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Copyright of Anbar Journal of Agricultural Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Anbar Journal of Agricultural Sciences is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Numerous studies have been investigated the potential of biochar (BC) derived from various materials and crop straw (CS) to decrease the bioavailability of heavy metals in soil contaminated with cadmium (Cd), and thereby reduce their potential risk to human health and the ecological environment. However, little attention has been given to the comparison of heavy metal remediation efficiency using BC and CS such as peanut vine (PV) and rice straw (RS), especially in soil contaminated with Cd. Here, we explore if Cd bioavailability is affected in contaminated soil by BC and CS. Peanuts were grown in plastic pots, which contained BC or CS at 5% (dry weight, w/w) in controlled environment mesocosms. The bioavailability of Cd in contaminated soil was measured by Cd concentration in the plant and the concentrations of various forms of Cd in the soil. At the same plant age, growth with BC (compared with PV and RS) led to 13.56% and 8.28% lower rates of Cd content in the aboveground parts, 40.65% and 35.67% lower rates of Cd content in the seeds, yet 9.08% and 7.09% lower rates of Cd content in the roots, yet 35.80% and 28.48% lower rates of exchangeable Cd content in the soil. Moreover, BC amendment enhanced the biomass of peanut and physiological quality. Thus, BC had a greater impact on immobilizing Cd in the soil. The results imply that BC was more significantly (P < 0.05) remarkable in decreasing the Cd bioavailability and improving the biomass of peanut. BC has greater potential for enhancing soil quality and promoting peanut growth. In conclusion, this research demonstrates an understanding of employing BC as a promising inexpensive and eco-friendly amendment to remediate soil contaminated with Cd. [ABSTRACT FROM AUTHOR]

The aim of this study was to characterize qualitatively and quantitatively the composition of the main rhizodeposits emitted from maize (Zea mays) under Cd stress, in order to discuss their role in Cd availability and tolerance. Maize was grown for 6 weeks in sand at four Cd exposure levels (0, 10, 20, and 40 μM Cd in nutrient solution) and two types of rhizodeposits were collected at the end of cultivation period. Mucilage and other molecules adhering to rhizospheric sand were extracted with a buffer before root exudates were collected by diffusion into water. Total carbon, proteins, amino acids, and sugars were analyzed for both rhizodeposit types and about 40 molecules were identified using GC-MS and LC-MS. Cadmium effect on plant morphology and functioning was slight, but consistent with previous works on Cd toxicity. However, rhizodeposition did tend to be impacted, with a decrease in total carbon, sugars, and amino acids correlating with an increasing Cd content. Such a decrease was not noticeable for proteins in root exudates. These observations were confirmed by the same trends in individual compound contents, although the results were generally not statistically significant. Many of the molecules determined are well-known to modify, whether directly or indirectly, Cd speciation and dynamics in the soil and could play a role in Cd tolerance. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the distribution of cadmium (Cd) and lead (Pb) in muscle and liver tissue of Haemulopsis axillaris and Diapterus peruvianus from the Eastern Pacific in Mexico and to assess the health risk to consumers. Fish were collected as bycatch on the continental shelf between the coasts of Sinaloa and Guerrero (Eastern Pacific). Cd and Pb were quantified in muscle and liver tissue using graphite-furnace atomic absorption spectrophotometry (GF-AAS). Concentration of Cd was greater in muscle tissue than in liver tissue; with Pb, however, the opposite pattern was found. The highest concentration of Cd (0.177 μg g−1) was found in muscle tissue of H. axillaris from Sinaloa. For Pb, the highest level (0.692 μg g−1) was found in the liver tissue of H. axillaris also from Sinaloa. Levels of Cd and Pb in muscle tissue were both below Mexican Guidelines (0.5, 1.0 μg g-1 wet weight for Cd and Pb respectively) and International Guidelines. The hazard index (HI) for both metals in the edible portion of studied considering metal levels in the edible portion and the rate of fish consumption by the Mexican population (in adults and children) was less than 1 (HI < 1), values which do not represent a health risk to consumers. [ABSTRACT FROM AUTHOR]

Heavy metal pollution, in particular with cadmium (Cd), threatens both the environment and human health. The phytoremediation of contaminated soil is one recently developed eco-friendly technique that can be applied to mitigate this issue. Repairing Cd-contaminated paddy soil during the fallow winter period can ensure future rice production while reducing heavy metal pollution. Seven winter crops were planted in this study to investigate the accumulation of this metal in mid-level Cd and low-level lead (Pb) and zinc (Zn)-contaminated paddy soils. Results show that after 4 or 5 months of growth, all crops had become moderately tolerant to toxicity; indeed, shoot Cd bioconcentration factor (BCF) values were 37.4, 17.0, 11.5, 10.5, 5.8, 3.9, and 1.4 for Sedum alfredii (SA), Witloof chicory (WC), edible-leaf beet (EB), Cardamine hupingshanensis (CH), leafy mustard (LM), oil mustard (OM), and perennial ryegrass (PR), respectively, while shoot Pb and Zn BCF values were less than 1 and 5, respectively. And SA, WC, EB, and CH all had higher shoot Cd accumulation capacities, especially SA in which the level reached 53.9 mg kg−1. The calculation results of restoration potential show that it will take at least 5 years for WC, 7 years for SA and EB, and 10 years for CH to reach the repair target. These results show that it is possible to grow winter crops to repair soil Cd pollution, with WC, EB, CH, and SA, the best candidates for making full use of fallow periods while simultaneously achieving soil phytoremediation. The results of this study will prove useful for establishing a new summer production model by ensuring the winter repair of contaminated paddy soil. [ABSTRACT FROM AUTHOR]

Endophyte-assisted phytoremediation is considered to be an effective approach for bioremediation of heavy metal–contaminated soil; however, few information is available on Trifolium repens L. and its endophytes to remediate heavy metal–polluted soils. In this study, heavy metal–resistant endophytes were isolated from T. repens growing in mining smelter and identified by BIOLOG system. The isolate was also evaluated for promoting plant growth in heavy metal–contaminated soils in pot experiments. A total of eight Cd2+-resistant endophytes were isolated and these isolates preferred to grow on l-aspartic acid and α-d-glucose. All the isolates had at least two plant growth–promoting properties including siderophore production, phosphate solubilization activity, indole acetic acid (IAA) production, and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity. Strain RE02, identified as Pseudomonas putida by Biolog system, showed the highest Cd tolerance and could reduce Cd concentration from 20 to 1.84 mg L−1 in about 49 h in liquid medium, amounting to about 90.8%. Among the five endophytes which have positive effect on the growth of T. repens, RE02, whose IAA production ability was 7.06 mg L−1 and phosphate solubilization was 134.76 mg L−1, could improve T. repens root and shoot biomass by 25.9% and 37.7% in cadmium-contained soil, respectively. Our research may provide a new microbial-enhanced phytoremediation of heavy metal–polluted soils and improve the remediation efficiency. [ABSTRACT FROM AUTHOR]

The effects of in-situ immobilization of heavy metals by applying natural and chitosan-introduced zeolite, bentonite, and activated carbon (AC) were systematically studied to remediate cadmium (Cd)-contaminated soils in a pot experiment using Brassica juncea as the indicator plant. The results show that zeolite, bentonite, and its chitosan composites can increase soil pH and reduce the biological effectiveness of heavy metals. The Brassica juncea dry weight increased with increasing of amendment dosage. Highest values were found for CS-AC, followed by CS-bentonite, CS-zeolite, AC, bentonite, and zeolite. With an amendment dosage of 75 g per pot, Brassica juncea dry weight increased by 41.91%, 39.00%, 27.64%, 35.93%, 23.78%, and 23.58%, respectively, for CS-AC, CS-bentonite, CS-zeolite, AC, bentonite, and zeolite, compared to the control. Cadmium uptake by Brassica juncea was lowest for this dosage. With a dosage of 75 g, 50 g, 75 g, 75 g, 50 g, and 75 g per pot for CS-AC, CS-bentonite, CS-zeolite, AC, bentonite, and zeolite, respectively, Cd uptake decreased by 21.89%, 19.88%, 19.48%, 18.67%, 17.47%, and 13.85%, respectively. Similarly, bioavailable Cd content decreased by 27.38%, 19.29%, 22.83%, 23.22%, 15.74%, and 8.66%, respectively, compared to the control. [ABSTRACT FROM AUTHOR]

