Concentrations Of Other Trace Elements Research Articles

Water quality dynamics and underlying controls in the Halton Region, Ontario.

We assessed the hydrochemistry of 15 watersheds in the Halton Region, southern Ontario, in high resolution (n > 500 samples across n > 40 streams) to characterize water quality dynamics and governing controls on major and trace element concentrations in this rapidly urbanizing region. In 2022, major water quality parameters were generally in line with historic monitoring data yet significantly different across catchments, e.g., in specific conductance, turbidity, phosphate and chloride, and trace element concentrations. Distinct hydrochemical signatures were observed between urban and rural creeks, with urban stream sections and sites near the river mouths close to Lake Ontario having consistently higher chloride (up to 700mg/L) and occasional enrichment in nutrients levels (up to 8 and 20mg/L phosphate and nitrate, respectively). Particularly upper reaches exhibited hydrochemical signatures that were reflective of the catchment surface lithologies, for instance through higher dissolved Ca to Mg ratios. Unlike for chloride and phosphate, provincial water quality guidelines for trace elements and heavy metals were seldom surpassed (on < 10 occasions for copper, zinc, cadmium, and uranium). Concentrations of other trace elements (e.g., platinum group elements or rare earth elements) were expectedly low (< 0.3µg/L) but showed spatiotemporal concentration patterns and concentration-discharge dynamics different from those of the major water quality parameters. Our results help improve the understanding of surface water conditions within Halton's regional Natural Heritage Systems and demonstrate how enhanced environmental monitoring can deliver actionable information for watershed decision-making.

The arsenic-lowering effect of inulin-type prebiotics in end-stage renal disease: a randomized crossover trial.

Background: Circulatory imbalance of trace elements is frequent in end-stage renal disease (ESRD), leading to a deficiency of essential elements and excess of toxic elements. The present study aimed to investigate whether inulin-type fructans (ITFs) could ameliorate the circulatory imbalance by modulating gut microbiota and regulating the absorption and elimination of trace elements. Methods: Peritoneal dialysis patients were enrolled in a randomized crossover trial, undergoing interventions with ITFs (10 g d-1) and maltodextrin (placebo) over a 9-month period (with a 3-month washout). The primary outcomes included essential elements Mn, Fe, Co, Cu, Zn, Se, Sr, and Mo and potential toxic elements V, Cr, Ni, As, Cd, Ba, Tl, Pb, Th, and U in plasma. Secondary outcomes included the gut microbiome, short chain fatty acids (SCFAs), bile acids (BAs), and daily removal of trace elements through urine, dialysate and feces. Results: Among the 44 participants initially randomized, 29 completed the prebiotic, placebo or both interventions. The daily dietary intake of macronutrients and trace elements remained consistent throughout the study. The administration of 10 g d-1 ITFs significantly reduced plasma arsenic (As) by 1.03 μg L-1 (95%CI: -1.74, -0.33) (FDR-adjusted P = 0.045) down from the baseline of 3.54 μg L-1 (IQRs: 2.61-4.40) and increased the As clearance rate by urine and dialysis (P = 0.033). Positive changes in gut microbiota were also observed, including an increase in the Firmicutes/Bacteroidetes ratio (P = 0.050), a trend towards higher fecal SCFAs (P = 0.082), and elevated excretion of primary BAs (P = 0.035). However, there were no significant changes in plasma concentrations of other trace elements or their daily removal by urine, dialysis and feces. Conclusions: The daily administration of 10 g d-1 ITFs proved to be effective in reducing the circulating retention of As but demonstrated to be ineffective for other trace elements in ESRD. These sentences are ok to include but as "The clinical trial registry number is ChiCTR-INR-17013739 (https://www.chictr.org.cn/showproj.aspx?proj=21228)".

