Differences In Trace Element Concentrations Research Articles

Discrimination of Quartz Genesis Based on Explainable Machine Learning

Quartz is an important mineral in many metal deposits and can provide important indications about the deposit's origin through its chemical composition. However, traditional low-dimensional analysis methods are ineffective in utilizing quartz's chemical composition to reveal the deposit's origin type. In this study, 1140 quartz samples from eight geological environments were collected, and three machine learning (ML) models—random forest, eXtremely Greedy tree Boosting (XGBoost), and light gradient boosting machine (LightGBM) were used to classify quartz deposits. The application of the Shapley Additive Explanation (SHAP) algorithm and Spearman correlation analysis is utilized to interpret the predictive results of the model and analyze feature correlations, aiming to enhance the credibility of the classification results and discover underlying patterns. Finally, a visualization method based on XGBoost and t-SNE was proposed. By calculating SHAP values, the key geochemical indicators that differentiate each type of quartz deposit were determined. Furthermore, the impact of varying concentrations of different trace elements on the identification of quartz deposits was analyzed. This study demonstrated the effectiveness of using machine-learning algorithms based on trace elements to classify quartz and provided new insights into the relationships between trace elements and quartz genesis, as well as the effects of different trace element combinations and concentrations on quartz identification.

Tracing nickel smelter emissions using European honey bees

This study investigated trace element contamination in honey bees inhabiting urban areas around the South Pacific's largest and longest operating nickel smelter in Nouméa, New Caledonia. There remains a paucity of research on the environmental impact of nickel smelting, and to date, there has been no assessment of its effects on the popular practice of beekeeping, or whether honey bees are a suitable tracer for nickel smelting emissions. Honey bees and honey were sampled from 15 hives across Nouméa to ascertain linkages between nickel smelter emissions, environmental contamination, and trace element uptake by bees. Comparison of washed and unwashed bees revealed no significant difference in trace element concentrations, indicating trace elements bioaccumulate within the internal tissues of bees over time. Accordingly, trace element concentrations were higher in dead bees than those that were sampled live, with smelter related elements chromium, cobalt and nickel being significantly different at p < 0.05. Except for boron, trace element concentrations were consistently higher in bees than in honey, suggesting that the transfer of trace elements from bees during honey production is negligible. Elevated concentrations of potentially toxic trace elements including cobalt, chromium and nickel in bees declined with distance from smelting operations (Spearman's Rho, p < 0.05), indicating the relationship between environmental contamination and the uptake of trace elements by bees. The findings of this study emphasise potential environmental and human health risks associated with trace element contamination from nickel smelting operations and affirm the use of honey bees as a biomonitor of potentially harmful nickel smelting emissions.

Effects of Diabetes on Elemental Levels and Nanostructure of Root Canal Dentin

IntroductionThis study evaluated the effects of diabetes mellitus (DM) on the nanostructure of root canal dentin using high-resolution transmission electron microscopy (HRTEM) and inductively coupled plasma mass spectrometry (ICP-MS). MethodsTwenty extracted human premolars from diabetic and nondiabetic patients (n = 10 in each group) were decoronated and sectioned horizontally into 40 2-mm-thick dentin discs, with each disc designated for a specific test. ICP-MS was used to determine the different elemental levels of copper, lithium, zinc, selenium, strontium, manganese, and magnesium in diabetic and nondiabetic specimens. HRTEM was used to analyze the shape and quantity of the apatite crystals in diabetic and nondiabetic dentin at the nanostructural level. Statistical analysis was performed using Kolmogorov-Smirnov and Student t test (P < .05). ResultsICP-MS revealed significant differences in trace element concentrations between the diabetic and nondiabetic specimens (P < .05), with lower levels of magnesium, zinc, strontium, lithium, manganese, and selenium (P < .05), and higher levels of copper in diabetic specimens (P < .05). HRTEM revealed that diabetic dentin exhibited a less compact structure with smaller crystallites and significantly more crystals in the 2500 nm2 area (P < .05). ConclusionDiabetic dentin exhibited smaller crystallites and altered elemental levels more than nondiabetic dentin, which could explain the higher root canal treatment failure rate in diabetic patients.