An experiment was carried out to compare cadmium and copper absorption and mineral nutrition accumulation in pennisetum and tall fescue in order to select an appropriate grass to remediate Cd/Cu-contaminated soil and explore their detoxification mechanisms of contamination by mineral elements. The biomass remained constant in tall fescue under each Cd addition level and increased in pennisetum until Cu reached 500 µM, whereas they dramatically decreased as the Cu or Cd solution increased, which was concurrent with quadratic regression model analysis. The Cd/Cu concentrations in tall fescue were mostly accumulated in the roots and were much higher than those in pennisetum. The extracted amount of Cd in the shoots and the total Cu concentrations of pennisetum were higher than the corresponding values in tall fescue at every Cd/Cu addition level. Negative correlations were observed between Cd and shoot Ca, Cu, K, Mg, and Zn, and root Cu and Na of tall fescue and the root K of pennisetum. The Cu concentration was negatively correlated with K and positively correlated with Na in tall fescue and pennisetum under the Cu treatments. As the Cd/Cu concentration in solution increased, K/Na values were significantly decreased in the roots of tall fescue under Cu stress and pennisetum under Cd/Cu stress, whereas they increased in the roots of tall fescue under Cd addition. In summary, pennisetum exhibited the greater biomass and Cd/Cu extraction; indicating it as a candidate energy grass for phytoextraction. The adjustment capacity of grass for K and Na might relate to the tolerance to Cd/Cu. [ABSTRACT FROM AUTHOR]

Indoor experiments were performed to determine the accumulation, subcellular distribution, and chemical forms of Cd at five S levels in Hydrilla verticillata. The Cd content increased from 1.229 mg/g to 3.329 mg/g in leaves, and decreased from 2.794 mg/g to 1.023 mg/g in roots, respectively. Excess S supply stimulated Cd assimilation in leaves as Cd accumulation was inhibited in roots. The Cd content in leaves at subcellular levels revealed that Cd was stored mainly in the soluble fraction (71.9-88.2%), and in small quantities in the cell wall (6.1-22.4%) and cell organelles (4.8-6.9%). As S increased, the Cd content in leaf soluble fractions and cell walls increased remarkably. The content of NaCl-extracted Cd in leaves increased as S supply increased, and this parameter was much higher than that of other Cd forms. In leaves, the Cd concentrations in the cell walls were significantly correlated with the chemical forms extracted by HAc, HCl, and NaCl, with correlation coefficients of 0.985, 0.964, and 0.957, respectively. The high correlation indicated that Cd in soluble fractions or cell walls was mainly in the form of pectates/protein, phosphate, and oxalate. The application of S alleviated Cd-induced oxidative stress by increasing the proline accumulation. Furthermore, sulfhydryl proteins such as glutathione and cysteine may play a crucial role in the reversal of Cd-induced oxidative stress. [ABSTRACT FROM AUTHOR]

Abstract There is a dire necessity of developing low cost waste water treatment systems, for the efficient removal of noxious heavy metals (and metalloids) such as Arsenic (As) and Cadmium (Cd). Magnetic biopolymer (CABs-MO) was synthesized by the entrapment of nanocrystalline MnO 2 in the polymeric microcapsules of calcium alginate (CABs). Batch experiments were conducted under constant pH (6.5), temperature (25OC), different initial concentrations (30–300 mg L−1) and contact times (0–48 h) to study the adsorption isotherms and removal kinetics of pristine (CABs) and hybrid biopolymer (CABs-MO) for the removal of As and Cd. The pseudo-equilibrium process was mathematically well explained by the pseudo-second-order kinetic (R2 ≥ 0.99) and Langmuir isotherm model (R2 ≥ 0.99) with the highest monolayer sorption capacity of 63.6 mg g−1 for Cd on CABs-MO. The As removal rate was maximum up to 6.5 mg g−1 after 12 h of contact period in a single contaminant system than in the mixed contaminant (As + Cd) system (0.8 mg g−1), though the effect was non-significant for Cd (p < 0.05; t -test). The performance of the 10 mM HCl as a regenerating agent was superior (for As in comparison to Cd, p < 0.05; t -test) compared to distilled water (DW) through three to five regeneration cycles. Therefore, the obtained results clearly validate the feasibility of CABs-MO as a potential promising adsorbent for removing metal contaminants from the wastewater. Further research is required to study the decontamination of emerging contaminants with such novel composite beads characterized by varied physico-chemical properties. Graphical abstract Image 1 Highlights • Calcium alginate (CABs) and MnO 2 (MO) were hybridized for the synthesis of CABs -MO. • The BET surface area of CABs-MO was of two orders of magnitude higher than CABs. • The removal of As (∼8X) and Cd (∼2X) was high in single contaminant system. • Maximum Langmuir monolayer sorption capacity was observed for Cd (63.6 mg g−1). • HCl showed better performance than water as a desorption agent upto five cycles. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Cadmium (Cd) is a typical and hazardous environmental pollutant. • Transcriptome analysis is a recently developed deep sequencing technique. • 3794 differently expressed genes were obtained from the Cd-treated carp spleens. • Cd exposure led to immunosuppression, oxidative stress and glycometabolism disorder. • Cd showed immunotoxicity to common carp at the top of the food chain. Abstract Cadmium (Cd), a hazardous environmental contaminant with irreversible toxicity to fish, has been detected in aquatic environment of many countries. The common carp is one of the most widely distributed fish in the world, so we used common carp to assess environmental contaminant risk. In present study, we investigated effects of Cd on immune function, oxidative defense, and glycometabolism in the spleens of common carp by transcriptome analysis. Obtained 3794 differentially expressed genes (including 1848 up-regulated and 1946 down-regulated genes) were enriched using databases of Kyoto Encyclopedia of Genes and Genomes, and Gene Ontology in David bioinformatics software (version 6.8). The pathways and gene functions of immune, oxidative defense, and glycometabolism were obtained and identified. Some relative genes were validated using qRT-PCR and gene expression of IL-1β, INF-γ, IL-6, Cxcl18b, HO-1a, CAT, GPx1, GCK, and FBA decreased; and gene expression of B4GALT1, GPAT3, and CYP26B1 increased. Our results indicated that Cd exposure led to immunosuppression, oxidative stress, and glycometabolism disorder in the common carp spleens. The present study gives a novel insight and method on environmental risk assessment. [ABSTRACT FROM AUTHOR]

Salix matsudana Koidz was exposed to different concentrations of Cd (0, 10, 50, and 100 μmol/L) to study the effects of Cd on mineral metabolism and antioxidant enzyme activities. The results showed that plant height and root length were inhibited by 50 and 100 μmol/L Cd, except the one under 10 μmol/L Cd treatment. The Cd content accumulated in different organs of S. matsudana, gradually increasing with increased Cd concentrations and prolonged treatment times. The root was the main organ for absorbing and accumulating Cd. Cd inhibited the accumulation of Fe, Zn, Mn, and Cu. In addition, the activities of antioxidant enzymes and the contents of reactive oxygen species were also changed by different concentrations of Cd. The results obtained here can provide scientific and objective data for the use of S. matsudana in the remediation of Cd-contaminated soil. [ABSTRACT FROM AUTHOR]

