Low Concentrations Of Cadmium Research Articles

Effect of Phosphate Addition on Cadmium Precipitation and Adsorption in Contaminated Arable Soil with a Low Concentration of Cadmium.

The objectives of this study were to determine (1) the phosphorus (P) level required to induce cadmium (Cd) precipitation in a contaminated arable soil with low concentrations of Cd and (2) the primary mechanism of Cd immobilization at different P levels. Phosphorus was added at levels of 0 800, 1600, and 16,000 mg P kg(-1) to a soil containing 5.57 mg Cd kg(-1). The concentration of 1 M NH4OAc extractable Cd decreased significantly with P levels up to 1600 mg kg(-1) due to an increase in soil pH and negative charge of soil (p<0.001). A further decrease in 1 M NH4OAc extractable Cd concentration was noted when P was increased to 16,000 mg P kg(-1) and may have been the result of Cd precipitation. This study suggest that adding P at high levels may help in the formation of geochemically stable Cd minerals in soil containing low levels of this heavy metal.

Sperm whales (Physeter macrocephalus), found stranded along the Adriatic coast (Southern Italy, Mediterranean Sea), as bioindicators of essential and non-essential trace elements in the environment

In September 2014, a pod of seven sperm whales (Physeter macrocephalus) was stranded along the Adriatic coast of Southern Italy. Concentrations of 20 essential and non-essential trace elements were quantified in the brain, muscle, liver and kidneys of three female sperm whales, which died in this event.The essential elements copper, iron, manganese and zinc showed low ranges of variability, suggesting a homeostatic physiological control, while selenium concentrations were associated with age. Molybdenum, nickel and chromium showed low ranges of concentrations and no evidence of preferential accumulation in selected organs. Very low concentrations of the non-essential elements cadmium, lead, tin and vanadium were detected in all tissues, suggesting a minor impact of these pollutants on the sperm whale populations of the Mediterranean Sea. Aluminum was revealed to have relatively high concentrations, together with a high variability between tissues and individuals, reaching the highest values in the kidneys and muscle of the oldest female, which was pregnant; the rare earth elements – lanthanum and cerium – were also detected in the kidneys of this female, indicating that pregnancy probably influenced metal concentrations in body tissues.

AAC Marchwell durum wheat

Singh, A. K, Clarke, J. M., Knox, R. E., DePauw, R. M., Wise, I., Thomas, J., McCaig, T. N., Cuthbert, R. D., Clarke, F. R. and Fernandez, M.R. 2015. AAC Marchwell durum wheat. Can. J. Plant Sci. 95: 189–195. AAC Marchwell durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.] is adapted to the durum production area of th Canadian prairies. AAC Marchwell is the first durum genotype registered for commercial production in Canada with the Sm1 gene for antibiosis-based resistance to orange wheat blossom midge [Sitodiplosis modellana (Gehin)]. It combines high grain yield, grain protein concentration, yellow pigment, test weight, and low grain cadmium concentration. AAC Marchwell has similar straw strength, plant height, and days to maturity as Strongfield. AAC Marchwell is resistant to leaf rust, stem rust, stripe rust, common bunt, loose smut, and common root rot. AAC Marchwell has end use quality suitable for the Canada Western Amber Durum class.

Effects of cadmium accumulation from suspended sediments and phytoplankton on the Oyster Saccostrea glomerata

Metals are accumulated by filter feeding organisms via water, ingestion of suspended sediments or food. The uptake pathway can affect metal toxicity. Saccostrea glomerata were exposed to cadmium through cadmium-spiked suspended sediments (19 and 93μg/g dry mass) and cadmium-enriched phytoplankton (1.6–3μg/g dry mass) and cadmium uptake and effects measured. Oysters accumulated appreciable amounts of cadmium from both low and high cadmium spiked suspended sediment treatments (5.9±0.4μg/g and 23±2μg/g respectively compared to controls 0.97±0.05μg/g dry mass). Only a small amount of cadmium was accumulated by ingestion of cadmium-enriched phytoplankton (1.9±0.1μg/g compared to controls 1.2±0.1μg/g). In the cadmium spiked suspended sediment experiments, most cadmium was desorbed from sediments and cadmium concentrations in S. glomerata were significantly related to dissolved cadmium concentrations (4–21μg/L) in the overlying water. In the phytoplankton feeding experiment cadmium concentrations in overlying water were <0.01μg/L. In both exposure experiments, cadmium-exposed oysters showed a significant reduction in total antioxidant capacity and significantly increased lipid peroxidation and percentage of destabilised lysosomes. Destabilised lysosomes in the suspended sediments experiments also resulted from stress of exposure to the suspended sediments. The study demonstrated that exposure to cadmium via suspended sediments and to low concentrations of cadmium through the ingestion of phytoplankton, can cause sublethal stress to S. glomerata.

