Trace Element Concentrations Research Articles

Seasonal dynamics of chemistry in an Arctic glacier-fed river

Arctic rivers, intricately linked to fjord systems, wield significant influence over the geochemical and biological dynamics of the upper Arctic Ocean, providing it with freshwater, nutrients, suspended particles, and potentially harmful pollutants. To comprehend the full picture of the Arctic ecosystem, it is crucial to understand how these rivers vary across regions and seasons, especially considering ongoing climate changes. However, comprehensive studies that address long-term observations and seasonal variations in Arctic rivers' geochemical composition remain scarce. In this study, we present comprehensive long-term investigations of the seasonal variations in elemental concentrations in Bayelva, a high Arctic glacier-fed river. By analyzing 224 surface water samples, collected during different seasons between 2011 and 2020, we elucidate the diverse influences of marine, geological and atmospheric factors on the river chemistry. Our findings underscore the importance of marine-influenced snowmelt in the early flow season, which leads to elevated concentrations of marine and trace elements in the runoff water at the onset of melting, with concentrations subsequently decreasing as the snow melting continues. Glacial meltwater dominates the river chemistry during the peak flow season, during which elemental concentrations are at their lowest. Late flow season exhibits high elemental concentrations, primarily driven by weathering processes. Additionally, heavy rain and freezing events play a crucial role in sudden alterations in river chemistry. We highlight the dynamic response of Arctic river systems to such environmental drivers as key players in transporting essential micro- and macro-nutrients, as well as potentially harmful pollutants to adjacent fjord systems. Given their susceptibility to climate change, continuous monitoring is essential for understanding future changes. This study provides data for a better foundation for accurate climate modeling of biogeochemical systems in the Arctic environment.

Toxic and essential elements in honeybee venom from Slovakia: Potential health risk to humans

Honeybee venom is one of the natural substances produced by bees (Apis mellifera). Their venom gland produces venom which plays a defensive role. In this study a concentration of macro and trace elements (Ag, Al, As, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Mo, Na, Ni, Sb, Se, Sr, Pb and Zn) in foragers′ and honeybees′ venom was analysed by axial inductively coupled plasma optical emission spectrometry (ICP OES) with good validation parameters to differentiate the element accumulation ability in honeybee venom. Cumulative ability for some elements (As, Al, Ba, Cr, Li, Mo, Pb, and Zn) in bee venom was clearly demonstrated. Oppositely, levels of macro elements (Ca, K, Mg and Na) in venom were several times lower compared to the levels detected in foragers. Moreover, PCA analysis of bee samples showed that Cr was associated with locality Košice, and Cd with locality Krompachy; both have rich industrial history. Since some of analysed elements are potentially toxic for humans, a risk assessment for bee-stung scenario was also calculated. A new way of exposure to potentially toxic elements via honeybee stung was showed in this study. Non-carcinogenic risk assessment for humans to selected toxic elements (As, Cd, Cr, Ni, and Pb) demonstrated acceptable risk and moreover the same we may conclude for potential carcinogenic risk for beekeepers exposed to As, Cd, Ni, and Pb via venom over their whole life.

From mother to egg: Variability in maternal transfer of trace elements and steroid hormones in common eider (Somateria mollissima)

