Distribution Of Trace Elements Research Articles

Trace Elements Spatial Distribution in the Groundwater near the Subarnarekha River Basin - Jamshedpur, India

The present study assessed the spatial distribution of trace elements in the groundwater near the Subarnarekha River Basin - Jamshedpur, India. Half of this city's water need (48.11%) relies on groundwater resources. GIS-based maps were constructed using ArcGIS 10.3 software to describe the spatial distribution of Arsenic (As), Barium (Ba), Cadmium (Cd), Chromium (Cr), Cobalt (Co), Copper (Cu), Iron (Fe), Manganese (Mn), Molybdenum (Mo), Nickel (Ni), Selenium (Se), and Strontium (Sr). The concentration of trace elements was investigated in the groundwater sample of 30 wells by the Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Many samples contained levels of Sr (100 µg/L), Cu (50 µg/L), Co (10 µg/L), and Mn (300 µg/L) that vastly exceeded the limits of the Bureau of Indian Standards (BIS) limit, which may directly affect the human health. The northern region of the study area exhibits higher concentrations of heavy metals. The groundwater table was monitored using a sensor-based water level recorder during pre and post-monsoon seasons. A significant fluctuation of 4.9 meters below ground level (mbgl) was observed, indicating potential water scarcity in the summer. The findings of this study offer valuable insights into various sources of contamination affecting groundwater in river basins within industrial regions.

Tracking HFSE associated with high salinity fluid during HP metamorphism in the Zavkhan Terrane, Western Mongolia

Garnets often exhibit high concentrations of heavy rare-earth elements, which provide crucial insights into element mobility and fluid dynamics during metamorphism. This research reports on the distributions of trace and major elements in garnets from the Khungui eclogite of the Zavkhan Terrane in Western Mongolia. Within the eclogite sample, two types of garnets were identified, featuring dissimilar microstructures and compositional zoning: aggregate-type garnet with asymmetric zoning (Grt1) and euhedral garnet with concentric zoning (Grt2). Previous studies determined that Grt2 formation occurred in the pre-eclogite stage to eclogite facies (2.1–2.2 GPa and 580–610 °C), associated with the infiltration of high-saline fluids. The hexagonal-shaped pseudomorphs of Ti-bearing minerals associated with Grt1 suggest that the nucleation of titanite and garnet was simultaneously accelerated by the destabilization of Ti-augite during pre-eclogite metamorphism. This process could have contributed to the formation of aggregation textures, where Ti-bearing minerals are closely associated with Grt1 in the Khungui eclogite. Based on major divalent elemental composition zoning and trace element characteristics, both Grt1 and Grt2 in the Khungui eclogite are formed simultaneously from the pre-eclogite to eclogite stages. The cores (high Fe + Mg + Mn; Y + REE) of Grt1 and Grt2 are attributed to Rayleigh fractionation or a diffusion-limited uptake process. In contrast, the growth mechanisms of the Grt1 rim and Grt2 rim are distinct during the eclogite stage. The Grt1 rim is explained by a dissolution–reprecipitation, which resulted in the atoll texture observed in Grt1. The Grt2 rim (high Ca; low Y + REE) grew through a mechanism consistent with that of the Grt2 core. The major and trace element zonings of these garnets provide insights into element mobility related to Ti-bearing minerals and infiltration of high salinity fluids at different stages: (1) the mobilization of Ti and V increased under eclogite facies conditions (growth stage of garnet) compared to the pre-eclogite stage, with the mobility of Ti, Nb, Ta elements being pronounced under the exhumation stage (Rt–Ilm–Ttn2), possibly because of the infiltration of high-saline fluids and an increase in temperature, and (2) post-growth compositional modification of Grt1 was induced by a localized transport of Fe, Mg, Mn, and Ca elements in response to the replacement of ilmenite by titanite during decompression (0.1–0.5 GPa and 421–534 °C). The contrasting zoning of garnet in Khungui eclogite indicates dissimilar scales of element mobility under eclogite facies conditions (over a thin-section scale) and during decompression (up to several centimeters or beyond).

Geochemical Characteristics of Melts from the Eastern Volcanic Belt and Sredinny Range of Kamchatka: Analysis of Evidence from Melt Inclusions

We analyzed sets of published data on the composition of glasses from melt inclusions in minerals of volcanics from the Eastern Volcanic Front and Sredinny Range of Kamchatka. A significant difference was revealed between the distribution of silica contents in the rocks and melts: intermediate compositions are most common among the rocks, whereas the melts are dominantly silicic. The distribution of major and trace element was analyzed. It was shown that the contents of some elements are environment-specific (e. g., Nb and light REE). We distinguished trace element ratios in melts that most strongly correlate with the geodynamic setting.

