High Concentrations Of Cu Research Articles

Detection of Mineral and Microbial Contaminants in some Types of Imported Meat

The main target of the current study is to investigate the microbial content and mineral contaminants of the imported meat available in the city of Baghdad and to ensure that it is free from harmful bacteria, safe and it compliances with the Iraqi standard specifications. Some trace mineral elements such as (Iron, Copper, Lead, and Cadmium) were also estimated, where 10 brands of these meats were collected. Bacteriological tests were carried out which included (total bacterial count, Staphylococcus bacteria, Salmonella bacteria). The results showed highest number of total bacterial count 13×105 CFU/g in F8 brand, while the lowest number of bacteria 5×101 CFU/g in F3 brand. However, Staphylococcal bacteria showed the highest number of 66×102 CFU/g in F7 brand, while the lowest number of Staphylococcal bacteria amounted to 1×101 CFU/g in F9 brand. The number of Salmonella bacteria in imported meat samples, the two brands contained Salmonella bacteria were (F2, F7), while the other brands were free of Salmonella bacteria. The results showed that the highest concentration of Cu was 1.658 μg/g in F7 brand, whereas the lowest concentration of Cu was in F6 brand amounting to 0.093 μg/g. However, highest concentration of Pb reached 0.040 μg/g in F6 brand, while the lowest concentration of Pb was recorded in F2 brand reaching 0.002 μg/g. Furthermore, the highest concentration of Cd was 0.004 μg/g in F7 brand whereas the lowest detected concentration of Cd was in (F1, F4, F5, F9, and F10) brands reaching 0.000 μg/g.

野外調査による地表検証データと衛星画像解析に基づく鉱山地域の環境影響評価

In the study area of eastern Serbia, which includes the Bor and Maidenpek mining areas of the Republic of Serbia, a research of environmental evaluation of the study area was carried out by means of field survey for environment and satellite image analysis in order to establish and improve methods for assessing the environmental impact of mining areas by satellite image analysis. The results of this study showed that it was possible to efficiently determine the distribution of overburdens and tailings in a wide area based on the distribution of points having jarosite spectra, and that it was possible to distinguish waste rocks such as overburdens and tailings with high environmental impact from those waste rocks with relatively low environmental impact based on the mineral assemblage of the waste rocks estimated from satellite image analysis. In addition, if topographical data before and after mining development are obtained from the satellite image analysis, the volume of the waste rocks can be estimated, and the quantitative estimation of the amount of toxic elements dissolved from the waste rocks could be possible by combining the experimental data on the extraction of toxic elements from the waste rocks. In addition, the predicted hazardous area (Type I), where high concentration of Cu may be leached from the waste rocks revealed by the surface survey, corresponds to the area where waste rocks such as overburdens and tailings is distributed around the mine and the area where waste rocks such as tailing is distributed along the river downstream of the mine as estimated by the satellite image analysis. These results indicate that it is possible to predict the environmental impact in advance of the survey in the mining area, and to predict the environmental impact in the mining area where it is not possible to go directly to the survey and to consider guidelines for countermeasures.

ECOLOGICAL ASSESSMENT OF THE CONTENT OF HEAVY METALS IN FISH OF THE RIVER IRTYSH

The article presents the results of a study of surface waters and fish (perch (Perca fluviatilis L.), carp (Cyprinus carpio L.), bream (Abramis brama L.), pike (Esox lucius L.) of the Irtysh river. The content of Cu and Pb in the organs and tissues of fish living in the Irtysh River within the city of Semey was determined by the ditizon photometric method. The ecological assessment of the results indicates that the concentrations of Cu and Pb in the studied fish specimens do not exceed the MPC. A significant difference in the specific features of the accumulation of heavy metals has been established, depending on the type of fish nutrition and the time of year. The Pb content in various organs of perch, carp, bream and pike ranges from 0.062 mg/kg to 0.083 mg/kg. The highest concentration of Cu is observed in predatory fish (3.27 mg/kg), the lowest – in planktonivores (2.82 mg/kg). Pb also mainly accumulates in pike (0.073 mg/kg). In spring, the content of Pb in the gills of perch and pike increases, Cu – in the gills of bream and pike. The maximum concentrations of Cu in fish were observed in summer, which is associated with an increase in the food supply. The Pb content in summer, on the contrary, decreases due to its adsorption by suspended solids and deposition with them into bottom sediments.