Adsorption is one of the most versatile and widely used techniques for the removal of toxic metals from the aqueous solutions. Cadmium is the toxic metal selected for adsorption in this study and adsorbent of interest was activated carbon prepared from Bauhinia purpurea leaves as a plant biomass. The following process parameters were investigated during the batch adsorption process: The adsorption efficiency and cadmium deposition on the adsorbent surface were increased from 15.95 to 89.98%, 0.074 to 0.418 mg/g, and 7.27 to 89.97%, 0.034 to 0.418 mg/g with increasing contact time from 2 to 50 min and pH from 2 to 6.5, respectively. The adsorption efficiency was decreased from 89.98 to 45.96% and the amount of cadmium deposited on the surface of the ACBPL adsorbent was increased from 0.418 to 1.032 mg/g with an increase in solute concentration. The adsorption efficiency of cadmium decreased from 98.41 to 84.51% and 0.457 to 0.392 mg/L with an increase in particle size from 74 to 177 μm. The rate of adsorption of cadmium was increased from 61.31 to 96.34% with an increase in dosage of the ACBPL adsorbent from 0.05 to 0.15 g. The adsorption efficiency and cadmium deposition was decreased from 89.98 to 97.90%, 0.418 to 0.454 mg/g as the temperature increased from 303K to 323K. The variation of thermodynamic energy parameters (ΔG°, ΔH° and ΔS°) with the solution temperature described that the adsorption process is endothermic, spontaneous at high temperatures and non-spontaneous at low temperatures. The positive value of ΔS, reflecting the high degree of disorder in the adsorbent/adsorbate interface that is formed during the transition. [ABSTRACT FROM AUTHOR]

The main purpose of our research was to assess the chronic exposure of red foxes to Cd, Pb and Zn. We have determined concentrations of these metals in the kidney, liver and muscle of 36 red foxes hunted between December 2002 and March 2003 in differently polluted areas in southern Poland. Tissue concentrations of Pb and Cd in the red foxes significantly co-varied with concentrations of these elements in the soil, and differed between the tissues. We compared concentrations of Pb, Cd, and Zn in red foxes with two rodent species, Apodemus flavicollis and Myodes glareolus, trapped simultaneously in the same area. Concentrations of Pb and Cd appeared significantly higher in the red foxes than in the rodents, but the slopes of the relationship between metal concentrations in tissues and in soil were similar in all species. This indicates that extrapolation from results of monitoring studies conducted on rodents to mammalian carnivores is possible but requires applying an extrapolation factor. [ABSTRACT FROM AUTHOR]

Abstract The objective of this study was to identify the effect of cadmium (Cd) contamination on the decomposition of aquatic macrophyte litter and its eutrophic secondary pollution. A laboratory experiment was conducted with three treatments: water Cd contamination (Cd-w), litter Cd contamination (Cd-l) and control (CK). The results showed that CK and Cd-w exhibited the typical decomposition dynamics of litter, i.e., early rapid decomposition followed by slow decomposition, while the litter biomass loss (BL) in Cd-l exhibited an approximately linear relationship with time over the 64-day experimental period. The BL in Cd-l was only 10.8% in the initial 4 days, while that in CK and Cd-w was 59.0% and 54.8%, respectively. Cd inhibited the fluctuation of the water chemical oxygen demand (COD) by reducing both the early increase and the subsequent decrease. The increases in water total nitrogen (TN) and total phosphorus (TP) were inhibited by Cd contamination throughout most of the decomposition period. The alterations of litter quality during the plant growth period and of the bacterial community during the litter decomposition period by Cd contamination could explain the variations in litter decomposition rate and its eutrophic secondary pollution during the early and late decomposition stages, respectively. The Cd inhibition of the eutrophic secondary pollution of aquatic macrophytes has great significance for the improved evaluation of Cd contamination. Graphical abstract Image 1 Highlights • Cd decreased the eutrophic secondary pollution of aquatic macrophytes. • Litter Cd exerted a greater effect than water Cd on decomposition and water quality. • Cd significantly altered bacterial diversity and community structure. • Litter quality and bacterial variation jointly determined the Cd effect. [ABSTRACT FROM AUTHOR]

Abstract A sample coal waste activated by rhamnolipid biosurfactants was used as an efficient adsorbent for the adsorption of cadmium from aqueous solution. The effects of three factors, namely, initial solution pH (3–11), absorbent to cadmium ratio (12.5–162.5) and contact time (3–31 h), on cadmium removal were studied and optimized using a central composite type response surface methodology. The two factors that play a key role in the adsorption process are pH and absorbent dosage. Optimum adsorption conditions achieved at pH 9, absorbent to cadmium ratio of 125 and equilibrium contact time of 10 h, resulted in more than 99% cadmium removal. Kinetic studies revealed that a maximum removal can be achieved before 10 min of adsorption process following a pseudo-second order model. The selectivity study in bimetal aqueous systems using copper, lead and zinc metals showed the adsorption order of Cu2+ > Cd2+ > Zn2+ > Pb2+. The cadmium adsorption on activated coal waste was also found to follows the Temkin isotherm model with a correlation coefficient of 92.43%. Graphical abstract Image 1 Highlights • Cadmium removal from aqueous solution by rhamnolipid-activated coal waste was investigated. • Adsorption conditions for maximum Cd removal have been studied. • Cd was successfully removed (>99%) with activated coal waste. • Cd adsorption followed the pseudo-second order kinetics and Temkin isotherm model. [ABSTRACT FROM AUTHOR]

The release of in situ heavy metals (cadmium [Cd], copper [Cu], lead [Pb], manganese [Mn], and zinc [Zn]) from contaminated river sediment near a Cu–iron mine in South China was experimentally studied. The effects of pH values and the kinetics of heavy metal release were investigated. In addition, species of the 5 metals in the sediment were determined as a function of pH and time. Rates and extents of metal desorption were studied over 30 d, and a 3‐parameter, 2‐compartment model was used to analyze the desorption kinetics. The rate constants (ks) for the slowly desorbing fraction of heavy metals were found to be 5 to 6 orders of magnitude lower than the corresponding rate constants (kr) for the rapidly desorbing fraction, suggesting that slow desorption is the rate‐limiting step. The partition coefficients (Kd) varied significantly among metals, on the order Pb > Cu >Zn > Cd > Mn, indicating that the sediment had a much higher retention capability for strongly hydrolyzed metals than for weakly hydrolyzed ones. The amount of metals released from the sediment decreased dramatically at the final pH of 2 to 4 and leveled off in the pH range of 5 to 8. Release time and pH exhibited a varied influence on the fractionation of metals, and had a more remarkable influence on more mobile fractions and hardly any effect on the residual fraction during the desorption process. The fractionation of strongly adsorbing metals like Pb was not as dependent on release time and pH as it was for the weakly bonded metals like Mn and Cd. The results indicate that in situ heavy metals may exhibit a sustainable potential for release and may increase health risks when the pH of the river is lowered. Environ Toxicol Chem 2019;38:464–473. © 2018 SETAC. [ABSTRACT FROM AUTHOR]

The toxic effects of cadmium (Cd) in Geophagus brasiliensis was investigated in the present study. For this, 32 specimens of G. brasiliensis were exposed in individual aquaria to Cd concentrations (0.00, 0.01, 0.07, and 0.67 mg/L) for 14 days. The micronuclei test did not detect the genotoxic damage at the studied concentrations and time of exposure. However, the comet assay proved to be more efficient, as DNA damage was found in the animals exposed to the higher Cd concentrations. Finally, exposure of G. brasiliensis to Cd was associated with Cd accumulation in the gills, while only the animals exposed to 0.67 mg/L of Cd exhibited muscle accumulation. These results demonstrate that Cd concentrations over 0.07 mg/L caused genotoxic damage, as well as Cd accumulation in G. brasiliensis individuals after a 14 days exposure. [ABSTRACT FROM AUTHOR]

Preconcentration of Cd(II) and Pb(II) was carried out by using column solid phase extraction method. Amberlyst 15 was used as solid phase for these analytes. The optimum extraction conditions such as pH (4), type and volume of eluent (5 mL of 2 mol L−1 HNO3) sample flow rate (1 mL min−1) and sample volume (100 mL for Cd(II) and 750 mL for Pb(II)) were determined. The recoveries were found for Cd(II) and Pb(II) as 104% ± 1% and 102 % ± 2%, respectively. The limit of detections were found as 0.23 µg L−1 for Cd(II) and 0.13 µg L−1 for Pb(II). The effects of foreign ions were also studied. The method was validated by analyzing standard reference material and spiked water samples. Percent relative error and relative standard deviation were below 3% and 4%, respectively. [ABSTRACT FROM AUTHOR]