Source of inorganic components in the Middle Jurassic inertinite-rich coals of the Southern Ordos Basin, China: With emphasis on formation of Sr- and Ba-bearing minerals

The Middle Jurassic coal seams located in the southern Ordos Basin display notably high concentrations of barium (Ba) and strontium (Sr). To acquire a comprehensive understanding of the source and occurrence of the elevated contents of Ba- and Sr-bearing minerals and their formation mechanism in the coal, a suite of petrological, mineralogical, and geochemical analyses was conducted on the Middle Jurassic coals of the Gaojiapu mine (No. 4 Coal) from the Binchang mining area, using optical microscopy, field emission-scanning electron microscopy, X-ray diffraction, X-ray fluorescence, and inductively coupled plasma mass spectrometry. The results indicate that the No. 4 Coal is a high volatile B bituminous coal, which is characterized by low ash, medium sulfur, and high inertinite contents. The modes of occurrence of minerals identified in the coal, including calcite, dolomite, pyrite, quartz, kaolinite, anatase, barite, and celestine, indicate that the No. 4 Coal may have been subjected to multiple stages of solutions injection. Barium and Sr in the investigated coals are significantly enriched, exhibiting maximum values of 19738 μg/g and 9932 μg/g, respectively, while concentrations of other trace elements are generally depleted. Barite and celestine, generally coexisting with carbonate minerals, commonly occur as cell- and fracture-fillings. Furthermore, the strong correlation coefficients (r) for Ba vs. Ca + Mg and Sr vs. Ca + Mg (0.78 and 0.61, respectively) indicate that most barite and celestine have a close association with carbonate minerals of epigenetic origin. The highly elevated concentrations of Ba and Sr are thought to be primarily derived from solutions leaching barite deposits developed in the Qinling Orogenic Belt, which is located in the south of the Ordos Basin. When mapped spatially, the distributions of Ba and Sr concentrations are fan-shaped, decreasing from the NW to the SE of the mining area. Meteoric water containing dissolved CO2 induced partial dissolution of carbonate rocks, and during this process, selected metal ions (e.g., Ca2+, Mg2+, Al3+, Si2+, Fe2+, Ba2+, and Sr2+) were redistributed and subsequently migrated along fracture zones to the coal seam. The fracture systems and abundant cavities within inertinite in the coal provided sufficient space and conduits for solutions migration.

Potentially harmful elements released by volcanic ash of the 2021 Tajogaite eruption (Cumbre Vieja, La Palma Island, Spain): Implications for human health

This study assesses the potential impacts on human health of volcanic ash emitted during the 2021 Tajogaite eruption (La Palma Island, Spain). Ash samples were physically and chemically characterized and leaching tests (with deionized water and acidic solution) were performed according to the IVHHN protocols to elucidate i) the leachable elements that may affect water quality and represent a potential threat for livestock and humans through drinking water supply; and ii) the bioaccessible fraction of toxicants able to be solubilized from ash surfaces if ashes are incidentally ingested by children. The most abundant readily water-soluble compounds were SO4, F, Cl, Na, Ca, Ba, Mg, and Zn. Fluoride and chloride (up to 1085 and 1347 mg/kg) showed higher values in distal ash samples than closer ones. The potential F availability assessed from water leachates may suggest important environmental and health implications. In addition, long-term health hazard due to a long–term weathering of tephra deposits should be possible as confirmed by the greater amount of F extracted by acidic solution. Concentration of other trace elements (e.g., As, V, Mn, Mo, Cr, Fe, Se, Ti, Pb) were low compared to global medians and within the range globally assessed. Indicative calculation of hazard for water supply showed that F concentration may exceed both the recommended value (1 mg/L) for irrigation purpose and the health-based drinking water limits of 1.5 mg/L (for humans) and 2 mg/L (for livestock). If the predicted concentrations in water were compared with the toxicologically dose, F showed a potential health-risk for children through drinking water. The indicative health-risk characterization via accidental ash ingestion showed that the direct exposure does not represent a primary source of F daily intake for children. This important outcome confirmed F as element with the greatest health threat during Tajogaite 2021 eruption.

