Concentrations Of Individual Elements Research Articles

Phase Fraction Estimation in Multicomponent Alloy from EDS Measurement Data.

To perform quality assessments of both metal alloys and many other engineering materials, measurements of the volume fractions of phases or microstructure components are utilized. For this purpose, quantitative analysis of the evaluated components' distribution on metallographic specimens is often employed. Phases or components of the microstructure are identified based on the variation in signal received in the band of light seen. Problems with the correct identification of measurement results in this spectral band can be caused by the inhomogeneity of the etching when the alloy components are segregated. Additional uncertainty arises when the analyzed image pixel contains a boundary between grains of different phases. This article attempts to use the results of local chemical composition measurements as a source signal for quantitative evaluation of phase composition. For this purpose, quantitative maps of elemental concentration distributions, obtained with a Tescan Mira GMU high-resolution scanning electron microscope in QuantMap mode, were used as input data for the phase composition evaluation of an EN AC 46000 alloy sample. The X-ray microanalysis signal generation area may contain grains of more than one phase. Therefore, evaluation of the phase fractions in areas of individual measurements were calculated by looking for the minimum of the objective function, calculated as the sum of the squares of the deviations of the results of measurements of the concentration of individual elements from the weighted average values of solubilities of these elements in the phases.

A Multi-Target Regression Method to Predict Element Concentrations in Tomato Leaves Using Hyperspectral Imaging.

Recent years have seen the development of novel, rapid, and inexpensive techniques for collecting plant data to monitor the nutritional status of crops. These techniques include hyperspectral imaging, which has been widely used in combination with machine learning models to predict element concentrations in plants. When there are multiple elements, the machine learning models are trained with spectral features to predict individual element concentrations; this type of single-target prediction is known as single-target regression. Although this method can achieve reliable accuracy for some elements, there are others that remain less accurate. We aimed to improve the accuracy of element concentration predictions by using a multi-target regression method that sequentially augmented the original input features (hyperspectral imaging) by chaining the predicted element concentration values. To evaluate the multi-target method, the concentrations of 17 elements in tomato leaves were predicted and compared with the single-target regression results. We trained 5 machine learning models with hyperspectral data and predicted element concentration values and found a significant improvement in the prediction accuracy for 10 elements (Mg, P, S, Mn, Fe, Co, Cu, Sr, Mo, and Cd). Furthermore, our multi-target regression method outperformed single-target predictions by increasing the coefficient of determination (R2) for elements such as Mn, Cu, Co, Fe, and Mg by 12.5%, 10.3%, 11%, 10%, and 8.4%, respectively. Hence, our multi-target method can improve the accuracy of predicting 10-element concentrations compared to single-target regression.

Anthropogenic soils in a marginal landscape – Fortified manorial sites in the woodland edge zone in western Czechia

This study presents the results of a geochemical and LiDAR survey analysis carried out at the deserted medieval settlement and fortified manorial farm (motte-and-bailey) in Čečín, in Czechia (Western Bohemia, Plzeň-North District). Focusing on the site of the medieval fortification and surrounding areas, different techniques of compositional data analysis have been used in order to detect geochemical signals. The most significant anthropogenic signal was picked up within the area of the fortification itself (i.e. the motte, elements P, Ca, Mn, and Zn); in contrast to this, samples from other areas – part of the bailey/manor, and the nearby fields and forest – did return weaker, or no such signals, as was documented by individual elemental concentrations, and by the results of PCA. The analysis of historical topographical, cartographical and LiDAR data points to continuity in the economic use of the area in medieval and post-medieval times and to the possibly marginal, or secondary role of arable management at this site. One may hypothetically argue that geochemical observations (i.e. the relatively less significant enrichment and concentration of anthropogenic elements at Čečín, compared to other sites) may also substantiate the claim, or interpretation that this landscape, in the vicinity of the manor, was less impacted by farming and fertilization, and its economic functions were other than crop farming (e.g. meadow, pasture, orchard). There have been a few similar sites (i.e. fortified manorial farms) identified in the LiDAR survey of the estate of the Plasy monastery, in the woodland area and in the woodland edge zone, which have been/are currently used as meadows, in the vicinity of hunting lodges. Their historical role – as medieval manorial sites – likely contribute to the fact that they appear now, in geochemical surveys, as ‘fertile’ islands surrounded by temperate forests.

