Trace Element Concentrations Research Articles

Industrial Deportment of Minor and Trace Elements in Direct Nickel Matte Smelting

A sampling campaign was carried out at an industrial nickel flash smelter with the aim of evaluating the trace element distributions along the smelting line from raw materials to high-grade nickel matte and discard slag. The industrial technology was direct-to-nickel matte smelting without conventional Peirce–Smith converters, thus having two different nickel mattes as smelting products and feeds in the refinery: the sulfidic low-iron nickel matte from smelting furnace and the low-sulfur electric furnace matte from slag cleaning. Major and trace element concentrations were obtained from the solidified samples by electron probe microanalysis and laser ablation–inductively coupled plasma–mass spectrometry. Due to the industrial sampling environment, i.e., the slow cooling rate of the samples, not all the trace element concentrations were able to be measured at the lowest detection limits of the techniques used in some of the phases formed after cooling. However, the obtained results and element distribution coefficients were in good agreement with equilibrium values published in the literature.

PM10-bound trace elements in pan-European urban atmosphere

Although many studies have discussed the impact of Europe's air quality, very limited research focused on the detailed phenomenology of ambient trace elements (TEs) in PM10 in urban atmosphere. This study compiled long-term (2013–2022) measurements of speciation of ambient urban PM10 from 55 sites of 7 countries (Switzerland, Spain, France, Greece, Italy, Portugal, UK), aiming to elucidate the phenomenology of 20 TEs in PM10 in urban Europe. The monitoring sites comprised urban background (UB, n = 26), traffic (TR, n = 10), industrial (IN, n = 5), suburban background (SUB, n = 7), and rural background (RB, n = 7) types. The sampling campaigns were conducted using standardized protocols to ensure data comparability. In each country, PM10 samples were collected over a fixed period using high-volume air samplers. The analysis encompassed the spatio-temporal distribution of TEs, and relationships between TEs at each site. Results indicated an annual average for the sum of 20 TEs of 90 ± 65 ng/m3, with TR and IN sites exhibiting the highest concentrations (130 ± 66 and 131 ± 80 ng/m3, respectively). Seasonal variability in TEs concentrations, influenced by emission sources and meteorology, revealed significant differences (p < 0.05) across all monitoring sites. Estimation of TE concentrations highlighted distinct ratios between non-carcinogenic and carcinogenic metals, with Zn (40 ± 49 ng/m3), Ti (21 ± 29 ng/m3), and Cu (23 ± 35 ng/m3) dominating non-carcinogenic TEs, while Cr (5 ± 7 ng/m3), and Ni (2 ± 6 ng/m3) were prominent among carcinogenic ones. Correlations between TEs across diverse locations and seasons varied, in agreement with differences in emission sources and meteorological conditions. This study provides valuable insights into TEs in pan-European urban atmosphere, contributing to a comprehensive dataset for future environmental protection policies.

Deciphering the benefits and intensity levels of primary metabolites from Allium macrostemon Bunge and Allium chinense G. Don

BackgroundAllii Macrostemonis Bulbus is also named Xiebai in China. It is an edible vegetable, and also a famous herb for treating coronary heart disease. Allium chinense G. Don (ACGD) and Allium macrostemon Bunge (AMB) are it botanical sources. The aim of this study was to explore the cardioprotective effects, and decipher the visual spatial distribution and absolute content of primary metabolites derived from these two herbs.MethodsH9c2 cells were used to perform the hypoxia-reoxygenation (H/R)-induced myocardial injury model. Their protective effects were evaluated by apoptosis levels. Furthermore, matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry imaging approach (MALDI-TOF MSI) was carried out to present the spatial location of primary metabolites including fatty acids, amino acids, carotenoids, and vitamins in these two Allium herbs. Multiple analytical methods were applied to perform quantitative analysis of these primary metabolites in AMB and ACGD bulbs by liquid chromatography tandem mass spectrometry (LC–MS).ResultsFirst, AMB and ACGD extracts both could increase the cell viability in H9c2 cells, and attenuate H/R-induced injury. They markedly decreased apoptosis, accompanied by activating the BCL-2/BAX pathway. Further, MALDI-TOF MSI-based relative quantification results showed several amino acids, fatty acids, carotenoids, and vitamins were largely rich in the tunics and outside scales of fresh bulbs, while some primary metabolites were abundant in their developing flower buds. Absolute quantification results displayed total contents of amino acids in ACGD bulbs were higher than those in AMB, while total contents of fatty acids and vitamins provides opposite trends in these two Allium herbs. The total contents of carotenoids and trace elements showed no significant differences between AMB and ACGD samples.ConclusionsThis study would be helpful to understand the myocardial injury protection effects of these two Allium herbs, and the spatial accumulation and quantitative content levels of their main nutrients.Graphical