Recently, the growing attention of the scientific community has been focused on the threat to health created by environmental pollutants, including toxic metals such as cadmium (Cd), and on the need of finding effective ways to prevent and treat the unfavorable health effects of exposure to them. Particularly promising for Cd, and thus arousing the greatest interest, is the possibility of using various ingredients present in plants, including mainly polyphenolic compounds. As the liver is one of the target organs for this toxic metal and disturbances in the proper functioning of this organ have serious consequences for health, the aim of the present review was to discuss the possibility of using polyphenol‐rich food products (e.g., chokeberry, black and green tea, blueberry, olive oil, rosemary and ginger) as the strategy in protection from this xenobiotic hepatotoxicity and treatment of this heavy metal‐induced liver damage. Owing to the ability of polyphenols to bind ions of Cd and the strong antioxidative potential of these compounds, as well as their abundance in dietary products, it seems to be of high importance to consider the possibility of using polyphenols as potential preventive and therapeutic agents against Cd hepatotoxicity, determined by its strong pro‐oxidative properties. Although most of the data on the effectiveness of polyphenols comes from studies in animals, the fact that some of them are derived from experimental models that reflect human exposure to this metal allows us to assume that some polyphenol‐rich food products may be promising protective agents against Cd hepatotoxicity in humans. Cadmium (Cd) is a common environmental pollutant to which the general population is exposed during a lifetime. Chronic intoxication with this metal creates a risk of damage to various organs and systems, including the liver. Owing to the strong antioxidative potential and ability to chelate Cd ions, polyphenols are considered as potential protective and therapeutic agents against unfavorable Cd action. This review focuses on polyphenol‐rich food products, which seem to be potential effective factors in the protection from Cd hepatotoxicity. [ABSTRACT FROM AUTHOR]

Rice (Oryza sativa L.) is one of the food crops, which is found to have the great capacity of cadmium (Cd) accumulation. This research was done to investigate the response to Cd accumulation in rice grown with different organic soil amendments (OA), namely soil supplemented with swine manure (SM), cow manure (CM), mixed chicken manure and rice husk (CR), vermicompost (VC), and greensward compost (GC), respectively. Each OA (4% w/w basis) was applied in each treatment with 3 Cd levels at 20, 40, and 60 mg/kg, respectively. The results showed that rice plants were not able to grow in 4% w/w of SM and CM, respectively and wither following 70 d of planting. It was found in the other treatment results that CR, VC, and GC increased harvest index (HI) as well as soil pH while decreasing soil Eh and Cd-HI, compared with the control treatment. All the Cd concentrations did not affect the height, but the wet weight of plants, decreased with increase in Cd concentrations. Regarding the Cd accumulation, it was found that CR is most effective in absorbing Cd in the paddy soils. In terms of Cd uptake, it was found that GC was the only OA that could reduce the Cd uptake in the rice plant parts. The result is consistent with reduction observed in the accumulation of cadmium in stems, leaves, and especially rice grain. Therefore, based on the current finding, both CR and GC soil amendments can be considered for immobilizing Cd in the contaminated fields. [ABSTRACT FROM AUTHOR]

Abstract The growth and development of living organisms is programmed in genes, but exogenous factors (e.g. cadmium) may modulate endogenous information. Heavy metals may disturb physiological functions and accumulate in the tissues. The insects under prolonged heavy metal stress show some modifications in their metabolism management. The aim of this study was to compare the reproduction and development between individuals of S. exigua from the strain, exposed over 130 generations to sublethal concentration of cadmium (44 mg Cd/kg dry weight of larval diet), and the individuals from the control strain, both additionally exposed to different concentration of cadmium (22-704 mg Cd/kg dry weight of larval diet). The exposure to various cadmium concentrations in the diet revealed survival difference between the cadmium and the control animals at the larvae stage. The differences between adults were not evident. The telomere length (responsible for the duration of a lifespan) in the cadmium strain was shorter in the females than in the males and the individuals from the control strain. TERF1 gene expression (indirectly responsible for the telomere length) was higher in the individuals from the cadmium strain 24 hrs after eclosion. The significant reduction in the larvae body mass was observed in both strains, when the metal concentration was equal to or higher than 264 mg/kg dry weight of larval diet. The EC50 values (defined as of body mass loss), calculated 48 hours after cadmium exposure of individuals from control and cadmium strains, were respectively 632 and 725 mg Cd/kg dry weight of diet. However, some difference in reproduction (the total number of eggs laid and the oviposition time) between the strains appeared only in the groups fed on the uncontaminated diet. The control females laid almost two times more eggs than those from the cadmium strain, and the control ones had more than two times longer oviposition time than the females from the cadmium strain. The fluctuation was also noted in the size of eggs and the hatching success on the following days when both strains were compared, while the hatching success was higher for the insects from the cadmium strain. In conclusion, the insects from the cadmium strain are more resistant to cadmium contamination, as it is evidenced by the EC50 parameter. However, the females from the cadmium strain start laying eggs statistically later, have shorter telomeres and slightly reduced TERF1 gene expression, but hutching success in the strain is significantly higher when compared with the control individuals. Highlights • Cadmium may cause selecting pressure for the insects. • Spodoptera exigua was selected toward cadmium resistance for over 130 generations. • Reproduction and development parameters show slightly different trends in both cadmium and control strains. • The telomere length and TERF1 gene expression between the breeding strains differ. • Individuals from the cadmium strain have better cadmium resistance compared to the control. [ABSTRACT FROM AUTHOR]

Chinese flowering cabbage is a commonly consumed vegetable that accumulates Cd easily from Cd-contaminated soils. Cultivations of low-Cd cultivars are promising strategies for food safety, but low-Cd-accumulating mechanisms are not fully elucidated. To address this issue, 37 cultivars were screened to identify high- and low-Cd cultivars upon exposure to sewage-irrigated garden soil pretreated with different Cd concentrations (1.81, 2.90, and 3.70 mg kg−1dry soil). The results showed that shoot Cd concentrations differed among the cultivars by maximum degrees of 2.67-, 3.71-, and 3.00-fold under control and treatments, respectively. Soil-pot trial and hydroponic trial found no significant difference in Cd and Ca mobilization, uptake, and transport ability by root per weight between high- and low-Cd cultivars. Interestingly, a stable R/S ratio difference among cultivars (p < 0.01) was observed, and the cultivar variation of Cd accumulation in shoots was mainly dependent on their R/S ratios. R/S ratio was also statistically positively associated with Cd and Ca accumulation in high- and low-Cd cultivars (p < 0.05), both in soil and hydroponics culture. This was mainly due to the lower root biomass of low-Cd cultivars resulted in lower total release of root exudates, lower total Cd and Ca mobilization in rhizosphere soil, and lower total Cd and Ca uptake and transport. The higher shoot biomass of low-Cd cultivars also has dilution effects on Cd concentration in shoot. Overall, low R/S ratio may be regarded as a direct and efficient indicator of low Cd accumulation in the shoot of Chinese flowering cabbage. These findings provided the possibilities to screening low-Cd cultivars using their R/S ratio. [ABSTRACT FROM AUTHOR]

The tolerance characteristics and phytostabilization potential of Platycladus orientalis grown in soil contaminated by cadmium (Cd) were studied using a greenhouse experiment. The results showed that the ornamental plant P. orientalis had high tolerance for Cd in contaminated soil at 24.6 mg·kg−1 and its physiological activities were slightly affected after 203 days (d) of cultivation. Moreover, Cd in soil at 9.6 mg·kg−1 was beneficial for P. orientalis growth, and the total biomass after 203 d cultivation was significantly (p < 0.05) increased by 35.03%, while the contents of chlorophyl a, chlorophyl b and carotenoid in leaves also increased by 20.84%, 44.06% and 28.25% compared to the control, respectively. Meanwhile, the Cd content in the tissues of P. orientalis was increased with both plant growth and the Cd content in the soil. The uptake of Cd in P. orientalis roots was greater than in shoots, with the Cd content in roots reaching 41.45 mg·kg−1. P. orientalis, an ornamental plant, that accumulates Cd predominantly in its roots, can be suggested as a promising plant for phytostabilization in Cd-contaminated soil. [ABSTRACT FROM AUTHOR]

