polymetallic belt of southern Tibet in the Tethys Himalayan belt, is a recently discovered medium-sized gold polymetallic deposit. The orebody consists primarily of gold-bearing quartz sulfide veins. Currently, the metallogenic mechanism of the deposit remains largely unexplored. Utilizing results from the mineralogical observation of principal ore minerals, LA-ICP-MS trace element analysis, and in-situ sulfur isotope analysis of pyrite, investigations reconstruct the evolution process of pyrite-arsenopyrite and constrain the metallogenic process of the Buzhu gold (antimony) deposit. It has been discovered that the gold-bearing sulfides in the Buzhu gold (antimony) deposit are primarily pyrite and arsenopyrite. Pyrite can be categorized into six generations: framboidal pyrite Py0, dissolution cavity pyrite Py1a (some exhibiting oscillatory zoning), disseminated pyrite Py1b, euhedral pyrite Py2a, irregular pyrite Py2b, and Py3. Arsenopyrite, on the other hand, can be classified into three generations: early arsenopyrite Apy0, disseminated arsenopyrite Apy1, and euhedral Apy2. The analysis of δ34S in pyrite throughout the ore-forming process indicates sulfur derives from multiple sources, with Py0 indicative of a biological sulfur source. The evolutionary process of pyrite, supported by trace element analysis, suggests that the remaining pyrite derives from sedimentary fluid transformation, with sulfur primarily sourced from metamorphic sediments. Elemental spectrum analysis and BSE observations indicate that the Buzhu gold (antimony) deposit primarily undergoes two distinct stages of mineralization: the initial stage is the gold-antimony mineralization phase, during which antimony precipitates in the fissures of Py1a as stibnite, while gold is primarily found in Py1-Apy1 as invisible gold, with the highest gold content in Apy1 (28.20–60.13 ppm, average 40.51 ppm). The subsequent stage of mineralization is characterized by gold mineralization, with gold primarily residing in the internal fissures of Apy2 as micron silver gold ore. The evolution characteristics of gold-bearing sulphide and the solubility curve of Au indicate that gold mainly derives from gold-bearing unsaturated fluid, rather than from early framboidal pyrite Py0 (0.52–1.06 ppm, average 0.79 ppm). Only a minor fraction of gold (originating from early sediments) in Py0 was liberated and integrated into subsequent pyrites. The content of antimony in Py0 significantly reduces after dissolution, suggesting that antimony predominantly originates from Py0 (206–440 ppm, average 335 ppm). Throughout the genesis of the Buzhu gold (antimony) deposit, the gold constituent underwent a sequence of pre-enrichment, re-enrichment, liberation, and precipitation. The processes of coupled dissolution-reprecipitation (CDR) and boiling fostered the reactivation and reenrichment of gold. The recrystallization into cubic pyrite led to the expulsion of gold from the pyrite lattice, and fluid oxidation resulting from multistage fluid boiling, coupled with a decrease in sulfur fugacity, led to gold precipitation.

Chemical composition of sediment and macrozoobenthos of small urban lakes, the Republic of Karelia, Russia

Assessing the benthic communities in water bodies under increasing anthropogenic pressure seems to be an urgent task of scientific research aimed at short-term and long-term monitoring of water bodies. This study focuses on the chemical composition of modern sediment and the current state of macrozoobenthos of small lakes in the Republic of Karelia (Kitaiskoe and Plotichie) influenced by anthropogenic factors. It was discovered that the lakes of Medvezhyegorsk have a higher concentration of heavy metals (such as lead (Pb), cadmium (Cd), molybdenum (Mo), and antimony (Sb),) compared to the Earth’s crust and natural background levels. The current study established the significant impact of industry and transportation on the movement and build up of pollutants in these lakes. The qualitative and quantitative parameters analysed for the benthic communities in the littoral and profundal zones included the species diversity, the structure of dominant species, and their percentage in the samples. According to the level of macrozoobenthos development, both reservoirs (lakes) were classified as mesotrophic, and according to the values of the chironomid index “K” as moderately polluted. The Pantle–Buck method (saprobic index) showed that the lakes can be classified as polluted (water quality class 4). Macrozoobenthos groups most tolerant to environmental conditions, for example, Chironomidae larvae, prevailed in the studied urban lakes. The economic development of the lakes leads to ecosystem transformation and long-term eutrophication over time affecting the biotic indicators of surface water quality. The results obtained can serve as a basis for complex environmental monitoring of the urbanized territories in the taiga zone.