AAC Current durum wheat

Singh, A. K., Clarke, J. M., DePauw, R. M., Knox, R. E., McCaig, T. N. and Cuthbert, R. D. 2015. AAC Current durum wheat. Can. J. Plant Sci. 95: 589–594. AAC Current durum wheat (Triticum turgidum L. subsp. durum (Desf.) Husn.) is adapted to the durum production area of the Canadian prairies. AAC Current combines high grain yield, high grain protein concentration, strong straw strength, very high test weight, high grain pigment and strong gluten strength, and low grain cadmium concentration.

Useful and Fast Method for Blood Lead and Cadmium Determination Using ICP-MS and GF-AAS; Validation Parameters.

In case of clinical analysis, especially in blood lead (Pb-B) and cadmium (Cd-B) determination, the accuracy and precision of the method are crucial. The objective of this article is to present a simple and useful method for Pb-B and Cd-B determination using ICP-MS (inductively coupled plasma-mass spectrometry) as well as GF-AAS (graphite furnace-atomic absorption spectrometry). The principle of the method is based on the deproteinization of blood samples by addition of 5% nitric acid that eliminates the presence of the protein in the samples, thereby excluding the influence of the organic matrix on the result determinations. A comparison of the two techniques ICP-MS and GF-AAS was established for Pb and Cd determinations in the same 40 blood samples collected from lead workers. The results showed that validation parameters for ICP-MS and GF-AAS were similar, however better for ICP-MS for Pb-B determinations. The detection limit (3×SD) for Pb-B determinations for ICP-MS and GF-AAS was, respectively, 0.16 and 1.0 μg/l, and for Cd-B it was, respectively, 0.08 and 0.02 μg/l. Correlation coefficients (rs) for comparable Pb-B and Cd-B determinations, using these two techniques, showed very good statistically significant correlations and were r = 0.9988, P < 0.0001 for Pb-B and r = 0.9949, P < 0.0001 for Cd-B. The obtained results indicate that the method of deproteinization of blood samples is still the best way to eliminate spectral interferences and influence of the organic matter. The elaborated method is especially dedicated to clinical laboratories and determined low concentrations of lead and cadmium in biological samples.

Soybean cadmium concentration: validation of a QTL affecting seed cadmium accumulation for improved food safety

Soybean can accumulate considerable amounts of cadmium depending on soil conditions. As low cadmium concentration of soybean is of great interest in soy food production, a major quantitative trait locus described earlier for controlling cadmium accumulation in the seed was utilized to classify early maturity genotypes with respect to cadmium uptake and to verify their cadmium accumulation level. Marker-selected soybean genotypes were then tested for cadmium accumulation in a pot experiment with three cadmium levels and at three field locations in Austria. Out of 48 soybean genotypes, 19 exhibited the microsatellite marker allele associated with low cadmium accumulation. In the pot experiment, seed cadmium concentration was below 0.15 mg kg−1 in low cadmium accumulating genotypes while it reached over 0.30 mg kg−1 in genotypes carrying the high cadmium allele. In field experiments, cadmium concentration was in the range between 0.03 and 0.16 mg kg−1, and both the cadmium accumulation locus as well as the experimental locations had a significant influence on seed cadmium. Marker-assisted selection of soybean genotypes for low cadmium accumulation could thus contribute to improved food safety which is particularly important for environments with unknown cadmium status of soil.