A three-level Box–Behnken model (BBM) under response surface methodology (RSM) was used to optimize the removal of cadmium (Cd) ion by pistachio residues biochar (PRB) and PRB supported by nanoscale zero-valent iron (PRB-nZVI) from aqueous solutions. Optimization experiments were carried out by evaluation of the effect of four variables (initial Cd concentration, initial solution pH, adsorbent dosage, and contact time) at three levels (high, medium, and low), and one category contained two variables (PRB and PRB-nZVI). For this purpose, a total of 58 experimental runs were set and the experimental data were fitted to the empirical second-order polynomial model of a suitable degree. The physical and chemical structure results of the adsorbents confirmed the formation of nZVI (with diameters ~35 nm) on the PRB surface. The results showed that the new composite of biochar (PRB-nZVI) exhibited higher Cd removal efficiency compared with PRB from aqueous solutions. The existence of functional groups and nZVI on the surface of PRB-nZVI could be better than PRB for Cd removal in aqueous solutions by the processes of sorption, precipitation, and co-precipitation. Numerical optimization revealed that the optimum removal (96.58%) was obtained at an initial Cd concentration of 25.99 mg L−1 (pH 6.58), adsorbent dose (PRB-nZVI) of 0.55 g L−1, and contact time of 34.11 min, with desirability of 1. Based on the results, it is recommended that PRB-nZVI can be effectively used for the removal of Cd from a contaminated aqueous solution with varying chemical and physical conditions. [ABSTRACT FROM AUTHOR]

Abstract Cadmium (Cd) is an environmental pollutant shown to induce multi organ dysfunction. In this study we present novel data about the effects of meso -2,3-dimercaptosuccinic acid (DMSA), monensin and salinomycin on the concentration of Cd in skeletal muscles of mice exposed to Cd (II) acetate treatment for 14 days. The impact of Cd and the chelating agents on the endogenous concentrations of calcium (Ca), copper (Cu), iron (Fe), magnesium (Mg), phosphorous (P), selenium (Se) and zinc (Zn) was also investigated. Subacute exposure of mice to Cd (II) acetate resulted in a significant accumulation of the toxic metal ion in the skeletal muscles compared to the untreated controls. Salinomycin most effectively mobilized Cd from the muscles compared to DMSA and monensin. The Cd exposure and the tested chelating agents did not significantly alter the endogenous concentrations of the selected essential elements in mouse muscles. The presented results confirmed that among the tested chelating agents salinomycin is superior as a potential antidote to Cd poisoning. [ABSTRACT FROM AUTHOR]

Phosphate fertilizers were first implicated by Schroeder and Balassa (Science 140(3568):819-820, 1963) for increasing the Cd concentration in cultivated soils and crops. This suggestion has become a part of the accepted paradigm on soil toxicity. Consequently, stringent fertilizer control programs to monitor Cd have been launched. Attempts to link Cd toxicity and fertilizers to chronic diseases, sometimes with good evidence, but mostly on less certain data are frequent. A re-assessment of this "accepted" paradigm is timely, given the larger body of data available today. The data show that both the input and output of Cd per hectare from fertilizers are negligibly small compared to the total amount of Cd/hectare usually present in the soil itself. Calculations based on current agricultural practices are used to show that it will take centuries to double the ambient soil Cd level, even after neglecting leaching and other removal effects. The concern of long-term agriculture should be the depletion of available phosphate fertilizers, rather than the negligible contamination of the soil by trace metals from fertilizer inputs. This conclusion is confirmed by showing that the claimed correlations between fertilizer input and Cd accumulation in crops are not robust. Alternative scenarios that explain the data are presented. Thus, soil acidulation on fertilizer loading and the effect of Mg, Zn and F ions contained in fertilizers are considered using recent Cd2+, Mg2+ and F- ion-association theories. The protective role of ions like Zn, Se, Fe is emphasized, and the question of Cd toxicity in the presence of other ions is considered. These help to clarify difficulties in the standard point of view. This analysis does not modify the accepted views on Cd contamination by airborne delivery, smoking, and industrial activity, or algal blooms caused by phosphates. [ABSTRACT FROM AUTHOR]

The aim of the study was to assess the content, distribution, soil binding capacity, and ecological risk of cadmium and lead in the soils of Malopolska (South Poland). The investigation of 320 soil samples from differently used land (grassland, arable land, forest, wasteland) revealed a very high variation in the metal content in the soils. The pollution of soils with cadmium and lead is moderate. Generally, a point source of lead and cadmium pollution was noted in the study area. The highest content of cadmium and lead was found in the northwestern part of the area—the industrial zones (mining and metallurgical activity). These findings are confirmed by the arrangement of semivariogram surfaces and bivariate Moran's correlation coefficients. Among the different types of land use, forest soils had by far the highest mean content of bioavailable forms of both metals. The results showed a higher soil binding capacity for lead than for cadmium. However, for both metals, extremely high (class 5) accumulation capacities were dominant. Based on the results, the investigated soils had a low (Pb) and moderate (Cd) ecological risk on living components. Soil properties, such as organic C, pH, sand, silt, and clay content, correlated with the content of total and bioavailable forms of metals in the soils. The correlations, despite being statistically significant, were characterized by very low values of correlation coefficient (r = 0.12-0.20, at p ≤ 0.05). Therefore, the obtained data do not allow to define any conclusions as to the relationships between these soil properties. However, it must be highlighted that there was a very strong positive correlation between the total content of cadmium and lead and their bioavailable forms in the soils. [ABSTRACT FROM AUTHOR]

Abstract A two stage multi-fraction 1st-order kinetic model was established herein, which incorporates Cd species distribution in the contaminated site, chelate dosage and washing time, and two distinct extraction mechanisms are also emphasized there. The model was found to successfully simulate the experimental data of Cd extraction by EDTA; with the obtained parameters, we also got a similarly good agreement in other two Cd-contaminated soils. All normalized root-mean-square error, the index of agreement and modeling efficiency values showed that this model can be used to predict Cd kinetic extraction process in different types of soils with an excellent validity. Both simulated and experimental results indicate that a greater EDTA dosage reasonably leads to a higher Cd extraction efficiency and a faster extraction by the direct EDTA-complex. Different Cd species also show different extraction behavior. Part of Cd species associated with Fe/Mn hydro(oxides) (FeMnOx) become destabilized by slow EDTA-promoted dissolution but not yet detached, leading to an apparently high removal efficiency of Cd in FeMnOx fraction dependent on EDTA dosage. While the removal of exchangeable Cd and carbonates (EXCH+CARB) seemed unchanged with the EDTA dosage, due to the transformation of the undetached Cd in FeMnOx fractions. However, an extreme dosage (i.e. molar ratio of EDTA to metal equal to 20 herein) may accelerate the detachment of these destabilized Cd species, resulting in a substantially high extraction efficiency of EXCH+CARB fraction. Highlights • A novel 2-stage model considering metal species and washing operation is established. • This model successfully predicts the Cd kinetic release from different soils. • The Cd removal rate by direct complex apparently depend on chelate dosage. • Metal fraction transformation from FeMnO x to EXCH+CARB overestimates its removal. [ABSTRACT FROM AUTHOR]

The orange-back flying squid, Sthenoteuthis pteropus , plays an important role in the eastern tropical Atlantic Ocean (ETA) pelagic food web, as both predator and prey. Specimens of S. pteropus were caught off the Cape Verde Islands and concentrations of Ag, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, V, and Zn were measured in the digestive gland. Among the analysed elements, Cd showed the highest average concentration with values among the highest ever recorded in cephalopods. In addition to the digestive gland, Hg concentrations were also analysed in the buccal mass and mantle tissue. Among the three tissues, buccal mass showed the highest Hg concentrations. In females, Hg concentrations in the buccal mass were positively correlated with stable isotope ratios (δ 13 C and δ 15 N) and mantle length, showing both bioaccumulation with age and bioamplification along the trophic levels. High Cd and Hg concentrations in the digestive gland and muscle respectively would lead to elevated exposure of squid-eating top predators such as yellowfin tuna, swordfish or dolphinfish, which are commercially harvested for human consumption. This study provides a deeper understanding of the trace element contamination in an abundant and ecologically important, but poorly studied pelagic squid in the ETA. [ABSTRACT FROM AUTHOR]