Variations in the oxidation potential of PM2.5 in an old industrial city in China from 2015 to 2018

PM2.5 pollution in China has decreased dramatically, but how its health effects change is not clear. There are 120 old industrial cities in China, where the sources, composition, and health effects of PM2.5 may be significantly different with other cities. Huangshi, an old industrial city in central China, underwent intense green transformations from 2015 to 2018. In this study, we collected ambient PM2.5 samples in 2015 and 2018 at an urban site in Huangshi. The average PM2.5 concentration decreased from 83.44 ± 48.04 μg/m3 in 2015 to 68.03 ± 39.41 μg/m3 in 2018. However, the average volume-normalized dithiothreitol (DTTv) of PM2.5 increased from 1.38 ± 0.45 nmol/min/m3 to 2.14 ± 1.31 nmol/min/m3 and the DTT normalized by particulate mass (DTTm) increased from 20.6 ± 10.1 pmol/min/μg to 40.07 ± 21.9 pmol/min/μg, indicating increased exposure risk and inherent toxicity. The increased toxicity of PM2.5 might be related to the increased trace elements (TEs) concentrations. The positive matrix factorization and multiple linear regression methods were employed to quantify the contributions of emission sources to PM2.5 and DTTv. The results showed that the contribution of coal combustion, industry, and dust to PM2.5 decreased significantly from 2015 to 2018, while that of vehicle emission and secondary sources increased. Despite the decreased fraction of coal combustion and industry sources, their contribution to DTTv increased slightly, which was caused by the increased intrinsic toxicity. The increased intrinsic toxicity was possibly caused by increased TEs, such as Pb, Cu, and V. Besides, the contribution of vehicle emission to DTTv also increased. Overall, these results provide valuable insights into the effectiveness of controlling strategies in reducing particulate health impacts in old industrial cities, and stress the necessity of formulating toxicity-oriented controlling strategies, with special attention to TEs from coal combustion and industry sources as well as vehicle emissions.

The Assessment of Selenium, Aluminum, and Zinc in Children with Autism Spectrum Disorder.

ASD is a complex condition defined by many causes, one of them being excessive concentrations of necessary and harmful chemicals in children. The serum, hair, and nails of children with ASD have lower levels of critical trace elements, according to studies. It is quite obvious that bio elements are involved in physiology and pathophysiology. Thus, this study examined trace element contents in serum samples from children with autism spectrum disorder (ASD), specifically zinc (Zn), aluminum (Al), and selenium (Se). The study also looked for links between trace element levels and autistic severity. The study included 47 children with autism spectrum disorder, and the Gilliam's Scale was used for severity. The study also included 53 healthy kids with age and gender-matched with those of ASD. For serum trace element analysis, graphite furnace atomic absorption spectrophotometry was used. The study found significant decreases in selenium and zinc concentration (OR, 5.25; CI, 1.96 ~ 14.08; p < 0.001) and increases in aluminum level (OR, 39.34; CI, 8.20 ~ 89.45; p < 0.001) in children with ASD compared to the control group. The area under the curve (AUC) values of 0.85 for Se, 0.98 for Al, and 0.7 for Zn showed high sensitivity and specificity for all parameters. Results indicate a strong positive connection between ASD and their levels of selenium (Se) and zinc (Zn) (β, 0.48; CI, 0.280 ~ 0.679; p < 0.001 and β, 0.31; CI, 0.10 ~ 0.52; p = 0.005). There is a negative correlation between ASD and aluminum (Al) (β 0.83; CI, 0.71 ~ 0.95; p < 0.001). This element may be a biomarker for autism in youngsters. High odds ratio (OR) values indicate trace element risk in autistic children.