In Situ Trace Element and Sulfur Isotope Composition of Pyrite from the Beiwagou Pb-Zn Deposit, Liaodong Peninsula, Northeast China: Implications for Ore Genesis

The Beiwagou Pb-Zn deposit, located in the western part of the Liaodong Peninsula, is a carbonate-hosted stratiform deposit with a Pb + Zn reserve of 0.08 Mt @ 4.14% (Pb + Zn). The orebodies occur as conformable layers and lenses and are strictly controlled by strata (the Paleoproterozoic Gaojiayu and Dashiqiao Formations) and lithology (plagioclase amphibolite and dolomitic marble). Given that previous studies have focused only on the mineralization features and mineralogy of deposits, herein, we report in situ trace element analyses of pyrite using LA-ICP-MS, together with in situ sulfur isotopes of pyrite, to constrain the composition, substitution mechanisms, source of sulfur, and sulfate reduction pathways of pyrite in the Beiwagou deposit. Based on pyrite morphology, texture, and chemistry, four pyrite types were identified: subhedral, porous-to-massive pyrite (Py1) related to chalcopyrite; subhedral, porous crushed pyrite (Py2) associated with fine-grained sphalerite; rounded and porous pyrite (Py3) related to the Zn-rich part of the laminated ore; and anhedral, porous-to-massive pyrite (Py4) associated with pyrrhotite, arsenopyrite, sphalerite, and galena. Py1 is characterized by high As, Ag, Cd, In, Au, Cu, and Zn concentrations and low Te, Bi, and Mo concentrations, whereas Py2 has high concentrations of Co and Ni and low concentrations of other trace elements, such as Cu, Zn, Bi, and Te. Py3 is characterized by elevated As concentrations, low Co, Ni, In, W, Te, and Tl concentrations, and varying Pb concentrations, whereas Py4 has low Ag, Cd, In, Zn, Cu, and Mn concentrations and varying W, Co, Ni, Pb, Sb, and As concentrations. Significant correlations between some elements in each pyrite type suggest substitution mechanisms, such as (Zn2+ + Cu2+ + Mn2+ + Cd2+) ↔ 2Fe2+, Ag+ + (Sb)3+ ↔ 2Fe2+, and (Te+ + Ag+) + Sb3+ ↔ 2Fe2+, and the existence of a negative correlation between Co and Ni implies competition between both elements. The strongly positive δ34S values (12.11‰–23.54‰) are similar to that of seawater sulfates and likely result from thermochemical sulfate reduction (TSR). In conclusion, the Beiwagou Pb-Zn deposit is a typical SEDEX deposit and mineralization likely occurred during diagenesis.

Relationship between trace element concentrations and body length in dolphinfish (Coryphaena hippurus) in the northwest Atlantic Ocean.

Dolphinfish (Coryphaena hippurus) is a popular seafood choice worldwide, however, except for mercury (Hg) and selenium (Se), little is known about the concentration of other trace elements in dolphinfish muscle tissue, especially in the northwest Atlantic Ocean. This study investigated the relationship between body length (61 to 94cm fork length) and trace element [silver (Ag), arsenic (As), cadmium (Cd), chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), Hg, manganese (Mn), nickel (Ni), lead (Pb), Se, and zinc (Zn)] concentrations in muscle tissue of dolphinfish caught off Long Island, New York (n = 16). There was a positive relationship with body length for As and Hg, a negative relationship with body length for Cu and Zn, and no relationship with body length for Cd, Fe, Mn, Pb, and Se. A negative relationship between the Se:Hg molar ratio and body length and Se:Hg molar ratio and Hg concentration was observed. Dolphinfish were low in Hg with only 18.9% (n = 3) of individuals exceeding the U.S. EPA human health criterion of 0.3µg/g wet weight, making this species a suitable seafood choice to reduce dietary intake of Hg at the investigated body length. All fish had a Se:Hg molar ratio > 1:1 indicating that Se may have a protective effect against Hg toxicity. The selenium health benefit value (HBVSe) for all individuals was > 1, indicating there may be health benefits from consuming dolphinfish.

Major and Trace-Element Chemistry of Cr-Spinel in Upper Mantle Xenoliths from East Antarctica