Buffer zone-based trace elements indicating the impact of human activities on karst urban groundwater

The tanglesome allocation of landscape types at various spatial dimensions is an important component influencing the quality of groundwater environment in karst cities. Trace elements can be used as indicators of the extent of impact on groundwater which is an effective means of tracing groundwater contamination. In this study, we studied the influence of landscape patterns on trace elements in groundwater of typical karst cities in Southwest China (Guiyang City) on a multi-spatial scale by using multivariate statistical analysis. According to the sampling points, buffer zone scales with different radii (500 m, 1000 m, 1500 m, and 4000 m) were established to quantify the land use model. There are suburban and urban differences in trace element content. The city center has higher levels of trace elements compared to suburban areas, especially Li, Ni, Tl, Cu, Sr, Co, As, and Mn. In addition, the outcomes of the multiple linear regression had shown that the size effect of the association from landscape pattern to trace elements varies with different indicators and parameters. The results of redundancy analysis showed an overall change in trace elements was better interpreted by the landscape pattern of the 1500 m-scale buffer. At the same time, at the 1500 m scale, Ni, Tl, Cu, Co, As, Cr, Sr, Li, and Mn were positively correlated with the urban landscape index (4LPI, 4LSI), influenced by urban anthropogenic activities, while Cd, Zn, and Pb were positively correlated with the cropland landscape index (1AI, 1LPI), influenced by agricultural activities. This study indicates that trace elements are a reliable indicator for tracing groundwater contamination. The buffer zone can reflect the extent of urban impacts on groundwater and provide a new and effective analytical tool for groundwater management.

The concentrations of bone calcium, phosphorus and trace metal elements in elderly patients with intertrochanteric hip fractures.

Trace metal elements may play a crucial role in bone mineralization and metabolism. However, the quantification of trace element concentrations in human bone tissue has received little attention. Bone tissue samples were collected from 55 elderly patients (15 males and 40 females) with intertrochanteric hip fractures. The calcium, phosphorus, manganese, iron, copper, and zinc concentrations in the cortical bone zone, cancellous bone zone, and junction zone between cortical and cancellous bone were determined by energy-dispersive X-ray fluorescence (EDX). The differences in trace element concentrations in the three regions were compared, and the correlation between gender and bone trace element contents of the bones was analyzed using the Kruskal-Wallis's test. The correlation between age, body mass index (BMI), and bone calcium, phosphorus concentrations, and trace elements in three bone zones was determined using Spearman correlation analysis. The Kruskal-Wallis test showed no difference in bone phosphorus concentration among the three regions. In contrast, the difference in the concentrations of bone calcium and four metal elements was statistically significant (P<0.01). In addition, no statistical differences were observed in the concentrations of trace elements among the three regions in elderly male and female patients. Spearman correlation analysis showed a strong negative correlation between bone calcium and phosphorus in three bone regions (r=-0.999, -0.95, -0.998, P < 0.01) and a significant positive correlation between trace metal elements in the cancellous bone zone. In the junction zone, the BMI showed a strong positive correlation with bone calcium content (r=0.347, P=0.009) and a significant negative correlation with phosphorus content (r=-0.349, P=0.009). Bone calcium and phosphorus were the main components of hydroxyapatite, and these two elements accounted for the majority of bone mineral salts. Trace metal elements are essential for bone metabolism and specific synergistic interactions. BMI may be associated with bone calcium and phosphorus contents in elderly patients with osteoporosis.

Variation in Trace Element Concentrations with Size in Sea Urchin Skeletal Components

Environmental ecotoxicology studies use sea urchin skeletal components to examine potential changes in concentrations of trace element pollutants. To date, such studies have not considered how body size may alter the innate concentrations of trace elements in a given skeletal component. The present study examines this issue using the common nearshore sea urchin Lytechinus variegatus as a model species. Concentrations of barium, boron, manganese, and strontium was measured using ICP-OES in three major skeletal subcomponents (Aristotle's lantern, spines, and test) of individuals' representative of five size cohorts spanning the late juvenile to adult. Concentrations of three of the four elements, barium, boron, and manganese, varied significantly with body size, largely declining as test diameter increased. As concentrations of trace elements was normalized to skeletal mass originated from collections of individuals in pristine bay waters and from the same population at the same time, differences in trace element concentrations are innately ontogenetic. Accordingly, future ecotoxicological studies employing skeletal subcomponents of sea urchins should consider the relationship between trace element concentration and body size when designing sampling regimes.

Comparison Study of Nontreated and Fermented Wheat Varieties 'Ada', 'Sarta', and New Breed Blue and Purple Wheat Lines Wholemeal Flour.

