Distribution Of Trace Elements Research Articles

Behaviors of trace elements under varying methane seepage intensity: Insight from tubular seep carbonates in the South China Sea

Seep carbonates are commonly used to study environmental conditions based on trace element patterns. However, the relationship between methane flux and trace element enrichments is not well understood. Tubular seep carbonates, which are interpreted as former fluid conduits, offer an opportunity to investigate how trace element distributions in these structures respond to changes in methane flux. Here, we examined the distribution of trace elements in three tubular seep carbonates collected from Jiulong Methane Reef in the northern South China Sea. The carbonates exhibit low δ13C values (−57.0‰ to −40.4‰ V-PDB). All tubes show a gradual increasing trend in the carbonate contents and a decreasing trend in δ13C values from the outer to the inner portions, indicating an overall increase in methane flux over time. The two tubular carbonates with lower carbon isotopic values likely precipitated in a more reducing environment, as evidenced by relatively higher enrichment factors of Molybdenum (MoEF) and higher Molybdenum/Uranium ratios. The MoEF values show an increasing trend for the outer to the inner portions for the two samples with lower δ13C values, while the UEF values show an increasing trend for the two samples with higher δ13C values. This suggests that the enrichments of Mo and U are influenced by methane flux, which regulates the redox conditions and the rate of elements supplied from seawater. Only Arsenic (As) and antimony (Sb) show identifiable enrichment among the other trace elements, which is unrelated to methane dynamics. This study provides insights into the behavior of redox-sensitive trace elements under changing methane flux, laying a groundwork for using trace element enrichments to reconstruct paleoenvironmental information, particularly in dynamic environments.

Distribution and human health risk assessment of trace elements in the bivalve Polymesoda erosa from mangroves on Hainan Island, China

Distributions and potential health risks of 14 trace elements in Polymesoda erosa from four mangrove wetlands on Hainan Island, China, were investigated. Concentrations (µg⋅g-1 d.w.) in P. erosa soft tissue decreased from Fe (935) > Al (642) > Zn (254) > Mn (44.1) > Sr (36.2) > Ni (13.5) > Cu (8.16) > As (4.54) > Se (3.06) > Cr (1.46) > Sn (0.63) > Pb (0.58) > Cd (0.44) > Hg (0.11), and tissue concentrations differed significantly among wetlands. Al, Fe, Cd, and Se contents were highest in P. erosa muscle from the estuary (S1-B); whereas, Cu, Zn, and Sn contents were highest in P. erosa muscle near the port. The average daily trace element dose for children and adults was acceptable and non-carcinogenic risks were not evident. For children and adults, carcinogenic risks posed by trace elements at the median percentile were 11.6- and 7.84-times higher than the acceptable level (10-4), respectively. The maximum allowable consumption rate and monthly meals highlighted the necessity to reduce trace elements exposure in most sampled regions, with the lowest values at the estuary site. The findings suggest a high risk of consuming P. erosa from inner bay of Dongzhai Harbor.

Genesis of Cu-Sn Mineralization in the Shuangjianzishan Super-Large Silver Deposit, Inner Mongolia: Trace Element Constraints from Chalcopyrite and Cassiterite

The Shuangjianzishan silver polymetallic deposit is located in the copper–tin–lead–zinc–silver polymetallic metallogenic belt in the Southern Great Xing’an Range, with silver resources of more than 18,000 t, which is the largest silver polymetallic deposit in Asia. Early studies concluded that the Shuangjianzishan deposit is typically an epithermal Ag-Pb-Zn deposit that lacks a high-temperature mineralization stage. In recent years, with the deepening of research, a large amount of Cu-Sn mineralization has been found in the deep part of the Shuangjianzishan deposit, but it is less studied. The laser-ablation inductively coupled mass spectroscopy (LA-ICP-MS) technique is used to investigate the distribution and substitution of trace elements in chalcopyrite and cassiterite. In this paper, the trace element study of chalcopyrite and cassiterite from the Shuangjianzishan deposit reveals that Sn, In, As, Se, Sb, and Tl mainly exist in chalcopyrite in isomorphic form, while Pb, Bi, and Ni mainly exist in chalcopyrite in the form of mineral inclusions. The enrichment of the high-temperature elements Sn and Se in chalcopyrite, and the deficit of the middle- and low-temperature elements Ga, Sb, etc., reflect that the chalcopyrite in the Shuangjianzishan deposit was formed in a middle- and high-temperature environment, and it also indicates that the early ore-forming hydrothermal solution may be rich in Sn. Fe, In, Co, and Ni mainly exist in cassiterite in isomorphic form, and the content of W in cassiterite is high. There are two main forms, one is isomorphic and the other is wolframite inclusion. Cassiterite has Fe-rich and W-U-poor characteristics, indicating that cassiterite from the Shuangjianzishan deposit was formed under relatively oxidized conditions, and the relative enrichment of elements such as Fe, W, Zr, and Hf indicates that the temperature of cassiterite formation was high. The elemental content and inter-ionic coupling relationships suggest that the cassiterite from the Shuangjianzishan deposit may have an elemental replacement mechanism of W6+ + Fe2+ ↔ 2Sn4+ or Fe3+ + OH− ↔ Sn4+ + O2−. The trace elements in cassiterite of the Shuangjianzishan deposit are rich in Fe and Mn and depleted in Nb and Ta, according to the Fe-W diagram, and the tin mineralization of the Shuangjianzishan deposit belongs to cassiterite–sulfide-type tin mineralization. Chalcopyrite Co/Ni ratios >1 are consistent with the characteristics of chalcopyrite genesis in hydrothermal deposits.