Cr-spinels in the upper mantle peridotite xenoliths from two Late Mesozoic intrusions of alkaline-ultramafic rocks in Jetty Peninsula (East Antarctica) were studied in situ for their major and trace-element compositions by SEM and LA-ICP-MS. The upper mantle xenoliths were collected from the magmatic bodies “sampled” from different upper mantle domains. One domain was represented by mostly lherzolites (Cpx-poor Spl, Cpx-rich Spl and Spl-Grt) and another one by Spl harzburgites and dunites. Spinels occur as grains of different shapes, sizes and origins. Three main textural types of spinel were identified: primary spinel represented by clean homogeneous grains, a rim of recrystallization/resorption surrounding primary spinel grains and irregular interstitial resorbed grains. Primary spinels are characterized by the concentrations of Al2O3 21–51 wt%, MgO 15–20 wt%, FeO 10–24 wt% and Cr2O3 14–37 wt% with the Cr# of 0.16–0.54. Most trace elements are present in spinels in very low amounts. Only Ti, V, Mn, Co, Ni, Zn and Ga display concentrations in the range of tens to hundreds (up to thousands) ppm. Concentrations of other trace elements vary from below the detection limit to &lt;10 ppm. Spinel major oxide and trace element features allowed the suggestion that the studied upper mantle peridotites represent both simple melt residues and residues strongly influenced by the MORB-like and the SSZ-related melts. The MORB-like melts may be related to the beginning of the Lambert–Amery rift system development, whereas SSZ-like melts could be related to reactivation of SSZ material buried during much earlier amalgamation of East Antarctica.

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

The relatively higher concentrations of trace elements to arsenic may have influenced on methylation process of inorg- As in humans

Selection of copper and zinc dosages in pig diets based on the mutual benefit of animal growth and environmental protection

Dietary copper and zinc additives facilitate the growth and development of animals, but heavy metal in feces threatens the ecological environment, and balance is the key to solving the problem. In this study, a trial of 2000 pigs (early nursery, 9–15 kg; late nursery, 15–25 kg; grower: 25–60 kg) was conducted to analyze the effects of different diets (gradient dosage of copper and zinc additives) on growth performance, antioxidant performance, immune function, and fecal heavy metal excretion of piglets and growing pigs. Although no significant differences were observed in average daily gain (ADG) and average daily feed intake (ADFI) between treatments during the entire nursery-grower period, the addition of appropriate high doses of copper and zinc to the diet had a beneficial effect on the antioxidant status and immune function of weaned piglets. Especially at early nursery, compared with the low-copper group (5 mg/kg Cu), the high-copper group (120 mg/kg Cu) could significantly increase the peroxidase (POD), glutathione peroxidase (GSH-PX), total antioxidant capacity (T-AOC), catalase (CAT) and copper/zinc superoxide dismutase (Cu/Zn-SOD), cortisol in the serum. Moreover, the addition of zinc and copper in the diet not only increased the concentration of corresponding trace elements in the serum, but also affected the concentration of other trace elements in the serum. The reduction of copper and zinc content in the diet contributed to reducing the copper and zinc content in feces. In conclusion, we have formulated the mutual benefit dosages of copper and zinc (9–15 kg: 5 mg/kg Cu and 50 mg/kg Zn; 15–25 kg: 4 mg/kg Cu and 50 mg/kg Zn; 25–60 kg: 4 mg/kg Cu and 10 mg/kg Zn) for weaning piglets and growing pigs, which would help ensure the healthy growth of animals and reduce environmental heavy metal residues. CapsuleThis study developed a mutually beneficial dose of copper and zinc in pig diets, which promotes animal growth and protects the environment.

Do concentrations of Mn, Eu and Ce in apatite reliably record oxygen fugacity in magmas?