Simple SummaryNowadays, consumers are looking for higher functional value products that can meet the nutritional requirements of functional compounds. Wheat is the most important crop in the world, and to improve its functional properties, colored wheat has become a very attractive option. However, most of the valuable compounds of the wheat cereal (including colored) are located in the outer layer of the cereal. From this point of view, application of non-refined (wholemeal) flour became very important. The aim of this study was to analyze and compare physico-chemical and microbiological parameters of the nontreated ‘Ada’, ‘Sarta’, and new breed blue and purple wholemeal wheat lines with those fermented with lactic acid bacteria (LAB) strains (Pediococcus acidilactici, Liquorilactobacillus uvarum, Lactiplantibacillus plantarum). It was found that all of the used LAB strains are suitable for the tested wheat wholemeal fermentation. However, most of the analyzed parameters were influenced by the wheat variety, the type of LAB used for fermentation, and their interaction. Despite the fact that fermented wheat wholemeal showed a large number of viable LAB, good acidification rates, and a more diverse volatile compound profile. further studies are needed to indicate the technological parameters that lead to the lowest BA formation and mycotoxin degradation.The aim of this study was to analyze and compare the acidity, microbiological, and chromaticity parameters; fatty acid (FA) and volatile compound (VC) profiles; and biogenic amine (BA), macro- and microelement, and mycotoxin concentrations in nontreated ‘Ada’, ‘Sarta’, and new breed blue (DS8472-5) and purple (DS8526-2) wheat lines wholemeal (WW) with those fermented with lactic acid bacteria (LAB) possessing antimicrobial/antifungal properties, isolated from spontaneous sourdough: Pediococcus acidilactici-LUHS29, Liquorilactobacillus uvarum-LUHS245, Lactiplantibacillus plantarum-LUHS122). All the fermented WW showed >8.0 log10 CFU/g of LAB count, and the type of LAB was a significant factor in the WW acidity parameters. Phenylethylamine was the predominant BA in WW, and the wheat variety (WV), the type of LAB, and their interaction were significant factors on the BA formation. Despite the fact that some differences in trace element concentrations in WW were obtained, in most of the cases fermentation was not a significant factor in their content. The main FAs in WW were palmitic acid, all-cis,trans-octadecenoic acid, and linoleic acid. Fermented WW showed a more diverse VC profile; however, the influence of fermentation on deoxynivalenol in WW was varied. Finally, further studies are needed to indicate the technological parameters that would be the most effective for each WV, including the lowest BA formation and mycotoxin degradation.

Effect of balanced mineral supplements on milk productivity of cows

The implementation of the genetic potential of cows is primarily related to the usefulness of providing cows with nutrients, including trace elements, during lactation. Therefore, the purpose of the study was to determine the optimal doses of mineral supplements of zinc (Zn), manganese (Mn), and cobalt (Co) in the diet of dairy cattle by lactation phases and evaluate the economic efficiency of their use. To achieve this goal, a scientific and economic experiment was conducted, for the organisation of which 5 subgroups of cows were formed, 10 individuals each – group 1, which was the control, and 4 experimental groups. According to the experiment design, animals of different groups were fed different amounts of mixed ligand complexes of Zn, Mn, and Co. During the experiment, productivity, dry matter consumption, metabolism, and economic efficiency were evaluated. Based on experimental studies of the use of mineral supplement complexes of Zn, Mn, and Co, in comparison with their sulphate salts, it was found that during the first 100 days of lactation, optimal for highly productive individuals were doses in one kg of dry matter of the feed mixture: Zn – 60.8 mg; Mn – 60.8 mg; Co – 0.78 mg, which were provided by their mixed ligand complexes and which were lower by 20% of the recommended ones and led to an increase in milk productivity of cows by 15%, and profit – by 47%. In the second 100 days of lactation, the best productivity indicators were found in cows that consumed a feed mixture in which the concentration in one kg of dry matter was: Zn – 35 mg, Mn – 35 mg, and Co – 0.4 mg due to the introduction of mixed ligand complexes of trace elements. The advantage of animals in this group over the control group in terms of milk productivity was 18%, in terms of profit – 29%. In the last 100 days of lactation, the best performance indicators were in cows with a dry matter content of Zn – 35 mg, Mn – 35 mg, Co – 0.4 mg per kg of feed mixture. They exceeded the control in terms of milk yield by 9%, and profit – by 42%. Thus, it is proved that highly productive cows require different concentrations of trace elements during lactation. It is proved that due to the introduction of balanced mineral supplements in the diet, the optimal amount of trace elements is less than the use of inorganic compounds, which has a positive effect on the environment by reducing the content of these minerals in manure