Source apportionment of water-soluble oxidative potential of PM2.5 in a port city of Xiamen, Southeast China

The main objective of this study was the source attribution of the water-soluble oxidative potential of PM2.5 in Xiamen, China. Mean concentrations of individual water-soluble trace elements varied within a wide range from <1 ng m−3 to >100 ng m−3 between November 2015 and May 2018. Their fractional solubility ranged from <5% to >70%, depending mainly on the origin, followed by meteorological conditions and atmospheric aging. The annual mean value of the volume-normalized dithiothreitol activity (DTTv) in PM2.5 between January 2017 and May 2018 in the urban area (0.632 ± 0.299 nmol min−1 m−3) was higher than in the suburban area (0.562 ± 0.247 nmol min−1 m−3) (p < 0.05), which was consistent with the spatial difference of transition metals and carbon species. DTTv were lower in summer than in winter (p < 0.05), consistent with the variations in Cu and Mn, which accounted for more than 94% of the reconstructed DTTv. DTTv could not be predicted well by lifetime cancer risk (LCR) and hazard index (HI), because the main contributors to HI (V, Ni, and Mn) and LCR (Cr(VI) and V) were different from those of DTTv. Based on the positive matrix factorization (PMF) and the multiple linear regression (MLR) models, the identified sources of DTTv at the urban/suburban sites were as follows: vehicle exhaust + biomass burning (39.9%/24.2%), primary organic aerosol (19.5%/23.9%), secondary nitrate/chlorine (10.5%/18.4%), secondary sulfate + ship emissions (18.2%/7.8%), mineral dust (2.3%/20.0%), and coal combustion (9.7%/5.6%). The results differed from those for PM2.5, LCR and HI, which had larger contributions from coal combustion and secondary sulfate + ship emission.

Australian brown seaweeds as a source of essential dietary minerals

Seaweeds are rich in essential dietary minerals, often lacking in terrestrial plant foods, with interest in Australian seaweeds rapidly increasing. We screened six Australian brown seaweeds with commercial potential for dietary mineral composition: Cystophora torulosa, Caulocystis uvifera, Durvillaea potatorum, Ecklonia radiata, Hormosira banksii and Phyllospora comosa. Spatial replicates of each species were collected from three non-urbanised sites remote from pollution sources and processed for human consumption. Dried samples were analysed by inductively coupled plasma mass spectrometry (ICP-MS) for 12 essential dietary minerals. Overall dietary mineral composition differed significantly amongst all species, except between sargassaceous species C. torulosa and C. uvifera; but concentrations of individual elements varied in complex ways. All species investigated had high concentrations of dietary minerals essential for optimal human health if consumed in realistic quantities (e.g. 10 g day−1 DW) as part of balanced diets, including the most common dietary minerals deficient in humans (iodine, iron, zinc, magnesium, calcium and selenium): iodine (888 ± 100 mg kg−1 DW) and zinc were highest in P. comosa; iron and calcium were highest in C. torulosa, but calcium was also high in E. radiata, H. banksii and D. potatorum; magnesium was highest in H. banksii, D. potatorum and P. comosa; selenium concentrations exceeded those previously reported for seaweeds for all species, except D. potatorum. The best nutritional outcomes may be achieved by regularly consumption of a diversity of seaweed species. However, further investigation into ways to reduce iodine content in some species may be required to maximise health benefits from regular consumption of these Australian seaweeds.