Projections of non-exhaust emissions from brake wear across Japan for 2020–2050

The concerns regarding the detrimental impacts of the increasing proportion of non-exhaust emissions are growing, even though there is a decrease in exhaust emissions from vehicles worldwide. Brake wear is a source of non-exhaust emissions. Despite the high density of traffic in Japan, the emission from brake wear has rarely been the target of studies. The objectives of this study are to estimate the environmental concentrations of copper (Cu) and antimony (Sb) released from brake wear in Japan and compare these concentrations on an annual basis (from 2020 to 2050). The Cu content in brake pads is estimated to decrease greatly from 2021 to 2025, whereas the Sb content is estimated to a moderate level by 2050. In this study, we used an atmospheric dispersion model to predict the reduction in Cu and Sb concentrations emitted from vehicles; owing to the transition to electric vehicles equipped with regenerative brakes (which will generate fewer wear particles), the Cu and Sb emissions in 2050 will decrease by 98 and 89 %, respectively, compared to the emissions noted in 2020. However, the contribution of conventional and electric vehicles to Cu and Sb concentrations will reverse in 30 years, owing to the country's goal that electric passenger vehicles will account for 100 % of the new-vehicle sales by 2035. By 2050, the contribution of conventional vehicles to Cu and Sb concentrations will be only 1 and 3 %, respectively, which will be from conventional vehicles supplied to the market by 2034. Thus, based on the future estimates of the number of vehicles and the composition of their brake pads, we predicted the environmental concentrations of Cu and Sb released from brake wear. The projections presented in this study can serve future interdisciplinary studies on environmental pollution, anthropological emissions reduction, and sustainable development.

Selective incorporation of antimony into gallium nitride

Dilute concentrations of antimony (Sb) incorporation into GaN induce strong bandgap bowing and tunable room-temperature photoluminescence from the UV to the green spectral regions. However, the atomistic details of the incorporation of Sb into the GaN host remain unclear. In this work, we use first-principles calculations to understand the thermodynamics of Sb substitution into GaN and its effect on the optical and Raman spectra. Although it is empirically considered that Sb is preferentially incorporated as an anion (Sb3−) into the N sublattice, we demonstrate that Sb can also be incorporated as a cation (Sb3+, Sb5+) into the metal sublattice. Our thermodynamic analysis demonstrates that SbN0, SbGa2+, and SbGa0 can co-exist under Ga-rich conditions in n-type samples. We further confirm the dual incorporation of Sb by calculating the vibrational frequencies of different anionic and cationic substitutions to explain the origins of experimentally observed additional Raman peaks of Sb-doped GaN. Moreover, the calculated band structures of different Sb substitutions into GaN explain the experimental photoluminescence and optical absorption spectra. Overall, our analysis suggests that the coexistence of Sb3−, Sb3+, and Sb5+ substitutions into GaN explains the totality of experimental measurements. Our results demonstrate that the selective incorporation of Sb into GaN (and potentially other group-V elements such as As, P, or Bi) by tuning the growth conditions can drastically modify the electronic properties, for applications in visible light emitters and photocatalysis.

The influence of the dopant concentration and sintering parameters on properties of antimony doped barium stannate ceramics

In this paper, the influence of antimony concentration and different sintering techniques on the structural, microstructural, and electrical properties of antimony-doped barium stannate, BaSn1-xSbxO3 (BSSO, x = 0.00, 0.04, 0.06, 0.08 and 0.10) was investigated. BSSO-based ceramic samples were obtained by conventional and spark plasma sintering. The XRD analysis confirmed the single-phase, cubic BaSnO3 lattice system in all conventionally sintered samples. Apart from the dominant cubic phase, the spark plasma sintering conditions led to the formation of a secondary phase, Ba2SnO4, in all samples. FESEM analysis revealed the presence of low angle grain boundaries (LAGBs) in BSSO samples with high antimony concentration (x = 0.08), independently of the sintering technique. However, the fraction of LAGBs is significantly higher in the BaSn0.92Sb0.08O3-SPS sample due to the simultaneous exposure of the conductive sample to the effects of high temperature and pressure during sintering process. These boundaries have low activation energy and allow free charge carrier transport through the grain boundary region. The high dopant concentration and the presence of large fraction of LAGBs in BaSn0.92Sb0.08O3-SPS sample reflected on its electrical properties through low and almost temperature-independent electrical resistivity in the temperature range of 25–150 °C.