DIAGNOSIS OF THYROID MALIGNANCY USING TRACE ELEMENTS OF NODULAR TISSUE DETERMINED BY X-RAY FLUORESCENCE ANALYSIS

Background: Benign (TBN) and malignant (TMN) thyroid nodules are a common thyroid lesion. The differentiation of TMN often remains a clinical challenge and further improvements of TMN diagnostic accuracy are warranted. The aim of this study is to evaluate the possibilities of using differences in trace element contents (TEs) in nodular tissue to diagnose thyroid malignancies and to determine the sensitivity, specificity, and accuracy for most informative TEs in the diagnosis of TMN. Methods: Contents of TEs such as bromine (Br), copper (Cu), iron (Fe), iodine (I), rubidium (Rb), strontium (Sr), and zinc (Zn) were prospectively evaluated in “normal” thyroid (NT) of 105 individuals as well as in nodular tissue of thyroids with TBN (79 patients) and to TMN (41 patients). Measurements were performed using energy-dispersive X-ray fluorescent analysis. Results: It was observed that in TMN tissue the mean mass fractions of I and Zn were lower while the mean mass fraction of Rb was higher than in NT and TBN tissue. It was demonstrated that the I contents is nodular tissue is the most informative parameter for the diagnosis of thyroid malignancy. It was found that “Sensitivity”, “Specificity” and “Accuracy” of TMN identification using the I level in the needle biopsy of affected thyroid tissue (87±5%, 96±2% and 94±2% respectively) were significantly higher than that made using ultrasound screening and cytological test of fine needle aspiration biopsy. Conclusions: It was concluded that determination the I level in a needle biopsy of TNs using energy-dispersive X-ray fluorescent analysis, is a fast, reliable, and informative diagnostic tool that can be successfully used as an additional test of thyroid malignancy identification. Peer Review History: Received: 11 March 2022; Revised: 9 April; Accepted: 28 April, Available online: 15 May 2022 Academic Editor: Dr. Emmanuel O. Olorunsola, Department of Pharmaceutics &amp; Pharmaceutical Technology, University of Uyo, Nigeria, olorunsolaeo@yahoo.com UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file: Reviewer's Comments: Average Peer review marks at initial stage: 6.0/10 Average Peer review marks at publication stage: 7.0/10 Reviewers: Prof. Dr. Hassan A.H. Al-Shamahy, Sana'a University, Yemen, shmahe@yemen.net.ye Dr. U. S. Mahadeva Rao, Universiti Sultan Zainal Abidin, Terengganu Malaysia, raousm@gmail.com

High resolution elemental characterization of prehistoric flint sources in southern Israel: Implications for archaeological provenance studies

Identifying the geological sources of archaeological flint is crucial to various studies in prehistoric research. Here we present a study of flint sources in southern Israel using elemental analysis. Six Neolithic quarries and three geological outcrops of several geological formations were sampled and analyzed by ICP-MS in order to investigate whether differences in trace element concentrations can be used to distinguish between flint sources. Using (1) patterns of chondrite-normalized rare earth elements (REE), and (2) new advanced statistical methods utilizing the concentrations of REE and 25 additional elements, we were able to clearly differentiate between Upper Cretaceous and Eocene flints, and in certain cases also between flint sources of different ages within the Upper Cretaceous across the southern Levantine landscape. In addition, we used the newly established elemental database and the methods developed in this research as a pilot study towards establishing a regional dataset and locating target sites for flint exploited in those sources. This concept is evaluated by investigating the elemental analyses of flint artifacts from the Neolithic settlement which is nearest to the quarries and outcrops in the eastern part of our research area – the late Pre-Pottery Neolithic settlement in the Wadi Faynan region (Jordan). The current results indicate that the flint from the studied quarrying sites in the eastern Negev was probably not exploited by the inhabitants of Wadi Faynan during the Neolithic, but suggest that multiple sources were used. This highlights the need to expand the database by analyzing additional flint from other potential sources.

Comparison of the Content of Several Elements in Seawater, Sea Cucumber Eupentacta fraudatrix and Its High-Molecular-Mass Multiprotein Complex.

Metal ions and other elements play many different critical roles in all biological processes. They can be especially important in high concentrations for the functioning of organisms living in seawater. It is important to understand how much the concentrations of different trace elements in such organisms can be higher than in seawater. Some marine organisms capable of rapid recovery after different injuries are fascinating in this regard. Sea cucumbers Eupentacta fraudatrix can completely restore all organs and the whole body within several weeks after their division into two parts. Here, for the first time, a comparison of the content of different elements in seawater, sea cucumber, and its very stable multiprotein complex (2000 kDa) was performed using two-jet plasma atomic emission spectrometry. Among the 18 elements we found in sea cucumbers, seawater contained only six elements in detectable amounts, and their content decreased in the following order: Mg > Ca > B > Sr ≈ Si > Cr (0.13–930 µg/g of seawater). The content of these elements in sea cucumbers was higher compared with seawater (-fold): Ca (714) > Sr (459) > Cr (75) > Si (42)> B (12) > Mg (6.9). Only four of them had a higher concentration in the protein complex than in seawater (-fold): Si (120.0) > Cr (31.5) > Ca (9.1) > Sr (8.8). The contents of Mg and B were lower in the protein complex than in seawater. The content of elements additionally found in sea cucumbers decreased in the order (µg/g of powder) of P (1100) > Fe (47) > Mn (26) > Ba (15) > Zn (13) > Al (9.3) > Mo (2.8) > Cu (1.4) > Cd (0.3), and in the protein complex, in the order of P (290) > Zn (51) > Fe (23) > Al (14) ≈ Ni (13) > Cu (7.5) > Ba (2.5) ≈ Co (2.0) ≈ Mn (1.6) > Cd (0.7) >Ag (0.2). Thus, sea cucumbers accumulate various elements, including those contained in very low concentrations in seawater. The possible biological roles of these elements are discussed here.