Spatial distribution of trace and rare earth elements of bottom sediments in Lake Ostrowite, Bory Tucholskie National Park, Poland

AbstractLake pollution has attracted concerns worldwide; especially the excessive accumulation of trace elements (TEs) and rare earth elements (REEs) in bottom sediments can pose a serious threat to ecosystem health. However, there is still a knowledge gap on the level of sediment pollution in lakes isolated from the direct impact of pollution sources, their spatial variability, and also on the factors influencing this state. The aim of this study is to investigate the level and spatial variability of TEs and REEs concentrations, as well as to determine their source and the factors determining their distribution in the bottom sediments of Lake Ostrowite. Lake Ostrowite is the largest and deepest water body located in the Bory Tuholskie National Park (in northern Poland), which completely isolates the lake from the direct impact of pollution sources. The study covered analyses of 32 surface samples of bottom sediments. The concentrations of 24 TEs and 14 REEs were determined using inductively coupled plasma mass spectrometry (ICP‐QQQ‐MS). The assessment of the enrichment of bottom sediments in TEs and REEs employed geochemical background values (GBV) that provided the basis for the calculation of relative concentrations and geochemical indices. The determination of their sources and supply routes was based on the cluster analysis and principal component analysis. The obtained results point to the enrichment of the bottom sediments with TEs and REEs. Relative concentration values of TEs and REEs in reference to geochemical background values were in ranges from 0.01 to 7.31, at an average of 0.99, and from 0.03 to 4.29, averaging 1.76, respectively. The enrichment factor values show moderately severe enrichment of sediments at the study sites. This was primarily determined by the concentrations of Ag (from the TEs group) and Lu (from the REEs group). The metal pollution index values showed an approximate spatial distribution of points in terms of the presence of TEs and REEs. The lowest concentrations of TEs and REEs occurred on the eastern shore of the western basin of Lake Ostrowite. TEs and REEs concentrations in sediments are positively correlated with the content of organic matter and depth and negatively correlated with distance of the sampling point from the river outflow from Lake Ostrowite. On the eastern shore of the western basin, TEs and REEs concentrations are additionally shaped by wind, predominantly from the western direction. With water wave action, organic matter is transported to the central part of the western basin, where it is accumulated. Since the lake is isolated from point and nonpoint pollution sources, relevant from a biogeochemical point of view are dry and wet depositions from the atmosphere as well as aquatic vegetation, shoreline vegetation, forest litter, soil, and groundwater.

Reference values for plasma and urine trace elements in a Swiss population-based cohort.