Dissolved and particulate metals and metalloids in the eastern Mekong Delta, Vietnam

The article reports the concentration levels of particulate and dissolved metals and metalloids (Be, Se, Sb, Tl, V, Pb, Cd, Cu, Zn, Ni, Mo, Co, Fe As, Ag) in the eastern region of the lower Mekong Delta (Vietnam) in order to assess their possible influence on the environmental quality of river water. To measure the concentrations of trace elements, a mass spectrometric method was used. The critical particulate elements had included V, Cu, Ni, Co, Pb, Cd and potentially critical – Mo, Ag, Se, Tl. In the dissolved phase these were Cu, Zn, and Pb, Cd, Co, Ag, Se respectively. The high accumulation ability of studied elements to suspended particulate matter (102–107) suggests their important role in the distribution of elements. The water salinization boundary in the riverbeds of the delta moves upstream 30–50 km further in the dry season compared to the wet season.

Tracking Trace Elements Found in Coffee and Infusions of Commercially Available Coffee Products Marketed in Poland.

Coffee is a source of micronutrients, including iron, zinc, copper, and manganese. It may also contain toxic metals, such as lead and cadmium. The effects of coffee on the human body may vary depending on its composition. The objective of this study was to assess the quality of ground and instant coffee with regard to the content of selected trace elements. The concentrations of trace elements, including copper, iron, manganese, and zinc, were determined by ICP-AES, while the levels of lead and cadmium were quantified by GF-AAS methods. Furthermore, the degree of coverage of the recommended intake of elements and the risk assessment for human health (EDI, THQ, PTMI, and TWI) were determined. Our findings indicate that the consumption of a cup of coffee provides the body with only small amounts of these elements. A coffee prepared from 6.33 g of ground coffee beans provides 0.08-1.52% of the RDA value, while a coffee prepared from 6.33 g of instant coffee provides 0.46-13.01% of the RDA, depending on the microelement. The low transfer to the brew (Pb = 7.1%; Cd = 30.0%) of the analyzed ground coffees renders them safe for the consumer, even at a consumption of six cups per day. The percentage of benchmark dose lower confidence limit (BMDL0.1) in the case of lead did not exceed 0.9%. The estimated value did not exceed 0.2% of the provisional tolerable monthly intake of cadmium (PTMI). None of the analyzed coffees exhibited any risk regarding the trace elements.

Correlation Between Severity of Schizophrenia with Certain Trace Elements and TNF-α Gene Expression and Its Circulatory Level in the Population of Western India.

This cross-sectional study aimed to assess serum trace element (TE) concentrations, TNF-α gene expression, protein levels in schizophrenia (SZ) patients, and their correlation with disease severity measured by Positive and Negative Syndrome Scale (PANSS) scores. Forty SZ cases and 40 healthy controls aged 18-60 were recruited. Forty (n = 40) cases who meet ICD-10 criteria for SZ and 40 (n = 40) healthy individuals (controls) between 18 and 60years of age were recruited in the study. Sandwich enzyme-linked immunosorbent assay (ELISA) and RT-qPCR (quantitative real-time PCR) were used to estimate pro-inflammatory cytokine TNF-α protein and gene expression. Inductively coupled plasma-optical emission spectroscopy (ICP-OES) and graphite furnace atomic absorption spectroscopy (GFAAS) were used to assess serum levels of trace elements (TEs): Fe, Zn, Cu, Mg, and Se. Compared to healthy controls, cases had significantly higher levels of TNF-α protein, as well as Fe, Cu, and Se (p < 0.05). Cu correlated positively with TNF-α protein level (rho = 0.234; p = 0.048) and gene expression (rho = 0.333; p = 0.041) and with PANSS negative (rho = 0.531), general (rho = 0.643), and total (rho = 0.541) scores. Additionally, Zn negatively correlated with serum Mg (rho = - 0.426, p < 0.01) and positively with serum Se (rho = 0.343, p < 0.05). In conclusion, elevated Cu levels could potentially contribute to the development of SZ. Elevated Cu levels in cases and their correlation with the TNF-α gene and protein and PANSS score indicate Cu's potential role in exacerbating SZ severity through inflammatory cytokines. This suggests the involvement of metals and cytokines in the pathophysiology of SZ.

