Low Concentrations Of Cadmium Research Articles

Overexpression of histone demethylase gene SlJMJ18 and SlJMJ23 from tomato confers cadmium tolerance by regulating metal transport and hormone content in Arabidopsis

A lower concentration of cadmium (Cd), a hazardous and non-essential element for plant growth, will have deleterious effects on plants and endanger human health. Histone demethylase (JHDM) is important for plants' ability to withstand abiotic stress, according to an increasing number of studies. The degree of expression of the SlJMJ18 and SlJMJ23 genes in different tomato tissues was confirmed by this study. These two genes were responsive to the heavy metals Cd, Hg, Pb, and Cu stress, according to fluorescence quantification and GUS staining. Interestingly, the overexpression transgenic Arabidopsis plants of two genes have different responses to Cd stress. While SlJMJ18-OE lines consistently display Cd resistance but an early-flowering phenotype, SlJMJ23-OE plants have sensitivity during the post-germination stage and then greater tolerance to Cd stress. It was discovered that these two genes may affect cadmium tolerance of plants by regulating the expression of hormone synthesis related genes and hormone contents (BRs and ABA). Moreover, SlJMJ23 may resist cadmium stress by increasing the total phenol content in plants. The functional significance of JMJs is better understood in this study, which also offers a theoretical foundation for the use of molecular technology to develop plants resistant to Cd and an experimental basis for the efficient use of land resources.

Loss of mutant p53 in HaCaT keratinocytes promotes cadmium-induced keratin 17 expression and cell death

BackgroundCadmium exposure induces dermatotoxicity and epidermal barrier disruption and leads to the development of various pathologies. HaCaT cells are immortalized human keratinocytes that are widely used as alternatives to primary human keratinocytes, particularly for evaluating cadmium toxicity. HaCaT cells bear two gain-of-function (GOF) mutations in the TP53 gene, which strongly affect p53 function. Mutant forms of p53 are known to correlate with increased resistance to various stimuli, including exposure to cytotoxic substances. In addition, keratin 17 (KRT17) was recently shown to be highly expressed in HaCaT cells in response to genotoxic stress. Moreover, p53 is a direct transcriptional repressor of KRT17. However, the impact of TP53 mutations in HaCaT cells on the regulation of cell death and keratin 17 expression is unclear. In this study, we aimed to evaluate the impact of p53 on the response to Cd-induced cytotoxicity. Methods and resultsEmploying the MTT assay and Annexin V/propidium iodide staining, we demonstrated that knockout of TP53 leads to a decrease in the sensitivity of HaCaT cells to the cytotoxic effects of cadmium. Specifically, HaCaT cells with TP53 knockout (TP53 KO HaCaT) exhibited cell death at a cadmium concentration of 10 μM or higher, whereas wild-type cells displayed cell death at a concentration of 30 μM. Furthermore, apoptotic cells were consistently detected in TP53 KO HaCaT cells upon exposure to low concentrations of cadmium (10 and 20 μM) but not in wild-type cells. Our findings also indicate that cadmium cytotoxicity is mediated by reactive oxygen species (ROS), which were significantly increased only in TP53 knockout cells treated with 30 μM cadmium. An examination of proteomic data revealed that TP53 knockout in HaCaT cells resulted in the upregulation of proteins involved in the regulation of apoptosis, redox systems, and DNA repair. Moreover, RT‒qPCR and immunoblotting showed that cadmium toxicity leads to dose-dependent induction of keratin 17 in p53-deficient cells but not in wild-type cells. ConclusionsThe connection between mutant p53 in HaCaT keratinocytes and increased resistance to cadmium toxicity was demonstrated for the first time. Proteomic profiling revealed that TP53 knockout in HaCaT cells led to the activation of apoptosis regulatory circuits, redox systems, and DNA repair. In addition, our data support the involvement of keratin 17 in the regulation of DNA repair and cell death. Apparently, the induction of keratin 17 is p53-independent but may be inhibited by mutant p53.