Distribution of trace elements and rare earth elements in coal from the Bhalukasba Surni coal block, Rajmahal coalfield, Eastern India

AbstractExploration of secondary resources for isolation of valuable constituents, such as rare earth elements (REEs) and trace elements (TEs), is of importance owing to the need to identify new domestic sources and reduce reliance on imports. The present study systematically discusses the distribution of REEs and TEs in core samples from the coal block of Bhalukasba Surni {(B1(125 m)-B9 (409 m)} located in Rajmahal coalfield, Jharkhand, India, which has not been investigated previously for its geochemistry. The studied coal samples were found to be enriched in TEs whose abundances were in the order of Mn > Mo > Zr > Ni > Cr > V > Cu > Zn > Pb, and REEs (La, Ce, Pr, Nd, Sm, Eu, Gd, Dy, Er, Tm, Yb, Lu) along with Sc and Y. The average concentration of REEs with yttrium (ΣREY) on an ash basis was 528 ppm, which is significantly higher than the world average for coal ash (435 ppm). Of the samples investigated, B3 (182–184 m) and B8 (396–399 m) demonstrated relatively higher concentrations of potentially economic elements, with B3 containing a higher proportion of middle to heavy REEs Gd, Dy, Ho and Er, and B8 showing relative enrichment in Nd and Y. On dry whole coal basis, B6 (275–278 m) showed a considerably higher concentration of Ge (55 ppm) than other samples, whereas the concentration of Zr varied in the range of 90–160 ppm in the whole coal block. X-ray diffraction studies revealed the presence of quartz, keatite, hematite, zircon, anatase and orthoclase in the coal ash samples prepared at 815 °C. REEs exhibited prominent positive correlation with Al2O3 (0.4 < r > 0.9) which is supportive of their residence in primary clay minerals such as kaolinite and illite-smectite. Additionally, a positive correlation of REEs with P2O5 (0.4 < r > 0.9) suggests their association with phosphate minerals (such as monazite, xenotime, apatite). Positive correlation with TiO2 (r > 0.7) corroborates the possible association of REEs with anatase. The morphology of the coal ash samples viewed in SEM showed the presence of Al2O3 and SiO2 enriched irregular-sponge particles likely derived from partly-fused clay minerals, which accounted for the lower extent of REE encapsulation. The Bhalukasba Surni coal block is potentially of economic importance due to its enrichment in Ge, Zr, and the REEs.

Mineralogical compositions and distributions of trace and rare earth elements in Eocene carbonaceous sediments of Western India: implications for paleoenvironment during peat accumulation

Mineralogical compositions and distributions of trace and rare earth elements in Eocene carbonaceous sediments of Western India: implications for paleoenvironment during peat accumulation

Land-Use Impacts on Soil Erosion: Geochemical Insights from an Urban Drinking Catchment, South-Central Chile

We investigate the influence of land use and land cover (LU/LC) changes on soil erosion and chemical weathering processes within the Nonguén watershed in the Coastal Cordillera of south-central Chile. The watershed is divided into three sub-basins, each characterized by distinct LU/LC patterns: native forest and exotic plantations. A comprehensive geochemical analysis, including trace elements and lithium (Li) isotopes, was conducted on river water and suspended sediment samples collected from streams within these sub-basins to assess how land management practices, particularly plantation activities, influence the geochemical composition of river systems. Our results show that sub-basins dominated by exotic plantations exhibit significantly higher concentrations of major and trace elements in suspended sediments compared to sub-basins dominated by native forests. The elevated trace element concentrations are primarily attributed to increased physical erosion due to forestry activities such as clear-cutting and soil disturbance, which enhance sediment mobilization. Notably, concentrations of elements such as Fe, Al, and As in plantation-dominated sub-basins are raised to ten times higher than in native-dominated sub-basins. In contrast, sub-basins with native forest cover exhibit lower levels of sediment transport and trace element mobilization, suggesting that native vegetation exerts a stabilizing effect that mitigates soil erosion. Despite the substantial differences in sediment transport and element concentrations, Li isotopic data (δ7Li) show minimal fractionation across the different LU/LC types. This indicates that land use changes impact the chemical weathering processes less compared to physical erosion. The isotopic signatures suggest that physical erosion, rather than chemical weathering, is the dominant process influencing trace element distribution in plantation-dominated areas. The study provides critical insights into how forestry practices, specifically the expansion of exotic plantations, accelerate soil degradation and affect the geochemical composition of river systems. The increased sediment loads, and trace element concentrations observed in plantation-dominated sub-basins, raise concerns about the long-term sustainability of forest management practices, particularly regarding their impacts on water quality in urban catchment areas. These results are of significant relevance for environmental management and policy, as they underscore the need for more investigation and sustainable land use strategies to minimize soil erosion and preserve water resources in regions undergoing rapid LU/LC changes.