Apatite is a common accessory mineral in igneous rocks, and its ability to readily accommodate a wide range of trace elements means that it may provide a useful record of magmatic composition and magmatic processes. Relative abundances of redox sensitive elements in apatite could also provide a much-needed probe of magmatic oxygen fugacity, fO2. Here, examination of a large data set of apatite and whole rock compositions is used to assess the recently proposed, and increasingly used, Mn-in-apatite oxybarometer. Correlation of apatite-whole rock Mn partition coefficients with whole rock SiO2, and calculated melt polymerisation and aluminosity, support a model where apatite Mn content is largely dependent on melt structure. In more evolved systems, a decrease in availability of non-bridging oxygens in silicate melts drives Mn from being incompatible, to an increasingly compatible element in apatite. Magmatic fO2 calculated from Ce concentrations in zircon also shows no discernible correlation with apatite Mn content. Mn content of apatite clearly does not record magmatic fO2, although it may be useful in indicating the extent of melt evolution. In contrast, concentrations of other trace elements in apatite have a much weaker, or no discernible dependence on melt structure and composition, supporting the assertion that apatite records key aspects of magmatic composition.Eu and Ce anomalies in chondrite-normalised Rare Earth Element (REE) data provide an alternative means of using apatite to probe magmatic fO2. A new method for more reliably comparing the extent of Eu and Ce anomalies in apatite REE data is used to assess controls on Eu and Ce content. Apatite Eu content shows a strong dependence on whole rock composition, indicating that Eu anomalies often reflect feldspar crystallisation. Ce anomalies in apatite are much smaller and vary from weakly positive to weakly negative. Predicted strong, negative Ce anomalies in apatite data are not observed, implying smaller differences in Ce3+ and Ce4+ compatibility in apatite than in minerals such as zircon. The cause of small positive Ce anomalies in apatite data is unclear. Comparison of apatite and zircon data suggests that fO2 may have some control on apatite Ce content. However, the narrow range of Ce anomalies in apatite data, and lack of an identifiable control of fO2, limit the extent to which apatite Ce records magmatic fO2. As such, REE contents of apatite also cannot currently be used to reliable indicate trends in magmatic fO2.

Reconnaissance geological and geochemical studies of the Precambrian rocks in Erijiyan Area, Southwestern Nigeria: Implications for mineral exploration

Reconnaissance geological and geochemical studies were carried out on the rocks at Erijiyan area to determine its mineral potentials thereby providing a framework for its exploration. Ten fresh rock samples were collected using grid controlled sampling method at a sampling density of one sample per 100sq km2. The rocks were subsequently prepared for petrographic studies followed by geochemical studies. The petrographic studies involve thin sectioning of the rocks into slides using the standard procedures while the geochemical studies include sample preparation and analyses for its major oxides and trace elements using Inductively Coupled Plasma Spectrophotometry (ICP-MS). The result of the geological mapping revealed three distinct lithologic units such as quartz schists, quartzites and pegmatites with well delineated boundaries, and the major or dominant foliation trend in the NE-SW direction. However, the results of the petrographic analysis showed dominant quartz with minor specks of muscovite while results of geochemical analysis revealed the dominance of Al2O3 and SiO2 with the quartz having an average percentage composition of 64.73%. Al2O3 indicated presence of aluminosilicate-bearing minerals such as feldspar, micas, and feldspathoids. The results of the trace elements analyses revealed that Mn is the most abundant with an average value of 1065.2 ppm while the average concentrations of other trace elements showed that Ba (1166.9 ppm), Zr (819.4 ppm), Sr (227.9 ppm) and Zn (130.7 ppm). Conclusively, The weathering index shows that the rocks in the study area are moderately weathered implying that the rocks are suitable for geochemical or mineralogical exploration.Considering the geochemical properties of the rocks in the study area, It could be deduced that Pb, Cu, Zn concentration is indicative of copper-zinc or sulphide mineralization. while. Pb, Sr, Ba and Zr also indicated the radio active nature of the rocks.

Associations of trace elements in blood with the risk of isolated ventricular septum defects and abnormal cardiac structure in children.

This study sought to determine correlations between the presence of isolated ventricular septum defects (VSDs) and blood levels of trace elements. A total of 144 patients with VSDs and 144 controls were recruited for cross-sectional assessment of trace elements and examination of cardiac structures in the Jiangsu and Anhui provinces between 2016 and 2018. Logistic regression was performed to explore the relationships between VSDs and trace elements. Additionally, general linear regression models were used to investigate relationships between trace elements and echocardiography indicators. Relative to the lowest zinc (Zn) concentrations, the highest Zn concentrations may be associated with lower odds of VSD development (OR = 0.03, 95% confidence interval [CI] = 0.01-0.29, P < 0.001). However, no significant relationships between the concentrations of other trace elements and the risk of VSD were identified. Aorta (AO) diameters were markedly smaller in the VSD group, whereas no significant between-group differences were observed for other echocardiography indicators. After adjusting for age and gender, linear regression indicated a significant association between Zn level and mean AO diameter (beta coefficient = 0.247, 95% CI = 0.126-0.367). Zn deficiency was observed in patients with isolated VSDs. Further work to explore the mechanisms by which Zn deficiency leads to VSDs is warranted.