AAC Raymore durum wheat

Singh, A. K., Clarke, J. M., Knox, R. E., DePauw, R. M., McCaig, T. N., Cuthbert, R. D., Clarke, F. R. and Fernandez, M. R. 2014. AAC Raymore durum wheat. Can. J. Plant Sci. 94: 1289–1296. AAC Raymore durum wheat [Triticum turgidum L. subsp. durum (Desf.) Husn.] is adapted to the durum production area of the Canadian prairies. AAC Raymore is the first solid stem durum genotype registered for production in Canada for protection against wheat stem sawfly, and combines high grain yield, grain protein concentration, test weight, and low grain cadmium concentration. AAC Raymore has similar straw strength, plant height, and days to maturity as Strongfield. AAC Raymore is resistant to leaf rust, stem rust, stripe rust, common bunt, is moderately susceptible to loose smut, and has improved resistance to common root rot compared with the check cultivars. AAC Raymore has end use quality suitable for the Canada Western Amber Durum class.

Release of Metals from Different Sections of Domestic Drinking Water Installations

Different metals can leach from piping materials into the tap water, which can be of health concern. This study investigated in which amount abundant metals were released from different parts of domestic installations into the cold tap water. For the approximate spatial allocation of the metal releasing sources, a sequential water sampling protocol was used after three hours of stagnation time representing the first five litre of the water column. After stagnation ten sample volumes were collected in series. Existing facilities of domestic installations constructed with different plumbing materials were examined predominantly from residential buildings. The elements Al, As, Cd, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Sb, Se, U and Zn were detected by means of ICP-MS. In total 16 water pipe strands of 11 domestic installation systems were examined. They comprised 401 single water samples and 5,614 single parameters. Depending upon the type of plumbing, different courses and concentration ranges of the elements could be measured in the tap water samples. Terminal taps or installation parts were in all investigated systems responsible for a release of nickel and in several cases of low concentrations of cadmium. The concentration courses of the element zinc proved as a good indicator for the allocation of the metal source to a brass containing section of the installation (zinc as an alloy component of brass). One can conclude that sequential water sampling protocol in combination with multi-element detection can be a valuable non-destructive method for drinking water-hygienic investigations of domestic installations.

Alleviation of arsenic stress in cardoon plants via the supply of a low cadmium concentration

The effect of As (0–80μM) and of As+Cd (0–80μM+5μM) combinations on plant growth, toxicological variables and As and Cd bioaccumulation was studied in cardoon plants under controlled conditions. Plants grown in the presence of As alone showed less reduction in overall root and shoot development than those exposed to As+Cd, although the main root was shorter than in the latter plants. The effective added concentrations of As that reduced shoot or root dry weight by 50% (EC50) and the critical toxic concentration that caused a 10% reduction in plant growth (CTC10%) were higher in plants grown with As alone. In both treatments (As and As+Cd), the CTC10% was higher in the roots, but the root EC50 was lower than the shoot EC50. The presence of Cd increased the accumulation of As in the shoot, but ≥20μM As reduced the shoot bioaccumulation of Cd. Thus, the presence of 5μM Cd with As appears to reduce the tolerance of cardoon plants to the latter element, but it increases their As phytoextraction capacity. Cardoon plants could be used as excluders in As-contaminated sites and as accumulators in those co-contaminated with As and Cd.

Higher antioxidant and lower cadmium concentrations and lower incidence of pesticide residues in organically grown crops: a systematic literature review and meta-analyses.

Demand for organic foods is partially driven by consumers' perceptions that they are more nutritious. However, scientific opinion is divided on whether there are significant nutritional differences between organic and non-organic foods, and two recent reviews have concluded that there are no differences. In the present study, we carried out meta-analyses based on 343 peer-reviewed publications that indicate statistically significant and meaningful differences in composition between organic and non-organic crops/crop-based foods. Most importantly, the concentrations of a range of antioxidants such as polyphenolics were found to be substantially higher in organic crops/crop-based foods, with those of phenolic acids, flavanones, stilbenes, flavones, flavonols and anthocyanins being an estimated 19 (95 % CI 5, 33) %, 69 (95 % CI 13, 125) %, 28 (95 % CI 12, 44) %, 26 (95 % CI 3, 48) %, 50 (95 % CI 28, 72) % and 51 (95 % CI 17, 86) % higher, respectively. Many of these compounds have previously been linked to a reduced risk of chronic diseases, including CVD and neurodegenerative diseases and certain cancers, in dietary intervention and epidemiological studies. Additionally, the frequency of occurrence of pesticide residues was found to be four times higher in conventional crops, which also contained significantly higher concentrations of the toxic metal Cd. Significant differences were also detected for some other (e.g. minerals and vitamins) compounds. There is evidence that higher antioxidant concentrations and lower Cd concentrations are linked to specific agronomic practices (e.g. non-use of mineral N and P fertilisers, respectively) prescribed in organic farming systems. In conclusion, organic crops, on average, have higher concentrations of antioxidants, lower concentrations of Cd and a lower incidence of pesticide residues than the non-organic comparators across regions and production seasons.