Spatial distribution, source apportionment, and health risks assessment of trace elements in pre- and post-monsoon soils in the coal-mining region of North Karanpura basin, India

Coal mining activities in the North Karanpura basin have significantly increased the trace element (TE) concentrations in the soil, resulting in soil pollution and potential health risks. To assess this, 113 soil samples, along with coal, shale, and overburden rocks, were collected from open-cast mining areas during pre-monsoon (Pre-M) and post-monsoon (Post-M) seasons. Seasonal analysis revealed higher TE concentrations in the Post-M period, especially in the SE direction, followed by NE and NW, likely due to surface runoff and deposition, demonstrating temporal variability in TE distribution which corroborated from the spatial distribution maps. Positive matrix factorization (PMF) model identified four factors: mixed sources (F1Pre-M: 37.6 %; F4Post-M: 28.9 %), coal-fired emissions (F2Pre-M: 20.5 %; F3Post-M: 26.0 %), overburden rocks (F3Pre-M: 25.5 %; F2Post-M: 16.7 %), and agricultural and lithogenic origin (F4Pre-M: 16.4 %) during the Pre-M period, attributed to coal mining. Post-M sources were similar, but agricultural and lithogenic origins were replaced by atmospheric deposition (F1Post-M: 28.4 %), enhanced by monsoon effects. Carcinogenic risk assessment revealed that As, Cr, and Ni exceeded acceptable levels for children via ingestion, though adults remained within safe limits. Inhalation and dermal contact were also considered, but ingestion posed the highest risk. The hazard index (HI) via ingestion showed that children had an HI of 1.6 in Pre-M, increasing to 2.66 in Post-M, highlighting their potential vulnerability to non-carcinogenic risks, while adults stayed within safe limits. The expansion of mining areas in the study region led to decrease in vegetative areas which could affect agriculture and local communities, raising a comprehensive environmental and public health issues. These results underline the need for implementing effective biannual soil monitoring and mitigation strategies, such as phytoremediation, bioremediation, rock dust remediation, chemical amendments and improved waste management, to reduce TE contamination.

Quantitative characterization on multistage formation of sedimentary pyrite driven by H2S derived from biogenic process in the northeastern Ordos Basin, China

Negative δ34S values of sedimentary pyrite associated with organic matter are routinely assumed to be the result of biogenic process. However, the distribution and evolution of isotopic values mediated by bacteria across sedimentary strata remains poorly understood. Abundant pyrite-rich nodules (PyRNs) are distributed in the bottom of the sandstone unconformably overlying the coal in middle Jurassic strata in the northeastern Ordos Basin, providing a good opportunity to quantitatively characterize the distribution, morphology and compositions of sulfur isotope and trace element of pyrite in the sandstone influenced by organic matter in the coal. A total of 1007 PyRNs occurs within a range of 4 m from the coal. From bottom to top in the sandstone, the shape of the nodule changes from oval to round on the vertical section, and the length and number gradually decrease at the rate of ~45 mm and ~ 228 for every 1 m increase in distance, respectively. Microscopically, pyrite occurs as euhedral crystals, and trace element mapping reveals multistage growth (up to a dozen times) and a marked compositional zoning with respect to Co, Ni, As, Se and Mo. The positive correlation between Co and Ni, with ratios of Co/Ni ranging from 0.06 to 0.45, indicates that Fe and those trace elements are sourced from diagenetic fluid. The organic sulfur in coal, serving as a sulfur source, is reduced by bacteria to generate H232S at a slow reduction rate. The H232S migrates upwards and reacts with Fe to form pyrite in the sandstone, resulting in extremely low δ34S values (from −53.9 to −43.1 ‰), which gradual decrease both from core to margin in individual grain and at the rate of 2.2 to 8.8 ‰ for every 1 m increase in distance away from the coal. This study highlights the significant variability of mineralogical (e.g., number, size, morphology) and geochemical (trace elements, sulfur isotope) characteristics of sedimentary pyrite. Results allow the relation of multistage growth of pyrite to biogenic fractionation, and provide fresh insights into biogenically derived sulfur from coals to be fixed in sandstones, which can be applied to quantitative characterization of formation processes of sedimentary minerals controlled by organic matter in sedimentary environments worldwide.