The Baltic Sea is among the most polluted seas worldwide with elevated concentrations of trace elements (TEs). TEs can induce negative effects on organisms and may be transferred to eggs causing endocrine-disrupting effects on embryos. The Baltic Sea population of common eider (Somateria mollissima) has declined over the last thirty years, but the potential contribution of TEs to this decline is understudied. The aim of this study was to assess maternal transfer of TEs during the incubation period. Associations between TEs and steroid hormone concentrations in eggs (androstenedione, testosterone, pregnenolone and progesterone) were also investigated. Ten nests from Bengtskär (Finland) were monitored, for which hens at the beginning and end of the egg-laying were blood-sampled and their clutches were collected. Red blood cells from females (n = 10) and homogenized eggs (n = 44) were analyzed for 10 TEs (As, Ca, Cd, Cu, Hg, Mg, Ni, Pb, Se and Zn). Maternal and egg concentrations were correlated for Cu, Hg and Se (R2 = 0.51, R2 = 0.51, R2 = 0.52, respectively and all p-values ≤0.01). Three eggs had the highest Pb concentrations (1.43–2.24 μg g−1 ww) ever reported for this species. Although maternal and egg Pb concentrations were not significantly correlated, those eggs were laid by the same female, also having the highest Pb concentration (3.4 μg g−1 ww). Most blood TE concentrations in females were below known toxicity limits, except for Pb where 20 % of 10 females (including one outlier) had concentrations above the toxicity limit reported for subclinical poisoning in Anatini (> 0.2 μg g−1 ww). Steroid hormones in eggs were interrelated, but not correlated to TEs. Overall, the results call for more urgent research into the origin and consequences of high Pb concentrations and continued monitoring of the common eider populations in the Baltic Sea.

Pyrite in-situ S–Fe isotope constraints on the ore-forming sources and mineralization processes of gold and polymetallic deposits in the Liaodong Peninsula, North China Craton

Plenty of gold and polymetallic deposits are widespread in the eastern part of the North China Craton. They are associated with mafic to felsic dikes and hosted by Precambrian basement or Mesozoic granitoids. However, the sources of gold and other metals in the ore-forming fluids remain controversial. Here we present in-situ S and Fe isotopes and trace element contents of pyrites from various gold and Pb–Zn–(Ag) deposits in the Liaodong Peninsula, China. Pyrites from quartz vein-type gold deposit hosted by Mesozoic granites in the Wulong deposit have relatively homogeneous magmatic-like S isotopes (δ34S values of 0.9 ‰ to 2.5 ‰) and Co/Ni ratios, indicating derivation of sulfur and, by inference, of ore fluids/materials most likely from Mesozoic magmas. In contrast, pyrites from gold and Pb–Zn–(Ag) deposits in the Qingchengzi orefield hosted by Precambrian basement have high and variable δ34S values (9.7 ‰ to 12.7 ‰ for the Wandigou altered rock-type gold deposit and 4.7 ‰ to 8.5 ‰ for the Xiquegou Pb–Zn deposit and the Zhenzigou Pb–Zn–Ag deposit), identical to those of host rocks, indicating the important contributions of gold and other metals from wall rocks to the ore deposits. Pyrites from the various deposits have variable δ56Fe values of 0.08 ‰ to 0.63 ‰ for the Pb–Zn–Ag deposit, –0.58 ‰ to 1.23 ‰ for the altered rock-type gold deposit, and –0.68 ‰ to 0.77 ‰ for the quartz vein-type gold deposit, indicating distinct mineralization processes. Rapid precipitation of pyrites (with negative δ56Fe values) in the alteration rock and subsequent deposition of pyrites (with positive δ56Fe values) from the residual fluids in an Fe-open hydrothermal system during intensive ore-forming fluid-wall rock interaction account for the Pb–Zn–Ag mineralization, while weak fluid-rock interaction and pyrites precipitation from a Fe-closed hydrothermal system contribute to gold mineralization. Our observations provide a robust S–Fe isotope evidence for the contribution of various sources and metallogenic processes for distinct gold and polymetallic deposits.

Microplastic Abundance, Characteristics, and Heavy Metal Contamination in Coastal Environments of Western Sri Lanka