GOLD ENRICHMENT MECHANISM IN MID-OCEAN RIDGE HYDROTHERMAL SYSTEMS: AN EXAMPLE FROM THE LONGQI HYDROTHERMAL FIELD ON THE ULTRASLOW-SPREADING SOUTHWEST INDIAN RIDGE

Abstract In mid-ocean ridge (MOR) hydrothermal systems, the gold grade of sea-floor massive sulfides (SMSs) is negatively correlated with the spreading rate of the ridge. Previous investigations have addressed the distribution of gold in sulfides from hydrothermal fields hosted by ultramafic rocks. In contrast, the gold enrichment mechanisms in sulfides from hydrothermal fields hosted by mafic rocks in ultraslow-spreading ridge environments are less well constrained. The basalt-hosted Longqi hydrothermal field, located on the classic ultraslow-spreading Southwest Indian Ridge, provides an opportunity to examine gold enrichment mechanisms in such an environment. Two ore-forming stages are identified in chimney fragments: anhydrite + barite + colloidal/porous pyrite (Py1) + marcasite + fine-grained sphalerite (stage 1); euhedral-subhedral pyrite (Py2) + coarse-grained sphalerite + chalcopyrite + isocubanite (stage 2). Py1 is usually overgrown by marcasite, which is in turn enclosed by Py2. Py2 coexists with coarse-grained sphalerite and chalcopyrite. Abundant native gold nanoparticles occur in Py1 or at the transition zone between Py1 and Py2. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis suggests that Py1 contains higher Mo, V, Sn, and Pb and lower As, Co/Ni, and Se/Tl values compared to Py2. In situ LA-multicollector (MC)-ICP-MS analyses show that Py1 has a higher mean δ34S (+7.1‰) value than Py2 (+6.6‰). Sulfur primarily derives from MORB and seawater sulfate, of which the proportion of sulfur from seawater sulfate is between 20.5 and 47.6%. Textures, mineral assemblages, and trace element contents of sulfides indicate that the degree of mixing between hydrothermal fluids and seawater decreases as the chimney grows and is accompanied by a gradual increase in temperature. Based on data compiled from 41 hydrothermal fields hosted by basalt, the large range of sulfide δ34S from slow- and ultraslow-spreading MORs may be attributed to the wide range of sulfur sources (e.g., leaching from MOR basalt, thermochemical reduction of seawater sulfate, magma degassing, and bacterial activity), fluid-basalt interaction, and redox state (CH4/CO2 ratios). Prolonged fluid-basalt interaction and the type of chimneys, such as beehive chimneys, may lead to higher gold grades in hydrothermal fields. Moreover, low H2S content may be an important contributor to gold enrichment in basalt-hosted SMS deposits in ultraslow-spreading MOR environments.

Assessing the impacts of trace element contamination on the physiology and health of seabirds breeding along the western and southern coasts of Portugal