Associations between sulfides, carbonaceous material, gold and other trace elements in polyframboids: Implications for the source of orogenic gold deposits, Otago Schist, New Zealand

Intimately intergrown micron-scale framboidal pyrite, carbonaceous material (CM), chalcopyrite, sphalerite and cobaltite form polyframboids in prehnite–pumpellyite facies rocks of the Otago Schist, New Zealand. This study quantifies the metal contents of these polyframboids using synchrotron X-ray fluorescence (SXRF) and laser ablation inductively coupled plasma spectrometry (LA-ICP-MS). Trace elements Au, Zn, As, Mo, Co, Ni, Cu, Ag and Pb are significantly enriched in the polyframboids. The distribution of Zn most closely follows that of CM, and was probably absorbed into the structure of the polyframboids during biogenic processes. The concentrations of Au and Ag are positively corrected with the Zn concentration in the polyframboids (R2 of Au–Zn and Ag–Zn are 0.81 and 0.89, respectively.). The concentration of other trace elements, such as As, Co and Cu, which occur adjacent to Zn on elemental maps, show a weak relationship with Zn and may have been incorporated into the polyframboids during later processes. These polyframboids are a probable source for gold and other elements in the orogenic gold mineralization system of the Otago Schist. Metamorphic transformation of the polyframboids may have released the metallic elements into the mineralizing fluid during prograde metamorphism of the schist belt.

Petrology, Palynology, and Geochemistry of Gray Hawk Coal (Early Pennsylvanian, Langsettian) in Eastern Kentucky, USA

This study presents recently collected data examining the organic petrology, palynology, mineralogy and geochemistry of the Gray Hawk coal bed. From the Early Pennsylvanian, Langsettian substage, Gray Hawk coal has been mined near the western edge of the eastern Kentucky portion of the Central Appalachian coalfield. While the coal is thin, rarely more than 0.5-m thick, it has a low-ash yield and a low-S content, making it an important local resource. The Gray Hawk coal palynology is dominated by Lycospora spp., and contains a diverse spectrum of small lycopods, tree ferns, small ferns, calamites, and gymnosperms. The maceral assemblages show an abundance of collotelinite, telinite, vitrodetrinite, fusinite, and semifusinite. Fecal pellet-derived macrinite, albeit with more compaction than is typically seen in younger coals, was observed in the Gray Hawk coal. The minerals in the coal are dominated by clay minerals (e.g., kaolinite, mixed-layer illite/smectite, illite), and to a lesser extent, pyrite, quartz, and iron III hydroxyl-sulfate, along with traces of chlorite, and in some cases, jarosite, szomolnokite, anatase, and calcite. The clay minerals are of authigenic and detrital origins. The occurrence of anatase as cell-fillings also indicates an authigenic origin. With the exception of Ge and As, which are slightly enriched in the coals, the concentrations of other trace elements are either close to or much lower than the averages for world hard coals. Arsenic and Hg are also enriched in the top bench of the coal and probably occur in pyrite. The elemental associations (e.g., Al2O3/TiO2, Cr/Th-Sc/Th) indicate a sediment-source region with intermediate and felsic compositions. Rare metals, including Ga, rare earth elements and Ge, are highly enriched in the coal ashes, and the Gray Hawk coals have a great potential for industrial use of these metals. The rare earth elements in the samples are weakly fractionated or are characterized by heavy-REE enrichment, indicating an input of natural waters or probably epithermal solutions.

Geochemical impacts of leaking CO2 from subsurface storage reservoirs to an unconfined oxidizing carbonate aquifer