Trace element and isotope composition of calcite, apatite, and zircon associated with magmatic sulfide globules

AbstractThe formation of volatile-rich phases in magmatic sulfide systems has been interpreted at least in six different ways. The most popular model attributes their origin to secondary processes, mostly due to the presence of serpentine, chlorite, phlogopite, amphibole, and calcite. While chlorite and serpentine are likely to form as alteration products, the other volatile-rich minerals have the potential to originate in a range of ways, including by primary magmatic processes. Based on mineralogical and petrological studies, it was recently suggested that volatile- and incompatible element-rich halos around sulfide globules may form due to the interaction between three immiscible liquids: silicate, carbonate, and sulfide. This hypothesis was confirmed by experimental data revealing the systematic envelopment of sulfide globules by carbonate melt, indicating their mutual affinity. In this study, we present data on isotopic signatures and trace element distributions of three minerals commonly found in spatial association with sulfides—calcite, apatite, and zircon—to address the question of the source and nature of volatiles and other incompatible elements involved in the formation of the halos. Here we compare our new hypothesis with all the previously proposed explanations to show if they can be consistent with obtained results. Our findings indicate that both mantle and crustal sources play a role in the formation of volatile- and incompatible element-rich halos, strongly correlating with sulfur isotope data previously reported for the sulfide globules in the same intrusions. This correlation confirms the shared origin of sulfides, carbonate and fluids during ore-forming processes, ruling out the secondary origin of volatile-rich phases. The isotope and trace element signatures support the newly proposed hypothesis that volatile- and incompatible element-rich halos could have been formed due to the interaction of immiscible sulfide, carbonate, and silicate melts. The volatile-rich carbonate melt could be sourced from the mantle or it could be added from the crust. Regardless of the origin, carbonate melt and sulfide liquid both immiscible with mafic magma tend to stick to each other resulting in the formation of volatile- and incompatible element-rich halos commonly documented in magmatic sulfide deposits.

Revealing Yukon’s hidden treasure: an atomic-scale investigation of Carlin-type gold mineralization in the Nadaleen Trend, Canada

AbstractThe invisible-gold deposits known as Carlin-type are becoming more important as easier to find deposits are progressively depleted. The combination of the invisible nature of the Au in these deposits, as well as the limited surface indicators of these deposits, makes exploration to find new Carlin-type deposits extremely difficult. Comprehensive mineralization models are essential to find new Carlin-type deposits in similar geologic settings. The Nadaleen Trend of Yukon, Canada, is one such district where an improved understanding of this deposit type has led to new discoveries. Previous studies compared and contrasted the tectonic setting, host rock depositional setting, structural preparation, and mineralization style of the Nadaleen Trend with those in Carlin-type localities, Nevada. However, the comparisons at an atomic scale, between Carlin-type Au deposits in the Nadaleen Trend and those in Nevada, has yet to be investigated. This study fills this knowledge gap by combining high resolution microanalytical techniques with atom probe tomography to examine the distribution of Au and other trace elements in the Nadaleen Trend, compare them to a representative Carlin-type deposit in Nevada (Turquoise Ridge), and determine how widespread the mineralization model is. Our findings show that in the Nadaleen Trend, as in Nevada, Au is generally directly linked with As at the macro to atomic scale, and is incorporated into As/Au rich overgrowths on sedimentary/diagenetic pyrite. Gold-rich pyrite rims in the Nadaleen Trend are generally smaller than those found in Nevada (0.5–2 µm vs > 10 µm), although the ore grades appear comparable. We find that the Au in the pyrite of the Nadaleen Trend is homogenously distributed (i.e. lattice bound) at the atomic scale, but that there is a notable enrichment of As surrounding individual Au atoms. These findings are in agreement with those from previous work on a representative deposit in Nevada, and support the assertation that As is the key ingredient in facilitating the incorporation of Au into the pyrite lattice. Arsenic as an essential component in the trapping mechanisms of Au in CTG deposits, is something that has been as to yet underappreciated in the current models of CTG deposit formation.