Protecting the Achilles heel: three FolE_I-type GTP-cyclohydrolases needed for full growth of metal-resistant Cupriavidus metallidurans under a variety of conditions.

In Cupriavidus metallidurans and other bacteria, biosynthesis of the essential biochemical cofactor tetrahydrofolate (THF) initiates from guanosine triphosphate (GTP). This step is catalyzed by FolE_I-type GTP cyclohydrolases, which are either zinc-dependent FolE_IA-type or metal-promiscuous FolE_IB-type enzymes. As THF is also essential for GTP biosynthesis, GTP and THF synthesis form a cooperative cycle, which may be influenced by the cellular homeostasis of zinc and other metal cations. Metal-resistant C. metallidurans harbors one FolE_IA-type and two FolE_IB-type enzymes. All three proteins were produced in Escherichia coli. FolE_IA was indeed zinc dependent and the two FolE_IB enzymes metal-promiscuous GTP cyclohydrolases in vitro, the latter, for example, functioning with iron, manganese, or cobalt. Single and double mutants of C. metallidurans with deletions in the folE_I genes were constructed to analyze the contribution of the individual FolE_I-type enzymes under various conditions. FolE_IA was required in the presence of cadmium, hydrogen peroxide, metal chelators, and under general metal starvation conditions. FolE_IB1 was important when zinc uptake was impaired in cells without the zinc importer ZupT (ZIP family) and in the presence of trimethoprim, an inhibitor of THF biosynthesis. FolE_IB2 was needed under conditions of low zinc and cobalt but high magnesium availability. Together, these data demonstrate that C. metallidurans requires all three enzymes to allow efficient growth under a variety of conditions.IMPORTANCETetrahydrofolate (THF) is an important cofactor in microbial biochemistry. This "Achilles heel" of metabolism has been exploited by anti-metabolites and antibiotics such as sulfonamide and trimethoprim. Since THF is essential for the synthesis of guanosine triphosphate (GTP) and THF biosynthesis starts from GTP, synthesis of both compounds forms a cooperative cycle. The first step of THF synthesis by GTP cyclohydrolases (FolEs) is metal dependent and catalyzed by zinc- or metal-promiscuous enzymes, so that the cooperative THF and GTP synthesis cycle may be influenced by the homeostasis of several metal cations, especially that of zinc. The metal-resistant bacterium C. metallidurans needs three FolEs to grow in environments with both high and low zinc and cadmium content. Consequently, bacterial metal homeostasis is required to guarantee THF biosynthesis.

Identification and expression of the Di19 gene family in response to abiotic stress in common bean (Phaseolus vulgaris L.).

Drought-induced 19 (Di19) protein plays critical biological functions in response to adversity as well as in plant growth and development. Exploring the role and mechanism of Di19 in abiotic stress responses is of great significance for improving plant tolerance. In this study, six Di19 genes were identified in the common bean (Phaseolus vulgaris L.), which were mainly derived from segmental duplications. These genes share conserved exon/intron structures and were classified into three subfamilies based on their phylogenetic relationships. The composition and arrangement of conserved motifs were consistent with their phylogenetic relationships. Many hormone- and stress-responsive elements were distributed in the promoters region of PvDi19 genes. Variations in histidine residues in the Cys2/His2 (C2H2) zinc-finger domains resulted in an atypical tertiary structure of PvDi19-5. Gene expression analysis showed rapid induction of PvDi19-1 in roots by 10% PEG treatment, and PvDi19-2 in leaves by 20% PEG treatment, respectively. Most PvDi19s exhibited insensitivity to saline-alkali stress, except for PvDi19-6, which was notably induced during later stages of treatment. The most common bean Di19 genes were inhibited or not regulated by cadmium stress, but the expression of PvDi19-6 in roots was significantly upregulated when subjected to lower concentrations of cadmium (5mmol). Moreover, Di19s exhibited greater sensitivity to severe cold stress (6°C). These findings enhance our understanding of the role of PvDi19s in common bean abiotic stress responses and provide a basis for future genetic enhancements in common bean stress tolerance.