Estimating the bioavailability and predicting the uptake of metals to hyperaccumulators is very important in developing the field application of phytoextraction. A pot experiment was conducted using 108 agricultural soils covering a wide range of soil properties by the cadmium (Cd) hyperaccumulator Sedum plumbizincicola . The contributions of a range of soil properties to Cd uptake were quantified. Soil total, soluble, CaCl 2 -extractable and diffusive gradients in thin films (DGT)-extractable Cd concentrations (Cd total , Cd soln , Cd CaCl 2 and Cd DGT ) were used to estimate Cd bioavailability and predict shoot Cd concentration (Cd shoot ) using a piecewise function. Cd total and pH were the two major contributors to Cd uptake. Cd shoot showed a logarithmic increase with Cd total from 0.30 to 10.0 mg kg −1 but no further increase when Cd levels exceeded 10 mg kg −1 . Soil pH had a discernible negative effect on Cd bioavailability from pH 5.5 to 7.5 but a weak influence at pH < 5.5 or pH > 7.5. This indicates that the optimum pH for phytoextraction with S . plumbizincicola was ~5.5 and lower pH produced little increase in shoot Cd uptake. DGT gave the best estimation of Cd bioavailability across all the data. When Cd total  > 10 mg kg −1 , none of the four measures was accurate enough to predict Cd shoot but when pH > 7.5 all the four measures were well correlated with Cd shoot . Piecewise equations in different ranges of Cd total or pH significantly improved the prediction of Cd shoot compared with the global equations derived from all the data. Compared with the piecewise equations, when pH > 7.5 Cd shoot was greatly overestimated with the global equation of Cd total . Our study provides useful information on the soils in which phytoextraction with S . plumbizincicola is feasible in the field. Capsule Cd availability to S . plumbizincicola was estimated by a piecewise function in soils with wide ranges of total Cd concentration and pH. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a metal of toxicological interest because of its potential high toxicity to organisms and ability to biomagnify. Evaluating concentrations of Cd in organisms on a large spatial scale can provide insights to its global distribution. This study examined Cd concentrations in kidney and liver tissues of 137 specimens of green turtles ( Chelonia mydas ) collected in Australia, Brazil, Hawaii, Japan, and the continental United States (Gulf of Mexico). We used comparative analyses of kidney and liver of 35 individuals, of which seven turtles from each locality belong to the same size class for comparison purposes between their ocean of origin. Cd was detected in all samples, with the highest bioconcentration in kidneys. Specimens originating from the Pacific Ocean had significantly higher mean Cd levels in liver (13.24 μg/g) and kidney (34.17 μg/g) than the specimens collected in the Atlantic Ocean with lower mean values in liver (1.00 μg/g) and kidney (4.04 μg/g). Furthermore, Cd concentrations in turtle tissues were generally greater than concentrations found in other marine organisms, for example dolphins. This result was unexpected because dolphins occupy a higher trophic level than green turtles which are only herbivorous. A possible explanation is a change in feeding habits of green turtles, in which juveniles feed in near shore habitats, potentially resulting in greater Cd accumulation in juveniles compared to adults. This global distribution trend has also been observed in other marine organisms (e.g., insects, birds, and mammals) and indicates that global factors may be more important than regional factors in determining Cd concentrations of marine organisms. Capsule Global factors are more relevant than local factors in the distribution of cadmium in biota, using green turtle as a sentinel species. [ABSTRACT FROM AUTHOR]

Background Mexico City has air, water and food pollution problems; however, human exposure to cadmium and its sources have not been described. Objectives To determine the blood cadmium (BCd) level and its main exposure sources among males aged 40 years or older living in different areas of Mexico City. Methods After receiving informed consent, we interviewed 702 males aged ≥40 years to collect data on their sociodemographic characteristics, lifetime occupation, smoking history, and dietary habits, using a validated questionnaire. The BCd level (μg/L) was determined by atomic absorption spectrophotometry. Results The BCd mean level ± SD was 2.61 ± 0.82 μg/L, and 20% of men reported a potential cadmium occupational exposure. After adjusting for age and other potential confounders, the main determinants of the BCd level were the current smoking status at interview, with low (β ≤8.5packs/year vs. non-smoker  = 0.46; 95% CI: 0.28–0.64 μg/L; p < 0.01) and high (β > 8.5 packs/year vs. non-smoker  = 0.71; 95% CI: 0.56–0.87 μg/L; p < 0.01) smoking intensity, and living in the Center (β Center vs. South  = 0.20; 95% CI: 0.02–0.37 μg/L; p = 0.02) or West area of the city (β West vs. South  = 0.40, 95% CI: 0.21–0.58 μg/L; p < 0.001). Moreover, the potential dietary sources of BCd included: liver (β Yes vs. No  = 0.13, 95% CI: 0.03–0.23 μg/L; p = 0.01), “ Chorizo” (β >1–3servings/month vs. No  = 0.14, 95% CI: 0.01–0.26 μg/L; p < 0.001), sausage and ham. Conclusions The BCd levels observed in this population are high and only similar to those observed in workers from a sanitary landfill area in Southern Thailand. Potential environmental Cd exposure sources, such as industrial activity and previous land use, in the West and Center areas of the city should be explored in detail, especially in vulnerable population groups, such as children. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) is a severely toxic heavy metal and environmental pollutant. Tall fescue is a cold season turf grass which has high resistance to Cd as well as the ability to enrich it. To investigate the molecular mechanism underlying the adaptability of tall fescue to Cd stress, RNA-Seq was used to examine Cd stress responses of tall fescue at a transcriptional level. A total of 12 cDNA libraries were constructed from the total RNA of roots or leaves of tall fescue with or without Cd treatments. A total of 2594 (1768 up- and 826 down-regulated) differentially expressed genes (DEGs) were detected in the roots of Cd-stressed tall fescue compared with control roots (R_cd vs R_ck), while only 52 (29 up- and 23 down-regulated) DEGs were found in the leaves of Cd-stressed plants versus the controls (L_cd vs L_ck). The genes encoding glutathione S-transferase (GST), transporter proteins including the ABC transporter, ZRT/IRT-like protein, potassium transporter/channel, nitrate transporter, putative iron-phytosiderophore transporter, copper-transporting ATPase or transporter and multidrug and toxic compound extrusion (MATE) proteins, and numerous transcription factors were found to be significantly induced in Cd-treated roots. In addition, pathogenesis/disease-related gene mRNAs were accumulated in Cd-treated roots of tall fescue. Furthermore, the significantly enriched KEGG pathways in roots were related to ‘Glutathione metabolism’, ‘Ribosome’, ‘alpha-Linolenic acid metabolism’, ‘Diterpenoid biosynthesis’, ‘Sulfur metabolism’, ‘Phenylpropanoid biosynthesis’, ‘Protein processing in endoplasmic reticulum’, ‘Protein export’ and ‘Nitrogen metabolism’. The study provides novel insights for further understanding the molecular mechanisms of tall fescue responses to Cd stress. [ABSTRACT FROM AUTHOR]