Bioaccumulation Patterns of Trace Elements in Jellyfish (Crambionella orsini and Cassiopea andromeda) from Northwestern Coastal Waters of the Persian Gulf

Trace element pollution in the Persian Gulf originates from industrial activities, urbanization, shipping, and oil extraction, leading to accumulation in sediments, water, and marine life such as jellyfish. This study investigated trace element bioaccumulation in two jellyfish species, Crambionella orsini and Cassiopea andromeda, across different locations. Jellyfish samples were collected from the Mahshahr and Dilam ports, and their trace element concentrations were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The study revealed no significant differences in trace element concentrations between C. orsini and C. andromeda. However, levels of copper, iron, manganese, and nickel were significantly higher in specimens from Mahshahr compared to those from Dilam. No significant differences were observed for cadmium, mercury, vanadium, tin, magnesium, and selenium across sites. Lower concentrations of lead, arsenic, zinc, and cobalt were found in C. orsini from Dilam compared to Mahshahr. Additionally, the study found no significant correlation between trace element concentrations in the water and their accumulation in jellyfish bodies. These findings offer valuable insights into the distribution and bioaccumulation of trace elements in jellyfish populations across different marine environments in the Persian Gulf.

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.

Do probiotics and iron supplementation have any impact on element distribution in rat kidneys? – bioimaging by laser ablation inductively coupled plasma mass spectrometry

This study investigates the influence of multistrain probiotics and iron supplementation on the distribution and interaction of trace elements in the kidneys of Wistar rats using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) bioimaging. Forty 6-week-old female Wistar rats were divided into five groups, each fed an AIN-93 M diet with varying additions or deficiencies of iron and probiotics, which included a control, an iron-deficient diet, an iron-deficient diet with probiotics, an iron-deficient diet with iron supplementation, and an iron-deficient diet with both probiotics and iron supplementation. The obtained two-dimensional maps of the distribution of elements reveal distinct locations of Cu, Fe, Mn, and Zn in specific tissues of rat kidneys. Specifically, Cu and Fe were co-localized in the renal cortex, while Zn was mostly absent from regions where Cu and Fe accumulated. Fe supplementation alone increased Fe in the renal cortex, while probiotics enhanced this effect, suggesting a synergistic role in Fe absorption. The total content of elements in the kidneys of all groups was determined after digestion: Cu 13.3–24.7 mg kg−1, Fe 218–509 mg kg−1, Mn 0.87–1.29 mg kg−1, and Zn 28.6–40.1 mg kg−1. Competitive interactions among Cu, Fe, and Zn were observed, with probiotics modulating their concentrations and distribution, highlighting their role in trace element homeostasis. Our research provides insights into the interactions between dietary supplements, probiotics, and trace element distribution in kidneys, paving the way for targeted nutritional interventions. This study highlights the need for further research on trace element functions in organisms and their impact on health.

U and Th zonation in apatite observed by synchrotron X-ray fluorescence tomography and implications for the (U–Th) ∕ He system

Abstract. Synchrotron X-ray fluorescence microtomography can non-destructively image the three-dimensional distribution of several trace elements in whole apatite crystals at the resolution of 1 µm3. This allows for precise determination of the physical geometry of a crystal and the quantification of the relative abundance of the radioactive parent nuclides uranium and thorium with high fidelity. We use these data to develop a more precise alpha ejection correction for (U–Th) / He thermochronology and high-resolution models of apatite crystals that are the foundation for a new generation of three-dimensional diffusion modeling. The application of synchrotron radiation to non-destructive imaging of minerals used for geochronology sheds light on causes of long-standing unresolved problems in the field that are rooted in previously unmeasurable parent nuclide zonation, especially the pervasive overdispersion of single-crystal ages.