Accumulation of Heavy Metals in the Needles of Scots Pine of the Semipalatinsk Pre-Irtysh Region and Burabay National Park

Relict bogs in the northeastern area of the Republic of Kazakhstan are located in close proximity to sources of heavy metal pollution – non-ferrous metal ore mining and processing facilities, and highways. Monitoring of heavy metal transport in the air by means of a bioindicator such as Scots pine (Pinus sylvestris L.) is relevant for preventing the damaging effects of heavy metals on the population living in this region. The purpose of this article is to study pine needles (Pinus sylvestris L.) on the territory of the Semipalatinsk Irtysh region and the Burabay National Park to identify the features of the accumulation of heavy metals carried by atmospheric air flows, depending on the age of its formation. To determine the content of chemical elements in needles of the first, second and third year of formation from six experimental plots mass spectrometry method ISO 17294-2׃2003 was used. Its results made it possible to conduct a primary analysis of the accumulation of heavy metals in the needles of Scots pine (Pinus sylvestris L.) depending on the year of its formation. General scientific methods were also used in the analytical selection of the scientific literature to formulate the objectives of the experiments and to compare the results obtained with those of other authors. Experimental studies revealed a direct correlation between the increase in concentrations of individual metals and the age of the needles. Furthermore, an increase in concentrations of individual chemical elements has been detected in the conifers of the second year of formation. The findings can be used for further scientific research on the use of pine needles (Pinus sylvestris L.) as a bioindicator, the impact of the heavy metal composition of the north-east of Kazakhstan on plant organisms, but also used in practice to monitor the state of the environment and the management of forests.&#x0D;

Contamination of selected heavy metals in Limnothrissa miodon (Boulenger, 1906) in the four strata of Lake Kariba Zambia: are the consumers at risk?

Pollution of aquatic ecosystems is one of the major challenges affecting many countries of the world. Heavy metal pollutants, in particular, threaten the life of aquatic organisms (fauna and flora) and, more importantly, humans who consume aquatic products as a critical source of proteins. In the present study, the concentrations of selected heavy metals (cobalt- Co, Chromium-Cr, nickel- Ni and manganese- Mn) in Limnothrissa miodon, locally known as ‘Kapenta’ were assessed using the Microwave Plasma Atomic Emission Spectrometer (MP AES) 4200 at the Zambia Agricultural Research Institute (ZARI). The fish was collected from Lake Kariba, Zambia, which is divided into four fisheries management strata (I, II, III, and IV). The health risks to consumers were evaluated using the Estimated Daily Intake (EDI), Target Hazard Quotient (THQ) and Hazard Index (HI). Analysis of variance (ANOVA) was used to assess the difference in the means of heavy metal concentration across the four strata for each element. The concentrations of all the heavy metal elements were within the permissible limits considered to be safe for human consumption based on the Food and Agriculture Organization (FAO) standards. However, the concentration of individual heavy metal elements varied significantly across the strata with stratum I and II showing higher levels in general except for Mn which was highest in stratum II and III compared with the other strata. Furthermore, Mn concentration was the highest in all the strata and the highest concentration was observed in the fish from stratum II. The EDIs, THQs and HIs of each heavy metal element did not show any threat to consumers of the fish from the lake. Further studies are required to better understand the potential sources of heavy metals and to regularly monitor existing activities that may elevate the concentration levels.

UV-C Seed Surface Sterilization and Fe, Zn, Mg, Cr Biofortification of Wheat Sprouts as an Effective Strategy of Bioelement Supplementation.