This study was conducted to assess the abundance of microplastics and associated metal contamination from selected beaches in the Western Province of Sri Lanka. Beach sand samples were collected from four beaches: Modera, Negombo, Mount Lavinia, and Panadura. Microplastics were extracted from dried sand samples using a saturated NaCl solution and sieved. Particles were identified using Fourier Transform InfraRed spectrophotometer, and associated heavy metals; Cr, Pb, Cu, Zn, and Ni were subjected to acid digestion for 24 hours before analysis using Microwave Plasma Atomic Emission spectrometry. More than half of the extracted plastics (56.31%) were identified as microplastics. The average microplastic abundance in beach sand samples ranged from 42.0-91.3 items/kg. The lowest and highest abundances were reported from the sand collected at Mount Lavinia and Panadura beaches, respectively. Hydrodynamic factors like ocean currents, wave patterns, associated Southwest monsoon period, and human activities may have caused the variability in microplastic abundances and metal contamination. The majority of the microplastics (52.29%) were polyethylene, whereas the second most abundant microplastic type was polypropylene (35.18%), resembling the records of the most common plastic waste types in the country. The majority of microplastics were fragments (87.95%) while white was the prominent color (53.49%). The toxic trace element concentration ranged from 5.0×10-3 to 1.8×102 μg/g in beaches. Furthermore, this study establishes a baseline for the west coastline prior to the X-press Pearl Ship Disaster in 2021. Future studies are encouraged to assess the beach microplastic pollution across the entire Sri Lankan coastline.

Erythrocyte trace element concentrations in critically ill children with sepsis

Erythrocyte trace element concentrations in critically ill children with sepsis

Semi-quantitative μLIBS mapping of germanium diffusion between metal and silicate during planetary core–mantle segregation

Understanding the distribution of elements between the cores and mantles of planetary bodies is essential for elucidating the geological and geochemical processes operating during their formation. Because the semi-metallic element Ge shows complex siderophile, chalcophile, and lithophile properties, it is particularly significant for investigating core–mantle segregation and ore deposit formation. Recent advancements in in situ microanalysis techniques, such as μLIBS, have enabled high-resolution elemental mapping of Ge and other trace elements.This study explores the application of μLIBS imaging to investigate the high-temperature/high-pressure distribution of Ge between metallic and silicate matrices analogous to planetary cores and mantles. By cross-calibrating the μLIBS intensities with electron microprobe profile analyses carried out on piston cylinder experimental samples, we produced semi-quantitative Ge maps from which we extracted Ge concentration profiles to assess Ge diffusion from the silicate to the metal. We determined, for the first time, the diffusion coefficient of Ge between metal and silicate to be D(Ge)metal = 4.03E−13 ± 3.6E−14 m2/s at 1 GPa and 1350 °C. Our results demonstrate the capability and efficiency of μLIBS for providing detailed, high-resolution (15 μm) trace element concentration data at few ppm levels, offering a time- and cost-effective alternative to conventional techniques.These findings bring insights on planetesimal differentiation and on chemical exchanges between metal and silicate phases in a magma ocean and between two different metal phases occurring at the bottom of the magma ocean during planetesimal formation.

Geochemical vectors for targeting hydrothermal gold mineralization in the Damang area, southwestern Ghana: Constraints from petrography, multi-element geochemistry and multivariate statistical analysis

The Damang Gold Mine in southwestern Ghana sits on two kinds of mineralization: the Tarkwaian paleoplacer and a hydrothermal type found within the Tarkwaian Group's meta-sedimentary rocks. Geochemical vectors related to the hydrothermal gold mineralization in the area are not well known. Therefore, this research was conducted to identify pathfinders for hydrothermal gold mineralization in the Damang area. A total of fifty (50) rock samples were collected from three diamond drill holes focusing on mineralized zones of the holes. The mineralogy of the host rocks was established using petrographic studies of twelve (12) selected representative drill core samples. Multi-element geochemical analysis of the host rocks (n = 50) involving Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) technique was conducted to quantify the trace element concentrations in the host rocks. The multi-element geochemical data was analyzed using multivariate statistics. The petrographic studies showed the abundance of quartz, biotite, pyrite, pyrrhotite, sericite, and minor amounts of feldspars (plagioclase and orthoclase). Al, Mg, Fe, and Ca dominated the geochemical data. The highest Au concentrations were found in Birimian quartz veins and the intrusive lithologies compared to the other lithologies in the region. Most of the data failed the Shapiro-Wilk and Kolmogorov-Smirnov tests. The deviations from normality were shown graphically by Q-Q plots. The centered log-ratio transformation was used to correct this, and the data tested again for normality. Spearman rank correlation showed a positive correlation between Te, Bi, U, Ba, Ag, and Au. When hierarchical cluster analysis was run, three clusters emerged with Au in the same cluster with Te, Ag, and Bi. Factor analysis served as a confirmatory test with Au in the same factor with Bi, Ag, and Te. Datamine Studio RM was used to create drillhole logs showing the anomalies of the three elements and Au with different lithologies downhole, which showed a similitude in the abnormal occurrences. Therefore, hydrothermal gold mineralization in the Damang area is related to Bi-Te-Ag-Au multi-element association.