Trace elements in whole blood in the general population in Trøndelag County, Norway: The HUNT3 Survey

BackgroundBiomonitoring of a cohort within a large health survey can provide reliable information on trace element status. The main aims of this study were 1) to determine the concentrations of 28 trace elements in whole blood samples from the general population of the Nord-Trøndelag region, Norway, and 2) to investigate how trace element concentrations vary with geographical area, lifestyle, and socio-demographic factors. MethodsWhole blood samples were collected in the third survey of the Trøndelag Health Survey (HUNT3), a large population-based study in Norway. In total, 1011 whole blood samples from individuals aged 20–91 years were analyzed using high resolution inductively coupled plasma-mass spectrometry (HR-ICP-MS). We compared trace element concentrations (As, B, Be, Br, Ca, Cd, Cr, Cs, Cu, Ga, Au, In, Fe, Pb, Hg, Tl, Mg, Mn, Mo, Ni, Rb, Sc, Se, Ag, Sr, Sn, W and Zn) between three geographical areas (coastal, fjord/town, inland/mountain) using multivariable linear regression and assessed differences in trace element concentrations with socio-demographic and lifestyle factors using general linear models. ResultsTrace element concentrations were generally comparable to levels reported in other recent studies and suggest low exposure to toxic trace elements in the region. We found geographical differences in concentrations of 19 trace elements. As, Br, Hg, and Se concentrations were higher on the coast compared to the fjord/town and inland/mountain areas, suggesting that the marine environment is an important source of exposure for these trace elements. In addition, socio-demographic and lifestyle characteristics, particularly age and sex, were associated with differences in trace element concentrations. ConclusionsWe report concentrations of 28 trace elements in the general population of a rural region with low exposure to pollution. Whole blood concentrations of trace elements varied with geographical area, the participants' lifestyle, and socio-demographic characteristics, highlighting the importance of considering these factors when evaluating trace element status in a population.

Natal origin and migration pathways of Mekong catfish (Pangasius krempfi) using strontium isotopes and trace element concentrations in environmental water and otoliths.

To improve our knowledge of the migration pathway of a highly threatened fish species along the Mekong River, strontium isotope ratios (87Sr/86Sr) and 18 trace element concentrations were measured in the water and in the otoliths of an anadromous catfish, Pangasius krempfi, to infer its natal origin and potential migration pathways. Water was sampled at 18 locations along the mainstream, tributaries and distributaries of the Mekong River. To check for accuracy and precision, measurements of the 87Sr/86Sr ratios and trace element concentrations were then compared in two laboratories that use different analytical methods. Differences in trace element concentrations between locations were not significant and could not, therefore, be used to discriminate between migration pathways. However, the Mekong mainstream, tributaries and distributaries could all be discriminated using Sr isotopes. The 87Sr/86Sr profiles recorded in P. krempfi otoliths showed that there were three contingents with obligate freshwater hatching and variable spawning sites along the Mekong mainstream, from Phnom Penh (Cambodia) to Nong Khai (Thailand) or further. After hatching, the fish migrated more or less rapidly to the Mekong Delta and then settled for most of their lifetime in brackish water. Spawning habitats and migration routes may be threatened by habitat shifts and the increasing number of hydropower dams along the river, especially the contingents born above Khone Falls (Laos). The conservation of P. krempfi, as well as other migratory fish in the Mekong River, requires agreements, common actions and management by all countries along the Mekong River. This study highlighted the importance of using both Sr/Ca and 87Sr/86Sr ratios to understand life history of anadromous fishes as the 87Sr/86Sr ratio in the water was shown to be less effective than the Sr/Ca ratio in identifying movements between different saline areas.