Metalloenzymes play an important role in the regulation of many biological functions. An effective way to prevent deficiencies of essential minerals in human diets is the biofortification of plant materials. The process of enriching crop sprouts under hydroponic conditions is the easiest and cheapest to conduct and control. In this study, the sprouts of the wheat (Triticum aestivum L.) varieties Arkadia and Tonacja underwent biofortification with Fe, Zn, Mg, and Cr solutions in hydroponic media at four concentrations (0, 50, 100, and 200 µg g-1) over four and seven days. Moreover, this study is the first to combine sprout biofortification with UV-C (λ = 254 nm) radiation treatment for seed surface sterilization. The results showed that UV-C radiation was effective in suppressing seed germination contamination by microorganisms. The seed germination energy was slightly affected by UV-C radiation but remained at a high level (79-95%). The influence of this non-chemical sterilization process on seeds was tested in an innovative manner using a scanning electron microscope (SEM) and EXAKT thin-section cutting. The applied sterilization process reduced neither the growth and development of sprouts nor nutrient bioassimilation. In general, wheat sprouts easily accumulate Fe, Zn, Mg, and Cr during the applied growth period. A very strong correlation between the ion concentration in the media and microelement assimilation in the plant tissues (R2 > 0.9) was detected. The results of the quantitative ion assays performed with atomic absorption spectrometry (AAS) using the flame atomization method were correlated with the morphological evaluation of sprouts in order to determine the optimum concentration of individual elements in the hydroponic solution. The best conditions were indicated for 7-day cultivation in 100 µg g-1 of solutions with Fe (218% and 322% better nutrient accumulation in comparison to the control condition) and Zn (19 and 29 times richer in zinc concentration compared to the sprouts without supplementation). The maximum plant product biofortification with magnesium did not exceed 40% in intensity compared to the control sample. The best-developed sprouts were grown in the solution with 50 µg g-1 of Cr. In contrast, the concentration of 200 µg g-1 was clearly toxic to the wheat sprouts.

Peculiarities of the total content of metals in oil deposits of the Dnipro-Donetsk depression

Purpose. To establish the peculiarities of the total content of metals in oil deposits of the Dnipro-Donetsk depression and to develop a classification of deposits by this indicator. Methodology. The factual basis of the research was the results of analyzes of metals in oil from 36 deposits of the Dnipro-Donetsk depression. With the help of X-ray fluorescent analysis, at least 30 oil samples from each deposit for metals content were investigated. The deposits are selected according to the principles of maximum completeness of geochemical information, their finding in different oil and gas areas of the Dnipro-Donetsk depression, different composition of the oil system, different geological types of traps, different structure of deposits and different ages of oil collectors. X-ray fluorescent analysis was performed on the energy-dispersive spectrometer "SPRUT" SEF 01. The time of accumulation of the spectrum 600 sec. Preparation and analysis were carried out according to the standard of ASTM D 4927 - "Determination of the elemental composition of components of lubricants by X-ray fluorescent spectroscopy with dispersion by wavelength". Correlation and regression analysis was carried out by methods that were implemented in the most popular professional statistical software platforms "Statistica" and "SPSS" and their analysis in geological concepts. Findigs. To evaluate the central characteristics of the total content of metals in oil, the deposits considered more correctly use not the arithmetic mean, but the median. It is proved that the total content of metals in oil considered is associated with a reverse correlation connection with resin content, the values of the modern temperature of the productive horizon, the modern depth of productive horizon, the mineralization productive horizons; and direct correlation with the concentrations of nickel, manganese, mercury, chromium, vanadium, aluminum, cobalt, zinc, iron, paraffin, asphalt, sulfur and oil viscos boiling and oil density. Scientific novelty. It consists in the development of the natural classification of oil deposits by the overall content of metals, and to establish a connection of this indicator with the concentration of individual elements of impurities, the main components of oil and the main geological and technological indicators of deposits of the Dnipro-Donetsk depression. Practical significance. Is to establish the concentrations and the possibility of forecasting the total content of metals in the Dnipro-Donetsk depression, which in turn provides the opportunity to solve the topical problems of practical direction. The solution of a number of industrial-raw materials based on the assessment of oil as an ore raw material, since the content of some elements in them sometimes exceeds ore concentrations, so there is a possibility of their concomitant industrial removal from by-products during processing processes. The solution of technological issues, which are caused by the negative impact of some elements contained in oil, on the geological environment, production technologies and the equipment used in the course of their extraction and processing.

