Concentrations Of Elements Research Articles

Micro PIXE mapping proves a differential distribution and concentration of trace elements in fungal structures of Rhizophagus intraradices

Arbuscular mycorrhizal (AM) fungi can sequester different potentially toxic elements, such as trace elements (TEs), within their structures to alleviate the toxicity for its host plant and themselves. To elucidate the role of AM fungi in TEs immobilization in the rhizosphere of host plants, it is important to know the TEs distribution in AM fungal structures. In the present study, we investigated the distribution and concentration of TEs within extraradical spores and mycelium of the AM fungus Rhizophagus intraradices, collected from the rhizosphere of Senecio bonariensis plants grown in a soil polluted with multiple TEs, by using Particle-Induced X-ray Emission with a micro-focused beam (micro PIXE). This technique enabled the simultaneous micrometric mapping of elements in a sample. The calculated values were compared with those in the polluted substrate, measured by the Wavelength Dispersive X-ray Fluorescence technique. The highest concentrations of Fe, P, Ti, Mn, Cr, Cu and Zn were found in AM fungal spores, where they were accumulated, while extraradical mycelium was enriched in Cu. Finally, we demonstrated that AM fungi can simultaneously accumulate high amounts of different TEs in their structures, thus reducing the toxicity of these elements to its host plant.

Microstructures of iron meteorites

Abstract Meteorites originate from the early phase of our solar system and are wonderfully undefined and inhomogeneous. In terms of its composition and microstructure, one single meteorite has quite a few surprises in store. The iron meteorite microstructure depends essentially on the initial solidification of the melt in a larger asteroid or minor planet. The solidification process itself is a function of local element concentrations and the very slow cooling rate. Various collisions in space resulted in the fragmentation of the asteroids and the deformation of the microstructure. However, whether visible microstructural changes occur or not depends on the microstructure itself. And finally, corrosion may also occur in the Earth’s atmosphere. An attempt is made to explain the different microstructures on the example of three iron meteorites, namely those found in Canyon Diablo, Gebel Kamil, and Dronino.

Deccan volcanism's influence on Chicxulub impact signatures at the continental Cretaceous-Paleogene boundary in the Sichuan Basin, China

The Cretaceous-Paleogene (K-Pg) extinction is linked to two primary causes: the Chicxulub asteroid impact in Mexico and the Deccan Traps eruptions in India. While substantial geological evidence supporting both events has been found worldwide, to understand their potential interactions, it is crucial to study sites that preserve records of both events simultaneously. The terrestrial K-Pg boundary located in the Sichuan Basin, China (∼15,500 km from the Chicxulub Crater and ∼5,600 km from the Deccan Traps correspond to 66 Ma), preserves evidence of both the Chicxulub impact and the Deccan Traps eruptions, along with the effects of subsequent events on the earlier ones. It offers a new perspective on the K-Pg boundary. Detailed petrological examination and geochemical analyses, including platinum-group element (PGE) and black carbon concentrations, were conducted across a 2 m K-Pg boundary section. The K-Pg boundary layer (∼2.5 cm thick) is composed of very fine-grained, brick-red sandstone and exhibits significant enrichments in Ir (9.050 ppb) and Os (10.72 ppb), along with elevated black carbon (1.10 ‰), strongly indicating contributions from the impact. Intriguingly, another PGE anomaly was detected approximately 50 cm below the K-Pg boundary. The strata surrounding the K-Pg boundary display evidence of alteration by acidic and HSˉ-rich fluids. These fluids likely caused the observed downward migration of PGE within the boundary, resulting in two distinct PGE anomalies - one at the K-Pg boundary itself and another approximately 50 cm below. These fluids resulted in the overlying sandstones exhibiting minimal matrix content and bleached the underlying brick-red sandstones. Volcanic gas emissions from the Deccan Traps after the impact are a potential source for these fluids. Our findings support the hypothesis that the most voluminous Deccan eruptions had occurred close to, but not necessarily immediately after, the Chicxulub impact, potentially lasting 100–131 ka. The hiatus after the impact weakens the possibility of a direct causal link between the Deccan eruptions and the impact.