Deep Subsoil Storage of Trace Elements and Pollution Assessment in Mountain Podzols (Tatra Mts., Poland)

Research highlights: this article refers to the deep storage of trace elements as a result of the podzolization process under different types of vegetation cover. This is also an attempt to trace differentiation in the distribution of trace elements in mountain soils under the podzolization process. Background and objectives: we focused on estimating whether the podzolization process of soils under various vegetation covers led to the deep storage of trace elements in the subsoil. Furthermore, the potential contamination of studied soils with trace elements using pollution indices was assessed. Materials and methods: in thirteen soil profiles under three different vegetation types, chosen chemical–physical properties, e.g., organically bonded and active forms of Al and Fe, podzolization indices, and trace element content (Cd, Pb, Zn, Cu, Cr, and Ni) were analyzed. Additionally, pollution indices, such as Geoaccumulation Index, Potential Ecological Risk, Pollution Load Index, and Contamination Security Index, were calculated. Results: the distribution of Al and Fe varied among the soil profiles, suggesting different rates of podzolization processes that were partially dependent on the type of vegetation. Exceptionally high values of Alo and Feo were noted in profiles P1 and P2 (1.53% and 2.52% for Alo, and 2.13% and 1.46% for Feo, respectively) in horizons Bs and BsC under Plagiothecio-Piceetum taricum. Some of the soils showed the expected distribution of trace elements as the result of the podzolization process revealed their accumulation in the spodic horizon. Moreover, four different patterns of trace element distribution were recognized. Often, the accumulation of trace elements occurred in Bs/BsC horizons, e.g., in case of Zn soils P8, P9, and P10, which reached 65.8, 68.0, and 72.30 mg∙kg−1, respectively. However, there were no large differences in trace element content in soils independent of the vegetation type. The pollution indices in most samples confirmed lack of contamination with trace elements. Only several soil horizons were moderately polluted and showed deterioration of soil quality or very low severity. Conclusions: in the majority of studied soils, the podzolization process resulted in the deep storage of trace elements, i.e., the accumulation of spodic horizon; however, in certain cases, it might have been related only to the different lithology, and appeared as anomalies not related to the dominant soil-forming process. Anomalies were characterized by a much higher content of trace elements in the BsC horizon compared to the upper O horizons. Obtained data of trace elements, as well as values of pollution indices, did not indicate pollution. This lack of pollution was related to localization of soils within a topographic barrier that protected them from the deposition of potential trace element–rich pollution.

Optimised ICP-MS quantification method for using animal faeces as a measure of protected area ecosystem health

Pollution is a key threat to biodiversity and ecosystem health within protected areas. Using a non-invasive, multi-matrix approach, sediment, vegetation and faecal material from lion (Panthera leo) and giraffe (Giraffa camelopardalis) were collected and assessed for the simultaneous quantification of 20 trace elements using an optimised method for Inductively Coupled Plasma-–Mass Spectrometry (ICP-MS). Method Linearity was confirmed over an analytical range of 0.1–50 mg/kg for aluminium (Al) and iron (Fe); 0.4–400 µg/kg for vanadium (V), cobalt (Co), molybdenum (Mo), and cadmium (Cd); 0.5–5 µg/kg for mercury (Hg); and 1–1 000 µg/kg for elements arsenic (As), boron (B), barium (Ba), chromium (Cr), copper (Cu), manganese (Mn), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), tin (Sn), strontium (Sr) and zinc (Zn). Coefficient of determination (R2) was above 0.99 for all elements. Accuracy (% recovery) and precision (% RSD) of replicate measurements for certified reference material controls fell within 20% of expected value at lower concentrations and 15% at higher concentrations for all elements except Al. Results for instrument and method limit of detections (LOD), method limit of quantification (LOQ) and expanded uncertainty were satisfactory. Preliminary data indicate As, Cd, Cr, Cu, Hg, Ni, Pb, Se, and Zn were present in all matrices evaluated. This raises concerns regarding the combined action of multiple elements at concentrations that can adversely affect ecosystem and wildlife integrity.•Sample quantity is reduced due to the power and sensitivity of ICP-MS.•The optimised method is capable of detecting differences in trace element concentrations over large orders of magnitude in animal faeces containing different amounts of organic content.•The method can be applied to the quantification of essential and potentially toxic elements in faeces across a wide range of terrestrial species.