Aspergillus luchuensis, an Endophyte Fungus from the Metal Hyperaccumulator Plant Prosopis laevigata, Promotes Its Growth and Increases Metal Translocation

Heavy metal pollution is a worldwide environmental and human health problem. Prosopis laevigata is a hyperaccumulator legume that bioaccumulates Pb, Cu and Zn. With interest in designing phytoremediation strategies for sites contaminated with heavy metals, we isolated and characterized endophytic fungi from the roots of P. laevigata growing on mine tailings located in Morelos, Mexico. Ten endophytic isolates were selected by morphological discrimination and a preliminary minimum inhibitory concentration was determined for zinc, lead and copper. A novel strain of Aspergillus closest to Aspergillus luchuensis was determined to be a metallophile and presented a marked tolerance to high concentrations of Cu, Zn and Pb, so it was further investigated for removal of metals and promotion of plant growth under greenhouse conditions. The control substrate with fungi promoted larger size characters in P. laevigata individuals in comparison with the other treatments, demonstrating that A. luchuensis strain C7 is a growth-promoting agent for P. laevigata individuals. The fungus favors the translocation of metals from roots to leaves in P. laevigata, promoting an increased Cu translocation. This new A. luchuensis strain showed endophytic character and plant growth-promotion activity, high metal tolerance, and an ability to increase copper translocation. We propose it as a novel, effective and sustainable bioremediation strategy for copper-polluted soils.

Emission Characteristics and Control of Heavy Metals in Secondary Copper Smelting Process

Secondary copper smelting is an important source of heavy metal emission. Flue gas samples were collected from different stages in secondary copper smelters to study the emission characteristics and control of particulate matters (PM) and heavy metals such as Cd, Cr, As, Pb, Sn, and Sb. The mass concentrations of heavy metals in flue gas and fly ash were determined using inductively coupled plasma-mass spectrometry. The emission factors of heavy metals were estimated. The results showed that the mass concentrations of heavy metals and PM in the flue gas were high in the cooling stage. After passing through a series of air pollution control devices, such as a bag filter and adsorption tower, the heavy metals and PM were simultaneously removed with a removal efficiency of 80%-99%. The concentration order of heavy metals in the stack gas from different anode furnace stages followed feeding-fusion>oxidation≈deoxidization. In general, the mass concentrations of heavy metals and PM in the stack gas could meet the industry emission standards. The average emission factors of As, Pb, Cr, Sn, Sb, and Cd were 2.6×103, 2.4×103, 2.7×103, 5.6×102, 34.1, and 9.8 mg·t-1, respectively. This could provide data support for estimating the annual emission amounts of heavy metals from the secondary copper industry and establishing the emission inventories. The fly ash contained high concentrations of Cu and Zn, which can be recycled as raw materials for recycling the valuable metals.

Exploring bioleaching potential of indigenous Bacillus sporothermodurans ISO1 for metals recovery from PCBs through sequential leaching process.