Fiber optic cadmium ion sensors based on functionalization of a magnetic ion-imprinted polymer.

Cadmium poisoning is a chronic accumulation process, and long-term drinking of even low cadmium content water will cause kidney damage, so an ultra-low detection limit is particularly important. However, at the present stage, the traditional detection method cannot reach a sufficiently low detection limit, the response time is too long, and the cost of detection is very high, so that real-time measurement cannot be realized. Therefore, the traditional cadmium ion detection method has a slow response and an insufficient detection limit. This paper presents a fiber optic cadmium ion sensor functionalized based on an Fe3O4@SiO2@CS magnetic ion imprinting polymer (M-IIP). The sensor is based on the coupling characteristics of the optical microfiber coupler (OMC) cone region to achieve a highly sensitive response to the change in the cadmium ion concentration. M-IIP materials were prepared by surface imprinting polymerization to achieve low cross-sensitivity and thus improve the detection limit of the sensor. The results show that the developed fiber sensor has high specificity and a rapid response to cadmium ions. The experimental limit of detection (LOD) reached 0.051 nM within 0-1 μM with a response time of less than 50 s. Moreover, the proposed fiber cadmium ion sensor exhibits excellent performance in terms of sensitivity, stability, repeatability and biocompatibility.

Effect of cadmium ions on photosystem II oxygen evolution

The paper presents the results of the study of the effect of cadmium (CdSO4) ions on photosystem II (PSII) photochemical activity. The presence of Cd2+ ions in the medium was found to significantly inhibit the oxygen evolution in the thylakoid membranes, indicating a clear correlation between the concentration of Cd2+ ions and the inhibition of PSII photochemical activity. Additionally, the study identified that this inhibition is strongly dependent on the pH level of the medium. The inhibition of PSII photochemical activity occurred quickly at low cadmium concentrations (1.0-30 mM). The study also observed that the inhibition of O2 evolution by Cd2+ ions was time-dependent, with a rapid 20-40% inhibition of oxygen evolution occurring when adding Cd2+. The photochemical activity of PSII was inhibited slowly during long-term incubation. The findings imply that PSII contains at least one high-affinity cadmium binding site. Keywords: Cadmium, photosynthesis, photosystem II, oxygen evolution

Lead and cadmium co-exposure modified PC12 viability and ER stress: study from a 3×3 factorial design.

Although exposure to individual metal does exhibit its toxicity, combined exposures provide a more effective representation of the toxic effects of different heavy metal exposures on public health as well as ecosystems. Furthermore, there are few studies on composite exposure to low concentrations of heavy metals, which is more consistent with real-life exposure. The purpose of this study was to explore the neurotoxicity induced by combined exposure to low concentrations of Lead (Pb) and cadmium (Cd) and the potential interaction of their mixture in vitro. PC12 cells were incubation with the corresponding concentration of cadmium chloride and/or lead acetate. Viability of PC12 cells was measured by CCK8 assay after 12, 24 and 48h incubation. Next, We measured the ROS, mitochondrial membrane potential (MMP) and apoptosis produced by different treated cells using ROS assay kit, JC-1 MMP assay kit and annexin V-FITC/propidium iodide (PI) apoptosis assay kit, respectively. Expression of proteins related to PI3K/AKT and endoplasmic reticulum (ER) stress in PC12 cells were tested by western blotting. Our study was the first to analyze the interaction between Pb and Cd using a 3 × 3 factorial design approach to observe neurotoxicity. The results showed that the combined exposure of them was more cytotoxic than the single metal. The activation of PI3K/AKT signaling pathway and several parameters related to oxidative stress and ER stress were significantly altered in combined exposure to low concentrations of Pb and Cd compared with the Pb or Cd. Regarding apoptosis and ER stress, a synergistic interaction between Pb and Cd was evident. Moreover, evoked ER stress as a mechanism involved in the apoptosis of PC12 cells by the combined exposure to Pb and Cd. The present study provides a theoretical basis used for the toxicological assessment of metal mixtures induced neurotoxicity of concern in terms of public health, and more effective control measures should be taken for the environmental pollution caused by various mixed heavy metals discharged from industry and agriculture.