Trace elements (TEs) are ubiquitous. TE concentrations vary among individuals and countries, depending on factors such as living area, workplaces and diet. Deficit or excessive TEs concentrations have consequences on the proper functioning of human organism so their biomonitoring is important. The aim of this project was to provide reference values for TEs concentrations in the Swiss population. The 1,078 participants to the SKiPOGH cohort included in this study were aged 18-90 years. Their 24-h urine and/or plasma samples were analyzed by inductively coupled plasma mass spectrometry (ICP-MS) to determine 24 TEs concentrations: Ag, Al, As, Be, Bi, Cd, Co, Cr, Cu, Hg, I, Li, Mn, Mo, Ni, Pb, Pd, Pt, Sb, Se, Sn, Tl, V and Zn. Statistical tests were performed to evaluate the influence of covariates (sex, age, BMI, smoking) on these results. Reference intervals for the Swiss adult population were also defined. TEs concentrations were obtained for respectively 994 and 903 persons in plasma and urine matrices. It was possible to define percentiles of interest (P50 and P95) for almost all the TEs. Differences in TEs distribution between men and women were noticed in both matrices; age was also a cofactor. This first Swiss biomonitoring of a large TEs-panel offers reference values in plasma and in urine for the Swiss population. The results obtained in this study were generally in line with clinical recommendations and comparable to levels reported in other population-based surveys.

Distribution, bioaccumulation, trophic transfer and risk assessment of trace elements in fish from a typical shallow outflow lake basin, China

Distribution, bioaccumulation, trophic transfer and risk assessment of trace elements in fish from a typical shallow outflow lake basin, China

“Hidden” mineralogical-geochemical zonality revealed by the laser microanalysis of sulfides at the Kyzyk-Chadr deposit, Republic of Tyva

A comprehensive study of the Kyzyk-Chadr porphyry copper deposit included determination of the composition and spatial distribution of trace elements in ore-forming sulfide minerals over the ore- hosting rock volume. The study was carried out using the mass spectrometric analysis with laser ablation of the analyzed material. Steady qualitative and quantitative elements of a “hidden” mineralogical and geochemical zonality have been identified, that are expressed in variations in the concentration of trace elements and their ratios in pyrites and chalcopyrites over the volume of the ore-bearing porphyry copper stockwork. The identified regularities correlate with the established centrifugal vector and concentric pattern of the mineralogical ore-metasomatic zonality of the ore deposit.

Chemical Speciation, Leaching Behavior, and Environmental Risk Assessment of Trace Elements in the Bottom Ash from Biomass Power Plant.

Biomass combustion for power generation stands as a pivotal method in energy utilization, offering a promising approach for renewable energy utilization. However, the substantial volume of slag produced by biomass burning plants poses environmental challenges, impeding sustainable energy practices. This article systematically studies the characteristics of ash generated from typical biomass direct combustion power plant ash and analyzes the chemical composition, trace element content characteristics, leaching characteristics, and chemical forms of biomass bottom ash. Furthermore, it assesses the environmental ecology and bioavailability of trace elements in bottom ash using the ecological risk assessment method and RAC method. The results demonstrate that the biomass bottom ash contains plant nutrients, such as K, Ca, Mg, and P, while the content of harmful trace elements is lower than the relevant Chinese standards. In dissolution experiments, the leaching rate of nearly all elements remains exceptionally low, primarily due to the distribution of trace elements within the lattice structure of stable minerals. Trace elements predominantly exist in the residual phase, Cu and Zn primarily found in organic compounds and sulfide bound states, while other elements mostly exist in the form of iron manganese oxide bound states. Ecological risk assessment indicates a significant risk level for Cd, contrasting with the slight risk associated with other elements. RAC results indicated no ecological risk of all of the trace elements. Consequently, the utilization of bottom ash in agricultural and forestry soils is deemed to be viable. These findings serve as a crucial foundation for biomass bottom ash resource utilization and underpin the sustainable utilization of biomass energy.

Determination of the Kinetic Parameters of Thermal Degradation and Hydrodemetallization of a Mixture of the Heavy Fraction of Low-Temperature Coal Tar and Coal Shale

The laws of thermal degradation of the mixture of the heavy fraction of low-temperature coal tar and coal shale were investigated using dynamic thermogravimetry. The kinetic characteristics of the process were determined using various methods, including the Ozawa–Flynn-Wall, Friedman, non-parametric kinetics and Šesták–Berggren methods. It is shown that coal shale initiated changes in the kinetic parameters and decomposition rate of the heavy fraction of coal tar. It was found that a 13% content of coal shale in the mixture led to the maximum rate of weight loss of the heavy fraction of coal tar. A hydrodemetallization kinetic model of the mixture of the heavy fraction of low-temperature coal tar and coal shale is proposed. The kinetic parameters of the hydrodemetallization process were determined; in addition, the rate constants at various temperatures were estimated. The study shows that the distribution of trace elements in the hydrogenate from the initial mixture and in the hydrogenate from the solid residue was characterized by relatively low values of reaction rate constants. The maximum microelement distribution rate was achieved in the hydrogenate solid residue. Energy indicators of activation processes indicated that hydrodemetallization at low temperatures is advantageous from an energy point of view.