A series of batch and column experiments combined with solid phase characterization studies was conducted to evaluate the impacts of the potential leakage of carbon dioxide (CO2) from deep subsurface storage reservoirs to overlying potable carbonate aquifers. The main objective was to gain an understanding on CO2 gas-induced changes in aquifer pH and mobilization of major, minor, and trace elements from dissolving minerals in rocks representative of an unconfined, oxidizing carbonate aquifer within the continental US. Samples from the unconfined portion of the Edwards limestone aquifer in Texas were exposed to a CO2 gas stream or were leached with a CO2-saturated influent solution simulating different leaking scenarios [i.e., sudden, fast, and short-lived release of CO2 (batch experiments) and gradual release (column experiments)]. The results from the batch and column experiments confirmed that exposure to excess CO2 gas caused significant decrease in pH (about two pH units); the release of major chemical elements into the contacting aqueous phase (such as Ca, Mg, Ba, Sr, Si, Na, and K); the mobilization and possible rapid immobilization of minor elements (such as Al and Mn), which are able to form highly reactive secondary phases; and sustained but low-concentration releases of some trace elements (such as Mo, Cs, Sn) in some samples. Spikes of low concentrations of other trace elements (such as As, Cd, Pb, Cu, Zn, Se, etc.), were observed sporadically during these experiments. The results help in developing a systematic understanding of how CO2 leakage is likely to influence pertinent geochemical processes (such as dissolution/precipitation and sorption/desorption) in the aquifer sediments and will support site selection, risk assessment, policy-making, and public education efforts associated with geologic CO2 sequestration.

Urban biogeochemistry of trace elements: What can the sediments of stormwater ponds tell us?

Humans are greatly modifying biogeochemical cycles, in part, by increasing the abundance of many trace elements in heavily developed environments. As a means to study the biogeochemical cycling of trace elements in the urban landscape, we examined their accumulation in the sediments of ponds located in residential developments. To do so, we measured the content of trace elements (Ti, V, Cr, Co, Ni, Cu, Zn, Mo, Ag, Cd, Ba, Tl, Pb) and minerals (Na, Mg, Al, K, Ca, Mn, Fe) in the sediments of stormwater management ponds located in residential catchments of southern Ontario, Canada. Trace elements and associated mineral composition of the sediments primarily clustered in three groups. In one group, several trace elements (e.g., Co and V) were correlated to soil-related minerals (Al and Fe), which indicate a predominant role of soil erosion in their movement across the urban landscape. Elements in the second group (Cd, Pb, Cu, Zn, and Mo) were positively correlated with sediment organic carbon content suggesting an importance of internal pond processing such as adsorption to organic matter. In the third group, Ca and Ag negatively correlated with most other elements likely because, at least for Ca, importation of carbonates in coarse particulate material (i.e., sand) dilutes the concentration of other trace elements. Variability in trace elements among ponds and between municipalities suggests that these elements are deposited and move differently among catchments in a relatively homogenous urban landscape. Our results demonstrate a trace element biogeochemistry in urban environments that is connected to human sources, physical disturbance of the landscape, biological processing, and underlying geological composition of the catchment.

Major and trace element geochemistry of the Bigadiç Borate deposit, Balikesir, Turkiye

This study investigates the major and trace element geochemistry of Bigadi borate deposits, the largest colemanite and ulexite deposits in the world. The known borate deposits of Turkiye were deposited in the lacustrine environment during Miocene when the volcanic activity occurred from Tertiary to Quaternary. All of the Turkish borate deposits are classified as volcanic related deposits. Boron ore deposits intercalated with claystone, mudstone, tufa and fine layered limestone show lens shape. Borate minerals formed in two zones. Tiilu and Acep-Simav open mines represented the lower and upper borate zones, respectively. Colemanite and ulexite are dominant minerals at all ore zones. The major elements of Bigadi borates contain Ca, Si, Mg, Al, Fe, S, Na, P and Mn at Tiilu, Ca, Na, Si, Mg, S, Al, P and Mn at Simav, and Ca, Na, Si, Mg, S, AI and Mn at Acep samples respectively. Except for Li, Mo, Sb, As, Sr and Se, concentrations of other trace elements are significantly lower than averages of earth crust and andesite at the three mines. With respect to averages of earth crust and andesite, Mo, Sr, As, Li and particularly Se are enriched significantly in the Bigadi. In examining depth-dependent variations of major and trace elements, four element groups at the Tiilu site and six element groups at the Simav and Acep sites were determined. Element abudances or element geochemical trends show differences at the Tulu, Simav and Acep mines. These differences can be explained by the diversity of physicochemical conditions in the deposition environment by the effect of differences at the recharge regime and source.