Strontium Isotope Composition of Triassic Coastal and Shallow Marine Carbonates in the Western Balkanides, NW Bulgaria

Whole-rock samples of Triassic coastal and shallow marine carbonates were analyzed for their Sr isotope signatures and trace element concentrations were measured in order to assess the possible impact of diagenetic alteration. The 87Sr/86Sr ratios of Anisian to lower Carnian calcite micrites reproduce the global Triassic seawater variations fairly well. The recorded higher values can be explained by an influence from detrital aluminosilicate phases and a minor postdepositional alteration. The samples of tidal-flat dolomicrites from the base of the Anisian show no significant diagenetic overprint but have considerably more radiogenic 87Sr/86Sr signatures compared to the global Sr isotope curve that corresponds to the Triassic (Mesozoic) maximum. These anomalously high values may have resulted from some interaction between the dolomitizing brines and the underlying fluvial siliciclastics (Buntsandstein facies), but more likely from the high 87Sr/86Sr river waters discharged from a silicate-dominated drainage basin to the coastal area at the beginning of the Middle Triassic. This study demonstrates that bulk micrite can be used as a proxy for seawater 87Sr/86Sr after proper sample selection and diagenetic screening. It also suggests that the 87Sr/86Sr ratios of ancient carbonates precipitated in coastal settings should be interpreted with caution, considering the possible influence of continentally-derived fluids.

Fluorescent sphalerite rich in tungsten, copper, gallium, silver, and other elements from the Cordilleran-style, polymetallic veins of Philipsburg, Montana

Sphalerite from the central, high-sulfidation zone (enargite-stable) of the Philipsburg polymetallic mining district, southwest Montana, displays unusually bright fluorescence (red, orange, yellow, blue, purple, green) under longwave UV light (365 nm). LA-ICP-MS analysis reveals the fluorescent sphalerite has very low Fe (average < 100 ppm) and variable content of other trace elements that correlate to luminescence color banding. Mean/maximum content (in ppm) in fluorescent sphalerite for selected elements are 5.7/7900 Ag, 107/11800 As, 1400/4730 Cd, 917/30400 Cu, 381/5000 Ga, 32/696 Ge, 119/2130 In, 230/8190 Mn, 43/3000 Pb, 16/1700 Sb, and 89/1980 W. This study is the first to document elevated tungsten content (>10 ppm) in sphalerite. Copper is closely correlated with Ga, consistent with the coupled substitution: Cu+ + Ga3+ = 2Zn2+. Similar coupled substitution reactions can be written for Ag+, In3+, As3+, Sb3+, Bi3+, and Ge4+. However, the brightest red fluorescent bands are most closely related to the unexpected presence of W. Sphalerite with high Cu and Ga but lacking W fluoresces yellow and shows a single Raman peak at 349 cm−1 corresponding to pure sphalerite. In contrast, red-fluorescent sphalerite shows the presence of a second peak at 427 cm−1 that increases in intensity with increased W content. We propose that tungsten enters the sphalerite lattice as W6+ via a substitution such as W6+ + 4Cu+ = 5Zn2+ and that this substitution creates lattice strain that results in the anomalous fluorescence and Raman signals. Sphalerite bands with low concentrations of Cu and Ga fluoresce blue or green. Vivid blue fluorescence is displayed by sphalerite with high Cd (>1000 ppm) but low concentrations of all other trace elements. Sphalerite from the low-sulfidation peripheral mines of the Philipsburg district contains high Fe (>10,000 ppm) and does not fluoresce. Nonetheless, this sphalerite is also highly enriched in trace metals, including Ag (mean 2480/max 8660 ppm), Cu (1610/3440), Mn (7020/8100), and Sb (1960/6390). The results of this study underscore the importance of including tungsten in the list of analytes in future studies of trace elements in sphalerite. In addition, a hand-held UV lamp may be a rapid and cost-effective method to screen sphalerite of variable composition in outcrop or drill core. It may be a useful exploration tool to vector towards a high-sulfidation zone of a zoned porphyry or epithermal deposit, when it is present.