Petrography and geochemistry of the Late Devonian Pirispiki Formation in northern Iraq: Implications for Reservoir Characteristics and reconstruction of depositional environments

Petrographic, mineralogical and whole-rock geochemical investigation of siliciclastic and interbedded carbonate rocks from the Devonian Pirispiki Formation in the Nazdur and Ora sections, extreme northern Iraq, were conducted to assess reservoir potential and to study the effects of Devonian deformation (Middle Paleozoic, Caledonian event) on paleogeography and sediment transport in northern Gondwana. Traditional petrographic and scanning electron microscopy, X-ray diffraction and X-ray fluorescence were used. The main results are: sandstones from the Ora section contain significantly more quartz and less lithic fragments than those from the Nazdur section. This variation in sandstones composition may reflect uplifting effect due to Middle Paleozoic event and/or different provenance. The most notable feature of the major and trace elements distribution in the studied mudstones and sandstones is that they are significantly enriched in U but significantly depleted in Zr and Hf. The relative absence of zircon in the samples could account for the depletion of Zr and Hf, two elements linked to zircon. The extremely high U concentrations seen in mudstones and sandstones may relates to precipitation by circulating groundwater where it transported into the sediment prior to cementation. No fauna or flora have previously been reported from the Pirispiki Formation at outcrop in Iraq. The widespread occurrence of shell fragments in sandstones from the Nazdur section combined with the presence of eight dolomite and dolomitic marl beds suggest that the lower and middle parts of this section were deposited in a marine environment. This has not previously been recognized. Previous correlations between the Chalki basalts in the Chia Zinnar anticline and conglomerates in the Ora anticline are not supported by our data. We propose a new correlation between the sections in northern Iraq and those from southern Turkey and western Iraq that suggests that the Pirispiki Formation was deposited during a relative sea-level fall. The paleo-shoreline advanced northward through the study area during the Late Devonian. The Pirispiki Formation has been proposed as a potential reservoir for hydrocarbons sourced in underlying Paleozoic units. However, the sandstones and carbonates investigated during this study have no potential as a reservoir due to pervasive carbonate cements.

Scallop shells as biosorbents for water remediation from heavy metals: Contributions and mechanism of shell components in the adsorption of cadmium from aqueous matrix

To ascertain their potential for heavy metal pollution remedy, we studied the adsorption mechanism of cadmium onto scallop shells and the interactions between the heavy metal and the shell matrix. Intact shells were used to investigate the uptake and diffusion of the metal contaminant onto the shell carbonatic layers, as well as to evaluate the distribution of major and trace elements in the matrix. LA-ICPMS measurements demonstrate that Cd is adsorbed on a very thin layer on the inner and outer surfaces of the shell. Structural and thermal analyses showed the presence of 9 wt.-% of a CdCO3 phase indicating that the adsorption is mainly a superficial process which involves different processes, including ion exchange of Ca by Cd. In addition, organic components of the shell could contribute to adsorption as highlighted by different metal uptake observed for shells with different colours. In particular, darker shells appeared to adsorb more contaminant than the white ones. The contribution of the organic shell components on the adsorption of heavy metals was also highlighted by the element bulk content which showed higher concentrations of different metals in the darker specimen. Raman spectroscopy allowed to identify the pigments as carotenoids, confirmed by XRD measurements which highlighted the presence of astaxanthin phases. The results presented here provide new insights into the Cd adsorption mechanism highlighting the important contribution given by the organic components present in the biogenic carbonate matrix. Furthermore, the high efficiency of Cd removal from water by scallop shells, supported by adsorption kinetic and isotherm studies, has been demonstrated.