Platinum-Group Elements and Nb-Ta geochemistry of the Deccan basalts from Kumbharli and other Ghat sections and the Koyna Seismic Zone, Maharashtra (India): Crustal contamination and implication for sulfide saturation of the magma

The Deccan basalts from Kumbharli, Nadlapur, Bijaynagar, Hazarmacchi, and Surli Ghat sections (surface samples) and the Koyna borehole-7 (KBH-7, sub-surface samples) from Maharashtra (western India) demonstrate a two-stage crystallization process. Olivine and chromite were crystallized earlier in a shallow crustal magma chamber while clinopyroxene and plagioclase phenocrysts were crystallized in the sub-volcanic conduits forming the crystal mush, and carried to the surface by the evolved Fe-Ti-rich ascending basaltic magma. The high modal abundance of plagioclase at the top and clinopyroxene at the bottom part of the Kumbharli Ghat section is responsible for an increase in Sr and a decrease in Sc content towards the upper flows. The surface and sub-surface basalt samples contain Pd = 5–31 ppb, Pt = 4–15 ppb, Ir = 1–4 ppb, Ru = 1–3 ppb, and Rh = 3–5 ppb. Negative relations of Pd/Ir, Pd/Ru, and Pd/Rh with MgO from both sets of samples indicate partitioning of Ir, Ru, and Rh to early fractionated cumulus chromite (or olivine). Magnetite is a late crystallizing phase from the evolved Fe-Ti-rich basaltic magma. With an increasing modal abundance of magnetite, there is an increase of FeO total , TiO 2 , and V with Pd indicating fractionation of Pd by magnetite. Geochemical characters show that the surface basalt samples are less contaminated compared to the sub-surface KBH-7 basalts. High Nb (6.8–13.6 ppm) and low Ta (0.2–0.37 ppm) content and elevated Nb/Ta ratios of the surface samples from the ghat sections indicate the possible interaction of the basaltic magma with the carbonate metasomatized subcontinental lithospheric mantle (SCLM). On the other hand, a high degree of partial melting with limited crustal contamination can also elevate the Nb/Ta ratios of the basalts from the ghat sections. Deccan basalts from the study areas do not bear the signature of sulfide supersaturation and subsequent immiscible sulfide segregation. This is evidenced by their high chalcophile element concentrations (Ni = 79–103 ppm, Cu = 121–259 ppm) and ratios like Cu/Zr (≥ 1), Ni/MgO (13.7–21.8) with low Cu/Pd (2140–29938) compared to other Ni-Cu (PGE) sulfide mineralized continental flood basalts. The lack of crustal sulfur in the various contaminants is perhaps the main reason for this sulfide-undersaturated character of the Deccan basalts of the current study.

Influence of overlapping process on the distribution of Cr element in laser cladding 316L powder on 45# steel substrate

To investigate the influence of the overlapping process on the distribution of Cr during the laser cladding process, a novel three-dimensional melting and solidification model based on the volume-average method coupled with Eulerian-Eulerian multiphase was established to simulate the process of laser cladding on a 45# steel substrate with different overlapping processes of 316 L powders. The reliability of the model was verified by comparing the simulation results with the melt pool morphology and melt flow rate measured by a high-speed camera. The height and depth of melt pool were verified through the cross-sectional metallographic diagram. The deviations of the melt pool height and depth for single-path cladding were 2.49 % and 6.35 %, respectively, while the deviations for overlapping process were 8.26 % and 6.88 %, respectively. The deviations of melt flow rate were 12.8 % for single-path cladding and 10.0 % for overlapping, respectively. The distribution of chromium (Cr) was verified based on the results of energy-dispersive spectroscopy (EDS), which demonstrated the accuracy of the model. The results demonstrate that reducing the overlapping rate during the overlapping process will increase the dilution rate of the second path of the molten cladding layer which in turn will decrease the concentration of Cr in the lapped area. Reverse overlapping, on the other hand, increases the temperature of the molten pool and the flow rate of the melt, resulting in a more homogeneous mixing of the elements within the second path of the cladding layer. This reduces the difference between the elemental concentration in the lapped area and the elemental concentration of the first and second paths of the cladding layer.