Identification of Genomic Regions Conferring Enhanced Zn and Fe Concentration in Wheat Varieties and Introgression Lines Derived from Wild Relatives.

Wild and cultivated relatives of wheat are an important source of genetic factors for improving the mineral composition of wheat. In this work, a wheat panel consisting of modern bread wheat varieties, landraces, and introgression lines with genetic material of the wheat species Triticum timopheevii, T. durum, T. dicoccum, and T. dicoccoides and the synthetic line T. kiharae was used to identify loci associated with the grain zinc (GZnC) and iron (GFeC) content. Using a BLINK model, we identified 31 and 73 marker-trait associations (MTAs) for GZnC and GFeC, respectively, of which 19 were novel. Twelve MTAs distributed on chromosomes 1B, 2A, 2B, 5A, and 5B were significantly associated with GZnC, five MTAs on 2A, 2B, and 5D chromosomes were significantly associated with GFeC, and two SNPs located on 2A and 2B were related to the grain concentration of both trace elements. Meanwhile, most of these MTAs were inherited from At and G genomes of T. timopheevii and T. kiharae and positively affected GZnC and GFeC. Eight genes related to iron or zinc transporters, representing diverse gene families, were proposed as the best candidates. Our findings provide an understanding of the genetic basis of grain Zn and Fe accumulation in species of the Timopheevi group and could help in selecting new genotypes containing valuable loci.

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.

High sensitivity fiber optic SPR sensor for selenium ion concentration detection

Balance of selenium content is of great significance to human health, and there is a need for rapid and sensitive detection of selenium ion concentrations in the human body and food. This article proposes a highly sensitive fiber surface plasmon resonance (SPR) sensor for selenium ion concentration detection. By fabricating a fiber U-shaped ring composite structure and modifying Cu3VSe4 material, the sensitivity of the fiber SPR sensor is improved to 6826.82 nm/RIU. Using 2,4-diamino-6phenyl-1,3,5-triazine to modify the surface of the sensor to achieve specific detection of selenium ion concentration. The experiment results indicate that the detection sensitivity of the sensor is 1.858 nm/(lg(pg/ml)) with range of 100 pg/ml to 1 μg/ml, and the LOD is 124.06 pg/ml. The highly sensitive SPR sensor proposed in this article, without labeling, can achieve high sensitivity and rapid detection of selenium ions, providing a new approach for trace element content detection.

ВЫНОС МИКРОЭЛЕМЕНТОВ ФУМАРОЛАМИ АВАЧИНСКОГО ВУЛКАНА (КАМЧАТКА)

The trace element composition of high-temperature gases of Avachinsky volcano was investigated. For that purpose 25 samples of gas condensates and sublimates deposited in four quartz tubes were analyzed. The total average concentration of trace elements (excluding S, Cl, F, Si) in the condensates was 87 mg/l, the maximum 210 mg/l, among which B, K, Na, Br, As predominated. A large number of samples taken over a period 2013–2023 allowed us to evaluate the variations of element concentrations, their dependence on fumarole temperature and the season of sampling. The enrichment factors normalized for magnesium, made it possible to determine the elements transported in the plume in the form of volatile compounds (S, Cl, Te, I, B, Br, Cd, As, F, Re, Se, Bi, Tl, Hg, Sn, Sb, Pb, etc.) and in the form of silicate aerosol (Ti, Fe, Ga, Al, Ca, Mn, REE et al.). The ore element emission by Avachinsky volcano is comparable to that of Mutnovsky volcano (Kamchatka) and significantly lower than the emission by volcanoes in the stage of stationary degassing, such as Kudryavy and Pallas Peak (Kuril Islands), which can be explained by higher concentrations of HCl in the gases of the latter.