Crude oil and bioproducts of castor bean (Ricinus communis L.) plants established naturally on metal mine tailings

Previous research suggested that Ricinus communis may be used for soil remediation and oil production. However, the quality of the oil and bioproducts under polluted conditions need to be tested to be assured of their potential use in biofuel production with environmentally friendly bioproducts (cake, seed coats and biomass). Oil characteristics and metal concentrations in oil, cake (de-oiled seeds) and seed coats, as well as the shoot carbon content were analyzed. The oil contents of palmitic and oleic acids from plants growing in polluted mine tailings were comparable to those for plants grown under non-polluted conditions. Linoleic acid content was significantly higher in oil of plants from mine tailings, which enriches the fuel properties. Cadmium and lead were mainly concentrated in the seed coat, whereas copper in the cake. Castor bean oil had low concentrations of cadmium, lead, zinc, nickel, manganese and copper-free. Cake and seed coats can be useful for soil fertilization applications since the metal concentrations are below safety regulations. The biomass carbon was around 43 %, which suggests it may be used for biogas production. These properties make castor bean valuable for its oil and bioproducts even when growing at metal-polluted sites. However, agronomic optimization is needed in order to produce higher plant productivity.

Amount and metal composition of midgut gland metallothionein in shore crabs (Carcinus maenas) after exposure to cadmium in the food

Accumulation of cadmium in aquatic invertebrates may compromise human food safety and anthropogenic additions of cadmium to coastal areas cause concern. Induction of crustacean metallothionein has been suggested as a useful biomarker for contamination of the aquatic environment with cadmium. We investigated how exposure to low concentrations of cadmium in the food affects the subcellular binding of cadmium with the shore crab Carcinus maenas as model organism. Approximately 80% of the assimilated cadmium was bound in the soluble fraction of the midgut gland and of this, 82% was found in the metallothionein fraction. Metallothionein synthesis was only induced at the highest exposure level. However, the number of cadmium atoms bound per molecule of metallothionein increased linearly with exposure, from approximately 0.18 in the control group to 1.4 in a group administered food containing 5.1μgCdg−1. We noted a marked interaction between the presence of copper and zinc in the midgut gland and the binding of cadmium. The usefulness of crustacean midgut gland metallothionein as a biomarker for cadmium exposure at modest levels was questioned since exposures at levels producing significant increases in the tissue contents of the metal did not result in elevated concentrations of metallothionein in the midgut gland.

Amelioration of lead- and cadmium-induced rat tracheal hypercontraction by linalool and eugenol

Relative contribution of various pathways to non-acute hypercontraction produced by low concentrations of lead (Pb) and cadmium (Cd) and its amelioration by eugenol and linalool was examined in rat tracheal system. Saturating effect producing concentrations of nitric oxide (NO) donor (sodium nitroprusside; 1 μM), reactive oxygen species (ROS) inhibitor (apocynin; 100 μM), and cyclooxygenase inhibitor (indomethacin; 100 μM) produced 38%, 55%, and 40% inhibition of hypercontraction in Pb-exposed and 27%, 45%, and 38% in Cd-treated trachea, respectively. These inhibitors decreased contraction by 20%, 29%, and 28%, respectively, in tissue indicating that ROS are the major contributors in both Pb- and Cd-induced hypercontraction. Depletion of NO contributes significantly to Pb-induced hypercontraction but not to Cd. Cyclooxygenases were found to play a non-significant role in hypercontraction produced by both pollutants. Relaxations provided by saturating concentrations of eugenol (100 μM) and linalool (100 μM) in the presence and absence of three inhibitors suggest that major effect of eugenol originates from inhibition of ROS whereas that of linalool from inhibition of cyclooxygenase signaling cascades. This correlates well with relaxation provided by eugenol and linalool in pollutant-exposed tracheal rings. Activities of key enzymes – superoxide dismutase, glutathione peroxidase, and nitric oxide synthase – showed that Pb generated oxidative stress by direct binding to these enzymes and Cd by other mechanisms.