Diverging fates of cadmium and glyphosate during pasta cooking

Durum wheat cultivars with varying abilities to accumulate cadmium were grown and treated in the field with a glyphosate-containing herbicide at different stages of maturity to produce grain with higher and lower concentrations of cadmium (0.066–0.214 mg/kg) and glyphosate (0.474–0.874 mg/kg). The grain was milled, and fractions were analysed for cadmium and glyphosate. The highest concentrations for both cadmium and glyphosate were associated with bran and shorts, although the percentage of total cadmium mass in bran (23–25%) was less than glyphosate (38%). The preparation of dried pasta from semolina and flour milling fractions reduced concentrations by a factor of 1.8 for glyphosate and 1.4 for cadmium. Dried pasta was cooked and analysed along with the cooking water for cadmium and glyphosate at seven-time points from 0 to 15 min. Concentrations of glyphosate in cooked pasta decreased significantly with cooking time; no decrease was observed for cadmium concentrations. Analysis of cooking water demonstrated that glyphosate migrated from pasta to the cooking water. After 15 min of cooking, approximately 73% of the total glyphosate mass had transferred from pasta to cooking water. Over the same time period, only 5% of the total cadmium mass had transferred from pasta to cooking water.

Accumulation of heavy metals in leaves of tree species on the ash and slag dumps of the Burshtyn Thermal Power Plant

Thermal power plant (TPP) facilities are considered as one of the major reasons for environmental pollution. Ash and slag dumps as a special construction for storage of combustion wastes of TPPs are recognized as sources of heavy metals (HMs) contamination for surrounding ecosystems. The present study is the first report of analyzing HMs contamination of the ash and slag dumps of the Burshtyn TPP.
 The aim of the study is to estimate the content of HMs in the technogenic substrates of ash and slag dumps and investigate soil-plant interactions through analyzing potential of HMs accumulation in the leaves of native dominant woody species.
 Materials and methods of research. Soil sampling was carried out in the period of July 2021 at previously determined points. The most common woody species (Populus tremula L., Betula pendula Roth., Salix caprea L.) were selected for testing of HMs accumulation abilities. Samples of plants and soil were subjected to an atomic absorption spectrometer for being analyzed for heavy metals: Cd, Zn, Ni, Cu, Pb, Mn and Fe.
 Results of research and discussion. The results showed that the substrates of ash and slag dumps of the Burshtyn TPP were mainly contaminated by lead, copper and cadmium. All tested species concentrated high amounts of magnesium, iron, zinc and low concentration of cadmium. Bioaccumulation factor reflected the highest abilities of accumulation of zinc in all tested species and low level of bioaccumulation of cadmium. The highest index of biochemical activity showed Betula pendula. Salix caprea were found as a promising species for remediation due to intensive accumulation of such elements like cadmium, lead, copper, zinc and nickel.
 Conclusions and prospects for further research. We consider plant organisms particularly useful for analyzing HMs accumulation as they can provide a cost-effective and long-term approach for bioindication and monitoring HMs pollution. Moreover, vegetation covers could be used for remediation of HMs contaminated sites

Complex resistivity spectrum of pollutant soils with low-concentration heavy metals