Coastal seabirds serve as sentinels of ecosystem health due to their vulnerability to contamination from human activities. However, our understanding on how contaminant burdens affect the physiological and health condition of seabirds is still scarce, raising the uncertainty on the species' vulnerability vs tolerance to environmental contamination. Here, we quantified 15 Trace Elements (TE) in the blood of gull (yellow-legged gull Larus michahellis and Audouin's gull Ichthyaetus audouinii) and shearwater (Cory's shearwater Calonectris borealis) adults, breeding in five colonies along the Portuguese coastline. Additionally, stable isotopes of carbon (δ13C) and nitrogen (δ15N) were quantified to elucidate foraging habitat and trophic ecology of adults, to identify potential patterns of TE contamination among colonies. We used immuno-haematological parameters as response variables to assess the influence of TE concentrations, stable isotope values, and breeding colony on adults' physiological and health condition. Remarkably, we found blood mercury (Hg) and lead (Pb) concentrations to exceed reported toxicity thresholds in 25% and 13% of individuals, respectively, raising ecotoxicological concerns for these populations. The breeding colony was the primary factor explaining variation in five out of six models, underlining the influence of inherent species needs on immuno-haematological parameters. Model selection indicated a negative relationship between erythrocyte sedimentation rate and both Hg and selenium (Se) concentrations, but a positive relationship with δ13C. The number of immature erythrocyte counts was positively related to Hg and Se, particularly in yellow-legged gulls from one colony, highlighting the colony-site context's influence on haematological parameters. Further research is needed to determine whether essential TE concentrations, particularly copper (Cu) and Se, are falling outside the normal range for seabirds or meet species-specific requirements. Continuous monitoring of non-essential TE concentrations like aluminium (Al), Hg, and Pb, is crucial due to their potential hazardous concentrations, as observed in our study colonies.

Aquatic food safety on e-commerce in China: profiles of trace elements in tilapia products and implication for general population exposure

The Internet has facilitated the sale of aquatic products on e-commerce platforms such as Taobao, Tmall, Jingdong, allowing people to meet their daily nutritional needs without leaving home. While e-commerce platforms have facilitated people's lives, they have also made the risk of food contamination difficult to control. Consequently, it is necessary to assess the risk of food sold by e-commerce. Trace elements contamination in aquatic food is a worldwide issue. In this study, an automated tool was written in Python to search 11,596 information about tilapia products sold on e-commerce platforms, and collect samples based on the above data. The content of trace elements in representative samples sold on these e-commerce platforms was quantitatively analyzed (n=147). The results indicate that over 90 % of the samples contained more than 9 trace elements. The levels of trace elements in canned tilapia were significantly higher than those in frozen and pickled tilapia (p<0.05). Based on target hazard factor assessment method, arsenic was found to have the highest potential dietary risk (THQ>1). Additionally, the risk of intake for children was found to be 2–3 times higher than that for adults. It is suggested that children limit their intake of canned tilapia, pickled tilapia, and frozen tilapia fillets to 0.05 kg/day, 0.17 kg/day, and 0.14 kg/day, respectively. The high detection frequency of trace elements provides a snapshot of the prevalence of trace elements in tilapia products sold on Chinese e-commerce platforms.

Assessment of Amphibola crenata as a bioindicator of estuarine trace element pollution using biochemical and physiological endpoints

To assess its utility as a bioindicator of estuarine contamination, Amphibola crenata, a pulmonate mud snail, was collected from 17 estuaries in New Zealand. Whole-body soft tissue trace element concentrations were measured via quadrupole inductively coupled plasma mass spectrophotometer (Q-ICP-MS) and were found to be significantly positively correlated with sediment trace element profiles for arsenic, copper and lead. Snails from polluted estuaries generally displayed higher ammonia excretion rates, elevated whole-body soft tissue catalase activity and lipid peroxidation compared to snails from reference sites. Across all sites haemolymph glucose was positively correlated with the tissue burdens of arsenic, copper, nickel and zinc, while haemolymph protein was negatively correlated with arsenic, cadmium and zinc soft tissue concentrations, indicative of altered energy metabolism associated with trace element contamination. Overall, sites were distinguishable by application of the array of measures employed. Our findings suggest that gastropods have significant value as bioindicators of estuarine health.

Bioaccumulation of Arsenic, Cadmium, Chromium, Cobalt, Copper, and Zinc in Uroteuthis edulis from the East China Sea.

In this study, the concentrations of trace elements (TEs) in Uroteuthis edulis caught from the East China Sea were determined. There were significant differences between TE concentrations in different body parts. Cu, Zn, and Cd were the most concentrated in the digestive glands and the concentrations of Cr and Co were highest in the gills. No significant differences in concentrations were shown between these tissues. In the four tissues analyzed, the mantle recorded the highest proportion of elemental load, while the digestive glands and gills had the lowest proportions. After maturity, TEs in the mantle showed no significant differences. In the digestive gland, the concentrations of all elements, except Zn, were significantly increased. The gonads illustrated apparent increases in the concentrations of Cr, Cu, and As. In the gills, the concentrations of Co and As were markedly increased.