The low efficiency and selectivity limitations of biohydrometallurgy technique compel the researchers to explore novel microbial strains acclimated to metal existence site with higher toxicity tolerance and bioleaching capability in order to improve the role of bioleaching process for e-waste management. The current study aimed to explore bioleaching potential of indigenous Bacillus sporothermodurans ISO1; isolated from metal habituated site. The statistical approach was utilized to optimize a variety of culture variables including temperature, pH, glycine concentration and pulp density that impact bio-cyanide production and leaching efficiency. The highest dissolution of Cu and Ag, 78% and 37% respectively, was obtained at 40 °C, pH 8, glycine concentration 5 g L-1, and pulp density 10 g L-1 through One Factor at a Time (OFAT), which was further increased up to 95% Cu and 44% Ag recovery through the interactive effect of key factors in the Response Surface Methodology (RSM) approach. Furthermore, Chemo-biohydrometallurgy approach was utilized to overwhelm the specificity limitation; as higher concentration of Cu in computer printed circuit boards (CPCBs) causes interference to recover other metals. The sequential leaching through ferric chloride (FeCl3), recovered Cu prior to bio-cyanidation by B. sporothermodurans ISO1 and resulted in the improved leaching of Ag (57%), Au (67%), Pt (60%), etc. The current work reports on B. sporothermodurans ISO1, a new Bacillus strain that exhibits highest toxicity tolerance (EC50 = 425 g L-1) than earlier reported stains and has higher leaching potential that can be implemented to large-scale biometallurgical process for e-waste treatment to achieve the agenda of sustainable development goal (SDG) under the strategies of urban mining.

Analysis of Heavy Metal Contents (Cu. Pb And Zn) of Coral Annual Band (Porites Lutea) in the Eastern Part of Bintan Island

This study analyzed the growth rate of massive corals Porites lutea and heavy metal contents in its annual band. The aims of this study were to perceive the age of corals, relation between growth rates and sea surface temperature, rainfall, and duration of sunlight as well as the heavy metal (Cu, Pb and Zn ) extent in their annual band. This study was conducted with radiographic approach to determine the direction and the annual band of corals. Sample preparation methods contained determining the annual growth direction, cutting the samples, and dissolving the coral samples. The prepared samples were analyzed using AAS to calculate their Cu, Pb and Zn concentrations. The results showed that the growth rate of P. lutea coral growth rate was range from 2.78 ± 0.25 to 9.90 ± 1.90 mm/year. The growth rate and sea surface temperature were positively correlated (18.28 %), the rainfall and sunlight duration were correlated negatively 37.82 % and 0.67 % respectively. The highest concentration of Cu and Pb were consecutively found at the stations Kawal, Malang Rapat, and Teluk Bakau, while the highest concentration of Zn were consecutively found in Teluk Bakau, Malang Rapat, and Kawal. Through annual band of coral, from surface to the core part of massive colony coral, we noticed The Cu, Zn and Pb increased variedly with value range of 2.087 ± 0.179 to 2.504 ± 0.117 mg/kg for Cu, 12.304 ± 4.815 to 32.944 ± 5.926 1mg/kg for Zn, and 1.761 ± 0.910 to 9.501 ± 0.483 926 mg/kg. The study may reveals an historical apportionment of anthropogenic heavy metals in the studied area.

Evaluation of the concentration of selected elements in serum patients with intervertebral disc degeneration