Soil contamination by heavy metals occurs globally, with varying degrees of severity, especially in agricultural fields. Investigating the frequency response characteristics of different types of heavy metal pollutants through induced polarization can provide valuable evidence for surveys based on this method. Soil specimens with varying low concentrations of copper (Cu), chromium (Cr), cadmium (Cd), and lead (Pb) heavy metals were prepared for this study, and parameters including complex resistivity, amplitude-frequency, and resistivity phase were measured. Our findings reveal the following trends: Complex resistivity decreases as heavy metal concentrations increase, demonstrating significant shifts within lower concentration ranges but presenting limitations for assessing pollution in high-concentration areas. Conversely, amplitude-frequency increases with higher heavy metal concentrations, displaying excellent performance in high-concentration scenarios. The differences in complex resistivity and amplitude-frequency among different types of heavy metal pollutants are distinct. In contrast, the absolute phase decreases with rising heavy metal concentrations. The resistivity phase spectra for various heavy metal pollutants exhibit unique patterns. For example, copper-contaminated soil exhibits phase peaks in the frequency range of 8–32 Hz, whereas chromium-contaminated soil shows phase peaks at 16–64 Hz. Cadmium-contaminated soil displays phase peaks ranging from 0.25 Hz to 2 Hz, while lead-contaminated soil exhibits phase peaks within the 0.5 Hz–4 Hz range. Leveraging the frequency range corresponding to phase peaks as an identification method for heavy metal pollution types proves effective. The frequency response characteristics of induced polarization vary significantly among different types and concentrations of heavy metal pollutants, providing important foundations for the application of induced polarization method in the field of heavy metal pollution detection.

Short-term Effects of Cadmium Exposure on Blood Pressure and Vascular Function in Wistar Rats.

Chronic cadmium exposure is known to be associated with vascular changes and increased blood pressure, but its short-term effects on the cardiovascular system remain poorly understood. This study aimed to investigate the pressoric and vascular effects of a 7-day exposure to CdCl2 in Wistar rats. The rats were divided in control group (Ct), which received tap water, and the Cd group, which received a 100mg/L CdCl2 solution via drinking water for 7days. We analyzed body weight, plasma Cadmium concentration, systolic blood pressure (SBP), and vascular responses. Despite relatively low plasma Cadmium concentration, the Cd group exhibited elevated SBP and increased contractile response to phenylephrine. Endothelium removal and NOS inhibition increased contractions in both groups. In the Cd group's aorta, we observed enhanced levels of phospho-eNOS (Ser1177) and basal NO release. Cd group showed reduced Catalase expression and increased basal release of H2O2, with catalase reducing the contractile response. In arteries pre-contracted with phenylephrine, Cd group showed impaired endothelium-dependent (Acetylcholine) and independent (sodium nitroprussiate-SNP) relaxation responses. However, responses to SNP were similar after pre-contraction with KCl in both groups. These data suggest early effects of Cadmium on blood pressure and aortic function, indicating impaired H2O2-scavenging by catalase. Increased H2O2 due to Cadmium exposure might explain heightened responses to phenylephrine and weakened relaxation responses mediated by the NO-K+-channels pathway. Our findings shed light on Cadmium's short-term impact on the cardiovascular system, providing insights into potential mechanisms underlying its effects on blood pressure regulation and vascular function.

Differences in nutrient and undesirable substance concentrations in Maurolicus muelleri across the Bay of Biscay, Norwegian fjords, and the North Sea

IntroductionWe are having pressing issues of global food insecurity and malnutrition. Mesopelagic communities in the North Atlantic have been estimated to have high biomasses of organisms. Some of these low-trophic organisms are known to be nutrient-dense and may thus contribute to food security and nutrition. Here, we aim to understand the variation in nutrient and undesirable substance concentrations in a common mesopelagic species, Maurolicus muelleri in the North Atlantic Ocean.MethodsWe sampled the M. muelleri from the Bay of Biscay (BB), Norwegian fjords (NF), and the North Sea (NS). The concentrations of micro- and macronutrients, undesirable metals, and persistent organic pollutants (POPs) were measured in composite whole fish samples.ResultsWe found no difference across the sampling areas in the selected micronutrients except that the NF and NS samples had higher vitamin A1 concentrations than the BB samples. The NF samples had higher concentrations of fat, fatty acids, and POPs but lower concentrations of cadmium than the BB and NS samples; the differences in fat and fatty acids were only marginal in the NF-BB pair. The BB samples had lower arsenic concentrations than the NS samples, and lower concentrations of erucic acid and mercury than the NF and NS samples. Comparing the measured values against existing EU regulation values for nutrients and undesirable substances for human consumption, we found that the samples from NS and BB may cause food safety concerns due to their high cadmium concentrations, while the M. muelleri from all the sampling areas are qualified as good sources of iron, selenium, vitamin A1, and ω-3 fatty acids.DiscussionThis study confirms that M. muelleri from the North Atlantic Ocean may play an important role in food security and nutrition. However, potential variations in nutrient and undesirable substance concentrations related to seasonality, fish body size, and maturity level shall be taken into consideration prior to exploiting such a marine resource. Further understanding of trophic ecology, life cycles, and productivity of M. muelleri is essential to investigate the drivers behind the observed variation in nutrient and undesirable substance concentrations.