Origin and Affinities of the Malmberget Iron Oxide-Apatite Deposit, Northern Sweden: Insights From Magnetite Chemistry and Fe-O Isotopes

European iron ore production is primarily sourced from magnetite dominated iron oxide-apatite ore deposits in the northern Norrbotten ore province of northernmost Sweden. The Malmberget iron oxide-apatite deposit is at present the largest iron ore resource in Europe and is an amphibolite facies grade analogue of the world-famous Kiirunavaara iron oxide-apatite deposit. The Malmberget rock association is characterised by multiple phases of deformation, metamorphism, and alteration that resulted in a geometrically and petrologically complex deposit that is genetically ambiguous. Primary ore textures and emplacement structures of the Malmberget iron oxide-apatite deposit have largely been recrystallised during metamorphic overprinting and now comprise dominantly medium- to coarse-grained granoblastic magnetite. However, isotopic characteristics are preserved and when combined with trace element chemistry, these can be used to understand magmatic vs. hydrothermal origin of the deposit. To unravel the primary origin of the Malmberget magnetite ore, we combined magnetite trace element chemistry and Fe-O stable isotopes to investigate the massive magnetite in the Fabian-Kapten and ViRi ore bodies of the Malmberget iron oxide-apatite deposit. Trace element correlations indicate a high-temperature magmatic to a transitional high-temperature magmatic-hydrothermal origin of the Malmberget iron oxide-apatite ore deposit, with data plotting into fields of clear magmatic affinity in trace element discrimination diagrams. Fe-O data fall into established magmatic fields regardless of subsequent metamorphic modifications, underlining a dominantly (ortho-)magmatic origin of the investigated deposits. Despite an overall magmatic to magmatic-hydrothermal origin for the two ore bodies studied, Fe-O isotope equilibrium calculations of the magnetite suggest a possible temperature discrepancy between the Fabian-Kapten ore body and the ViRi ore body, the latter showing a more pronounced magmatic character. These variations in trace element contents and Fe-O isotopes can be explained by the proximity of the more magmatic signatures to the centre of the ore forming magmatic system.

Campylobacter infection of young children in Colombia and its impact on the gastrointestinal environment.

Campylobacter infections are a leading cause of bacterial-derived gastroenteritis worldwide with particularly profound impacts on pediatric patients in low- and middle-income countries. It remains unclear how Campylobacter impacts these hosts, though it is becoming increasingly evident that it is a multifactorial process that depends on the host immune response, the gastrointestinal microbiota, various bacterial factors, and host nutritional status. Since these factors likely vary between adult and pediatric patients in different regions of the world, it is important that studies define these attributes in well-characterized clinical cohorts in diverse settings. In this study, we analyzed the fecal microbiota and the metabolomic and micronutrient profiles of asymptomatic and symptomatic pediatric patients in Colombia who were either infected or uninfected with Campylobacter during a case-controlled study on acute diarrheal disease. Here, we report that the microbiome of Campylobacter-infected children only changed in their abundance of Campylobacter spp. despite the inclusion of children with or without diarrhea. In addition to increased Campylobacter, computational models were used to identify fecal metabolites that were associated with Campylobacter infection and found that glucose-6-phosphate and homovanillic acid were the strongest predictors of infection in these pediatric patients, which suggests that colonocyte metabolism is impacted during infection. Despite changes to the fecal metabolome, the concentrations of intestinal minerals and trace elements were not significantly impacted by Campylobacter infection but were elevated in uninfected children with diarrhea.IMPORTANCEGastrointestinal infection with pathogenic Campylobacter species has long been recognized as a significant cause of human morbidity. Recently, it has been observed that pediatric populations in low- and middle-income countries are uniquely impacted by these organisms in that infected children can be persistently colonized, develop enteric dysfunction, and exhibit reduced development and growth. While the association of Campylobacter species with these long-term effects continues to emerge, the impact of infection on the gastrointestinal environment of these children remains uncharacterized. To address this knowledge gap, our group leveraged clinical samples collected during a previous study on gastrointestinal infections in pediatric patients to examine the fecal microbiota, metabolome, and micronutrient profiles of those infected with Campylobacter species and found that the metabolome was impacted in a way that suggests gastrointestinal cell metabolism is affected during infection, which is some of the first data indicating how gastrointestinal health in these patients may be affected.