Палеогеографічні та фізико-хімічні дослідження ґрунту в межах античного полісу Ольвія

The publication presents the results of the palaeosols study within the antic polis of Olvia, which was located within the Dnieper-Bug estuary near the modern village of Parutino (Mykolaiv region). Field palaeogeographic research was conducted here in 2007 (Zh. Matviishyna, O. Parkhomenko) and in 2021 (A. Kushnir). During the archaeological research, several soil profiles were investigated, their macromorphological analysis was made, and soil samples were taken. The micromorphological analysis and soil analysis were carried out for the content of biogenic elements along genetic horizons at the stage of laboratory research. The results of the palaeopedological analysis indicate that full-profile Chestnut soils salinized or Salinized soils were formed on the watersheds, and on the lower terraces in the South Bug River valley – dark Chestnut salinized soils or Southern chernozems salinized. The physical-chemical composition of the soil is demonstrated primarily its alkaline character and relatively homogeneous concentration of individual chemical elements. General palaeopedology research indicates that soil cover could be a favourable factor in urbanization processes in this area in Classical Antiquity.

Variability in the Chemical Composition of Spring Waters in the Postomia River Catchment (Northwest Poland)

The paper presents the results of physicochemical analyses of spring waters in the Postomia River valley (Northwest Poland). Multivariate statistical methods, i.e., cluster analysis (CA) and principal component analysis (PCA) were used to assess the spatial distribution of similarities and differences in the concentrations of individual elements. Concentrations of macro elements (MEs), trace elements (TEs) and rare-earth elements (REEs) were analysed concerning the spring’s typology, land use structure and the distance from roads. The results showed that the springs waters are of the Ca2+-HCO3− and Ca2+-HCO3−-SO42− types, medium hardness and low mineralisation. The study revealed differences between valley springs and scarp-foot springs in terms of electrical conductivity and concentrations of F−, SO42−, NO3−, Mg2+, Ba, Zn, and U. Greater variability was observed between the physical and chemical conditions of the spring waters due to their location in terms of land use. Springs located in agricultural areas had lower pH values than those in other areas, and higher NO3− concentrations. The pH values and concentrations of Fe, Mo, Rb, and Th in urban areas were higher than in agricultural areas. Moreover, the concentrations of F−, Cl−, K+, Na+, Mo, Sb, Se, and Sr were higher in urban areas than in forested areas. The study shows that only HCO3− values and SO42− concentrations were related to the distance from the road network. The concentrations of Cl−, SO42−, and K+ were higher in the waters of springs located more than 50 m from the road network. The Ca and PCA analysis did not permit the identification of a single dominant origin of pollutants, suggesting an interaction of different types of pollution sources.

Geochemistry of Late Permian coals from the Yueliangtian coal deposit, Guizhou: Evidence of sediment source and evaluation on critical elements

The enrichment of rare, scattered, rare earth, and noble elements, such as Li, Ga, Ge, rare earth elements and yttrium (REY), platinum group elements (PGE), Au, and Ag, have been discovered in the Late Permian coals from southwestern China. With the gradual depletion of traditional ore deposits, the geochemistry and resource utilization of critical metals in coals have received considerable attention. The geochemistry of associated elements in the Late Permian coals from the No. 10 coal profile of the Yueliangtian (YLT) underground mine, Liupanshui coalfield in Guizhou, were investigated to reveal the sediment source of inorganic components, as well as utilization prospects and controlling factors of critical metals. Silver and Pb were slightly enriched in the Yueliangtian coals, while Be, Rb, Sr, Mo, Cs, Ba, Tl, Bi, and U were significantly lower than that of world hard coals. The concentrations of total REY and individual elements in the Yueliangtian coals were similar to those of world hard coals. The minerals kaolinite, pyrite, calcite, and quartz predominated in coals, with trace amounts of anatase, gypsum, and apatite. High anatase proportion was identified in the floor and roof rock samples. Based on the Al2O3/TiO2 and Zr/TiO2 versus Nb/Y ratios, elemental assemblages, REY distribution, and paleogeography, the sediment source of mineral matter in the Yueliangtian coals dominated by felsic-intermediate rocks that from a distal volcanic arc or orogens was inferred. The terrigenous debris in the roof and floor rocks primarily originated from the high-Ti basalt of the Emeishan Large Igneous Province (ELIP). The relatively low elemental concentrations in these coals were primarily determined by their sediment sources. Although most critical metals in this coal were not enriched, the concentration of REY in coal ash was high enough to be considered as a potential resource for REY recovery given the extremely low ash yields of this coal.

