Cd Kg-1 Research Articles

Morpho-physiological and biochemical responses of radish (Raphanus sativus L.) under cadmium stress

The accumulation of cadmium (Cd) in plants poses a major risk to consumer health, in addition to affecting plant growth, development and quality. The study aimed to examine the effects of cadmium on the plants' ability for photosynthesis and antioxidant enzyme activity. In this study, radishes were planted in Petri dishes and pots containing soil supplemented with different concentrations of cadmium sulphate (25, 50, and 100 mg Cd kg-1 soil). The results showed that the percentage of germination, seedlings length, and fresh and dry matter significantly declined its increasing cadmium concentrations. In addition, cadmium hindered plant growth, as evidenced by the fresh and dried weight of radish roots and leaves after a 100 mg Cd kg-1 soil treatment. There was also a notable decrease in chlorophyll a and chlorophyll b, total chlorophyll, and total leaf area per plant. The leaves of radish plant exhibited a significant increase in lipid peroxidation and electrolyte leakage contents under Cd stress, while, the relative water content (RWC) decreased. However, leaves and roots of radish plant showed a considerable increase in antioxidant enzymes (catalase; CAT, peroxidase; POD, and superoxide dismutase; SOD). Furthermore, radish showed a significant increase in Cd accumulation in all applications, however, there were no obvious symptoms of Cd toxicity following the 25 and 50 mg Cd kg-1 soil applications. In conclusion, the radish plants accumulated cadmium at higher concentrations (100 mg Cd kg-1 soil). So, we recommended cultivating the radish plants in soil that has low concentrations of cadmium.

GIS- and Multivariate-Based Approaches for Assessing Potential Environmental Hazards in Some Areas of Southwestern Saudi Arabia.

Soil contamination is a major issue that endangers the ecology in most countries. Total concentrations of As, Cd, Co, Cr, Cu, Mn, Ni, Pb, VFe, and Zn were determined by analyzing soil samples from 32 surface soil samples in southwest Saudi Arabia, including certain areas of Al-Baha. Kriging techniques were used to create maps of the distribution of metal. To assess the levels of soil contamination in the research area, principal component analysis (PCA), contamination factors (CF), and pollution load index were used. The results show the stable model gave the best fit to the As and Zn semivariograms. The circular model fits the Cd, Co, and Ni semivariograms the best, while the exponential model fits the Cr, V, and Fe semivariograms the best. For Ni and Pb, respectively, spherical and Gaussian models are fitted. The findings demonstrated two clusters containing different soil heavy metal concentrations. According to the data, there were two different pollution levels in the research region: 36.58% of it is strongly contaminated, while 63.41% of it has a moderate level of contamination (with average levels of these metals 5.28 ± 5.83, 0.81 ± 0.19, 18.65 ± 6.22, 45.15 ± 23.25, 60.55 ± 23.74, 972.30 ± 223.50, 33.45 ± 14.11, 10.05 ± 5.13, 84.15 ± 30.72, 97.40 ± 30.05, and 43,245.00 ± 8942.95 mg kg-1 for As, Cd, Co, Cr, Cu, Mn, Ni, Pb, V, Fe, and Zn, respectively). The research area's poor management practices are reflected in the current results, which raised the concentration of harmful elements in the soil's surface layers. Ultimately, the outcomes of pollution concentration and spatial distribution maps could aid in informing decision-makers when creating suitable heavy metal mitigation strategies.

Evaluating phytoremediation potential and nutrients status of Bassia indica (Wight) A. J. Scott (Indian Bassia) in a cadmium-contaminated saline soil.