Smelter wastelands containing high amounts of zinc, lead, cadmium, and arsenic constitute a major problem worldwide. Serious hazards for human health and ecosystem functioning are related to a lack of vegetative cover, causing fugitive dust fluxes, runoff and leaching of metals, affecting post-industrial ecosystems, often in heavily populated areas. Previous studies demonstrated the short term effectiveness of assisted phytostabilisation of zinc and lead smelter slags, using biosolids and liming. However, a long term persistence of plant communities introduced for remediation and risk reduction has not been adequately evaluated. The work was aimed at characterising trace element solubility, plant and microbial communities of the top layer of the reclaimed zinc and lead smelter waste heaps in Piekary Slaskie, Poland, 20 years after the treatment and revegetation. The surface layer of the waste heaps treated with various rates of biosolids and the by-product lime was sampled for measuring chemical and biochemical parameters, which are indicative for metals bioavailability as well as for microorganisms activity. Microbial processes were characterised by enzyme activities, abundance of specific groups of microorganisms and identification of N fixing bacteria. Plant communities of the area were characterised by a percent coverage of the surface and by a composition of plant species and plant diversity. The study provides a strong evidence that the implemented remediation approach enables a sustainable functioning of the ecosystem established on the toxic waste heaps. Enzyme activities and the count of various groups of microorganisms were the highest in areas treated with both biosolids and lime, regardless their rates. A high plant species diversity and microbial activities are sustainable after almost two decades from the treatment, which is indicative of a strong resistance of the established ecosystem to a metal stress and a poor physical quality of the anthropogenic soil formed by the treatment. [ABSTRACT FROM AUTHOR]

Contamination of cadmium (Cd) in paddy soil is a serious environmental problem threatening food safety in some parts of southern China, where rice grain Cd concentration often exceeds the Chinese limit (0.2 mg kg −1 ). We tested the effect of CaCO 3 liming combined with growing low Cd cultivars on Cd accumulation in rice grain in 2-year field trials. A liming model was used to predict the doses of lime required. Lime (2.25–7.5 t ha −1 ) was applied in 2016 only and the effect monitored in both 2016 and 2017. Soil pH was increased from the initial 5.5 to the target value 6.5 by 7.5 t ha −1 CaCO 3 . Liming greatly reduced CaCl 2 -extractable Cd in the rhizospheric soil. Grain Cd concentration in the control exceeded the limit by 2–5 times. Liming at 7.5 t ha −1 decreased grain Cd concentration by 70–80% in both seasons without affecting grain yield. Grain Cd concentration was below the limit in the 7.5 t ha −1 liming treatment in both seasons. Grain Cd concentration correlated closely with CaCl 2 -extractable Cd in rhizospheric soil at the grain maturing stage. Seasonal difference in grain Cd concentration was attributed to the soil water status at the grain maturing stage. Liming had no significant effect on grain arsenic concentration or speciation. A single application of CaCO 3 to raise soil pH to 6.5, combined with low Cd cultivars and delayed drainage of paddy water during late grain filling stage, was highly effective at reducing Cd accumulation in rice grain. [ABSTRACT FROM AUTHOR]

Abstract: In this work, N‐doped hollow porous carbon spheres (N‐HPCSs) were synthesized by silicon dioxide template‐assisted polybenzoxazine (PB) coating strategy. The prepared N‐HPCSs have a smooth hollow ball structure surrounded by a well‐defined porous shell. Combining with in‐situ plating of Bi film, the N‐HPCSs were further fabricated a sensitive electrochemical platform for determination trace levels of Cd(II) by differential pulse anodic stripping voltammetry (DPASV). Under the optimized conditions, the Bi‐N‐HPCSs based sensor displays a linear response to Cd(II) over the range of 0.5 μg L−1 to 150 μg L−1. Meanwhile, the limit of detection (LOD, S/N=3) is estimated to be around 0.16 μg L−1 for Cd(II), which is 31 times lower than the safety values set by United States Environmental Protection Agency (EPA) for the drinking water. Moreover, the proposed method was successfully applied to detection of Cd(II) in tap water and lake water, and the analytical results of the presented method are agreed well with inductively coupled plasma‐mass spectrometry (ICP‐MS) data. Due to the excellent analytical performance, the fabricated electrode is promised for future development in monitoring of cadmium pollution in the environment. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) and arsenate (As) are notorious environmental contaminants, and co‐contamination usually requires opposing treatment strategies due to their differing physico‐chemical properties. Developing adsorbents that can bind both contrasting contaminants simultaneously is desirable. Two prepared graphene materials, graphene oxide (GO) and iron‐oxide‐modified reduced‐GO (FeG), are evaluated for Cd‐ and As‐sorption, and performance is compared to a mixed‐mode commercial adsorbent. Negatively charged GO shows affinity toward cationic Cd, and positively charged FeG shows affinity toward anionic As. Sorption is pH dependent: Increase in pH‐promotes Cd‐sorption and retards As‐sorption. GO displays excellent Cd‐sorption even in acidic conditions. The maximum amounts adsorbed by GO and FeG are 782 μmol Cd g−1 and 408 μmol As g−1, respectively. Competition by calcium strongly suppresses Cd‐sorption, whereas competition by phosphate does not hinder As‐sorption. A mixture of GO and FeG demonstrates successful simultaneous sorption of Cd and As from co‐contaminated solutions, including a natural water sample, displaying greater sorption than the commercial adsorbent. Data highlight the potential application of graphene materials in effective mixed‐mode remediation of multiple contaminants (cations and anions). [ABSTRACT FROM AUTHOR]

The purpose of this study is to evaluate the capability of hybrid poplar (Populus deltoides × Populus nigra) to reduce cadmium (Cd) concentrations in an experimental site of Campania Region (southern Italy) subjected to illegal deposit of industrial and household waste. We propose to evaluate the efficiency of poplar for Cd phytoextraction by coupling the use of a process-based, distributed hydrological model (HydroGeoSphere, HGS) with photogrammetric images acquired by Unmanned Aerial Vehicle (UAV). This scenario-based approach exploits in-situ measurements so as to be able to reproduce reliable near-real-world processes. The original bare soil (BS; unplanted reference location) is used as benchmark and compared to the situation where poplar trees are planted (PP) for bioremediation purposes. The 'virtual' positions of poplars were chosen by considering the expected Cd accumulation areas that are correlated to topographic indices retrieved from the high-resolution (0.03 × 0.03 m) digital elevation model (DEM) generated by UAV photogrammetric photos. Transfer and accumulation of Cd in the poplars were described by a timevariant sink term featuring the HGS transport equation. The numerical simulations show that poplar trees are able to reduce Cd concentrations by 15%, 36%, and 64% in spring, summer, and autumn, respectively. Coupling an advanced 3D hydrological model with a high-resolution DEM generated by UAV-photogrammetry seems a promising and viable approach for assessing the efficiency of phytoremediation techniques. [ABSTRACT FROM AUTHOR]

Dietary exposure of cadmium (Cd) has not been studied in Southwest China. The objective of the study was to determine the pollution characteristics and contamination levels in various agriculture products in Southwest China and to conduct a comparison of dietary exposure assessment of Cd in polluted and non-polluted areas. Results showed that the mean Cd contents in rice were 0.53 and 0.52 mg/kg in the high-polluted and low-polluted areas, respectively, with the average value was 0.03 mg/kg in the control area. The mean dietary Cd exposure from rice and vegetables of the selected non-occupational residents in Southwest China was 113.10 μg/kg bodyweight (bw)/month, 88.80 μg/kg bw/month, and 16.50 μg/kg bw/month in the high-polluted, low-polluted, and control areas, respectively, which correspond to 4.5 times, 3.6 times, and 0.66 times of the provisional tolerable monthly intake (25 μg/kg bw/month) established by the Joint FAO/WHO Expert Committee on Food Additives. The findings indicated that the risk for Cd exposure of residents was high due to home-grown food (most especially rice) being near polluted areas and is of great concern. [ABSTRACT FROM AUTHOR]

The composition of shoot cell walls of two maize hybrids (Zea mays L.), the sensitive Novania and the tolerant Almansa, both after cadmium treatment was studied. Previous results showed a smaller effect of cadmium on shoot physiological parameters (e.g., elongation, dry mass, photosynthetic pigments content) in both hybrids compared to their roots. Changes in the composition of shoot cell walls were observed. It was ascertained that the amount of hemicelluloses in shoot cell walls decreased and the amount of lignocellulose complex increased in the sensitive hybrid; the opposite was observed in the tolerant Almansa. Dissimilarities in the cell wall structure of shoots, compared to the roots, in both hybrids were observed mainly in higher quantities of total lignin, in hemicelluloses fractions. The lignocellulose complex remained unchanged in the shoots in comparison to the roots. Nevertheless, in both hybrids, the highest Cd2+ amount was found in hemicelluloses. Such modification of the cell walls might affect the amount of binding sites resulting in lower cell wall permeability and subsequently in a lower pollutant influx into the protoplast. [ABSTRACT FROM AUTHOR]