Clay and soil organic matter drive wood multi-elemental composition of a tropical tree species: Implications for timber tracing

Forensic methods to independently trace timber origin are essential to combat illegal timber trade. Tracing product origin by analysing their multi-element composition has been successfully applied in several commodities, but its potential for timber is not yet known. To evaluate this potential the drivers of wood multi-elemental composition need to be studied. Here we report on the first study relating wood multi-elemental composition of forest trees to soil chemical and physical properties.We studied the reactive soil element pools and the multi-elemental composition in sapwood and heartwood for 37 Azobé (Lophira alata) trees at two forest sites in Cameroon. A total of 46 elements were measured using ICP-MS. We also measured three potential drivers of soil and wood elemental composition: clay content, soil organic matter and pH. We tested associations between soil and wood using multiple regressions and multivariate analyses (Mantel test, db-RDA). Finally, we performed a Random Forest analysis of heartwood elemental composition to check site assignment accuracy.We found elemental compositions of soil, sapwood and heartwood to be significantly associated. Soil clay content and organic matter positively influenced individual element concentrations (for 13 and 9 elements out of 46 respectively) as well as the multi-elemental composition in wood. However, associations between wood and topsoil elemental concentrations were only significant for one element. We found close associations between element concentrations and composition in sapwood and heartwood. Lastly, the Random Forest assignment success was 97.3 %.Our findings indicate that wood elemental composition is associated with that in the topsoil and its variation is related to soil clay and organic matter content. These associations suggests that the multi-elemental composition of wood can yield chemical fingerprints obtained from sites that differ in soil properties. This finding in addition to the high assignment accuracy shows potential of multi-element analysis for tracing wood origin.

Changes in Elements and Relationships among Elements in Intervertebral Disc Degeneration.

Intervertebral disc degeneration (IVDD) is a complex and progressive process of disc aging. One of the most important causes of changes in the internal environment, leading to IVDD, can be changes in the concentration of individual metal elements. This study aimed to analyze the concentrations of copper, iron, manganese, lead, zinc, sodium, potassium, phosphorus, and calcium in the degenerated intervertebral discs of the lumbosacral spine, compared to healthy intervertebral discs. The study group (S) consisted of 113 Caucasian patients, qualified by a specialist surgeon for IVDD of the lumbosacral spine. The control group (C) consisted of 81 individuals. The biological material was obtained from Caucasian human cadavers during post-mortem examination. The concentrations of individual elements were assessed using inductively coupled plasma–optical emission spectroscopy (ICP-OES). Statistically significant differences in the concentrations of microelements, depending on the degree of pain intensity, were noted for only potassium (p < 0.05). Statistically significant differences in the concentrations of the assessed microelements, depending on the degree of radiological advancement of the lesions, were noted for copper and iron (p < 0.05). In the degenerated intervertebral discs, the strongest relationships were noted between the concentrations of zinc and lead (r = 0.67; p < 0.05), zinc and phosphorus (r = 0.74; p < 0.05), and zinc and calcium (r = 0.77; p < 0.05). It has been indicated that, above all, the concentrations of copper and iron depend on the advancement of radiological changes, according to the Pfirrmann scale; however, no influence on the pain intensity, depending on the concentration of the assessed elements, was found.

Mosses as a biomonitor to identify elements released into the air as a result of car workshop activities

Human activity as a result of civilization development contributes to creating new sources of environmental pollution. Air pollution is one of the major problems because it affects the fauna and flora, and people themselves. There is a lack of public awareness of the level of atmospheric analytes pollution emitted from people's occupational and recreational (leisure) activities. A quick, cheap and easy way to investigate the state of the environment is to use organisms-biomonitors that indicate the level of environmental pollution. The study aimed to assess air pollution in an urban area using three moss species: Sphagnum fallax, Pleurozium schreberi and Dicranum polysetum. Mosses were exposed for 90 days, and the effects of traffic and car workshop activity on the increments in elemental concentrations were assessed using instrumental neutron activation analysis (INAA) and flame atomic absorption spectrometry (F-AAS). The actual quantum yield of Photo System II (PSII) photochemical was also analyzed to assess changes in moss vitality during the experiment. The results showed that the concentrations of individual elements in mosses and thus in the atmospheric aerosol depend on the site of exposure. The difference in analyte concentrations between outdoor and indoor environments depends on the type of element and its source. The mosses exposed in the workshop were good bioaccumulators of elements such as Al, Cr, Fe and Ba, whose concentrations were higher inside than outside and their emission sources related to the activities of the car workshop were defined. The mosses remained vital in the air during the exposure period, while they worked as a natural sorbent inside the workshop.