Stress-induced stimulation of choline transport in cultured choroid plexus epithelium exposed to low concentrations of cadmium

The choroid plexus epithelium forms the blood-cerebrospinal fluid barrier and accumulates essential minerals and heavy metals. Choroid plexus is cited as being a "sink" for heavy metals and excess minerals, serving to minimize accumulation of these potentially toxic agents in the brain. An understanding of how low doses of contaminant metals might alter transport of other solutes in the choroid plexus is limited. Using primary cultures of epithelial cells isolated from neonatal rat choroid plexus, our objective was to characterize modulation of apical uptake of the model organic cation choline elicited by low concentrations of the contaminant metal cadmium (CdCl₂). At 50-1,000 nM, cadmium did not directly decrease or increase 30-min apical uptake of 10 μM [(3)H]choline. However, extended exposure to 250-500 nM cadmium increased [(3)H]choline uptake by as much as 75% without marked cytotoxicity. In addition, cadmium induced heat shock protein 70 and heme oxygenase-1 protein expression and markedly induced metallothionein gene expression. The antioxidant N-acetylcysteine attenuated stimulation of choline uptake and induction of stress proteins. Conversely, an inhibitor of glutathione synthesis l-buthionine-sulfoximine (BSO) enhanced stimulation of choline uptake and induction of stress proteins. Cadmium also activated ERK1/2 MAP kinase. The MEK1 inhibitor PD98059 diminished ERK1/2 activation and attenuated stimulation of choline uptake. Furthermore, inhibition of ERK1/2 activation abated stimulation of choline uptake in cells exposed to cadmium with BSO. These data indicate that in the choroid plexus, exposure to low concentrations of cadmium may induce oxidative stress and consequently stimulate apical choline transport through activation of ERK1/2 MAP kinase.

Evaluation of the adverse effect of low concentration of cadmium on interleukin-4 induced class switch recombination in Burkett's lymphoma Raji cell line.

Affinity maturation of B lymphocytes, a process that includes somatic hypermutation and class switch recombination, initiates global DNA rearrangements. The interruption of this process has an adverse effect on human health and results in immunodeficiency and autoimmune disease. Class switch recombination is a fundamental factor of the human adaptive immunity. Evaluation of the class switch recombination efficiency is an important component of laboratory diagnostic of immunotoxic components. Here, we describe a method for testing the efficiency of the class switch recombination. Cultivation of Raji Burkett's lymphoma cell line with anti-CD40 antibodies and recombinant interleukin-4 (IL-4) triggers a cascade of signal transduction network events that lead to switching the immunoglobulin isotopes from IgM to IgE. This chapter describes the methodology of class switch recombination assay for assessment of the effect of the environmental pollutants in toxicological laboratory diagnostics.

Bioaccumulation of cadmium by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae

Bioaccumulation via growing cells is a potential technique for heavy metal removal from food materials. The cadmium bioaccumulation characteristics by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae were investigated. Z. rouxii displayed powerful cadmium removal ability at low cadmium concentrations, which mainly depended on the intracellular cadmium bioaccumulation. The percentage of intracellular cadmium bioaccumulation of both yeasts obviously decreased with the increase of initial biomass and cadmium concentrations. Low pH and elevated concentrations of zinc and copper significantly decreased the intracellular cadmium bioaccumulation of both yeasts but improved the cadmium tolerance and the cell-surface cadmium bioaccumulation of Z. rouxii. Cadmium removal of Z. rouxii was improved by zinc and copper conditionally. Z. rouxii that possessed more powerful cadmium tolerance and removal ability at low pH and high concentration of competing ions can be developed into a potential cadmium removal agent using in complex food environment in future.