Formation and hydrothermal alteration of a volcanic center: Melt pooling and mass transfers at Langseth Ridge (Gakkel Ridge, Arctic Ocean)

Volcanic centers are characteristic features of ultraslow-spreading mid-ocean ridges, the least-explored parts of the global ridge system. Volcanic centers can provide insights into deep magmatic and metamorphic processes at these ridges. Here, we present data from the largest volcanic center on the Gakkel Ridge, the Langseth Ridge, situated at 60–62°E. Langseth is ∼10 km wide, consisting of three peaks that rise to 585 m water depth, some 3–4 km above the surrounding seafloor. It strikes perpendicular to Gakkel's spreading direction and can be traced for ∼40 km, which translates to an age of ∼8 Myr. Seafloor imaging revealed abundant (pillow) basalt but also fissures and geologic faults across the Langseth Ridge. Basaltic rocks were sampled at all summits and diabase at the slope of the northern summit that dips into the rift valley.Our samples are of normal to depleted mid-ocean ridge basalt composition and exhibit a wide range of major and trace element contents, due to magmatic processes, accumulation of macrocrysts, and hydrothermal alteration. Radiogenic isotope ratios, most notably 143Nd/144Nd and 208Pb/206Pb, trend from typical rift valley compositions to isotopically enriched values with increasing distance to the rift valley. This trend may imply melt pooling from different sources, potentially representing a shift from shallow melting beneath the rift valley to deeper melting of enriched sources and higher degrees of melting underneath Langseth. Mineral compositions and plagioclase sieve textures imply prolonged storage of magma at depth prior to eruption. Hydrothermal alteration occurred over a range of conditions. Basalt from the summits is weakly altered at temperatures ≪100 °C, which likely occurred in situ at the summit sites. Diabase samples experienced chloritization and albitization and display epidote and quartz veins, which formed at >300 °C. These assemblages and temperatures are typical for lower crustal levels and imply uplift of the samples of >1 km. Diabase samples from the Afanasenkov Seamount, another volcanic center on the Gakkel Ridge that we investigated for comparison, were altered under comparable conditions.Our findings suggest a combined volcanic–tectonic origin of the studied volcanic centers, potentially implying that such complexes may generally form due to the interplay of magmatism and tectonics. Researching volcanic centers has the potential to further our understanding of both deep and shallow crustal processes at ultraslow-spreading ridges, providing further insights into the role of these centers as linkages between lithosphere and hydrosphere and the (deep) biosphere they sustain.

Association between the MTHFR (rs1801133) gene variation and serum trace elements levels (Copper and Zinc) in individuals diagnosed with neural tube defects

Background and AimsNeural tube defects (NTDs) occur when the neural tube fails to close within 28 days of human embryonic development. This results in central nervous system disorders like anencephaly, spina bifida, and encephalocele. Early diagnosis and treatment are crucial to minimize their impact on an individual’s health and well-being. The present study aims to define the association between prenatal exposure to trace elements (Cu and Zn) and the single nucleotide polymorphism (SNP) of the MTHFR gene involved in folate metabolism pathways in neural tube defects in children and their mothers. Material and MethodsA cross-sectional study involving 331 participants (90 NTD cases, 88 healthy mothers, 85 NTD children, and 68 healthy children) from antenatal check-ups in Obstetrics and Gynaecology and Pediatric Surgery for Neural Tube Defects in the Outpatient Department (OPD) and Inpatient Department (IPD). Assessed Cu and Zn concentrations and their associations. Genomic DNA was extracted, and real-time PCR was used to determine genotypes. Atomic absorption spectrophotometry measured trace elements. Statistical analyses included Chi-Square tests, odds ratios, and Mann-Whitney U tests. ResultsSignificant associations were found between MTHFR C677T genotypes and NTD risk in mothers (p = 0.0491) and children (p = 0.0297). Allelic frequency analysis indicated a T allele association with NTD risk in children (p = 0.0107). Recessive models showed significant associations in mothers (p = 0.0169) and children (p = 0.1678). Cu levels differed significantly between NTD cases and controls (p < 0.0001), with MTHFR genotypes influencing Cu levels. Zinc levels also varied significantly (p < 0.0001). ConclusionThis study reveals complex associations between MTHFR C677T genotypes, trace element concentrations, and NTD risk in mothers and children. This targeted approach allows healthcare providers to identify at-risk pregnancies early, enabling personalised interventions like folic acid supplementation and counselling to moderate neural tube defect (NTD) risk in a future pregnancy.