Sphagnum moss and peat comparative study: Metal release, binding properties and antioxidant activity.

Peat is the main constituent of cultivation substrates and a precious non-renewable fossil material. Peatlands provide important ecosystem services and allow the absorption and storage of carbon. Protecting peatlands helps tackle climate change and contributes to biodiversity conservation. Due to its importance, it is necessary to implement strategies to reduce the use of peat, such as replacing it with biomass-based alternative growing media constituents, such as Sphagnum moss. In this study, we compared the metal release and binding properties at two different pH, antioxidant activity, and total phenolic content of peat and Sphagnum moss from the Tierra del Fuego (TdF) region of southern Patagonia. Levels of the elements were determined by inductively coupled plasma mass spectrometry (ICP-MS), while the types and amounts of functional groups were characterized and compared using Fourier transform infrared (FTIR) spectroscopy. The total phenol level and antioxidant capacity were assessed using the Folin-Ciocalteu method and 2,2-diphenyl-1-picrylhydrazyl test. There are generally higher concentrations of leachable elements in peat than in Sphagnum moss at pH = 2, except Cs, Rb, Ti, and Zr. In contrast, at pH = 5, levels of all leached elements are highest in Sphagnum moss. Sphagnum moss shows a higher metal adsorption capacity than peat, except for Be, Mn, Tl, and Zn. Finally, the results showed that both matrices contained similar total phenolic contents: 0.018 ± 0.011 mg gallic acid equivalent (GAE) per gram dry sample for peat and 0.020 ± 0.007 mg GAE g-1 for Sphagnum moss. Instead, Sphagnum moss extracts showed a significantly higher antioxidant activity [0.026 ± 0.028 mmol Trolox equivalents (TE) g-1] than that estimated in peat (0.009 ± 0.005 mmol TE g-1). Humic acids, carboxylic acids, and phenolic and lignin groups were identified as the functional groups that mainly determined the antioxidant activity of the Sphagnum moss compared to peat. The present study resulted in an advancement of knowledge of these materials for more thoughtful future use and possible replacements.

The corrosion products of proprietary and generic orthodontic fixed lingual retainers and their in-vitro cytotoxicity.

To assess the corrosion products and cytotoxicity of generic and proprietary fixed lingual retainers (FLRs). Seven FLRs were investigated. Wires were submersed in solution for 34 days, at 37°C, under constant agitation. A proportion of this solution was analyzed to determine the concentration of metallic ions leaching off the wires. The remainder was diluted to 5%, 10% and 20% followed by exposure to human gingival fibroblasts and analysis of cytotoxicity of the wires. Three wires (Dentaflex, Universal, and AZDent) released excessive concentrations of lead, two wires (MeshMark and Orthoflex) released excessive concentrations of nickel, and one wire (Universal) released excessive concentrations of molybdenum into solution. No statistically significant difference was found between the wires analyzed (P = .24). Slight cytotoxicity was noted in only one wire (Dentaflex) at a 20% dilution of eluent. This was also the wire which released the highest concentration of lead into solution. All other wires, at all concentrations, were deemed noncytotoxic, but five samples overall were deemed statistically significant (P < .0024). A statistically significant difference existed between wires (P = .013) and concentrations analyzed (P < .001). Metals were released in differing quantities from all wires, with some elemental concentrations measuring more than that deemed acceptable in drinking water in Australia. A trend toward increased cell viability across samples was found with only one demonstrating cytotoxicity. There was no indication that generic FLRs were more or less biocompatible than their proprietary counterparts.