Quantitative analysis of the trace element content of human intervertebral discs (IVDs) is essential because it can identify specific enzymes or metabolites that may be related to human intervertebral disc degeneration (IVDD). The goal of this study was to assess the concentrations of copper (Cu), iron (Fe), manganese (Mn), lead (Pb), zinc (Zn), sodium (Na), magnesium (Mg), potassium (K), phosphorus (P), and calcium (Ca) in serum samples obtained from patients with IVDD in comparison to healthy volunteers (a control group). The study group consisted of 113 Caucasian patients qualified by a specialist neurosurgeon for microdiscectomy. The control group consisted of 113 healthy volunteers who met the eligibility criteria for blood donors. The examined clinical material was the serum samples obtained from both groups.Based on the quantitative analysis of selected elements, there were statistically significantly (p 0.05) higher concentrations of Cu (1180 μg/L±800 μg/L vs. 1230 μg/L±750 μg/L), Zn (790 μg/L±300 μg/L vs. 850 μg/L±200 μg/L), and Mg (21730 μg/L±4360 μg/L vs. 23820 μg/L±4990 μg/L) in the serum of healthy volunteers compared to those in the study group. In addition, statistically significant changes were not detected in the concentrations of any elements among either sex in either the study or control group or in their body mass index (BMI) values (p > 0.05). In the serum samples from the study group, the strongest relationships were noted between the concentrations of Zn and Pb (r = 0.61), Zn and P (r = 0.69), Zn and Ca (r = 0.84), Zn and Cu (r = 0.83), Mg and Ca (r = 0.74), and Ca and P (r = 0.98).It has been indicated that, above all, the concentrations of Cu, Zn, Ca, and Mg depend on the advancement of radiological changes, according to the Pfirrmann scale. However, no influence on pain intensity was found, depending on the concentration of the assessed elements.The analysis indicates that the determination of serum Cu, Zn, Ca, and Mg concentrations may have diagnostic significance in predicting the onset of lumbosacral IVDD. The predictive evaluation of changes in the concentrations of selected elements in patients with degenerative lumbar IVD lesions appears to be a promising, cost-effective strategy.

Environmental Applications of Zeolites: Preparation and Screening of Cu-Modified Zeolites as Potential CO Sensors

This work is focused on the application of Cu-containing zeolites as potential environmental sensors for monitoring carbon monoxide. A number of commercial zeolites with different structural properties (NaX, NaY, MOR, FER, BEA and ZSM-5) were modified using CuSO4, Cu(NO3)2 and Cu(OAc)2 solutions as copper sources to prepare Cu+-containing zeolites, since Cu+ forms stable complexes with CO at room temperature that can be monitored by infrared spectroscopy. Zeolite impregnation with Cu(NO3)2 resulted in the highest total Cu-loadings, while the Cu(OAc)2-treated samples had the highest Cu+/Cutotal ratio. Cu(NO3)2-impregnated MOR, which displayed the highest concentration of Cu+, was subjected to a number of tests to evaluate its performance as a potential CO sensor. The working temperature and concentration ranges of the sensor were determined to be from 20 to 300 °C and from 10 to 10,000 ppm, respectively. The stepwise CO desorption experiments indicated that the sensor can be regenerated at 400 °C if required. Additional analyses under realistic flow conditions demonstrated that for hydrophilic zeolites, the co-adsorption of water can compromise the sensor’s performance. Therefore, a hydrophobic Sn-BEA was utilised as a parent material for the preparation of an impregnated Cu-Sn-BEA zeolite, which exhibited superior resistance to interfering water while maintaining its sensing properties. Overall, the prepared Cu-modified zeolites showed promising potential as environmental CO sensors, displaying high sensitivity and selectivity under representative testing conditions.

Improving corrosion, antibacterial and biocompatibility properties of MAO-coated AZ31 magnesium alloy by Cu(II)-chitosan/PVA nanofibers post-treatment

In this study, a novel Cu(II)-Chitosan/PVA electrospun coating containing different concentrations of Cu(II) was applied to AZ31 magnesium alloy samples, pre-treated with the MAO (micro-arc oxidation) method, in order to enhance its antibacterial activity, cell viability, and corrosion resistance for orthopedic applications. Structure and morphology, water absorption and wettability, Cu(II) ion release, antibacterial activities, and cell biology were all studied in these coatings. Electrochemical impedance spectroscopy (EIS) was used to determine the corrosion resistance of the coatings. SEM images showed that all fibers of electrospun samples exhibited crack-free, unbeaded, and uniform fibrous structures with an average diameter range of about 220–340 nm. The corrosion resistance of the MAO pretreatment enhanced cell viability, and the unique structure of the electrospun layer promoted cell attachment and proliferation to the coating. The coatings demonstrated satisfactory antibacterial activity against both gram-positive and gram-negative bacteria. Furthermore, coatings with higher Cu(II) concentrations released more Cu(II) ions, resulting in improved antibacterial properties. However, despite the reduced cell viability for the coatings containing 8.42% Cu(II), the cell viability of the coatings with 0.77% and 2.97% Cu(II) was not significantly affected, and they were not harmful to MG63 cells, but high concentrations of Cu(II) ions caused significant cytotoxicity.