Iron Metabolism, Calcium, Magnesium and Trace Elements: A Review.

Iron (Fe) is fundamental to life on earth. In the human body, it is both essential and harmful if above threshold. A similar balance applies to other elements: calcium (Ca), magnesium (Mg), and trace elements including copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), mercury (Hg), and nickel (Ni). These elements share some proteins involved in the absorption and transport of Fe. Cu and Cd can inhibit Fe absorption, while excess of Fe may antagonize Cu metabolism and reduce ceruloplasmin (Cp). Excessive Fe can hinder Zn absorption and transferrin (Trf) can bind to both Zn and Ni. Ca is able to inhibit the divalent metal transporter 1 (DMT1) in a dose-dependent manner to reduce Fe absorption and low Mg concentrations can exacerbate Fe deficiency. Pb competitively inhibits Fe distribution and elevated Cd absorption reduces Fe uptake. Exposure to Hg is associated with higher ferritin concentrations and Ni alters intracellular Fe metabolism. Fe removal by phlebotomy in hemochromatosis patients has shown to increase the levels of Cd and Pb and alter the concentrations of trace elements in some types of anemia. Yet, the effects of chronic exposure of most trace elements remain poorly understood.

Genesis of the Neoarchean Algoma-type banded iron formation: constraints from Fe isotope and element geochemistry of the Qian’an iron deposit, eastern North China craton

The Neoarchean Qian’an BIF deposit in eastern Hebei, eastern North China Craton has attracted extensive attention of study in the last decades, but the genesis, e.g., Fe sources, metallogenic mechanism, as well as tectonic attributes of the BIFs remains highly disputed. Based on field investigations, microscopic observations and geochemical analysis, this study tries to unravel the source characteristics of ore-forming materials in the Qian’an deposit. The results show that the chemical compositions of the BIF ore samples are mainly composed of TFe2O3 and SiO2, with minor Al2O3 and TiO2. The total trace element contents of the samples are relatively low. The PAAS-normalized REE distribution patterns of the ores show LREE depletion and HREE enrichment, with robust positive anomalies of Eu, Y and La. These characteristics indicate that the BIFs are attributed to dominant chemical precipitation originated from paleo-ocean with obvious volcanic hydrothermal contributions and minor clastic input. Their positive to no Ce anomalies and positive δ56Femagnetite values unveil that the iron was precipitated at low oxygen fugacity. These results, in collaboration with evidence from previous lithological, structural geology, metamorphic P-T paths, geochemistry, geochronology and numerical modeling studies, support a mantle plume model to explain the complicated tectono-thermal processes, and the sources of BIFs in Eastern Hebei, eastern North China Craton.

Trace elements in the Upper Indus River Basin (UIRB) of Western Himalayas: Quantification, sources modeling, and impacts