Associations of urinary heavy metals with age at menarche, age at menopause, and reproductive lifespan: A cross-sectional study in U.S. women

Female reproductive timing and lifespan, with a close relation to long-term health outcomes, have been altered in U.S. women over the past decades. However, epidemiologic evidence of the potential causes was lacking. On the basis of 1981 naturally postmenopausal women from the National Health and Nutrition Examination Survey 1999–2020, this study aimed to investigate the associations of urinary heavy metals with age at menarche, age at menopause, and reproductive lifespan. Multivariate generalized linear regression and addictive models were used for single metal exposure analysis, and weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) models were employed for mixed exposures. In the fully adjusted model, higher urinary antimony concentration was associated with earlier age at menarche of 0.137 years, while higher concentrations of cadmium, cesium, lead, antimony, and thallium were associated with delayed age at menopause of 0.396–0.687 years. Additionally, urinary barium, cesium, lead, antimony, and thallium levels were associated with longer reproductive lifespan ranging between 0.277 and 0.713 years. Both WQS and BKMR models showed significantly positive associations of metal mixtures with age at menopause (β: 0.667, 95 % CI: 0.120–1.213) and reproductive lifespan (β: 0.686, 95 % CI: 0.092–1.280), with cadmium and lead identified as principal contributors. In conclusion, heavy metal exposures were associated with reproductive timing and lifespan of U.S. women, highlighting the need for further prevention and intervention strategies.

Degradation of Aniline and Antimony in Printing and Dyeing Wastewater by Micro-Oxygenated Hydrolytic Acidification and Their Removal Effects on Chemical Oxygen Demand and Ammonia Nitrogen

The degradation characteristics of aniline and antimony in printing and dyeing wastewater during the micro-oxygenated hydrolytic acidification process and its effect on COD and ammonia nitrogen removal were investigated in this experiment. Firstly, the effects of control factors such as pH, dissolved oxygen (DO), and sludge concentration on COD and ammonia nitrogen removal in the hydrolysis acidification section were optimized. It was recommended that the pH value should be maintained at 6.5; low DO (0–0.5 mg/L) could assist in the conversion of nitrogen for subsequent treatment; the optimum treatment temperature was 25 °C; finally, it was recommended that the sludge concentration should be controlled at 4 mg/L during the operation. Secondly, the effects of aniline and antimony on COD and nitrogen removal were investigated. It was found that when the concentration of aniline was increased from 0.4 mg/L to 5.4 mg/L, the COD concentration in the effluent increased by 96.5%, which indicated that aniline was toxic to anaerobic sludge and obviously inhibited the degradation of COD. When the concentration of antimony was increased from 0.05 mg/L to 2.05 mg/L, the COD removal rate was only 2.9%, which was much lower than that of the water samples with no antimony added. The anaerobic sludge concentration decreased from 5.58 g/L to 3.44 g/L, which indicated that aniline and antimony had a strong inhibitory effect on the activity of anaerobic bacteria and inversely affected COD removal.

Biochar-Sulfate Reducing Bacteria synergy: A green approach for antimony removal and recovery from high-concentrated waters