Copper exposure does not alter the ability of intertidal sea cucumber Cucumaria miniata to tolerate emersion during low tide

Intertidal animals experience cycles of tidal emersion from water and are vulnerable to copper (Cu) exposure due to anthropogenic toxicant input into marine waters. Both emersion and Cu toxicity can cause damage to physiological processes like aerobic metabolism, ammonia excretion, and osmoregulation, but the interactions of the combination of these two stressors on marine invertebrates are understudied. Mixed effects of 96 h of low and high Cu exposure (20 and 200 μg/L) followed by 6 h of tidal emersion were evaluated on the intertidal sea cucumber Cucumaria miniata. The respiratory tree accumulated the highest concentrations of Cu, followed by the introvert retractor muscle, body wall, and coelomic fluid. Emersion affected accumulation of Cu, perhaps by inhibiting excretion. 200 μg/L of Cu increased lactate production in the respiratory tree, indicative of damaged aerobic metabolism. Cu diminished ammonia excretion, but emersion increased oxygen uptake and ammonia excretion upon re-immersion. The combination of the two stressors did not have any interactive effects on metabolism or ammonia excretion. Neither Cu exposure nor emersion altered ion (sodium, potassium, calcium, magnesium) content of the coelomic fluid. Overall, results of this study suggest that Cu exposure does not alter C. miniata's high tolerance to emersion, and some potential strategies that this species uses to overcome environmental stress are illuminated.

Using native fish in eco-genotoxic assessment of heavy metal contamination pollution arising from nearby large Brazilian rivers

ABSTRACT Worldwide water quality has declined progressively due to continuous pollution of aquatic resources by agrochemicals in particular heavy metals. Fish genotoxicity biomarkers are vital to identify and complement chemical parameters for determining environmental risk of adverse effects. Therefore, it was of interest to examine the eco-genotoxicity attributed to water pollution over different stream sections of Brazilian rivers by using Cichlasoma paranaense (Teleostei: Cichlidae), a neotropical freshwater cichlid fish, as a biological model. Chemical analysis of water and sediments collected from different Brazilian rivers sites demonstrated contamination by metals. Cichlasoma paranaense were collected at a reference location (a permanent water preservation area), maintained in the lab under standard conditions (controlled temperature, lighting, daily feeding, and constant aeration) and exposed to environmental samples of water and sediments. Subsequently, micronucleus (MN) and nuclear abnormalities (NA) frequencies were assessed in erythrocytes obtained from the caudal and gill regions. The highest concentrations of Cu were found in samples from river sites with forest fragmentation attributed to intensive agriculture practices. Similarly, exposure of fish to samples from agricultural areas induced significantly higher number of genotoxic effects. There was no marked difference between the tissues (tail and gill) regarding the observed frequencies of MN and NA. Thus C. paranaense fish served as a reliable model for detecting genotoxic effects, especially when water samples were collected near the discharge of agrochemicals. Evidence indicates that this method be considered for other global river sites which are also exposed to agrochemicals discharges containing Cu.

Base Metals Extraction from Printed Circuit Boards by Pressure Acid Leaching

Printed circuit boards (PCBs) are a valuable source of raw materials for metal recycling considering that base metal concentration analyses have confirmed that PCB powders are multimetallic in nature and contain high concentrations of Cu, Zn, Ni, and Fe. Given that minerals are not renewable resources, these metals can be recycled through hydrometallurgical processes. In this study, we determined that 2 M sulfuric acid, 0.55 MPa oxygen pressure, and a temperature of 90 °C represent the optimal conditions for leaching of Cu, Zn, and Ni of PCBs, obtaining the highest observed values of recovery of greater than 90% for Zn and 98% for Cu and Ni. The characterization of PCBs by SEM–EDS analyses showed that plates mainly consist of Cu, Ni, and Zn. PCBs can be seen as a potential secondary resource for the recovery of copper, nickel, and zinc. The best potential and pH conditions for the extraction of Cu, Zn, and Ni were also determined on the basis of thermodynamic diagrams.