Blood selenium level can alleviate the nephrotoxicity of lead and cadmium in the general population of the United States: a retrospective cross section analysis of population-based nationally representative data.

The current understanding of the interplay between blood selenium, cadmium and lead levels, and chronic kidney disease (CKD) is limited. Our objective was to investigate whether elevated blood selenium levels can mitigate the nephrotoxic effects of lead and cadmium. The exposure variables examined in this study include blood selenium, cadmium, and lead levels measured by ICP-MS. The outcome of interest was CKD, defined as an estimated glomerular filtration rate (eGFR) below 60mL/min/1.73 m2. In total, 10630 participants (mean (SD) age:48.9 ± 18.4; 48.3% male) were included in this analysis. The median (IQR) of blood selenium, cadmium, and lead levels was 191 (177-207) μg/L, 0.300 (0.180-0.540) μg/L, and 0.940 (0.570-1.510) μg/dL, respectively. We observed a significant positive association between cadmium and lead levels and CKD (OR; 1.86; 95%CI: 1.31- 2.64; OR:2.23; 95%CI:1.54-3.24). However, selenium had a negative association with CKD (OR:0.096; 95%CI:0.020-0.457). Based on a reference group with a selenium concentration of ≤ 191μg/L and cadmium level of > 0.300μg/L, a significant protective factor in the CKD was seen in subjects with high plasma selenium and lower cadmium concentrations (OR:0.685; 95%CI:0.515-0.912). Then selenium concentration of ≤ 191μg/L and lead level of > 0.940μg/dL were set as a reference group, and the OR for CKD decreased among the other group (OR:0.564; 95%CI;0.417- 0.762). The subgroup analysis indicated that there were no effect modifiers. Blood selenium has the potential to mitigate the nephrotoxic effects of lead and cadmium in the general population of the United States.

Ascorbic Acid and Calcium Silicate Improve MorphoPhysiological Characteristics of Cadmium Stressed Mung Bean Crop

A rise in heavy metal contamination especially in the rhizosphere affecting the growth and yield of crops is a major concern. We aimed to study the influence of using calcium silicate (CS) and ascorbic acid (AsA) supplements on lowering the impact of cadmium-induced toxicityin mung bean. Both the supplements alone or in combination improved growth characteristics of cadmium (Cd) stressed mung bean plants like root-shoot length and fresh-dry weight. Leaf pigments like chlorophyll and carotenoids were also restored. A significant improvement in the relative leaf water content (RLWC) and low electrolyte leakage (EL) at the membrane was recorded. Results were more promising when combinations of CS and AsA treatments were used against the lower concentration of cadmium. Hence, both CS and AsA interact synergistically to alleviate Cd induced metal toxicity in mung bean plants.

Comparative genomic damage among three shark species with different habits: Sublethal impacts of human origin in a protected island environment in the South Atlantic

Elasmobranchs can bioaccumulate and biomagnify pollutants. However, few studies are directed to the effects of pollutants on the health of these animals, and in most cases, are limited to the analysis of biochemical markers. Thus, the incidence of genomic damage among shark species inhabiting a protected ocean island in the South Atlantic was investigated in association with the analysis of pollutants in seawater sample. High levels of genomic damage were identified, especially in Negaprion brevirostris and Galeocerdo cuvier, in addition to interspecific variations that may be related to characteristics such as animal size, metabolism and habits. High concentrations of Surfactants were observed in seawater sample, in addition to low concentrations of Cadmium, Lead, Copper, Chromium, Zinc, Manganese, and Mercury. The results evidenced the potential of shark species as a bioindicator of environmental quality and allowed assessing the anthropic impact on the archipelago, which currently drives its economy through tourism.