Pseudo-stir bar hollow fiber solid/liquid phase microextraction combined with anodic stripping voltammetry for determination of lead and cadmium in water samples

A new procedure is presented for the determination of low concentrations of lead and cadmium in water samples. Ligand assisted pseudo-stir bar hollow fiber solid/liquid phase microextraction using sol–gel sorbent reinforced with carbon nanotubes was combined with differential pulse anodic stripping voltammetry for simultaneous determination of cadmium and lead in tap water, and Darongar river water samples. In the present work, differential pulse anodic stripping voltammetry (DPASV) using a hanging mercury drop electrode (HMDE) was used in order to determine the ultra trace level of lead and cadmium ions in real samples. This method is based on accumulation of lead and cadmium ions on the electrode using different ligands; Quinolin-8-ol, 5,7-diiodo quinoline-8-ol, 4,5-diphenyl-1H-imidazole-2(3H)-one and 2-{[2-(2-Hydroxy-ethylamino)-ethylamino]-methyl}-phenol as the complexing agent. The optimized conditions were obtained. The relationship between the peak current versus concentration was linear over the range of 0.05–500ngmL−1 for Cd (II) and Pb (II). The limits of detection for lead and cadmium were 0.015ngmL−1 and 0.012ngmL−1, respectively. Under the optimized conditions, the pre-concentration factors are 2440 and 3710 for Cd (II) and Pb (II) in 5mL of water sample, respectively.

NF-κB acts downstream of EGFR in regulating low dose cadmium induced primary lung cell proliferation

Apart from cytotoxicity cadmium has no special attributes towards cell's physiological function. The role of cadmium with respect to cell growth is still under debate. Mitogen activated protein kinase and Ca(2+)/calmodulin dependent protein kinase dependent pathways are the two elaborately studied concerning cadmium induced cell proliferation. Low concentration of cadmium chloride (2.5 μM) was applied to mice primary lung epithelial cells and cell proliferation was measured both by cell cycle analysis and Brdu incorporation assay. Effects of differential dose of cadmium chloride on lung epithelial cells were evaluated morphologically by atomic force microscopy. RT-PCR and western blot altogether corroborated the specific signalling pathways concerning cadmium induced lung cell proliferation. Cadmium induced lung epithelial cells which over-expressed EGFR, were transfected with siEGFR, revealed downstream molecules and RNAi induced EGFR silencing. Use of siEGFR effectively prevents expression of proinflammatory and cell proliferative markers. Moreover N-acetyl cysteine and ascorbic acid mediated inhibition of EGFR and downstream signalling molecules indicate the involvement of reactive oxygen species. Exposure to low concentration of cadmium promotes the growth of primary mice lung epithelial cell by EGFR signalling. We have also transfected the primary lung epithelial cell with siRNA against the regulatory subunit of nuclear factor-κB (NF-κB) and the data shows that cadmium induced lung cell proliferation is the effect of EGFR mediated NF-κB activation.

Cadmium is a potent inhibitor of PPM phosphatases and targets the M1 binding site

The heavy metal cadmium is a non-degradable pollutant. By screening the effects of a panel of metal ions on the phosphatase activity, we unexpectedly identified cadmium as a potent inhibitor of PPM1A and PPM1G. In contrast, low micromolar concentrations of cadmium did not inhibit PP1 or tyrosine phosphatases. Kinetic studies revealed that cadmium inhibits PPM phosphatases through the M1 metal ion binding site. In particular, the negative charged D441 in PPM1G specific recognized cadmium. Our results suggest that cadmium is likely a potent inhibitor of most PPM family members except for PHLPPs. Furthermore, we demonstrated that cadmium inhibits PPM1A-regulated MAPK signaling and PPM1G-regulated AKT signaling potently in vivo. Cadmium reversed PPM1A-induced cell cycle arrest and cadmium insensitive PPM1A mutant rescued cadmium induced cell death. Taken together, these findings provide a better understanding of the effects of the toxicity of cadmium in the contexts of human physiology and pathology.