Experimental constraints on the role of temperature and pyrogenic mineral assemblage in wildfire-induced major and trace element mobilisation

Wildfires impact a large and increasing proportion of the Earth’s surface. With documented soil surface temperatures of up to ∼850 °C, wildfires may fundamentally alter the mineralogy and geochemistry of soils and regolith, more conventionally thought to be dominated by low temperature weathering processes. Here we use an experimental approach to test the effect of temperature on the formation of pyrogenic minerals, and on the distribution and mobility of major, trace and rare earth elements following post-fire chemical weathering. We focus on ferruginous nodules, common Fe-oxide cemented components of soils, which transform from non-magnetic to maghemite-bearing, magnetic nodules under wildfire conditions. These transformations provide a valuable record of fire impacts and facilitate the study of thermal processes and element mobility. Our results show heating produces a typical pyrogenic mineral assemblage of hematite, maghemite, metakaolin and transition alumina. At 900 °C the high temperature Fe2O3 polymorph luogufengite forms, which has never been reported in natural fire-affected substrates and therefore places an upper boundary on palaeowildfire temperatures at the soil-fire interface. Chemical leaching, employed to simulate the impacts of post-fire weathering, demonstrates that formation and subsequent breakdown of these pyrogenic minerals results in increased mobility of several elements including Li, Si, Sc, Cr, Co, Cu, Zn, Rb, Cs, La, Pb and U. Further, we propose that incongruent dissolution of pyrogenic metakaolin may be responsible for the formation of fusic material, an aluminous cement commonly found in soils. We conclude by discussing the significance of these results for the release of potentially toxic metals following a fire, identify trace elements that have the greatest potential to be used as palaeowildfire geochemical proxies (decreased alkali metal concentrations, decreased U/Th ratios, and decreased La compared to other rare earth elements), and the potential impact of wildfire on global geochemical cycles.

Influence of habitat utilization strategies on trace element signatures in egg contents of green turtles nesting on Xisha Islands, South China Sea

Habitat utilization significantly influences the accumulation of chemical pollutants, including trace elements (TEs), in the tissues of large marine organisms. Previous research has demonstrated that sea turtles nesting in the same location may employ distinct foraging strategies. This study investigated the influence of habitat use strategies on the concentrations of 16 TEs in the eggs of green turtles (Chelonia mydas) nesting on the Xisha Islands. The analysis incorporated stable carbon (δ13C) and nitrogen (δ15N) isotopes, as well as characteristic elements. Additionally, inter-relationships between TEs were examined. The nesting female green turtles were categorized into two foraging groups based on isotopic signatures, namely oceanic (δ13C values: −21.5 to −17.0 ‰; δ15N values: 7.10 to 12.5 ‰) and neritic (δ13C values: −14.4 to −9.95 ‰ and δ15N values: 5.10 to 10.0 ‰). Different TE patterns were observed in the egg contents of these two groups. The neritic group exhibited elevated levels of V and Cu, which positively corrected with δ13C values. Conversely, the oceanic group displayed higher levels of Zn, Cd, Se, Sn, As and Hg, which positively associated with δ15N values. This distribution pattern is attributed to variations in background TE concentrations in the respective foraging habitats. Additionally, prey items and trophic levels of green turtles may contribute to the observed inter-group differences in TE concentrations (e.g. Zn, As, Se, Sn) found in their eggs, warranting further research. This study provides valuable information about habitat utilization patterns and TE distribution in green turtles nesting on the Xisha Islands. The findings enhance our understanding of TE accumulation mechanisms in turtle tissues and eggs, which is significant for the conservation of this endangered species, the green sea turtle.

Geochemical baseline values determination and spatial distribution of trace elements in topsoils: An application in Sicily region (Italy)

This study proposed an approach to determine the geochemical baseline values in topsoils. The chosen study area is Sicily (Italy), a region characterized by significant lithological heterogeneity. Eighty-three topsoil samples were collected at several sites away from potential anthropogenic pollution sources. The concentrations of potentially toxic elements (As, Cd, Cr, Cu, Mo, Pb, Sb, V, and Zn) were quantified via inductively coupled plasma (ICP-MS). The elements showed median concentrations in the range 68.8–0.23 μg g−1 and the trend of abundance was: Zn > V > Cr > Cu > Pb > As>Mo > Sb > Cd. Regional geochemical baseline values for trace elements were determined using statistical methods (Me±2MAD; P95 and UTL95–95). The use of UTL95–95 was found to be the most suitable, obtaining appropriate geochemical baseline values for the entire region, regardless of lithology. The spatial distribution of the elements was determined by stochastic simulations on a convex-concave boundary with a resolution of 5 km, obtaining detailed geochemical maps that predict the distribution of concentrations of each element even in unsampled areas. The results of this study provide a methodology for a more correct assessment of the environmental contamination status of soils.