Assessment of Essential Trace Elements Cu, Zn, Mn, and Ni in Mediterranean Mussels (Mytilus galloprovincialis) from the Algerian Coast.

The aim of this study was to determine the levels of essential trace elements copper, zinc, manganese, and nickel in two size groups of mussels, Mytilus galloprovincialis, sampled from three sites along the Algerian coast with different levels of pollution. The results of this work are very interesting for determining the effect of mussel size on the variation of contaminant levels in environmental monitoring studies. Thirty individuals from 2 size groups, less than 4-cm and more than 4-cm shell length, were collected over 4 seasons at each site studied. The samples were dissected, and copper, zinc, manganese, and nickel were measured in the whole soft tissues by inductively coupled plasma mass spectrometry (ICP-MS). The maximum concentrations of copper, zinc, manganese, and nickel expressed in mg/kg dry weight at the three sites were 54.01, 146.25, 20.69, and 8.85, respectively. A clear distribution pattern of the studied elements was observed in the two size classes. In fact, significantly higher concentrations (P < 0.05) were found in individuals with a shell length of less than 4 cm. Significantly, higher concentrations (P < 0.05) were found in individuals with a shell length of less than 4 cm due to their high filtration and low excretion activities compared to long individuals. In addition, metal pollution index (MPI) values were higher in small bivalve individuals. The trace element contents found in the mussel samples of the present study showed large spatial and temporal variations among the different sites studied, highlighting the typical exposure of marine sites to different marine pollutants. Notably, elevated concentrations of copper were observed in the port of Zemmouri, likely due to port activities. Conversely, the highest levels of manganese and nickel were recorded at Boudouaou El Bahri, potentially attributable to the use of fertilisers by agricultural activities. Some shellfish samples had exceeded the permissible concentration levels of copper and manganese, thereby posing a danger to bivalve consumers.

Concentrations of radionuclides and trace elements in wetlands.

Environmental risks in wetlands are considered with radionuclides and trace elements to understand pollution accumulation. In this study, we aimed to determine the levels of radiation and heavy metals in water systems and assess pollution configurations. Radionuclides (222Rn, 210Pb and 210Po) and trace elements (Ag, As, Ba, Be, Cd, Co, Cr, Cu, Fe, Li, Mo, Ni, Pb, V and Zn) were measured to evaluate anthropogenic factors. Water pollution in wetlands was indicated by mean concentrations of 66.2mBq/L for 222Rn, 3mBq/L for 210Pb, 42mBq/L for 210Po, 41ppb for Zn, 37ppb for Ba, 190ppb for Fe and 481ppb for Sr. These pollutants may be related to industrial facilities in Kırklareli city, Türkiye.