Environments with elevated antimony (Sb) levels often result from industrial and mining activities, causing harm to ecosystems due to the inherent toxicity. Traditional treatments aim to eliminate or decrease Sb toxicity, yet they often result in the generation of secondary pollution. This study explores a novel approach for enhancing biological sulfate-reduction by biochar addition to cope with high Sb concentrations. Moreover, this research postulates sulfate-reduction bioprocess as a feasible alternative to obtain valuable antimony sulfide. The findings indicate that sulfate reduction effectively removes antimony, particularly at high concentrations, using a non-specialized inoculum. Biochar plays a pivotal role in enhancing sulfate-reduction rates, reducing lag-phase periods, and enriching the microorganisms responsible for sulfate reduction.Interestingly, lower concentrations of Sb(III) (5–40 mg/L) and Sb(V) (5–100 mg/L) exhibited a lower removal percentage compared to higher concentrations of Sb(III) (80–500 mg/L) and Sb(V) (200–1000 mg/L). This phenomenon was attributed to the excess sulfide hindering the equilibrium of the first-order reaction at lower concentrations, while at higher concentrations, the reaction proceeded more rapidly. A combination of biochemical and physicochemical reactions facilitated the removal of >95 % Sb(III) and >97 % Sb(V) using biochar.Furthermore, various taxa displayed a significant logarithmic rate of change in their abundance, influenced by the application of biochar or the introduction of distinct antimony species. The biogenic sulfide generated through the sulfate reduction process reacted with the Sb species, resulting in the precipitation of stibnite (Sb2S3), Na3SbS3, and Na3SbS4. These precipitates are considered crucial precursors in electronic applications.In conclusion, this study constitutes a pioneering exploration of elevated antimony (Sb) concentrations under sulfate-reducing conditions, significantly contributing to an advancement of knowledge in the application of biological processes.

Effects of antimony on antioxidant system, damage indexes of blood-brain barrier and ultrastructure of zebrafish (Danio rerio)

Antimony (Sb) and its compounds can be harmful to people and are known to cause cancer, so they are a key pollutant to control. This study investigated the influence of antimony on non-enzymatic antioxidants and the blood-brain barrier (BBB) in zebrafish(Danio rerio), a model organism that shares a high degree of genetic similarity with humans. Zebrafish were exposed to different doses of antimony in water for 7, 18, and 30 days. The results indicated that antimony accumulated most in the liver, followed by the gills, flesh, and brain, with the accumulation increasing as the exposure duration extends. Additionally, under identical antimony concentrations, the buildup in the four tissues was positively correlated with the duration of exposure. After 18 days of exposure, the total antioxidant capacity (T-AOC) and endogenous non-enzymatic antioxidants vitamin C (VC) and vitamin E (VE) decreased as a result of antimony ingestion in zebrafish, although cysteine secretion was increased in the liver, gills, and brain. The structural integrity of the BBB was compromised by the elevation of ApoE4 and MMP-9 levels as a result of antimony exposure, which led to the breakdown of the basal lamina, tight junctions, and nerve fibers in the brain. At this injured region, 5-HT and MBP were also able to easily enter and leave the BBB, albeit at variable rates. Additionally, when the antimony exposure level reached 16.58 mg·L−1, antimony penetrated the BBB and bound to erythrocytes, causing their lysis.

Selective recovery of antimony from Sb-bearing copper concentrates by integration of alkaline sulphide leaching solutions and microwave-assisted heating: A new sustainable processing route

The technical feasibility of leaching antimony from an antimony-bearing copper sulphide concentrate, using alkaline sulphide solutions and microwave-assisted and non-assisted heating technology, is investigated at a laboratory scale. The leaching test examines the influence of selective leaching reagent (Na2S and NaOH) concentrations, solid/liquid ratio, and temperature. The results indicate that antimony dissolution is highly selective (e.g. only Sb and As are leached), depending on the concentrations of leaching reagents and the leaching temperature. The influence of temperature on the mineral's dissolution, in the range 25–140 °C, is analysed from a thermochemical point of view using equilibrium databases. Under the optimal conditions: leaching agent: 250 g/L Na2S, 60 g/L NaOH, 2 h, 140 °C, with microwave assisted, the leaching efficiency of Sb reached 95.7 %. The antimony content in the copper concentrate is successfully reduced from 1.1 wt% to <0.2 wt% Sb, making it suitable for copper concentrate metallurgical processing. The study demonstrates that increasing temperature and NaOH/Na2S concentrations collectively enhance leaching efficiency, with a statistical significance, reducing both leaching time and the required temperature, compared to non-microwave-assisted leaching. Furthermore, it is established that excess free hydrogen sulphide ions ensure the efficient dissolution of the main impurities associated with penalties, such as antimony and arsenic, with limited copper and iron dissolution from the copper concentrate, predominantly chalcopyrite. Finally, an integrated hydrometallurgical process flowsheet for antimony removal and recovery from a sulphide copper concentrate is proposed.