Exploring the potential of wild leafy vegetables widespread in European Alps as functional food

Wild leafy vegetables, historically vital for Alpine biodiversity and nutrition during hardship, are regaining importance due to the demand for healthy and sustainable food. This study evaluated mineral and phytochemical compositions of eight species: Achillea millefolium, Alchemilla xanthochlora, Bistorta officinalis, Blitum bonus-henricus, Phyteuma betonicifolium, Plantago lanceolata, Silene vulgaris, Taraxacum sect. Taraxacum. Total trace element concentrations ranged from 26 mg kg−1 (T. officinalis) to 92 mg kg−1 (B. officinalis), and potential toxic elements were below legal limits. The sum of the phenolic compounds analysed ranged from 155.30 mg GAE 100 g−1 FW (A. millefolium) to 1200.38 mg GAE 100 g−1 FW (A. xanthochlora). Flavanols were the most abundant phenolic class, but cinnamic acids, flavonols, benzoic acids and vitamin C also showed high values in the analysed species, contributing to high antioxidant activity (from 0.59 μmol TE g−1 FW in A. millefolium to 149.39 μmol TE g−1 FW in A. xanthochlora for DPPH). Overall, A. xanthochlora stood out for its richness in phenolic compounds. These findings underscore wild vegetables potential as functional foods, offering bioactive compounds comparable to or exceeding cultivated plants. Emphasizing preservation of traditional diets and rural innovation, this research supports the integration of wild leafy vegetables into contemporary nutrition strategies.

Ilex paraguariensis Extracts: A Source of Bioelements and Biologically Active Compounds for Food Supplements

Ilex paraguariensis, commonly known as yerba mate, is a plant belonging to the holly genus Ilex and the Aquifoliaceae family, indigenous to South America, and is used for the production of yerba mate. Yerba mate is renowned for its abundance of essential nutrients and bioactive compounds. Based on test results, it can be assumed that the selection of raw material for the preparation of extracts as well as the extraction method significantly influence the final content of biologically active compounds in the extracts. Consequently, this variability impacts the ultimate concentration of biologically active substances within the end product, potentially influencing human consumption. The present study aimed to quantify and compare the content of selected biological active compounds in supplements and products containing I. paraguariensis extracts, along with organic yerba mate dried through a smoke-free process, available in the European market (P-1–P-10). The evaluation focused on antioxidant substances such as neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, 4-feruloylquinic acid, isochlorogenic acid, rutoside astragalin, and caffeine. Additionally, the concentration of specific macro and trace elements was ascertained. The antioxidant compound makeup differs between methanol-extracted samples and aqueous extracts. In both cases, methanol extracts, particularly those in instant and traditional herb forms, showed the highest content of organic compounds with antioxidant properties (such as phenolic compounds and caffeine). The highest content of chlorogenic acid was detected in both methanol (14.7412 mg/g d.w.) and water (8.3120 mg/g d.w.) extracts in product P-4. The caffeic acid content ranged from 0.1491 mg/g d.w. to 1.7938 mg/g d.w. in methanol extracts and from 0.0760 mg/g d.w. to 0.4892 mg/g d.w. in water extracts. The neochlorogenic acid content ranged from 2.6869 to 23.9750 mg/g d.w. in ethanol extracts and from 0.4529 to 10.2299 mg/g d.w. in water extracts. Therefore, the traditional preparation of yerba mate as a water infusion does not fully exploit the raw material’s potential. Among the tested products, only the dietary supplement in capsule form contained protocatechuic acid, which was not present in any other tested products. Conversely, compounds characteristic of yerba mate found in other preparations were absent in this supplement. The caffeine content was also the lowest in this product. The determined content of active substances did not consistently match the declarations made by producers if stated on the packaging.

The influence of vertebrate scavengers on leakage of nutrients from carcasses

The decomposition of carcasses by scavengers and microbial decomposers is an important component of the biochemical cycle that can strongly alter the chemical composition of soils locally. Different scavenger guilds are assumed to have a different influence on the chemical elements that leak into the soil, although this assumption has not been empirically tested. Here, we experimentally determine how different guilds of vertebrate scavengers influence local nutrient dynamics. We performed a field experiment in which we systematically excluded different subsets of vertebrate scavengers from decomposing carcasses of fallow deer (Dama dama), and compared elemental concentrations in the soil beneath and in the vegetation next to the carcasses over time throughout the decomposition process. We used four exclusion treatments: excluding (1) no scavengers, thus allowing them all; (2) wild boar (Sus scrofa); (3) all mammals; and (4) all mammals and birds. We found that fluxes of several elements into the soil showed distinct peaks when all vertebrates were excluded. Especially, trace elements (Cu and Zn) seemed to be influenced by carcass decomposition. However, we found no differences in fluxes between partial exclusion treatments. Thus, vertebrate scavengers indeed reduce leakage of elements from carcasses into the soil, hence influencing local biochemical cycles, but did so independent of which vertebrate scavenger guild had access. Our results suggest that carcass-derived elements are dispersed over larger areas rather than locally leak into the soil when vertebrate scavengers dominate the decomposition process.