Bassia indica (Wight) A. J. Scott is a fast-growing halophyte suitable for the remediation of saline lands on a large scale. However, no information is available regarding its phytoremediation potential for cadmium (Cd) alone or in combination with salinity. Besides evaluating phytoremediation, assessing micronutrient hemostasis as a crucial physiological insight into the mechanism involved in the tolerance of B. indica under saline soil contaminated with Cd was subjected. Under salinity stress, a considerable amount of sodium accumulates in the plant. Moreover, the accumulation of sodium increased by Cd stress levels. The increase in the exchangeable form of Cd in the rhizosphere in the presence of NaCl ions further elevated the Cd content in the plant tissues. For instance, compared to non-saline conditions, applying 2.5 and 5 g NaCl kg-1 to soil treated with 60 mg Cd kg-1 increased exchangeable Cd by 28.4 and 49.5% in rhizosphere soil, which led to increased cadmium content by 16.1 and 29.6% in the root (as amainpart of Cd accumulation), respectively. Under most stress conditions, potassium homeostasis in the shoot remained undisturbed. It was observed that this plant could transfer an optimal level of potassium from the roots to the shoots at a moderate salinity level. Changes and the distribution of Cu and Zn levels followed a similar pattern in the plant, indicating a common regulation mechanism for these nutrients. Generally, the plant could maintain an appropriate level of Fe, Zn, and Cu ions under most stressed conditions. However, the level of Mn decreased significantly under severe stress levels. Growth parameters, tolerance index, and the values of translocation factor < 1 and shoot bioconcentration factor > 1 under 5 mg Cd kg-1 soil treatment at different salinity levels indicated that B. indica could mitigate the detrimental effect of Cd toxicity and tolerate the NaCl stress via a phytostabilizer mechanism. However, the shoot bioconcentration factor values were very close to one at other Cd levels. Therefore, considering the obtained evidence and the innate ability of B. indica to remediation salinity, this plant is still recommended, even for higher Cd levels (even until 30 mg kg-1), in the presence of salinity.

Foliar-applied melatonin and titanium nanoparticles modulate cadmium (Cd) toxicity through minimizing Cd accumulation and optimizing physiological and biochemical properties in sage (Salvia officinalis L.).

Notwithstanding the fact that melatonin (MT) and titanium nanoparticles (Ti NPs) alone have been widely used recently to modulate cadmium (Cd) stress in plants, there is a gap in the comparative impacts of these materials on lowering Cd toxicity in sage plants. The objective of this study was to determine how foliar application of MT and Ti NPs affected the growth, Cd accumulation, photosynthesis, water content, lipid peroxidation, and essential oil (EO) quality and quantity of sage plants in Cd-contaminated soils. A factorial experiment was conducted using MT at 100 and 200μM and Ti NPs at 50 and 100mg L-1 topically, together with Cd toxicity at 10 and 20mg Cd kg-1 soil. The results showed that Cd toxicity decreased plant growth and enhanced lipid peroxidation. The Cd stress at 20mgkg-1 soil resulted in increases in Cd root (693%), Cd shoot (429%), electrolyte leakage (EL, 29%), malondialdehyde (MDA, 72%), shoot weight (31%), root weight (27%), chlorophyll (Chl) a + b (26%), relative water content (RWC, 23%), and EO yield (30%). The application of MT and Ti NPs controlled drought stress by reducing MDA and EL, enhancing plant weight, Chl, RWC, and EO production, and minimizing Cd accumulation in plant tissues. The predominant compounds in the EO were α-thujone, 1,8-cineole, β-thujone, camphor, and α-humulene. MT and Ti NPs caused α-thujone to rise, whereas Cd stress caused it to fall. Based on heat map analysis, MDA was the trait that was most sensitive to treatments. In summary, the research emphasizes the possibility of MT and Ti NPs, particularly MT at 200μM, to mitigate Cd toxicity in sage plants and enhance their biochemical reactions.

Plant Cadmium Toxicity and Biomarkers Are Differentially Modulated by Degradable and Nondegradable Microplastics in Soil.

The impact of microplastics (MPs) as emerging pollutants on plant heavy metal toxicity has been extensively reported in vegetable-soil systems over recent years. However, little attention has been given to cultivar variations between degradable and non-degradable MPs. This study investigated the effects of degradable polylactic acid (PLA) and nondegradable polypropylene (PP) MPs on plant growth and biomarker (malonaldehyde (MDA) and antioxidant enzymes) performance in Cd-contaminated arable soil. The results show that both types of MPs significantly impacted plant biomass and biomarker contents across all three Cd levels. The degree of impact was significantly sensitive to both the type and dose of MPs, as they reduced the soil pH and cation exchange capacity (CEC) while increasing soil dissolved organic carbon (DOC), microbial biomass carbon, and nitrogen. PP exhibited greater root growth inhibition and phytotoxicity at higher doses of 1% and 5% compared to PLA. Specifically, the highest MDA contents were 1.44 and 2.20 mmol mg-1 protein for shoots and roots, respectively, in the 5% PLA treatment under a 10.1 mg kg-1 Cd level, which were 1.22 and 1.18 times higher than those in corresponding treatments of 5% PP. Overall, PLA had less significant effects on plant phytotoxicity, Cd availability, and soil properties compared to PP. Regression pathway analysis indicated that MPs increased shoot Cd uptake by altering both soil physical-chemical and microbial characteristics. Among the soil variables, pH, CEC, and Cd bioavailability were found to play vital roles. Yet, no single variable acts alone in the mechanism for plant Cd uptake. PLAs are suggested to replace conventional non-biodegradable plastics to control environmental MP pollution, particularly in agricultural systems with higher Cd contamination. However, the long-term effects of the by-products generated during the biodegradation process require further investigation.