Trace element composition of stibnite: Substitution mechanism and implications for the genesis of Sb deposits in southern China

Though stibnite is among the most predominant Sb-bearing mineral phases in most Sb deposits, little is known about the trace elements and their substitution mechanism in stibnite that are valuable to better decipher the genesis of Sb deposits. This study determined quantitatively the trace element compositions of stibnite from two representative Sb deposits (Xikuangshan and Woxi) in southern China using high-resolution LA-ICP-MS. Results show that stibnite at Xikuangshan contains measurable Hg and As (typically 10–100 ppm); however, As, Cu, and Pb are the most abundant trace elements at Woxi (generally 100–500 ppm). Furthermore, the relatively smooth LA-ICP-MS profiles indicate As, Cu, and Pb primarily occurs as solid solution in stibnite. Hence the substitution 2Sb3+↔Cu++Pb2++As3+ is likely responsible for the enrichment of Cu, Pb, and As in stibnite. Other trace elements, including Au, Ag, Bi, In, Mo, Sn, Co, Cr, V, Zn, Ni, Ga, Ge, Rb, Sr, Pd, Cd and U, are generally at concentrations of 0.01–1 ppm, with spiky LA-ICP-MS depth profiles, which are indicative of their presence as sparse micro-inclusions within stibnite. The apparent differences in trace element concentrations of stibnite suggest that the stibnite from two deposits may have been generated by different processes, or may reflect differences in fluid chemistry. The relative enrichment of As, Cu, and Pb indicate that the original Sb-bearing fluids for the Woxi deposit were likely enriched in these elements in the source region, but a geochemical segregation led to the formation of stibnite-dominated ores. In contrast, the monomineralic ores at Xikuangshan was likely originated from an initial absence of these elements in their source regions. The Hg/(Cu + Pb) ratio for the Xikuangshan Sb deposits is typically greater than 1 but the Woxi deposit tends to be much lower than 1. Therefore, the differences in trace element composition in stibnite can be useful to discriminate between Sb deposit types.

Compositional modification and trace element decoupling in rutile: Insight from the Capricorn Orogen, Western Australia

The trace element composition of rutile is widely used to constrain the temperature and timing of geological events, the provenance of detrital grains and as a potential indicator of proximal ore mineralisation. Understanding the processes of trace element mobility in rutile is therefore paramount to the successful application of rutile geochemistry to geological research. Using a combination of electron backscattered diffraction and laser-ablation split-stream ICP-MS, we studied the microtextures, trace-element contents and U–Pb isotopes of rutile from the siliciclastic rocks of the Mesoproterozoic Edmund Group, Capricorn Orogen (Western Australia). The Capricorn Orogen experienced multiple tectonothermal events during the Proterozoic under conditions spanning from low- to high-grade metamorphism. Rutile textures, U–Pb ages, trace-element variations and calculated Zr-in-rutile temperatures reveal different generations of rutile, including detrital or metamorphic-hydrothermal grains.U–Pb age data of detrital rutile indicate a wide span of ages (ca. 2.7–1.7 Ga) of the source rocks and Cr-Nb compositions point to metamafic, metapelitic and granitic origins for this rutile. The youngest detrital ages of 1.68 Ga constrain the maximum depositional age of the sedimentary package. The comparison of age spectra across the stratigraphy indicates a change in provenance, with sourcing from circa 1.7 Ga rocks during early stages of deposition, followed by unroofing of older basement during deposition of the youngest units of the Edmund Group. Partial resetting of detrital rutile is observed in the increase of 207Pb/206Pb ratios, accompanied by a decrease of Zr-in-rutile calculated temperatures. Lower-temperature metamorphic-hydrothermal rutile yielded imprecise Mesoproterozoic ages (1.3–1.1 Ga). This rutile has significant variations of Zr/Hf and Nb/Ta extending to values both lower and higher than primitive mantle, which may record crystallisation from, or interaction with hydrothermal fluids. Partial remobilisation of trace elements in metamorphic-hydrothermal rutile is demonstrated by sub-grain domains with sharp geochemical variations and by evidence of element diffusion at grain margins. Orders of magnitude differences in trace element concentrations (including Nb, Cr and Zr) in metamorphic-hydrothermal rutile grains suggest thorough investigation of rutile textures needs to be carried out prior to using the trace element concentrations in rutile for provenance and Zr-in-rutile temperature studies.

Structure, kinematics and composition of fluid-controlled brittle faults and veins in Lower Cretaceous claystones (Lower Saxony Basin, Northern Germany): Constraints from petrographic studies, microfabrics, stable isotopes and biomarker analyses