Major and trace elements determination in organic and conventional Moroccan vegetables using the k0-standardisation method of neutron activation analysis

The aim of the present work is the determination of different essential (minor and trace) elements found in five Moroccan vegetables collected from large commercial markets in Kenitra city, Morocco, and in some organic vegetables which were traditionally grown without the use of pesticides or chemical fertilizers, in a plot located in the rural commune of Dar Laaslouji, 48 km from Kenitra city. The k0-standardisation method of the Neutron Activation Analysis (k0-INAA) using the TRIGA Mark II research reactor of 2 MW at the National Centre for Nuclear Energy, Science and Technology (CNESTEN) and gamma-ray spectroscopy facility were employed. For quality control, the accuracy of measurements has been investigated using certified reference materials (IAEA-336 lichens, and NIST SRM 1547 peach leaves) which were analyzed simultaneously with the samples. Good agreement was found between certified and determined values. The primary results are presented and discussed for the concentration of minor and trace elements in some vegetables (tomatoes, carrots, green peppers, cilantro and mint), that are widely used in Moroccan meals.

Ruthenium isotopes show the Chicxulub impactor was a carbonaceous-type asteroid.

An impact at Chicxulub, Mexico, occurred 66 million years ago, producing a global stratigraphic layer that marks the boundary between the Cretaceous and Paleogene eras. That layer contains elevated concentrations of platinum-group elements, including ruthenium. We measured ruthenium isotopes in samples taken from three Cretaceous-Paleogene boundary sites, five other impacts that occurred between 36 million to 470 million years ago, and ancient 3.5-billion- to 3.2-billion-year-old impact spherule layers. Our data indicate that the Chicxulub impactor was a carbonaceous-type asteroid, which had formed beyond the orbit of Jupiter. The five other impact structures have isotopic signatures that are more consistent with siliceous-type asteroids, which formed closer to the Sun. The ancient spherule layer samples are consistent with impacts of carbonaceous-type asteroids during Earth's final stages of accretion.

Analysis of Kidney Stones Using Single Pulse Laser-Induced Breakdown Spectroscopy (SP-LIBS) to Determine the Concentrations of Elements

Analysis of Kidney Stones Using Single Pulse Laser-Induced Breakdown Spectroscopy (SP-LIBS) to Determine the Concentrations of Elements

Are Hair Scalp Trace Elements Correlated with Atherosclerosis Location in Coronary Artery Disease?

Coronary artery disease is among the leading current epidemiological challenges. The genetic, clinical, and lifestyle-related risk factors are well documented. The reason for specific epicardial artery locations remains unsolved. The coronary artery topography and blood flow characteristics may induce local inflammatory activation. The atherosclerotic plaque formation is believed to represent inflammatory response involving enzymatic processes co-factored by trace elements. The possible relation between trace elements and coronary artery disease location was the subject of the study. There were 175 patients (107 (61) men and 68 (39) females) in a median (Q1-3) age of 71years (65-76) admitted for coronary angiography due to chronic coronary syndrome. The angiographic results focused on the percentage of lumen stenosis in certain arteries and were compared with the results for hair scalp trace elements. The correlation between left main coronary artery atherosclerotic plaques and nickel (Ni), zinc (Zn), and antimony (Sb) hair scalp concentration was noted. The analysis revealed a positive relation between left descending artery disease and chromium (Cr), sodium (Na), arsenic (As), and molybdenum (Mo) and a negative correlation with strontium (Sr). The atherosclerotic lesion in the circumflex artery revealed correlations in our analysis with sodium (Na), potassium (K), chromium (Cr), nickel (Ni), arsenic (As), and negative with strontium (Sr) (r) hair scalp concentrations. The negative correlations between right coronary artery disease and magnesium (Mg) and strontium (Sr) concentrations were noted. The possible explanation of different epicardial artery involvement and severity by atherosclerotic processes may lay in their topography and blood rheological characteristics that induce different inflammatory reactions co0factored by specific trace elements. The trace element concentration in the hair scalp may correlate with a particular coronary atherosclerotic involvement, including the severity of lumen reduction. This may indicate the missing link between the pathophysiological processes of atherosclerosis development and its location in coronary arteries.