Vermicompost Supply Enhances Fragrant-Rice Yield by Improving Soil Fertility and Eukaryotic Microbial Community Composition under Environmental Stress Conditions.

Heavy-metal contamination in agricultural soil, particularly of cadmium (Cd), poses serious threats to soil biodiversity, rice production, and food safety. Soil microbes improve soil fertility by regulating soil organic matter production, plant nutrient accumulation, and pollutant transformation. Addressing the impact of Cd toxicity on soil fungal community composition, soil health, and rice yield is urgently required for sustainable rice production. Vermicompost (VC) is an organic fertilizer that alleviates the toxic effects of Cd on soil microbial biodiversity and functionality and improves crop productivity sustainably. In the present study, we examined the effects of different doses of VC (i.e., 0, 3, and 6 tons ha-1) and levels of Cd stress (i.e., 0 and 25 mg Cd kg-1) on soil biochemical attributes, soil fungal community composition, and fragrant-rice grain yield. The results showed that the Cd toxicity significantly reduced soil fertility, eukaryotic microbial community composition and rice grain yield. However, the VC addition alleviated the Cd toxicity and significantly improved the soil fungal community; additionally, it enhanced the relative abundance of Ascomycota, Chlorophyta, Ciliophora, Basidiomycota, and Glomeromycta in Cd-contaminated soils. Moreover, the VC addition enhanced the soil's chemical attributes, including soil pH, soil organic carbon (SOC), available nitrogen (AN), total nitrogen (TN), and microbial biomass C and N, compared to non-VC treated soil under Cd toxicity conditions. Similarly, the VC application significantly increased rice grain yield and decreased the Cd uptake in rice. One possible explanation for the reduced Cd uptake in plants is that VC amendments influence the soil's biological properties, which ultimately reduces soil Cd bioavailability and subsequently influences the Cd uptake and accumulation in rice plants. RDA analysis determined that the leading fungal species were highly related to soil environmental attributes and microbial biomass C and N production. However, the relative abundance levels of Ascomycota, Basidiomycota, and Glomeromycta were strongly associated with soil environmental variables. Thus, the outcomes of this study reveal that the use of VC in Cd-contaminated soils could be useful for sustainable rice production and safe utilization of Cd-polluted soil.

Transcriptome analysis shows that Glomus versiforme decrease the accumulation and toxicity of cadmium in Ipomoea aquatic Forsk.

So far, the physiological and molecular mechanisms of the impact of arbuscular mycorrhizal fungus (AMF) on Cd absorption, transport and detoxification in Ipomoea aquatica (water spinach) are still unclear. In the present study, a pot experiment was performed to investigate the impact of AMF-Glomus versiforme (Gv) on the photosynthetic characteristics, Cd uptake, antioxidative system and transcriptome in water spinach in the soils supplemented with 5mg Cd kg-1. Gv inoculation improved significantly the photosynthetic characteristics and growth of water spinach. Furthermore, Gv colonization significantly promoted the activities of catalase (CAT), peroxidase (POD) and glutathione reductase (GR), contents of glutathione (GSH) and ascorbic acid (AsA), and the total antioxidant capacity (TCA), but decreased malondialdehyde (MDA) content in water spinach. In addition, Gv inoculation significantly increased pH in rhizosphere soils and decreased the Cd concentrations and uptakes in water spinach. Importantly, 2670 differentially expressed genes (DEGs) were screened in water spinach root colonized with Gv in 5mg Cd kg-1 soil, of which 2008 DEGs were upregulated and 662 DEGs were downregulated. Especially, the expression levels of POD, CAT, GR, dehydroascorbate reductase 2 (DHAR2), glutathione S-transferase U8 (GSTU8) and glutathione synthetase (GSHS) and cytochrome P450 (Cyt P450) genes were significantly up-regulated in water spinach inoculated with Gv. Meanwhile, the plant cadmium resistance protein 2 (PCR2), metal tolerance protein 4 (MTP4), ATP-binding cassette transporter C family member (ABCC), ABC-yeast cadmium factor 1 (ABC-YCF1) and metallothionein (MT) genes were also up-regulated in mycorrhizal water spinach. Our results firstly elucidated the mechanism by which AMF reduced the uptake and phytotoxicity of Cd in water spinach through a transcriptome analysis.