Spatial Risk Assessment and Source Identification of Heavy Metals in Riverine Sediments of Lake Chaohu Basin, China

In recent decades, the rivers in Lake Chaohu Basin have been subjected to intensive anthropogenic disturbance. However, previous studies have mainly focused on Lake Chaohu, and the inflowing and outflowing rivers have not been well examined. To characterize the pollution status of heavy metals in the entire Lake Chaohu Basin, 8 heavy metals (Cu, Zn, Pb, Cr, Cd, As, Hg, and Ni) in riverine surface sediments were measured at 131 sampling sites in 7 subbasins. Spatial patterns and pollution characteristics were evaluated based on the potential ecological risk, geoaccumulation, and pollution load indexes. The results showed that Cr and Hg were the 2 main heavy metal pollutants in the surface sediments, with mean contents exceeding background values by a factor of 4.12 and 2.64, respectively. The Nanfei River (NF), which flows through Hefei city (a metropolis of the capital of Anhui Province), is characterized by large amounts of domestic and industrial waste discharged into the water body due to human activities; this waste caused serious heavy metal pollution, and NF substantially contributed to heavy metal pollution inputs to Lake Chaohu. Several subbasins in the southern part of Lake Chaohu Basin exhibited high concentrations of Cu in surface sediments, mainly from mining and agriculture. This study identified the main contamination areas, revealed the possible sources of each heavy metal, and can serve as a reference for the remediation and management of Lake Chaohu Basin to ensure the water safety of Lake Chaohu.

Short and long-term phytoremediation capacity of aquatic plants in Cu-polluted environments

Freshwater ecosystems face numerous threats from human populations, including heavy metal contamination. Phytoremediation, the use of plants to remediate contaminated soils and sediments, is an effective and low-cost means of removing chemical contaminants, including heavy metals, from polluted environments. However, key questions remain unanswered in the application of this technology in aquatic environments, such as the long-term fate of pollutants following plant uptake. In this study, using two common wetland plant species (duckweed and tape grass), we first examined the capacity of plants to remove copper (Cu) from polluted water. Next, we evaluated the leaching potential of plant tissues following decomposition and how it is affected by a simulated freeze-thaw cycle. Using phytoremediated water and leachates from senesced plants we assessed phytoremediation success and Cu leaching potential by conducting standard toxicity assays using pond snails (Physa acuta), a species with known Cu sensitivity. We found that duckweed outperformed tape grass as a phytoremediator at low Cu concentrations. In addition, for plants grown in low concentrations of Cu, leaching from decaying plant material did not negatively impact snail survival, while at high concentrations of Cu, leaching did result in toxicity. Lastly, we found that a simulated freeze-thaw cycle increased the release of Cu from plant tissue in the presence of high Cu concentrations only, resulting in reduced snail survival. Our results indicate that in moderately Cu-polluted environments, some aquatic plants can remove contaminants without a long-term risk of leaching. In contrast, phytoremediation in highly polluted environments will likely require removal of plant tissue to prevent leaching of previously accumulated metals. Land managers must not only consider plant species and degree of contamination, but also geographic location, as freeze-thaw cycles may enhance plant decomposition and increase the likelihood of contaminant leaching following phytoremediation efforts in aquatic ecosystems.