Association between maternal serum essential trace element concentration in early pregnancy and the risk of gestational diabetes mellitus

Association between maternal serum essential trace element concentration in early pregnancy and the risk of gestational diabetes mellitus

Geologically constrained unsupervised dual-branch deep learning algorithm for geochemical anomalies identification

The identification of geochemical anomalies is crucial in mineral exploration. However, the limited sample size, high-dimensional features, and mixed geochemical information make identifying geochemical anomalies a significant challenge. Machine learning algorithms (MLAs), especially those with spatial and spectrum branches, have been proven to be a high efficiency tools for detecting geochemical anomalies related to mineralization. The spatial branch MLAs take two-dimensional images (pixel-patches) as input and mainly capture the spatial characteristics of geochemical patterns. The spectrum branch MLAs take one-dimensional sequence data (pixels) as input and mainly consider the elemental concentration and assemblies. Simultaneously considering the spatial patterns and geochemical concentrations of the geochemical survey data can mitigate geochemical concentration variations arising from objective factors and amplify subtle mineralization anomalies. This study proposes an unsupervised spatial-spectrum autoencoder (AE), namely dual-AE, which consists of a graph convolutional autoencoder (GCN-AE) and a long short-term memory network autoencoder (LSTM-AE) for geochemical anomalies identification. The spatial branch is constructed using the GCN-AE, which can effectively capture spatial geochemical patterns and extract spatial relationships between neighboring pixels. The spectrum branch consists of an LSTM-AE that can study geochemical elemental assemblies within a single pixel. A key ore-controlling factor was added into the dual-AE as a soft constraint to construct a geologically constrained dual-AE. A case study was conducted to recognize geochemical anomalies associated with iron polymetallic mineralization in Southwest Fujian Province, China. The obtained results demonstrated that (1) the unsupervised spatial-spectrum deep learning algorithm serves as a potent method for detecting geochemical anomalies related to mineralization, (2) the geologically constrained unsupervised spatial-spectrum dual-branch model can improve the accuracy and interpretability of geochemical anomaly identification, and (3) the identified anomalous areas can provide essential clues for further mineral exploration.

Magmatic water content in HIMU basalts from the Cook-Austral Islands: constraints on degassing processes and source composition from clinopyroxene phenocrysts

The amount of water recycled during subduction is unclear. Water/Ce estimates in HIMU (high-238U/204Pb) basalts are variable, ranging from < 100 to > 250 in glasses and melt inclusions. Because clinopyroxene (cpx) is a common early liquidus phase and the cpx/melt partitioning of water is well constrained, cpx phenocrysts provide an additional constraint on magmatic water contents. We present water and trace element concentrations in HIMU-basalt-hosted cpx phenocrysts from the Austral Islands. Calculated melt [H2O] (up to 4.3 wt.%) and H2O/Ce ratios (22–825) are higher than in olivine-hosted inclusions, as are estimated equilibration pressures. Correlation between estimated melt [H2O] and crystallization or entrapment pressure suggests significant water loss during magma ascent. Most ocean island basalts (OIBs) span a limited range in H2O (~ 1–1.5 wt.%), and low (< 100) H2O/Ce ratios are primarily observed in melts with unusually high [Ce] (up to 350 ppm). Additionally, [H2O] and H2O/Ce in some suites correlate with entrapment pressure despite having quench pressures high enough to prevent significant water loss from open- or closed-system degassing (< 100 MPa). Polybaric “sparging”, whereby low-P melts re-equilibrate with CO2-rich fluids exsolved at higher pressure, may result in water loss at pressures less than CO2 saturation. This may more accurately describe OIB degassing processes than open or closed system degassing. After correcting for degassing, primary Australs melts likely have H2O/Ce of ~ 300–600. If applicable to OIB sources in general, this limits the total water budget of the mantle, including the mantle transition zone, to < 2.4 ocean masses.