Arsenic, cadmium, and lead in rice and rice products on the Austrian market

ABSTRACT Fifty-one rice samples, i.e. 25 rice varieties, 8 rice products, and 18 rice containing baby foods from the Austrian market were surveyed for arsenic, cadmium, and lead. Inorganic arsenic (iAs) is most toxic to human health, and its mean concentrations in rice were 120 µg kg−1, 191 µg kg−1 in rice products, and 77 µg kg−1 in baby foods. The average dimethylarsinic acid and methylarsonic acid concentrations were 56 µg kg−1 and 2 µg kg−1, respectively. The highest iAs concentration was found in rice flakes (237 ± 15 µg kg−1), close to the Maximum Level (ML) set by the EU regulation for husked rice (250 µg kg−1). The levels of cadmium (12 to 182 µg kg−1) and lead (6 to 30 µg kg−1) in the majority of rice samples were below the European ML. Upland grown rice from Austria showed both, low inorganic arsenic (<19 µg kg−1) and cadmium (<38 µg kg−1) concentrations.

Onsite detection of cadmium and nickel using gold nanospheres and nanotriangles capped with Cyclea peltata phytochemicals

Small-sized gold nanospheres and nanotriangles (CPAuNPs) were synthesized to visually identify low concentrations of cadmium and nickel (20 ppm) in polluted water samples. Three factors i.e Cyclea peltata extract concentration (X1), temperature (X2), pH (X3) and agitation speed (X4) were optimized for maximum CPAuNPs synthesis by central composite design. The optimized conditions were found to be CP extract concentration of 24.20%, pH of 7.68 and agitation speed of 43 RPM at which maximum yield of 0.412 g/L was obtained with a fold increase of 1.42 as compared to unoptimized conditions. Gold nanospheres were in the size range of 25–36 nm and nano triangles of 100–140 nm with zetapotential of −31.8 mV. The synthesized CPAuNPs demonstrated good selectivity for visual detection of cadmium and nickel at ppm levels, where the colour of CPAuNPs changed from pink to purple. Upon interaction of CPAuNPs with Cd+3 and Ni+2 in the varied concentration ranges, a maximum red shift was seen at 20 ppm, which confirmed agglomeration. The variation in absorbance ratio (A640nm/A523nm) for Cd+3 and (A610nm,/A523nm) for Ni+2 showed linearity upto 50 ppm with respect to increased concentration in both the cases with R2 = 0.926 in case of Cd+3 and R2 = 0.950 for Ni+2. Hence, a portable low-cost detection kit for specific heavy metals could be constructed, employing this plant reduced nanospheres, for on-site detection sensing of cadmium and nickel in industrial effluents upto 20 ppm limits.

Bioaccumulation of trace elements in vegetables grown in various anthropogenic conditions

Hazardous compounds accumulate in plants and animals as a result of anthropogenic impact. Trace elements, such as heavy metals, move up in the system of snow – soil – water – plant – animal. When contaminants accumulate in plants that serve as animal feed, they eventually accumulate in the animals that consume the feed because heavy metals usually enter living organisms via digestive tract, i.e., with food.&#x0D; In 2003–2021, we studied fodder plants grown and harvested by urban zoological organizations, e.g., zoos, nature corners, etc. This research covered the Central Federal District represented by the cities of Moscow, Ivanovo, Yaroslavl, and Uglich. The empirical part of the study relied on a combination of modern ecological, biochemical, and statistical methods. A KVANT-2AT atomic absorption spectrometer was used to define the trace elements and their quantities.&#x0D; Broccoli proved to be the most resistant feed vegetable to all the toxic elements in this study. Kohlrabi, sweet potato, and dill had low content of lead and cadmium, while garlic was highly resistant to cadmium and arsenic. Spinach, fennel, potatoes, beets, and bell peppers, which were used as fodder in metropolis conditions, exceeded the maximal permissible concentration of heavy metals. The samples obtained from the Moscow Zoo contained by 1.98 times more zinc, by 1.06 times more copper, and by 89.47 times more lead than average. The samples from Ivanovo accumulated the greatest extent of iron, which exceeded the average level by 3.26 times. The vegetables from Uglich and Ivanovo had the lowest concentration of zinc, which was by 67.86 and 62.70% below the average, respectively. The samples from Yaroslavl contained by 33.08% less copper. In 2003–2021, feed vegetables grown in the Central Federal District had an average increase in zinc, copper, and lead by 1.13, 1.45, and 2.80 times, respectively. The level of iron stayed almost the same throughout 2018–2021, while that of arsenic gradually decreased in concentration. The accumulation level of zinc, copper, iron, and arsenic in feed vegetables appeared to depend on the concentration of their water-soluble metal forms in the soil.&#x0D; Therefore, forage agriculture in urban areas requires constant chemical and toxicological tests to prevent contaminated feed from entering animal diet.