Distribution and bioaccumulation of trace elements in two Cyprinidae fish species in the Indus river, Pakistan, including the impact of hydraulic structure on macroinvertebrates' biodiversity

The concentration of trace elements (chromium, lead, zinc, copper, manganese, and iron) was determined in water, sediment and tissues of two Cyprinidae fish species - Labeo rohita and Tor putitora – collected from the eight sampling stations of Indus River in 2022 for four successive seasons (autumn, winter, spring, summer), and also study the present condition of macroinvertebrates after the construction of hydraulic structure. The obtained results of trace element concentrations in the Indus River were higher than the acceptable drinking water standards by WHO. The nitrate concentration ranges from 5.2 to 59.6 mg l−1, turbidity ranges from 3.00 to 63.9 NTU, total suspended solids and ammonium ions are below the detection limit (<0.05). In the liver, highest dry wt trace elements (μg/g) such as Cr (4.32), Pb (7.07), Zn (58.26), Cu (8.38), Mn (50.27), and Fe (83.9) for the Labeo rohita; and Tor Putitora has significantly greater accumulated concentration (Cr, Pb, Zn, Cu, Mn, Fe) in muscle and liver than did Labeo rohita species. Additionally, lower number of macroinvertebrates were recorded during the monsoonal season than pre-monsoon and post-monsoon. Local communities surrounded by polluted environments are more probably to consume more fish and expose them to higher concentrations of toxic trace elements (lead and copper). The findings also provide a basis for broader ecological management of the Indus River, which significantly influenced human beings and socioeconomic disasters, particularly in the local community.

Mo-Mg isotopes trace the role of serpentinite in generating arc magmatism

Serpentinite-derived components play an important role in chemical cycling in subduction zones. However, it is difficult to identify recycled serpentinite in subarc mantle due to the overprinting of other slab components, and how serpentinite contributes to arc magmatism is poorly understood. Here we report Mo and Mg isotopic compositions of Early Paleozoic Qushiang arc mafic rocks in the East Kunlun orogen. The Qushiang mafic rocks have variable δ98Mo values of −0.50‰ to 0.78% and δ26Mg values of −0.31‰ to −0.05‰. These features, combining with arc-type trace element distribution patterns, enriched SrNd isotopes, and variable zircon HfO isotopes, suggest the incorporation of different subducting components in their mantle source. Some mafic rocks show high δ98Mo values together with low Mo/Ce ratios and enriched SrNd isotopes, suggesting the contribution of subducted sediment (SSD)-derived melts. Additionally, light Mo isotopes are also identified in mafic rocks, which are closely related to depleted SrNd isotopes. These features are mainly inherited from the subducted dehydrated altered oceanic crust (SAOC)-derived melts. More importantly, the coexisting and significantly high δ26Mg and δ98Mo values of these rocks could not be explained by the SSD or SAOC components, but require serpentinite components in the subarc mantle source. Our study reveals that combined Mo and Mg isotopic studies are potential tools for tracing serpentinite recycling, and provides new insight into the mechanisms by which different subducting components contribute to arc magmatism.

Evaluate the spatial distribution of trace elements in soil of a karst terrain

Evaluate the spatial distribution of trace elements in soil of a karst terrain

Study on the distribution, enrichment and migration characteristics of trace elements in particulate matter during solid waste combustion

Trace element emissions caused by the entrainment of particulate matter (PM) has led to serious environmental pollution. This research focuses on the distribution, enrichment and migration characteristics of trace elements in different sizes of PM during the typical solid waste combustion. The results indicate that the mass concentration of trace elements in different PM is closely related to their volatility. Volatile trace elements such as Cu, In, Ag, Pb, and Cd tend to distribute in PM1. Higher temperatures facilitate the volatilization of trace elements, promoting their migration and enrichment in finer PM. The removal effect of Si–Al-based additives on trace elements in PM1 decreases with the increase of Si/Al ratio. Among them, the removal efficiency of 5% kaolin is the best. After the addition of Si–Al-additives, Zn and In mainly migrate to PM1-10, while Cu, V, Mo, As, Se, Cr, Ba, Mn, Co, Sr, and Ti mainly migrate to PM10+. Ag, Pb, and Cd migrate to both PM1-10 and PM10+ simultaneously.

Abstract 4949: Multimodal analysis of metals, spatial transcriptomics, and histological structures in colorectal cancer