Soil microbial biomass, activities and diversity in Southern Italy areas chronically exposed to trace element input from industrial and agricultural activities

High concentrations of trace elements in the soil can have toxic effects on the microbial community which plays a key role in fundamental ecosystem processes like the organic matter decomposition and nutrient cycles. The aim of this study was to evaluate if trace element concentrations in soils chronically exposed to industrial and agricultural activities did affect the soil microbial community, in terms of biomass, activity and diversity. Soil samples differing in trace elements (As, Cd, Co, Cr, Cu, Ni, Pb, V, Zn) concentrations were analysed for the total microbial biomass (Cmic), fungal mycelium, microbial activity, indexes of microbial community structure (fungal percentage of total Cmic) and microbial metabolism (metabolic quotient or qCO2; carbon mineralization rate or CMR), and genetic bacterial diversity (richness, Shannon index and evenness of bacterial groups). Relationships of the microbial variables with individual trace element concentrations, relative Overall Contamination Index (OCI), and ordinary soil properties (pH, water content, organic C content, electrical conductivity) were assessed by simple and multivariate statistical analysis. Neither OCI nor single element concentrations determined a significant reduction in soil microbial biomass, activity and diversity, these variables being mainly driven by soil organic C and water content. Only soil Cr concentration affected indexes of the microbial metabolism and structure, without causing stressful conditions. Even Cmic and bacterial diversity showed higher values in soils richer of Cr. The results suggest that the concentrations of considered trace elements measured in our soils, or probably their bioavailable fractions, did not cause toxic effects on the microbial community. However, the chronic exposure to different patterns of trace element contamination probably elicited site-specific adaptive responses in microbial populations.

Evaluation of the Impact of Tractor Field Works on Changes in Selected Elements of Engine Oils

Abstract Tractors are used for various types of field work, as well as for transport on public roads, in difficult and changing environmental conditions. The main goal of the study was to analyze the changes of trace elements in engine oil during various field works. For this purpose, engine oils from two tractors were selected for the study. These tractors were coupled with: a cultivator, a reversible plow, a tillage-sowing unit, and a trailer. The samples were taken at the beginning and after the field work with a given unit was completed. The instrumental chemical analysis method HDXRF was used to determine changes in the content of the trace elements: Cr, Cu, Fe, Pb, Ni, Ca, P, Zn, and Mo in the engine oil. The comparison of oil from tractors coupled with various agricultural machines allowed the conclusion that the distribution of the consumption of tested metals, as well as the concentrations of individual elements, differed significantly depending on the coupled machine. The research showed that agricultural treatments with a cultivator caused the highest percentage of wear-induced changes in the content of metal elements such as Cr, Cu, and Pb. On the other hand, the operation of a tractor coupled with a tillage-sowing unit resulted in the vehicle’s accelerated wear.

Composition of Stallion Seminal Plasma and Its Impact on Oxidative Stress Markers and Spermatozoa Quality.