Soil Contamination with Metals in Mountainous: A Case Study of Jaworzyna Krynicka in the Beskidy Mountains (Poland).

The paper presents the content of six metals (Cd, Cr, Cu, Ni, Pb, and Zn) in the soils of the southern slope of Jaworzyna Krynicka in Poland. Soil samples were collected in polygons, starting from an altitude of 500 m above sea level and ending at an altitude of 1100 m above sea level. Ten soil samples were collected in each polygon. The polygons were set at every 100 m of absolute altitude. The selected research area is an important natural area. The fertile mountain beech forests located there are the most important forest communities in the mountain areas of Poland. They are valuable habitats for plants and animals (especially for large predatory mammals). Every year, numerous tourists and health resort patients visit this place. The results of the research showed that soil contamination in the study area is not high, in particular for altitudes of 500 and 900 m above sea level. At these altitudes, the contents of Cd, Cr, Cu, Ni, Pb, and Zn were similar to the concentrations of these metals in uncontaminated soils. The tests carried out showed very low cadmium content for all absolute altitudes. Zinc, the concentrations of which exceeded natural values, showed the highest content in the tested soils. All the metals tested showed a common tendency of increases in their content in the soils of Jaworzyna Krynicka up to 800 m above sea level. From an altitude of 900 m above sea level, the content of these metals decreased, except for Pb. Only Pb concentrations in Jaworzyna Krynicka soils also increased with the increasing altitude. The research significance of this work is that it is important for assessing the ecological balance in the selected area.

Digital Soil Mapping of Cadmium: Identifying Arable Land for Producing Winter Wheat with Low Concentrations of Cadmium

Intake of cadmium (Cd) via vegetable food poses a possible health risk. Cereals are one of the major sources of Cd, and the Cd concentration in the soil has a great effect on the levels in the grain. The aim of the study was to produce decision support for identification of areas suitable for low-Cd winter wheat production in the form of a detailed digital soil map covering an important agricultural region in southern Sweden. A two-step approach was used: (1) we increased the number of soil Cd observations by combining two sets of soil samples, one with laboratory Cd analyses (304 samples) and one with predicted Cd from a portable x-ray fluorescent (PXRF) sensor (2097 samples); and (2) a digital soil mapping (DSM) model (gradient boosting regression) was calibrated on all 2401 soil samples to create a soil Cd concentration map using a number of covariates, of which airborne gamma ray data was identified as the most important. In the first step, cross-validation of the PXRF model obtained a model efficiency (E) of 0.82 and mean absolute error (MAE) of 0.08 mg kg−1. The DSM model had an E of 0.69 and MAE of 0.11 mg kg−1. The map of predicted soil Cd concentrations were compared against 307 winter wheat (Triticum aestivum L.) grain samples with laboratory-analyzed Cd concentrations. Areas in the map with low soil Cd concentrations had a high frequency of lower grain Cd concentrations. The map thus seemed to have potential for finding areas suitable for production of low-Cd winter wheat; e.g., for baby food.