Abstract Colorectal Cancer (CRC) accounts for nearly 10% of all cancer cases and is the second-leading cause of cancer-related deaths worldwide. The increased incidence of CRC in younger demographics underscores the need for improved screening and prognostication. These enhancements are crucial to augment staging practices which focus on accurate evaluation of local lymph node involvement and distant metastasis. Essential trace elements such as copper and iron within the tumor microenvironment (TME) present novel therapeutic strategies- e.g., copper in cell proliferation/signaling and iron in pro-tumorigenic pathways, amongst other multifaceted roles. Despite advancements in spatial imaging/sequencing for detailed mapping of elemental abundance and gene expression profiles at near-subcellular resolution, the understanding of metal signaling and transport pathways in tumors is limited. This gap highlights the need for sophisticated informatics software for data integration and analysis. We developed a computational workflow for spatial multimodal analysis of elements, genes, cell-types, and histological features, applied to a unique CRC case (pT3) as proof-of-concept. Elemental imaging at 5-micron resolution was performed using laser ablation inductively coupled plasma time-of-flight mass spectrometry (LA-ICPTOF-MS). The 10x Genomics Visium spatial transcriptomic (ST) CytAssist assay captured spatial variation in gene expression within 55-micron spots, with 40X H&amp;E-stained whole slide imaging (Leica Aperio GT450). Cell type proportions within spots were determined through integration of single cell RNASeq. Regions within, around and away from tumor were annotated by a pathologist. ST and LA-ICPTOF-MS were integrated through co-registration software developed at Biomedical National Elemental Imaging Resource. Local Getis-Ord spatial statistics defined hotspots with high elemental concentration. Wilcoxon tests were used to perform differential expression analysis based on metal hotspots, followed by identification of associated biological pathways through Enrichr with Bonferroni adjustment. Preliminary findings revealed distinct trace element distributions in the TME. For instance, Copper was localized within tumor, correlating with pathways related to immune response and activation (overlap=10/89, p&amp;lt;0.0001). Iron was found concentrated at the proliferative front of the tumor, associated with the epithelial to mesenchymal transition pathway and extracellular matrix remodeling (overlap=25/291, p&amp;lt;0.0001), as well as with a mesenchymal phenotype (W=11.7, p&amp;lt;0.0001), identified through cell type deconvolution. Future work will expand on these findings across multiple tissue contexts as means to capture biological processes governing tumor metastasis, recurrence and survival for biomarker discovery and therapeutics development. Citation Format: Aruesha Srivastava, Neha Shaik, Yunrui Lu, Matthew Chan, Alos Diallo, Serin Han, Ramsey Steiner, Tracy Punshon, Brian Jackson, Linda Vahdat, Louis Vaickus, Jack Hoopes, Fred Kolling, Jonathan Marotti, Joshua Levy. Multimodal analysis of metals, spatial transcriptomics, and histological structures in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 4949.

Mineralogical and geochemical characteristics of the Nkoteng-Mbandjock alluvial clays from Sanaga valley deposits (Cameroon, Central Africa): Implications for source weathering and provenance

This research investigates the physico-chemical, mineralogical and geochemical attributes of alluvial clayey sediments in the Nkoteng-Mbandjock regions of the Sanaga valley, Cameroon. The primary objective is to elucidate the source area-weathering and provenance of these sediments. Grain size distribution analyses were conducted using the Robinson-Kӧln's pipetting method. The physico-chemical parameters were evaluated by an HACH-HQ11d brand electric pH meter, while the mineralogical compositions were determined by X-ray Diffraction. Major and trace element concentrations were measured employing X-ray Fluorescence and Inductively Coupled Plasmas-Mass Spectrometry. Textural classification identified the Sanaga valley alluvial clay deposits as predominantly silty clayey and clayey muddy. Geochemical classification diagram positioned them in the shale and Fe-shale fields. Weathering indices of alteration exhibited a consistent trend indicating a high degree of weathering in the source rock. A low Na2O/K2O ratio (average 0.18) and a high Index of Compositional Variability (ICV; average 2.29) suggested immature sediments. Additionally, low SiO2/Al2O3 ratio (average 3.93) implied an origin from stable settings with recycled inputs. These characteristics were further supported by elemental ratios such as Zr/Sc (average 47.12), U/Th (average 0.24) and Th/Sc (average 1.48). Furthermore, indicators like V/Cr (average 1.17), U/Th (average 0.24) and authigenic U (average −1.67) values suggested the deposition of the Sanaga valley alluvial clay under oxic conditions. The collective analysis of major and trace element distribution revealed felsic sources with minimal contributions from mafic rocks. These findings contribute to a comprehensive understanding of the geological processes and conditions influencing the composition and characteristics of the studied alluvial clay deposits in the Sanaga valley.

High-energy SR-XRF Imaging of Cesium and Trace Elements in Mouse Kidneys: Short Communication.