Hiekkapohja hydrothermal system – ore mineral, lithogeochemical and paleomagnetic evidence from the Paleoproterozoic Central Finland Granitoid Complex

The Paleoproterozoic Svecofennian Central Finland Granitoid Complex (CFGC) has been regarded as an area of low mineralisation potential. The Hiekkapohja area, 20km north-east of the town of Jyväskylä, host a concentration of variable metalliferous showings. Samples from mineralised boulders and outcrops display variable combinations of anomalously high concentrations of Cu, Mo, Zn, Pb, W, Pb, Ag, As, and Au. The area is composed mainly of peraluminous and ferroan granitoids. The dominant porphyritic Hiekkapohja granodiorite (~1.88 Ga) is cross-cut by the equigranular Soimavuori granite of similar age. The porphyritic Lehesvuori granite on the western side of the study area represents marginally older (~1.89 Ga) magmatism. The paragenetic sequence of the ore minerals shows that the Hiekkapohja area has been affected by at least two separate stages of hydrothermal activity. The first mineralisation stage was widespread, crystallising typically chalcopyrite, pyrrhotite, sphalerite, galena, arsenopyrite, magnetite and Ag-bearing minerals. After the first stage, a low temperature oxidising phase formed hematite and marcasite. The second mineralisation stage enclosed low temperature minerals, such as marcasite and native Ag and Ag-minerals, as inclusions inside chalcopyrite, pyrite, pyrrhotite, sphalerite, and arsenopyrite. The mineralised samples typically display signs of K-metasomatism and less commonly signs of propylitic alteration. During the second mineralisation stage the fluid flow was controlled by the dominant 120°–135° trending shear zones. Both the hydrothermal activity and the regional geology indicate that porphyry type ore forming processes have occurred in the Hiekkapohja area. Paleoproterozoic resetting of the remanent magnetisation is further evidence for the role of the hydrothermal system.

Content of potentially toxic elements (PTEs) in various animal meats: a meta-analysis study, systematic review, and health risk assessment.

Meat comprises the main part of the diet in many countries around the world. The present study aimed to assess potentially toxic elements (PTEs) lead (Pb), arsenic (As), cadmium (Cd), copper (Cu), nickel (Ni), zinc (Zn), and iron (Fe) in various meats (camel, chicken, cow, pork, birds, seafood (fish and crab), and sheep). The present study was performed on the concentration of PTEs in various meats by different databases including Scopus, PubMed, and Web of Science along with a meta-analysis. Additionally, the non-carcinogenic risk was assessed by calculating the total hazard quotient (TTHQ). According to findings, the highest concentration of Cd was related to sea (0.460mg/kg). The highest concentrations of Cd and As were reported in camel meat (1.965 and 1.503mg/kg, respectively). Regarding trace elements, the highest concentrations of Zn, Fe, Cu, and Ni were observed in seafood (fish and crab), cow meat, and bird's meat (71.159mg/kg, 36.608mg/kg, 8.680mg/kg, and 1.592mg/kg, respectively). Moreover, considering the type of continents based on the concentration of PTEs in various meats, the highest concentrations of As (0.792mg/kg), Cd (0.315mg/kg), Pb (1.049mg/kg), Fe (44.088mg/kg), and Ni (1.113mg/kg) were related to Eastern Mediterranean region (EMRO), African Region (AFRO), EMRO, the Pan American Health Organization (PAHO), and EMRO, respectively. However, the highest concentrations of Cu (4.846mg/kg) and Zn (60.742mg/kg) were related to European Region (EURO) and AFRO, respectively. On the other hand, the result of the risk assessment indicated that the risk pattern was different among countries.

ТОКСИКОЛОГИЧЕСКИЕ ИССЛЕДОВАНИЯ ВОДЫ И ДОННЫХ ОТЛОЖЕНИЙ УГЛИЧСКОГО ВОДОХРАНИЛИЩА ЗА ПЕРИОД 2012–2020 ГГ.