Co-tracing of groundwater emerging and conventional contaminants in karst area of Southwest China: Distribution, source, and source-specific health risks

Groundwater pollution, especially the co-contamination of emerging contaminants (ECs) and conventional contaminants, is increasingly recognized as a critical global concern. Karst aquifers are found throughout the world, providing critical water sources and sustaining rivers and ecosystems, and are particularly vulnerable to pollution. In this study, the characteristics of the contamination, potential sources, and source-specific health risks related to ECs and trace elements (TEs) in groundwater were investigated in Guiyang (a typical karst city in southwest China). The distribution of TEs followed a descending pattern from urban to suburban to rural areas. Interestingly, the median concentrations (217 ng/L) of Caffeine (CAF) in rural areas surpassed those in urban areas (145 ng/L) and even exceeded these in densely populated areas. Additionally, ECs and TEs in groundwater are significantly influenced by population density and land use types within a 1000-meter buffer zone around the sampling sites. Hierarchical cluster analysis and positive matrix factorization suggested that five principal sources of contamination were identified: domestic wastewater (29.7 %), industrial production (25.2 %), agricultural activities (16.3 %), natural and industrial sources (14.9 %), and pharmaceuticals (13.9 %). Monte Carlo simulations revealed that the non-carcinogenic risks to children in urban areas are significant, with 30.0 % of these risks exceeding the safety threshold. Source-specific health risk assessments indicated that industrial production is the primary source of risk. Furthermore, this study introduces a co-tracing method to trace the sources of groundwater contamination in karst systems. The co-tracing method based on the ECs and TEs allows for a deeper understanding of contaminant transfer and its fate in karst groundwater.

Distribution and contamination of trace elements in surface sediments of the Yellow River Estuary and Laizhou Bay, China

Abstract This study analyzed trace elements (Cu, Pb, Zn, Cr, Cd, As, and Hg) in 42 surface sediment samples collected from the Yellow River Estuary and Laizhou Bay to characterize their spatial distributions and pollution statuses. Determination of trace elements was carried out by ICP-MS for Cu, Pb, Zn, Cr, and Cd, and by AFS for As and Hg. The results showed that the average concentrations for Cu, Pb, Zn, Cr, Cd, As, and Hg were 13.21 mg kg−1, 10 .61 mg kg−1, 21 .03 mg kg−1, 24 .41 mg kg−1, 0.14 mg kg−1, 6.47 mg kg−1, and 14.15 μg kg−1, respectively. All the trace elements were classified in the first-class sediment according to the Chinese national standard ‘Marine Sediment Quality’. The higher concentrations and pollution levels were found in the eastern Yellow River estuary which due to inputs from the Yellow River, and northeastern Laizhou Bay which could be attributed to the impacts of human activities at Longkou Port. This study has important scientific value for further understanding the source-sink effects of pollutants and regional environmental effects of heavy metals.

Trace element analysis and luminescence behavior of quartz in pegmatites of the Tørdal Region, Norway

This publication presents a study on the mineral chemistry and luminescence properties of quartz samples from pegmatites of the Tørdal region in Norway. A total of 12 samples were analyzed using Secondary Ion Mass Spectrometry (SIMS), Electron Paramagnetic Resonance Spectroscopy (EPR), and Cathodoluminescence (CL) to gain insights into their trace element concentration and distribution as well as their luminescence behavior. The samples are characterized by different Cl emissions at 450 nm, 500 nm 650 nm and an additional shoulder at 390 nm, which is only partially visible due to the absorption of the glass optics. Of these luminescence bands, the 500 nm band is the most dominant in most samples and it is characterized by an initial blue-green luminescence, which is not stable under electron irradiation. Moreover, it is characterized by a heterogeneous distribution within the samples. This luminescence can be mostly assigned to [AlO4/M+]0 defects, with charge compensation mostly achieved by Li+. Analyses by EPR spectroscopy prove the dominance of structurally bound Al, Li, and Ti ions in the investigated samples. Further analyses using SIMS mapping demonstrate that Na and K are mainly bound to micro fractures or inclusions, suggesting a limited role in the compensation of the luminescence centers. Additionally, the SIMS mappings show that some samples contain Al-rich clusters of 10 to 20 μm in diameter, whereas other trace elements are characterized by a homogeneous distribution. These clusters correspond to bright luminescence areas in size and shape and could potentially indicate H+ compensated [AlO4/M+]0 defects.