Embedded high-quality ternary GaAs1−x Sb x quantum dots in GaAs nanowires by molecular-beam epitaxy

Semiconductor quantum dots are promising candidates for preparing high-performance single photon sources. A basic requirement for this application is realizing the controlled growth of high-quality semiconductor quantum dots. Here, we report the growth of embedded GaAs1−x Sb x quantum dots in GaAs nanowires by molecular-beam epitaxy. It is found that the size of the GaAs1−x Sb x quantum dot can be well-defined by the GaAs nanowire. Energy dispersive spectroscopy analyses show that the antimony content x can be up to 0.36 by tuning the growth temperature. All GaAs1−x Sb x quantum dots exhibit a pure zinc-blende phase. In addition, we have developed a new technology to grow GaAs passivation layers on the sidewalls of the GaAs1−x Sb x quantum dots. Different from the traditional growth process of the passivation layer, GaAs passivation layers can be grown simultaneously with the growth of the embedded GaAs1−x Sb x quantum dots. The spontaneous GaAs passivation layer shows a pure zinc-blende phase due to the strict epitaxial relationship between the quantum dot and the passivation layer. The successful fabrication of embedded high-quality GaAs1−x Sb x quantum dots lays the foundation for the realization of GaAs1−x Sb x -based single photon sources.

Application of soil magnetometry and geochemical methods to investigate soil contamination with antimony

The aim of the study was an assessment of the pollution level and identification of the antimony sources in soils in areas subjected to industrial anthropopressure from: transport, metallurgy and electrical waste recycling. The combination of soil magnetometry, chemical analyzes using atomic spectrometry (ICP-OES and ICP-MS), Sb fractionation analysis, statistical analysis (Pearson’s correlation matrix, factor analysis) as well as Geoaccumulation Index, Pollution Load Index, and Sb/As factor allowed not only the assessment of soil contamination degree, but also comprehensive identification of different Sb sources. The results indicate that the soil in the vicinity of the studied objects was characterized by high values of magnetic susceptibility and thus, high contents of potentially toxic elements. The most polluted area was in the vicinity of electrical waste processing plants. Research has shown that the impact of road traffic and wearing off brake blocks, i.e. traffic anthropopression in general, has little effect on the surrounding soil in terms of antimony content. Large amounts of Pb, Zn, As and Cd were found in the soil collected in the vicinity of the heap after the processing of zinc–lead ores, the average antimony (11.31 mg kg−1) content was lower in the vicinity of the heap than in the area around the electrical and electronic waste processing plant, but still very high. Antimony in the studied soils was demobilized and associated mainly with the residual fraction.

Integrating machine learning and electrochemistry: A hybrid SA-DE-RF approach for optimizing electrode composition in water treatment

The imperative to address the burgeoning challenge of industrial water pollution has catalyzed the pursuit of sophisticated treatment methodologies capable of neutralizing non-biodegradable contaminants. This investigation focuses on the optimization of Ti/SnO2-Sb-Ni anode composition, leveraging a synergistic hybrid machine learning strategy that integrates Simulated Annealing (SA), Differential Evolution (DE), and Random Forest (RF) algorithms. This triad of algorithms is meticulously applied to ascertain the optimal doping concentrations of antimony (Sb) and nickel (Ni), pivotal in maximizing the efficacy of electrochemical oxidation processes. Our findings elucidate that the meticulously optimized Ti/SnO2-Sb-Ni anode, with a specific doping ratio of 100:3.74:5.36, engenders a degradation efficiency of benzoic acid (BA) that approximates completeness within a constrained temporal framework of 60 minutes. The RF regression model, exemplifying a robust R² value of 0.9565 and an RMSE of 0.0576, surpasses its counterparts in prognostication accuracy, underscoring its preeminence in electrode composition optimization for the amelioration of electrochemical water treatment matrices. The convergence of SA, DE, and RF methodologies not only refines the predictive fidelity of the degradation kinetics but also extricates the optimization process from the conventional constraints, thereby enhancing the scalability and precision of the model. This research advances the frontiers of electrochemical oxidation and etches a pioneering niche for the amalgamation of machine learning within environmental engineering paradigms. The hybrid algorithmic scaffolding proffered herein is suggested as a robust and versatile framework, propelling forward the discourse on the remediation of polluted water bodies and offering a springboard for future investigative endeavors.

Investigation of the Properties of Anti-Friction Coatings Deposited with Different Casting Methods.