Blood levels of 21 metals and metalloids in riverside villagers of the Brazilian Amazon: A human biomonitoring study with associations with sociodemographic, dietary, and lifestyle factors

Human biomonitoring of toxic and essential trace elements is critically important for public health protection. Amazonian riverine communities exhibit distinctive dietary patterns, heavily reliant on locally sourced fish, fruits, and vegetables. These habits may result in unique exposure profiles compared to urban populations. However, comprehensive assessments of their exposure to toxic and essential metals are lacking, representing a critical gap in understanding the health risks faced by these communities. This study aimed to establish baseline levels of 21 metals and metalloids in human blood and explore the influence of sociodemographic factors, dietary habits, and lifestyle choices as potential sources of exposure to these elements. A cross-sectional biomonitoring investigation was conducted with 1,024 individuals from 13 communities in the Tapajós and Amazon Basins (Pará, Brazil). Most of the elements in study was determined for the first time in the region. Blood samples were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The levels of all elements were summarized by quantiles and compared with cutoff values from other Brazilian populations. Multiple linear regression was used to assess possible associations between element concentrations and sociodemographic characteristics, dietary habits, and lifestyle choices. High detection rates (64%–100%) were observed, indicating the widespread presence of these elements. Elevated blood concentrations were found for mercury (median 21.1 μg.L−1, interquartile range: 12–34 μg.L−1), selenium (median 166 μg.L−1, interquartile range: 137–208 μg.L−1), and lead (median 34 μg.L−1, interquartile range: 20.8–64 μg.L−1). Regression analysis revealed a positive association between mercury levels and fish consumption, while manioc flour intake showed no relationship to lead levels. In conclusion, our findings emphasize the need for continued monitoring and public policy development for these vulnerable populations. Further studies should assess long-term trends and investigate the health implications of prolonged exposure to diverse chemicals in Amazonian riverside communities.

Evaluation of polypropylene CSF low-bind collection tubes for trace metal contamination.

Due to the ability of metal ions to cross the blood-brain barrier, there has been interest in analyzing cerebrospinal fluid (CSF) for trace element concentrations to investigate possible correlations with neurodegenerative diseases. In this study, Sarstedt polypropylene CSF collection tubes were analyzed to determine the contamination levels of aluminum, titanium, chromium, manganese, cobalt, nickel, molybdenum, gadolinium, vanadium, arsenic, cadmium, mercury, lead, thallium, selenium, copper, zinc, and iron. Sarstedt polypropylene CSF collection tubes from 2 separate lots (n = 10 per lot) were filled with a 2 mL aliquot of a CSF pool with known element concentrations. After 24 hours of leaching at room temperature, all 18 elements were analyzed via inductively coupled plasma mass spectrometry (ICP-MS). Results were subtracted from the initial pool concentration to determine contamination levels. No detectable contamination above the assay limit of detection was found in 11 analytes. Molybdenum and selenium contamination was measured in all tubes, and aluminum, titanium, manganese, thallium, and zinc had minimal levels of sporadic detectable contamination in 25% or fewer of the tubes tested. Sarstedt polypropylene CSF tubes are an acceptable collection tube for the analysis of most assessed metals in CSF.

In situ testing of micro-ecological elements in offshore engineering

With the increasing human development and utilization of the ocean, the impact of offshore engineering on the ocean ecological environment is becoming more and more serious. In this article, a technique for in situ monitoring of marine micro-ecological elements based on laser-induced fluorescence is proposed. Combining laser-induced fluorescence with different types, contents, and proportions of micro-ecological elements, we establish the relationships between the concentration of marine micro-ecological elements, their diversity, and the fluorescence intensity of different wavelengths in order to detect the abundance and dominant species of micro-ecological elements in the ocean in situ. The experimental results show that this technique has the advantages of in situ, rapid, convenient, and continuous measurement, which provides a technical basis for accurate and rapid intelligent testing of marine micro-ecological elements for the development and maintenance of offshore engineering.