Investigation of fault rocks is crucial for the evaluation of sealing properties of rock formations considered as oil and gas storage or for the disposal of heat-generating radioactive waste. Even in tight rock formations, fluid flow may concentrate along brittle faults. The present study focuses on the sealing properties of faulted Lower Cretaceous clay- and siltstones encountered in drill cores from the central and eastern Lower Saxony Basin (Germany). Our investigations are based on a multidisciplinary approach including microstructural, mineralogical-geochemical, stable isotope and biomarker analyses.The new data suggest that preexisting discontinuities and/or sedimentary heterogeneities played a significant role for the increase in fluid pressure and formation of mode I veins within low permeability claystones. High-strain domains of fault cores consist of fine-grained fault gouge. A scaly fabric of varying deformation intensity is present around larger faults. Calcite-precipitation in faults and complex mineralized veins, and the differences in trace element concentrations of various veins, reflect several phases of palaeofluid activity. Calcite precipitation in the fault rocks led to elevated amounts of Mn, Ba and/or Sr. Isotope signatures indicate a local carbonate source for the origin of thin calcite coatings of fault planes, but a more complex palaeofluid interaction for the larger faults and for complex veins, consistent with the microfabrics. Biomarker signatures reveal the presence of mature hydrocarbons pointing to hydrocarbon migration in sections where steep, only weakly mineralized faults occur.The new results suggest that faulted claystones represent critical zones with a potentially reduced barrier capability consistent with published data.

Organic matter and metal contents within the Cretaceous rocks of the Slata-Guern Halfaya area, North-Central Tunisia: Implication for ore genesis

The proximity of ore deposits, in the Slata-Guern Halfaya area (north-central Tunisia), to the Cretaceous Fahdene and Bahloul Formations raises the question of the role that these formations played in the emplacement of the ore. These formations are rich in organic matter (OM) with total organic carbon (TOC) values in the range of 0.2–1.4% and 0.62–5.46%, respectively, for the Albian–Vraconian facies of the Fahdene Formation at Slata and the Cenomano–Turonian facies of the Bahloul Formation at Guern Halfaya. Rock-Eval pyrolysis data indicates that the OM in the Fahdene Formation at Slata is relatively mature (oil window, 431 °C < Tmax < 447 °C) and with variable Production Index (PI, %)). Conversely, the OM preserved in the Bahloul Formation at Guern-Halfaya is immature (423 °C < Tmax < 433 °C). The analysis of whole rocks and the LA-ICP-MS analysis of inorganic fraction reveal high concentrations of trace elements (e.g., Pb, Zn) in both formations. We infer that seawaters were enriched in trace elements during the deposition of both formations. These trace elements were then sequestered by both organic and inorganic matter. Given the similar OM-rich lithologies (carbonates and marls) of these formations, the difference in trace element concentrations can be due to their contrasting thermal maturities. Concentrations of trace elements (Pb, Zn, Cd, and Ni) moderately correlate with OM content (TOC, pyrolyzable hydrocarbons and residual OM) positively in the organically-immature Guern-Halfaya ore district and negatively in the organically-mature Slata mining district. Subsidence of the OM-rich Cretaceous Formations (Fahdene and Bahloul), located in the deep part of the basin, resulted in thermal cracking of kerogen in these formations. This catagenesis allowed the dissociation of organo-metal ligands and subsequent expulsion of metals in low viscosity hydrocarbons during the Alpine orogeny. Metals and hydrocarbons migrated together from the subsiding areas of the basin and ultimately encountered salt diapirs. The mixing between metal-rich hydrocarbons and ore-bearing associated fluids, on the one hand, and the Triassic-derived sulfate-rich fluids, on the other hand, led to the precipitation of sulfides and sulfates at different times. A potentially effective trilogy to be targeted for base metal exploration is the juxtaposition of (i) mature OM-rich formations – potential sources of metals and hydrocarbons – with (ii) diapiric evaporites that served as a source of sulfur and sulfate, and (iii) a permeable reservoir that acted as a suitable site for ore precipitation.

Tissue and Serum Trace Elements Concentration among Colorectal Patients: A Systematic Review of Case-Control Studies

Trace elements play a pivotal role in Colorectal Cancer (CRC) inhibition and development process. This systematic review provides the basic comparison of case-control studies focusing on concentration of trace elements between those with CRC and controls. The systematic review searched through two databases of Medline and Cochrane up to 24th June 2017. The search strategy focused on Population, Intervention, Comparison, and Outcomes (PICO). We searched the role of trace elements in cancer and focusing on case-control studies in CRC to obtain an insight into the differences in trace element concentrations between those with and without cancer. The serum concentrations of Ca, Cu, Mg, Mn, Se, Si, and Zn were lower in CRC patients but for Co and S the levels were higher in CRC patients. The concentrations of Cd, Cr, Cu, Mg, Mn, Pb, and Zn were increased in patients with metastasis, but not in Se. As for colon tissue specimens, inconsistent levels were reported between studies, notably in Cu, Se, and Zn. No changes were reported for B and Ca levels. Most of the trace elements in the tissue specimens showed higher concentrations of Cr, Fe, K, Mg, P, Rb, S, and Si compared to Br. With the growing interest to understand the link between trace elements in carcinogenesis and the possible interactions, multi assessment analysis of a larger cohort of samples is necessary.