This article presents the research results of depositing anti-friction coatings (Babbitt) using three different casting methods: static casting, flame soldering, and clad welding. Babbitt alloy coatings deposited with different casting methods are discussed and explained in terms of changes in the coating properties, such as the microstructure, hardness, strength, and chemical composition. The results showed significant differences in the aforementioned properties, depending on the chosen coating deposition method. The results of the tests confirmed the importance of using shielding gas during deposition to ensure the chemical composition of the coating. The analysis revealed that decreases in the amounts of antimony and copper in the Babbitt coating compared with the initial concentrations were influenced by selective evaporation, oxidation, and the coating process parameters associated with different coating methods. To maintain the desired balance of mechanical properties in Babbitt coatings, it is important to control the antimony and copper contents. Clad welding deposition using a non-consumable tungsten electrode and argon shielding gas achieved a chemically stable coating quite close to the initial chemical composition of the Babbitt alloy.

A multi-environmental source approach to explore associations between metals exposure and olfactory identification among school-age children residing in northern Italy.

Metal exposures can adversely impact olfactory function. Few studies have examined this association in children. Further, metal exposure occurs as a mixture, yet previous studies of metal-associated olfactory dysfunction only examined individual metals. Preventing olfactory dysfunctions can improve quality of life and prevent neurodegenerative diseases with long-term health implications. We aimed to test the association between exposure to a mixture of 12 metals measured in environmental sources and olfactory function among children and adolescents residing in the industrialized province of Brescia, Italy. We enrolled 130 children between 6 and 13 years old (51.5% females) and used the "Sniffin' Sticks" test to measure olfactory performance in identifying smells. We used a portable X-ray fluorescence instrument to determine concentrations of metals (arsenic (As), calcium, cadmium (Cd), chromium, copper, iron, manganese, lead (Pb), antimony, titanium, vanadium and zinc) in outdoor and indoor deposited dust and soil samples collected from participants' households. We used an extension of weighted quantile sum (WQS) regression to test the association between exposure to metal mixtures in multiple environmental media and olfactory function adjusting for age, sex, socio-economic status, intelligence quotient and parents' smoking status. A higher multi-source mixture was significantly associated with a reduced Sniffin' Sticks identification score (β = -0.228; 95% CI -0.433, -0.020). Indoor dust concentrations of Pb, Cd and As provided the strongest contributions to this association (13.8%, 13.3% and 10.1%, respectively). The metal mixture in indoor dust contributed more (for 8 metals out of 12) to the association between metals and olfactory function compared to soil or outdoor dust. Among a mixture of 12 metals measured in three different environmental sources (soil, outdoor and indoor dust), we identified Pb, Cd and As measured in indoor dust as the main contributors to reduced olfactory function in children and adolescents residing in an industrialized area. Exposure to indoor pollution can be effectively reduced through individual and public health interventions allowing to prevent the deterioration of olfactory functions. Moreover, the identification of the factors that can deteriorate olfactory functions can be a helpful instrument to improve quality of life and prevent neurodegenerative diseases as long-term health implications.

Tracing toxic path of antimony: From bioaccumulation to DNA hypomethylation in zebrafish (Danio rerio)

The increasing concentration of Antimony (Sb) in ecological environments has raised serious concerns about its potential biotoxicological impact. This study investigated the toxicokinetics, Global DNA Methylation (GDM), biomarker expression, and Integrated Biological Response (IBR) of Sb at different concentrations in zebrafish. The toxic mechanism of Sb exposure was simulated using molecular dynamics (MD). The results showed that significant differences effect existed (BCFk: liver > ovary > gut > brain) and uptake saturation phenomenon of Sb among zebrafish tissues. Over a 54-day exposure period, the liver emerged as the main target site for Sb-induced GDM, and the restoration was slower than in other tissues during the 54-day recovery period. Moreover, the concentration of Sb had a significant impact on the normally expression of biomarkers, with GSTM1 inhibited and MTF2, MT1, TET3, and p53 showing varying degrees of activation at different Sb concentrations. This could be attributed to Sb3+ potentially occupying the active site or tightly binding to the deep cavity of these genes. The IBR and MD results highlighted DNMT1 as the most sensitive biomarker among those assessed. This heightened sensitivity can be attributed to the stable binding of Sb3+ to DNMT1, resulting in alterations in the conformation of DNMT1's catalytic domain and inhibition of its activity. Consequently, this disruption leads to damage to the integrity of GDM. The study suggests that DNA methylation could serve as a valuable biomarker for assessing the ecotoxicological impact of Sb exposure. It contributes to a better understanding of the toxicity mechanisms in aquatic environments caused potential pollutants.