For understanding trace element dynamics in tissues, methods for analyzing elemental distribution and localization without destroying tissue structures and cell arrangements are desired. Synchrotron radiation X-ray fluorescence (SR-XRF) analysis is one of the non-destructive and multi-element simultaneous analyses. The kidney is the major excretion pathway of cesium (Cs) taken into the body, and an understanding of cesium distribution in the kidney would be useful for establishing technology to facilitate the excretion of radioactive Cs from the body due to nuclear disasters. In the present study, the distribution of cesium and trace elements, such as iron (Fe) and zinc (Zn), corresponding to the kidney structure was examined in Cs-administered mice by SR-XRF imaging with high-energy excitation X-rays (40keV). By beam scanning with a 200-µm square beam, clear Cs images corresponding to the renal layer structure were obtained for the renal specimen at the early phase after Cs administration with the mean renal Cs concentration of 24.1 ± 3.2μg/g. Cs was distributed mainly in the medulla and the outer stripe of the outer medulla located in the center area of the kidney. Unlike the Cs distribution, endogenous Fe and Zn tended to be lower in the medulla than in the outer stripe of the outer medulla and the cortex. This method is effective for analyzing Cs distribution because it can simultaneously analyze the distribution of endogenous trace elements.

Size-resolved distribution of trace elements in lysimeter soil solutions under contrasting long-term agricultural management to assess their bioavailability

The chemical species of trace elements (TEs) in agricultural soils is highly variable under diverse conditions, requiring tools with clear resolution and minimal disturbance for exploration. A novel surgical (316L) stainless steel (SS) lysimeter with a 5 μm pore size was developed to collect field soil solutions. The size-resolved distribution of TEs were characterized into total (nitric acid digestion), particulate (0.45–5 μm), dissolved (<0.45 μm), colloidal (1 kDa to 0.45 μm), and mainly ionic (<1 kDa) fractions in the lysimeter soil solutions. Total concentrations of TEs (dry weight basis) in acid digested Gray Luvisolic soils were analyzed. Most TEs in lysimeter soil solutions were present in particulate phases, relevant to their geochemical affinities and occurrences in soil minerals. Among dissolved fractions, As, Ba, Co, Li, Mn, Tl, and V existed as mainly ionic species in the soil solutions. Copper, Pb, Al, Th, and U showed variable associations with dissolved organic matter (DOM) and/or inorganic colloids among agricultural treatments. Inorganic NPKS or NKS fertilizer applications with lower pH (5.25–5.74) enhanced mobility and potential bioavailability of Ba, Co, Li, Mn, and Pb present in mainly ionic species, compared with other locations (pH 5.82–6.37). Manure application exhibited a dual effect, potentially increasing bioavailability for As, Tl, and V due to probably enhanced cation exchange capacity (CEC), while also facilitating specific adsorption of Cu and U on DOM, potentially reducing their bioavailability depending on DOM molecular weight. Colloidal and ionic Al and Th concentrations were higher in forest soils than agricultural soils, with extremely low potential bioavailability of Th attributed to strong precipitation with inorganic colloids and adsorption on DOM. The lysimeter sampling and size fractionation method provided a clear insight into agricultural effects on TE distributions and enhancing understanding of agricultural soil health in terms of TE bioavailability in situ.

Elemental Characterization of Ambient Particulate Matter for a Globally Distributed Monitoring Network: Methodology and Implications.

Global ground-level measurements of elements in ambient particulate matter (PM) can provide valuable information to understand the distribution of dust and trace elements, assess health impacts, and investigate emission sources. We use X-ray fluorescence spectroscopy to characterize the elemental composition of PM samples collected from 27 globally distributed sites in the Surface PARTiculate mAtter Network (SPARTAN) over 2019-2023. Consistent protocols are applied to collect all samples and analyze them at one central laboratory, which facilitates comparison across different sites. Multiple quality assurance measures are performed, including applying reference materials that resemble typical PM samples, acceptance testing, and routine quality control. Method detection limits and uncertainties are estimated. Concentrations of dust and trace element oxides (TEO) are determined from the elemental dataset. In addition to sites in arid regions, a moderately high mean dust concentration (6 μg/m3) in PM2.5 is also found in Dhaka (Bangladesh) along with a high average TEO level (6 μg/m3). High carcinogenic risk (>1 cancer case per 100000 adults) from airborne arsenic is observed in Dhaka (Bangladesh), Kanpur (India), and Hanoi (Vietnam). Industries of informal lead-acid battery and e-waste recycling as well as coal-fired brick kilns likely contribute to the elevated trace element concentrations found in Dhaka.