Rock glacier springs: cool habitats for species on the edge

AbstractUnder climate change, glacier recession and the loss of cold habitats are major threats to aquatic biodiversity. In mountain areas, streams originating from rock glaciers, called “icy seeps”, may represent climate refugia for cold-adapted organisms, given the major persistence of cold waters from these landforms even in unfavourable climates. During late summer 2021, we investigated discharge, turbidity, water chemistry (major ions and trace elements), stable water isotopes (δ18O, δ2H), and macroinvertebrate communities of five rock glacier springs (icy seeps), five glacier springs (glacier springs) and five non-glacial springs (spring brooks) in catchments of the Eastern Italian Alps. In icy seeps, meltwater contribution to runoff (estimated with end-member mixing models) was intermediate between those of the other two spring types. Icy seeps had very cold waters (&lt; 1.5 °C) that were enriched in trace elements, like glacier springs, whereas discharge and turbidity were low, like in spring brooks. Community composition, diversity, and species associations of icy seeps were strongly related to a gradient of chemical harshness (built using trace element concentrations), with less contaminated springs hosting communities like those dwelling in spring brooks. Like glacier springs, those icy seeps with the harshest water chemistry (particularly because of Ni concentrations) and higher meltwater contribution hosted species (e.g., Diamesa steinboecki) that are currently in decline due to glacier loss. This suggests a high conservation value for icy seeps. The protection of these habitats, nowadays overlooked, will be fundamental under the progressive warming and dry-out risk of alpine springs.

The Ain Dibba and Ain Kissa phosphorites, Tebessa (NE Algeria): REE depletion versus shallow, open depositional environment during the Paleocene-Eocene phosphogenesis in North Africa

The Ain Dibba and Ain Kissa phosphorites, located north of Tebessa town, NE Algeria, belong to the Upper Cretaceous-Paleocene-Eocene Afro-Arabian phosphatic province that extends from Morrocco to the Middle East. These two phosphorite showings, which were partly exploited at the beginning of the 20th century, were deposited during the Late Paleocene (Thanetian) times on the northern basin of the Kasserine Paleo-Island. Although they are not yet economically very important, the present petrological and geochemical study contribute highly to the knowledge of their critical trace and REE contents as well as the understanding of their paleo-depositional environment. Petrographic and XRD data show that these phosphorites are mainly composed of pellets, coprolites, bioclasts and rare glauconite, gypsum, quartz grains and zeolites. These constituents are cemented by calcareous, siliceous or rarely clayey matrix. The pellets and coprolites are composed mainly of cryptocrystalline carbonate fluor-apatite (CFA). The XRF and ICP-MS chemical analyses of these phosphorites, show they are not as rich as those from Kef Essenoun and Bled El Hadba southern basin, neither in P2O5 nor in REE contents. P2O5 concentrations range from 14.16 to 26.57 wt% (average = 20.24 ± 4.33 wt%, n = 15), with only one sample having 31.89 wt% P2O5, whereas ΣREE contents range from 171 to 344 ppm (average = 252 ± 69 ppm, n = 9) and, therefore, considered as moderately REE-enriched phosphorites. Ce anomaly values display a decrease from the lower to the upper phosphorite sub-layers (from −0.57 down to −0.72), suggesting an increase from relatively sub-oxic to more oxic conditions. The Eu anomalies range from 0.89 to 1.35 for Ain Dibba and from 0.93 to 1.35 for Ain Kissa phosphorites. The highest Ce/Ce∗ and lowest Eu/Eu∗ anomalies are recorded in the lower layers, often enriched in both REE and glauconite contents, whereas the lowest Ce/Ce∗ and highest Eu/Eu∗ anomalies, reflecting more oxic conditions, are characteristics of the glauconite-free and REE-poor upper layers. The gradual timewise transition from relatively sub-oxic to oxic conditions (from the lower to the upper layers) is also recorded in the redox-sensitive (Cr, Ni, V, U) trace element data. This implies that during early diagenesis, the sedimentary environment became slightly reduced, which enabled intensive uptake of both REE and some trace element (e.g., Cr, V, Ni, U) mainly from pore-water through substitution and adsorption mechanisms onto apatite and glauconite minerals. This is noticed especially in the lower phosphorite layers of both Ain Dibba and Ain Kissa deposits. In a larger scale, the Ain Dibba and Ain Kissa phosphorites show lower REE contents, lower Ce and Eu anomalies, and lower redox-sensitive trace element contents than those of the southern (Kef Essenoun and Bled El Hadba) and eastern (Tunisian) basins of the Kasserine paleo-Island. These geochemical features indicate that phosphorites from the northern basin were deposited, through upwelling current, in a more open, shallower, oxygenated and agitated environment during the Paleocene-Eocene phosphogenesis in North Africa and Middle East.