Mobilization and transformation of antimony in stibnite by microbial induced oxidation in mining environment

Elevated concentrations of antimony (Sb) in environmental and biological systems due to mining activities are of particular global concern. Microorganisms play a crucial role in the oxidation process of metallic sulfide minerals, leading to the release of metal ions into surrounding soil or water systems. However, the mechanisms and potential environmental effects of microbial induced oxidation of stibnite (Sb2S3) in mine environment remain unclear. In this study, compared with the abiotic controls, the microbial community screened from the highly contaminated soil of the Xikuangshan antimony mine in aerobic experiments did not promote Sb mobilization as expected. However, they had a significant effect on the morphology and species of oxidation products of Sb2S3 by mediating the oxidation of Sb(III) and sulfide on surface and in solution. These naturally coexisting bacteria could partially oxidize Sb2S3 to Sb(V) and SO42− directly on the mineral surface, completely oxidize the dissolved Sb(III) to Sb(V), facilitate the oxidation of S0 to S2O32−, and form the secondary Sb(V)-bearing mineral [NaSb(OH)6]. These findings support the important role of microorganisms in the mobilization and transformation of Sb from minerals/rocks in the mining environment and provide further insight into their potential environmental impacts and effective mitigation strategies.

The enrichment of low-grade antimony concentrate by matte smelting and the metallurgy of antimony matte

ABSTRACT This study employed the B2O3-Al2O3-CaO-SiO2 slag system, characterised by a low melting point, to conduct matte smelting for concentrating antimony in low-grade antimony concentrate. The process effectively eliminated major impurities, particularly quartz. An investigation delved into the reaction mechanism between the additive and the concentrate. A single-factor experiment was conducted to investigate the impact of temperature, SiO2 mass ratio, and basicity on the direct recovery rate of Sb. Optimal conditions were achieved at a temperature of 1050°C, a WSiO2/Wslag ratio of 40:100, and a basicity of 0.5. Under these conditions, the direct retrieval rate of antimony reached 91.16%, with the concentration of antimony in the slag measured at 2.34%. The acquired matte contained 53.27% antimony, further utilised in the mainstream process of antimony metallurgy. This study aimed to address the issue of exorbitant smelting expenses associated with low-grade antimony concentrate.

Time-specific impact of trace metals on breast density of adolescent girls in Santiago, Chile.

Whether trace metals modify breast density, the strongest predictor for breast cancer, during critical developmental stages such as puberty remains understudied. Our study prospectively evaluated the association between trace metals at Tanner breast stage B1 (n = 291) and at stages both B1 and B4 (n = 253) and breast density at 2 years post-menarche among Chilean girls from the Growth and Obesity Cohort Study. Dual-energy x-ray absorptiometry assessed the volume of dense breast tissue (absolute fibroglandular volume [FGV]) and percent breast density (%FGV). Urine trace metals included arsenic, barium, cadmium, cobalt, cesium, copper, magnesium, manganese, molybdenum, nickel, lead, antimony, selenium, tin, thallium, vanadium, and zinc. At B1, a doubling of thallium concentration resulted in 13.69 cm3 increase in absolute FGV (β: 13.69, 95% confidence interval [CI]: 2.81, 24.52), while a doubling of lead concentration resulted in a 7.76 cm3 decrease in absolute FGV (β: -7.76, 95%CI: -14.71, -0.73). At B4, a doubling of barium concentration was associated with a 10.06 cm3 increase (β: 10.06, 95% CI: 1.44, 18.60), copper concentration with a 12.29 cm3 increase (β: 12.29, 95% CI: 2.78, 21.56), lead concentration with a 9.86 cm3 increase (β: 9.86, 95% CI: 0.73, 18.98), antimony concentration with a 12.97 cm3 increase (β: 12.97, 95% CI: 1.98, 23.79) and vanadium concentration with a 13.14 cm3 increase in absolute FGV (β: 13.14, 95% CI: 2.73, 23.58). Trace metals may affect pubertal breast density at varying developmental stages with implications for increased susceptibility for breast cancer.