Influence of Anthropogenic Pollution on Soil and Plants of Gosa Dumpsite, Abuja, Nigeria

Despite increased awareness of the causes of environmental pollution, it continues to pose a serious threat to both developed and developing countries worldwide. The Gosa dumpsite in Abuja serves as a receptacle for various waste materials from both high and low-income areas of the metropolis. Surprisingly, peri-urban farmers residing in the vicinity still cultivate edible crops on this polluted land. This study aims to assess the impact of waste dumping at Gosa dumpsite on selected soil properties and the uptake of heavy metals by plants. In order to achieve this objective, soil and plant samples were collected from established 5 x 5 m2 quadrants during the early and late dry as well as rainy seasons of 2019 and 2020. The collected samples underwent analysis using standard methods to determine their physical and chemical properties. Additionally, the study identified the dominant plant species within the dumpsite through standard methods. The findings revealed that the dumpsite soil exhibited characteristics of loamy sand, with the highest pH value of 8.85 ± 0.90 recorded during the dry season of 2020. Other significant soil results included total nitrogen at 1.09 ± 0.64 g kg-1, organic carbon at 9.88 ± 0.10 g kg-1, Cd at 11.93 ± 2.25 mg kg-1, Hg at 2.18 ± 1.08 mg kg-1, and Pb at 54.68 ± 8.68 mg kg-1, all of which were observed during the early rainy season of 2020. During the remaining seasons considered, lower values were obtained. Notably, these values exceeded the permissible levels set by the FAO for soil intended for cultivating edible crops. Furthermore, the plant species Ageratum conyzoides demonstrated the highest uptake of heavy metals, with concentrations of 4.47 ± 1.15 mg kg-1 for Cd, 1.77 ± 1.08 mg kg-1 for Hg, and 19.56 ± 4.83 mg kg-1 for Pb, all recorded during the early dry season of 2020. In conclusion, although the Gosa dumpsite in Abuja may appear fertile enough for cultivation, the study's results highlight that it cannot be deemed suitable for the production of edible crops. The presence of heavy metals and other pollutants in the soil poses a significant risk to crop health and, consequently, to human consumption.

Mercury and rare earth elements (REEs) show different spatial trends in feathers of Kentish plover (Charadrius alexandrinus) breeding along the Adriatic Sea coast, Italy.

Feather analysis is an ethical and effective method for assessing the exposure of wild birds to environmental contamination due to trace elements and organic pollutants. We used feather to monitor the exposure to three toxic and non-essential metals (Hg, Cd, and Pb) and rare earth elements (REEs) of Kentish plover (Charadrius alexandrinus) breeding in different coastal areas (Veneto, Emilia-Romagna, Marche, Abruzzo, and Apulia) along the Italian coast of the Adriatic Sea. Feathers (n = 113) were collected from April to June. Feather concentrations evidenced a significant exposure to Hg (13.05 ± 1.71 mg kg−1 dw) and REEs (447.3 ± 52.8 ng g−1 dw) in the Kentish plover breeding in Veneto (n = 21) compared to the other coastal areas, with several individuals showing Hg concentrations above the adverse effect (5 mg kg−1 dw) and high-risk (9.14 mg kg−1 dw) thresholds reported for birds. Higher REE concentrations compared to Marche (n = 29), Abruzzo (n = 11) and Apulia (n = 13) were also reported for birds breeding in Emilia-Romagna (474.9 ± 41.9 ng g−1 dw; n = 29). The exposure to Cd and Pb was low in all the coastal areas, and only a few samples (n = 6 and n = 4 for Cd and Pb, respectively) exceeded the adverse effect thresholds (0.1 and 4 mg kg−1 for Cd and Pb, respectively). A significant sex-related difference was observed for REE-concentrations, with females showing higher concentration than males. These data highlight the need to monitor the exposure of the Kentish plover to Hg and REEs, especially in the northern basin of the Adriatic Sea, since these elements might negatively affect species' reproductive success and threaten its conservation.