Effect of CoCl2 treatment on major and trace elements metabolism and protein concentration in mice

Cobalt (Co) is a transition metal and an essential trace element, required for vitamin B12 biosynthesis, enzyme activation and other biological processes, but toxic in high concentrations. There is lack of data for the effect of long-term Co(II) treatment on the concentrations of other trace elements. We estimate the influence of cobalt chloride (CoCl2) on the relative content of different metals in mouse plasma using two-jet arc plasmatron atomic emission and on the total protein content. On average, the content of different elements in the plasma of 2-month-old balb/c mice (control group) decreased in the order: Ca>Mg>Si>Fe>Zn>Cu≥Al≥B. The treatment of mice for 60days with CoCl2 (daily dose 125mg/kg) did not appreciably change the relative content of Ca, Cu, and Zn, while a 2.4-fold statistically significant decrease in the content of B and significant increase in the content of Mg (1.4-fold), Al and Fe (2.0-fold) and Si (3.2-fold) was found. A detectable amount of Mo was observed only for two control mice, while the plasma of 9 out of 16 mice of the treated group contained this metal. The administration of Co made its concentration detectable in the plasma of all mice of the treated group, but the relative content varied significantly. The treatment led to a 2.2-fold decrease in the concentration of the total plasma protein. Chronic exposure to CoCl2 affects homeostasis as well as the concentrations and metabolism of other essential elements, probably due to competition of Co ions for similar binding sites within cells, altered signal transduction and protein biosynthesis. Long-term treatment also leads to significant weight changes and reduces the total protein concentration.The data may be useful for an understanding of Co toxicity, its effect on the concentration of other metal ions and different physiological processes.

Trace Elements Mobilization in Sediments of the Eagle Wash, Nelson, Nevada (USA)

This study examines the mobilization of cyanide (CN-) and trace elements from the Eagle Milling Site situated in the Eagle Wash of Nelson, Nevada. Contaminants (CN- and mercury [Hg]) utilized for the extraction of precious metals from ores are subject to environmental release, but concentrations of other trace elements in sediments and their enrichment ratios indicate that mobilization of trace elements lead (Pb), arsenic (As), selenium (Se), and barium (Ba) has also occurred. Storage of milling wastes in Eagle Wash and subsequent storm water mobilization and transport has resulted in increases in CN-, Hg, Pb, As, Se, and Ba in wash sediments some 6,000 m from the source area. On the basis of enrichment ratios, the Eagle Wash was found to contain CN-, Hg, Pb, As, and Ba above background levels in wash sediments. Selenium increased slightly in concentration; chromium (Cr) decreased consistently; and silver (Ag) and cadmium (Cd) were not detected. Cyanide, Hg, Pb, Ba, Se, and As enrichment ratios were > 1.5, indicating anthropogenic enrichment in sediments, whereas Cr enrichment ratios were <1.5, indicating no anthropogenic enrichment.

Using watershed characteristics, sediment, and tissue of resident mollusks to identify potential sources of trace elements to streams in a complex agricultural landscape

Trace elements used in animal feed additives can be introduced to aquatic environments through application of manures from animal feeding operations to agricultural land as fertilizer. The use of poultry feed additives containing arsenic (As) is of particular concern in the Shenandoah River watershed (Virginia, USA), an agricultural landscape with a high density of poultry operations. This study investigated the relationship between watershed characteristics of Shenandoah River tributaries and trace element concentrations in streambed sediment and tissue of resident mollusks, including: Asian clams (Corbicula fluminea), which are commonly used biomonitors, and pleurocerid snails (Leptoxis carinata), which are generally understudied. Results failed to support the primary hypothesis of a predictive relationship between watershed densities of poultry operations and As concentrations in sediment and mollusk tissue. However, there were statistical relationships between land use in tributary watersheds and other trace elements in sediment (Cu, Mn, Pb, Zn) and tissue (Cd, Hg, Pb). Principal components analysis of the sediment data suggested a possible geologic source of As at some sites. Tissue concentrations of As were significantly higher in snails than in clams, but clams accumulated higher concentrations of other trace elements (Cd, Cr, Hg, Pb, Se). Snails may be useful biomonitors of environmental As, but appear to be less suitable than clams for studies of landscape sources of other trace elements.