This study conducted a comprehensive analysis of trace element concentrations in the Upper Indus River Basin (UIRB), a glacier-fed region in the Western Himalayas (WH), aiming to discern their environmental and anthropogenic sources and implications. Despite limited prior data, 69 samples were collected in 2019 from diverse sources within the UIRB, including mainstream, tributaries, and groundwater, to assess trace element concentrations. Enrichment factor (EF) results and comparisons with regional and global averages suggest that rising levels of Zn, Cd, and As may pose safety concerns for drinking water quality. Advanced multivariate statistical techniques such as principal component analysis (PCA), absolute principal component scores (APCS-MLR), Monte Carlo simulation (MCS), etc were applied to estimate the associated human health hazards and also identified key sources of trace elements. The 95th percentile of the MCS results indicates that the estimated total cancer risk for children is significantly greater than (>1000 times) the USEPA’s acceptable risk threshold of 1.0 × 10−6. The results classified most of the trace elements into two distinct groups: Group A (Li, Rb, Sr, U, Cs, V, Ni, TI, Sb, Mo, Ge), linked to geogenic sources, showed lower concentrations in the lower-middle river reaches, including tributaries and downstream regions. Group B (Pb, Nb, Cr, Zn, Be, Al, Th, Ga, Cu, Co), influenced by both geogenic and anthropogenic activities, exhibited higher concentrations near urban centers and midstream areas, aligning with increased municipal waste and agricultural activities. Furthermore, APCS-MLR source apportionment indicated that trace elements originated from natural geogenic processes, including rock-water interactions and mineral dissolution, as well as anthropogenic activities. These findings underscore the need for targeted measures to mitigate anthropogenic impacts and safeguard water resources for communities along the IRB and WH.

Interannual and spatial variations in acid-soluble trace elements in snow: comparison with the mineralogy of dusts from open pit bitumen mining

There is ongoing concern about trace element (TE) emissions to the global environment from the dusts generated by open pit mining of coal, iron ore, stone quarries, and aggregate extraction. However, the chemical composition and acid solubility of these dusts is highly variable. Here, TEs were determined in snow collected in 2016 and 2017 in the vicinity of open-pit bitumen mines in northern Alberta, Canada. Acid solubility was assessed quantitatively by comparing TE concentrations in leachates and acid digests. The mineralogical composition of the particles extracted from the snow was examined using SEM-EDS. The data is reproducible from one year to the next. TE concentrations were greater throughout the industrial zone compared to the reference location (UTK), with the midpoint between the two central upgraders being especially impacted. Regardless of their geochemical class (lithophile: Al, Be, Cs, La, Li, Sr, Th; chalcophile: As, Cd, Pb, Sb, Tl; or enriched in bitumen: Mo, Ni, V), all TEs showed strong, positive correlations with Y, a conservative element which serves as a surrogate for the abundance of mineral particles. The ratio V:Ni in the snow is less than the corresponding values for bitumen and petcoke, but similar to that of local road dust. The ratio La:Al in snow is elevated, relative to the earth's crust, suggesting an enrichment of heavy minerals monazite and zircon. The predominance of quartz and other stable silicates helps to explain the limited chemical solubility of the dusts, and predicts a low bioaccessibility of these TEs in the environment.

Subzero project: comparing trace element profiles of enriched mitochondria fractions from frozen and fresh liver tissue

From organs to subcellular organelles, trace element (TE) homeostasis is fundamental for many physiological processes. While often overlooked in early stages, manifested TE disbalance can have severe health consequences, particularly in the context of aging or pathological conditions. Monitoring TE concentrations at the mitochondrial level could identify organelle-specific imbalances, contributing to targeted diagnostics and a healthier aging process. However, mitochondria isolation from frozen tissue is challenging, as it poses the risk of TE losses from the organelles due to cryodamage, but would significantly ease routine laboratory work. To address this, a novel method to isolate an enriched mitochondria fraction (EMF) from frozen tissue was adapted from already established protocols. Validation of manganese (Mn), iron (Fe), and copper (Cu) quantification via inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) showed sufficiently low quantification limits for EMF TE analysis. Successful mitochondrial enrichment from frozen liver samples was confirmed via immunoblots and transmission electron microscopy (TEM) revealed sufficient structural integrity of the EMFs. No significant differences in EMF TEs between frozen and fresh tissue were evident for Mn and Cu and only slight decreases in EMF Fe. Consequently, EMF TEs were highly comparable for isolates from both tissue states. In application, this method effectively detected dietary differences in EMF Fe of a murine feeding study and identified the disease status in a Wilson disease rat model based on drastically increased EMF Cu. In summary, the present method is suitable for future applications, facilitating sample storage and high-throughput analyses of mitochondrial TEs.Graphical abstract