Inoculation with endophytic bacterium has been considered as a prospective application to improve the efficiency of phytoextraction. In this study, the effect of Buttiauxella sp. SaSR13 (SaSR13), a novel endophytic bacterium isolated from the root of hyperaccumulator Sedum alfredii, on plant growth and cadmium (Cd) accumulation in S. alfredii was investigated. Laser scanning confocal microscopic (LSCM) images showed that SaSR13 was mainly colonized in the root elongation and mature zones. The inoculation with SaSR13 to Cd-treated plants significantly enhanced plant growth (by 39 and 42% for shoot and root biomass, respectively), chlorophyll contents (by 38%), and Cd concentration in the shoot and root (by 32 and 22%, respectively). SaSR13 stimulated the development of roots (increased root length, surface area, and root tips number) due to an increase in the indole-3-acid (IAA) concentrations and a decrease in the concentrations of superoxide anion (O2.−) in plants grown under Cd stress. Furthermore, inoculation with SaSR13 enhanced the release of root exudates, especially malic acid and oxalic acid, which might have facilitated the uptake of Cd by S. alfredii. It is suggested that inoculation with endophytic bacterium SaSR13 is a promising bioaugmentation method to enhance the Cd phytoextraction efficiency by S. alfredii. [ABSTRACT FROM AUTHOR]

Finding effective methodologies for the removal of heavy metals from contaminated water are really significant. Facile and “green” techniques for adsorbents fabrication are in high demand to satisfy a wide range of practical applications. This report presents of an efficient method for preparing Fe 3 O 4 @ layered double hydroxide@ guargum bionanocomposites (GLF-BNCs). First of all, the LDH coated Fe 3 O 4 nanoparticles were simply synthesized, using ultrasonic irradiation. The citrate coated Fe 3 O 4 nanoparticles which were under negative charging and LDH nanocrystals which were charged positively make electrostatic interaction which formed a stable self-assembly component, and then guargum as a biopolymer were linked onto Fe 3 O 4 @LDH via an in situ growth method. Furthermore, the GLF-BNCs had the ability to remove cadmium ions (Cd 2+ ) from the aqueous solutions. Adsorption studies indicate that the Langmuir isotherm model and the kinetic model in pseudo-second order were appropriate for Cd(II) removal. The maximum Cd(II) adsorption capacity of the GLF8% was 258 mg g −1 . The Cd(II) was adsorbed from aqueous solutions very quickly with the contact time of 5 min by the GLF 8%, suggesting that GLF-BNCs may be a promising adsorbent for removing Cd(II) from wastewater. The effect of Fe 3 O 4 @LDH contents (2, 4 and 8 wt.%) on the thermal, physicomechanical, and morphological properties of guargum were investigated by Fourier transform infrared spectroscopy, X-ray diffraction (XRD), thermal gravimetric analysis (TGA), field emission scanning electron microscopy, transmission electron microscopy (TEM), Energy-dispersive X-ray spectroscopy and Brunauer–Emmett–Teller (BET) specific surface area techniques. The TEM results indicated that the LDH platelets are distributed within the polymer matrix. [ABSTRACT FROM AUTHOR]

In order to improve the adsorption capacities of corncob-based biochars for heavy metal, the different pyrolysis temperature (350 °C, 450 °C and 550 °C) of corncob-based biochars were modified with the acrylonitrile, and adsorption capacities of Cadmium from solution by biochars were studied. The results showed that only at 350 °C the biochar can be successfully modified. The Cd adsorption capacity (85.65 mg/g) by the biosorbent was higher than other methods of modifying biochars previously reported. SEM-EDS and FTIR confirmed that the C N group was grafted on the biochar at low pyrolysis temperature. Batch adsorption experiment including pH-dependence, adsorption kinetics, and isotherms and XPS results showed that the removal mechanism of Cd(II) by the modified biochar was ion exchange and adsorption-complexation. This research not only obtained a novel method to modify biochar but also furthered research into the lignin of biochar composition, and provided an efficient sorbent for heavy metal. [ABSTRACT FROM AUTHOR]

Cadmium (Cd) contamination in soil is a global environmental pollution issue. Nanohydroxyapatite (NHAP) has been used in soil remediation to immobilize cadmium in contaminated soils. However, the effect of acid rain on the export of cadmium from topsoil and its behavior in deep soil and leachate is unclear. In this study, column experiments and development of parsimonious model were performed to estimate Cd leaching behavior from topsoil and environmental risk of groundwater after 0.5% NHAP remediation. Four leaching events were performed and total Cd, different fractions of Cd determined by sequential extraction procedure and pH were determined for each leaching. The results show that with the export of Cd in topsoil, the total Cd concentration in soil at different depths had the following vertical distributions: 0–5 cm > 5–10 cm > 10–15 cm > 15–20 cm. NHAP treatment increased the soil pH and decreased Cd leaching loss by 56.45% compared to the control, and the results fit the parabolic diffusion model. With sequential extraction it was observed that NHAP application increased the residual fraction of cadmium in soil. After leaching, there was a positive correlation between soil pH and Cd concentration with regards to the exchangeable, reducible, oxidizable and residual Cd fractions. The parabolic diffusion model showed that Cd-contaminated soil with NHAP remediation is harmless to humans after sufficient remediation duration, whereas the resultant concentrations from the CK treatment could be toxic. The results indicate that nanohydroxyapatite could significantly reduce the bioavailability of cadmium and the environmental risk. However, the release of Ca and P from the dissolution of NHAP should be carefully studied as this will impact the mobilization of Cd or colloid Cd, and high leaching of P may result in P-induced eutrophication risk. [ABSTRACT FROM AUTHOR]

To effectively reuse adsorbent in removal of Cd (II), magnetic modification was considered as an alternative. In this study, iron oxide nanoparticles (IONPs) synthesized from the extract of Excoecaria cochinchinensis Lour leaves were modified by low-temperature calcination, and used to remove Cd (II). Transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and magnetic properties analysis confirmed the successful synthesis of nanoscale magnetic Fe O C composite. Response surface methodology (RSM) served to optimize the adsorption of Cd (II) by IONPs based on Box-Behnken design (BBD). According to the quadratic model, the effect of each factor on the removal of Cd (II) by IONPs was: pH > dosage > ionic strength > temperature. In percentage terms, 98.50% of Cd (II) (10 mg L −1 ) was removed when the pH, absorbent dosage, temperature and ionic strength conditions were 8.07, 2.5 g L −1 , 45 °C, and 0.07 mol L −1 , respectively. The adsorption of Cd (II) by IONPs is consistent with pseudo-second order kinetics and Langmuir adsorption isotherm models, indicating that the process of adsorption of Cd (II) by IONPs belongs to monolayer chemical adsorption. The –COOH, –COH, Cπ electron and ≡FeOH may be the binding sites for Cd (II) on the surface of IONPs. Overall, IONPs can be used to remove Cd (II) effectively from aqueous solution in a wide range of conditions. [ABSTRACT FROM AUTHOR]

Several sulfur compounds are thought to play important roles in the plant tolerance to cadmium (Cd), but the role of inorganic sulfide in Cd tolerance remains largely unknown. In this study, we found that Cd exposure increased the accumulation of soluble sulfide in Arabidopsis plants. When exogenous sulfide, in the form of NaHS, was foliarly applied, Cd-induced growth inhibition and oxidative stress were alleviated. In addition, although the foliar application of sulfide did not affect the total Cd levels, it significantly decreased the soluble Cd fractions in plants. Furthermore, foliar applications of sulfide decreased Cd distribution in the cytoplasm and organelles, but increased Cd retention in the cell wall, which is a less sensitive compartment. These results suggest that the Cd-induced accumulation of soluble sulfide alleviates Cd toxicity in plants by inactivating Cd and sequestering it into the cell wall. [ABSTRACT FROM AUTHOR]