The composition of seminal plasma of individual sires varies and so does the fertilizing ability. Micro and macro elements along with seminal enzymes, hormones, proteins, and lipids contained in seminal plasma are essential for the proper physiological function of spermatozoa. However, elevated levels against the normal physiological values, especially in the case of trace metals, result in the production of reactive oxygen species. The deficiency of antioxidants in the seminal plasma that could scavenge free radicals causes an impairment of spermatozoa quality. Ejaculates were obtained from 19 stallions. The fresh semen was analyzed to evaluate qualitative parameters of spermatozoa in terms of the motility, viability, and integrity of DNA. Separated seminal plasma underwent the assessment of the chemical and biochemical composition and RedOx markers. Based on the obtained concentrations of individual chemical elements, the correlation analysis suggested a negative impact of Cu in seminal plasma on the SOD, GPx, and LPO. Contrary, positive correlation was detected between FRAP and motility features. While Cu negatively correlated with sperm motion parameters, the adverse effect on viability was suggested for Cd. Our data suggest that seminal plasma has a potential due to its availability to become the potential biomarker of the reproductive health of farm animals.

Honey bees as biomonitors – Variability in the elemental composition of individual bees

Homogenized or pooled samples of honey bees are already used for monitoring of metal pollution in the environment for a couple of decades. This is the first study that analyzed the elemental composition of individual honey bees. One apiary with 21 hives was used to test in-hive and between-hive differences at the same location. Highest in-hive variability was observed for Al (14.1x), Li (10.3x), V (10.3x), As (8.9x) and Cd (7.9x). For the elements Cu, K, Mg, Na, P, S and Zn the smallest both in-hive (2.3x, 1.8x, 2.0x, 2.2x, 1.9x, 1.7x, 2.4x respectively) as well as between-hive variability (1.5x, 1.4x, 1.4x, 1.6x, 1.4x, 1.4x and 1.5x respectively) was observed. Nonetheless, between-hive variability was statistically significant for all the analyzed elements. We proved that these differences significantly influence comparison of element concentrations in bees from different locations. One hive from Mesić apiary had significantly lower concentrations of Al (hive 18: 18.6 mg kg−1) and U (hive 1: 0.0013 mg kg−1), while at the same time a different hive from the same apiary showed higher concentration of these elements (Al, hive 14: 125 mg kg−1; U, hive 13: 0.012 mg kg−1) compared to another location (thermal power plant, Al: 97 mg kg−1, U: 0.0044 mg kg−1). Therefore, when using honey bees as biomonitors, we recommend a larger number of hives to be sampled at each location to provide an adequate dataset for reliable interpretation of results. Comparing individual bee elemental concentrations, for Na, Mg, P, S, K, Fe, Cu, and Zn negative correlations were found between dry mass of a bee and concentrations of these elements. These negative correlations could be a consequence of higher honey or nectar content in some of the sampled bees. However, this should also be considered when using honey bees as bioindicators.

Effects of pH on arsenic mineralogy and stability in Poldice Valley, Cornwall, United Kingdom

Many abandoned mine sites in Cornwall, UK, are characterised by elevated concentrations of arsenic (As), which can cause contamination of surrounding soil and water resources. These sites have important historical value that requires access to be maintained, despite exposure of humans to toxins that may lead to health issues including hyperpigmentation keratosis (including skin cancers) and liver fibrosis. The abandoned mine tailings at Wheal Maid has been assessed for As-bearing mineralogy and stability taking into account the public footpaths made by the local council to areas of potential contamination.To assess the potential risk associated with these mine sites, the As concentration in waters along the tailings dam and Carnon River have been measured and range up to 3.6 ppm, which is 2 orders of magnitude above the WHO guideline value of 0.01 ppm for drinking water. Samples of water, rocks and soils from the mine tailings ponds and the Carnon River were analysed using Inductively Coupled Plasma – Optical Emission Spectrometry (ICP-OES) and Inductively Coupled Plasma – Mass Spectrometry (ICP-MS) to determine the concentration of individual elements in each sample followed by mineral identification using X-Ray Diffraction (XRD). Mineralogical evaluation indicated that the majority of mine tailings consist of clay-rich rocks, with few associated As-bearing minerals. Scorodite (FeAsO4·2H2O) is observed in the mine tailings pond and appears critical to the As distribution and storage in this surface environment. Using the analysed water chemistry, a modified version of PHREEQC is used to calculate the saturation index of scorodite as a function of pH conditions. The strong variation of the solubility of this mineral with pH and oxidation state highlights potential risks for using scorodite for As fixation and storage.