A long-term assessment of the toxicological condition of certain areas of the Uglich reservoir is given based on the results of bioassay of water and bottom sediments. During the research period 2012–2020, there was a tendency of the toxicity reduction of water in all sections of the reservoir. The maximum values of reproductive indicators of Ceriodaphnia affinis were registered in 2019. The toxicity of bottom sediments had a slight tendency to decrease in the upper section of the reservoir and did not change in the middle and lower sections. During the teratological study of the Uglich reservoir in 2012–2013 years it was found that the proportion of chironomid larvae with pathomorphological changes in the structures of the mouth parts during the observation period was on average 14.5%, which is higher than the established control (6.7–7.0%) and background values (0–8.0%). The results of the bioassay are confirmed by analytical data on water and sediment pollution. Significant differences in the pollution coefficient of water between the reservoir areas, both in individual elements and in total, have not been recorded. The highest values of the total and average pollution coefficient were reached in the middle section, where higher concentrations of Cu and Zn were determined. Despite the tendency of decreasing concentrations of Cr, Ni, Cu, Zn, Cd and Pb in the bottom sediments of the reservoir, the levels of Cd, Cr, Ni and Zn exceeded their background concentrations established for the Upper Volga basin.

Exogenous application of citric acid alleviates copper-induced stress in Withania coagulans (Dunal)

The current study aimed to determine the mitigating effect of citric acid (CA) on various physiological and biochemical attributes in Withania coagulans, exposed to copper (Cu) stress. The viable seeds of Withania coagulans were planted in a controlled environment. After reaching the four-leaf stage, the plants were given simultaneous treatment with two concentrations of Cu [TCu1 and TCu2 (10mM, 15mM)] alone and/or with CA [TCa1 and TCa2 (05mM, 10mM)]. After harvesting, the physiological and biochemical characteristics of the plants were assessed. The findings demonstrated that using a higher dosage of Cu has significant toxic effects on plant growth and biomass. The agronomic attributes of the plant were significantly reduced by 24% (number of leaves), 22% (shoot length), 7% (root length), 8% (fresh weight), and 38% (dry weight) compared to the control. Higher concentration of Cu was also found toxic to photosynthetic pigments and significantly reduced by 27% (chl a), 6% (chl b), and 35% (carotenoids) compared to the control. However, the application of CA under Cu stress significantly improved the physiological attributes of Withania coagulans. The plant's agronomic traits significantly increased by 66% (number of leaves), 31% (shoot length), 87% (root length), 43% (fresh weight), and 78% (dry weight), whereas photosynthetic pigments by 25% (chl a), 58% (chl b), and 125% (carotenoids). Based on the results, it could be concluded that CA can play a role in mitigating the toxic effect of Cu in Withania coagulans

A new approach to enhance the thermoelectric performance of quaternary chalcogenides copper zinc tin sulfide thin films by varying copper molar concentration

This manuscript revealed an enhancement in the thermoelectric performance of quaternary chalcogenides Cu2ZnSnS4 (CZTS) TFs by the copper (Cu) atoms (1–2.5 mM) modulation during solution growth. Thermo-power data suggested that various performance parameters such as electrical conductivity (σ), Seebeck coefficient (S) and thermo-power factor (P) were improved significantly [(19–183 S/cm), (97–884 μV/°C) and (1.78 × 10−5–1.43 × 10−2 Wm−1K−2)] when the atomic concentration of Copper atoms increased from 01 to 2.5 mM respectively. This trend of thermo-power for CZTS thin films is correlate with development of additional holes along with the generation of Cu based secondary phases. The presence of extra/secondary phases due to additional Cu atoms is supported by some supplementary measurements. XRD data confirmed that some Cu based extra phases were developed at higher concentration of Cu atoms. Raman spectroscopy measurements further revealed that the intensity of Cu based extra/secondary phases was noticed towards higher values when the molar ratio of Cu atoms increased. SEM micrographs demonstrated the rougher surface of CZTS samples which were prepared using higher concentration of Cu when compared with lower concentration samples. UV/VIS Spectroscopy data further confirmed our argument that numbers of other secondary phases were expended with the concentration of Cu atoms.