Growth and cadmium and nickel uptake of maize (Zea mays L.) in a cadmium and nickel co‑contaminated soil and phytoremediation efficiency using ethylenediamine tetraacetic acid

Background: Anthropogenic activities release cadmium (Cd), nickel (Ni), and other heavy metals into soil. Zea mays can clean up contaminated soils, but little is known about how Cd and Ni co-contamination stress affects ethylenediamine tetraacetic acid (EDTA)-based phytoextraction and phytoremediation, hence this study was conducted. Methods: The experiment involved nine treatment levels (0, 5, 10, 15, and 20 mg kg-1 Cd and 0, 15, 30, 45, and 60 mg kg-1 Ni), grouped into three categories: CT as the control group, P as Cd + Ni only, and CAP as Cd + Ni + EDTA (n=3). The treatments used (CH3COO)2Cd•2H2O and NiSO4 as the source of Cd and Ni, respectively, and EDTA was applied at two rates (0 and 0.5 g/kg). After the experimental period, measurements were taken for shoot length, biomass, and metal concentrations in both the roots and shoots using established procedures. Results: The concentrations of metals in plants' roots and shoots increased as the concentrations in soil increased, but shoot length, biomass, bioconcentration factor (BCF), and translocation factor (TF) values decreased with increasing soil metal content. The application of EDTA increased metal uptake but led to greater root and shoot biomass loss. Generally, TF values for Cd and Ni were less than 1 but most of the BCF values were greater than 1. Conclusions: The study found that phytostabilization is the main mechanism for phytoremediation of Cd-Ni-co-contaminated soils with Zea mays, with EDTA addition enhancing metal accumulation and reducing biomass yield.

Phosphate-solubilizing bacteria improve the antioxidant enzyme activity of Potamogeton crispus L. and enhance the remediation effect on Cd-contaminated sediment

Phosphorus-solubilizing bacteria (PSB) assisted phytoremediation of cadmium (Cd) pollution is an effective method, but the mechanism of PSB-enhanced in-situ remediation of Cd contaminated sediment by submerged plants is still rare. In this study, PSB (Leclercia adecarboxylata L1–5) was inoculated in the rhizosphere of Potamogeton crispus L. (P. crispus) to explore the effect of PSB on phytoremediation. The results showed that the inoculation of PSB effectively improved the Cd extraction by P. crispus under different Cd pollution and the Cd content in the aboveground and underground parts of P. crispus all increased. The μ-XRF images showed that most of the Cd was enriched in the roots of P. crispus. PSB especially showed positive effects on root development and chlorophyll synthesis. The root length of P. crispus increased by 51.7 %, 80.5 % and 74.2 % under different Cd pollution, and the Ca/Cb increased by 38.9 %, 15.2 % and 8.6 %, respectively. Furthermore, PSB enhanced the tolerance of P. crispus to Cd. The contents of soluble protein, MDA and H2O2 in 5 mg·kg−1 and 7 mg·kg−1 Cd content groups were decreased and the activities of antioxidant enzymes were increased after adding PSB. The results showed that the application of PSB was beneficial to the in-situ remediation of submerged plants.

Golden mussel shell (&lt;i&gt;Limnoperna fortunei&lt;/i&gt;) flour contaminated with cadmium as a calcium source for broiler chickens

The objective of this study was to evaluate the effects of golden mussel flour (GMSF) contaminated with increasing rates of cadmium (Cd) as a replacement for limestone as a Ca source, in broiler chicken feed from 14 to 42 days of age. A total of 60 animals were assigned to four treatments (inclusion rates of Cd: 6.94, 14.55, 22.40, and 30.00 mg Cd kg-¹) with five replications in a completely randomized design. At 42 d, blood samples were collected to evaluate serum concentrations of aspartate amino transferase (AST), alanine amino transferase (ALT), gamma glutamyl transferase (GGT), total bilirubin, Ca, P, and Cd. After slaughter, tissues were collected to evaluate Cd concentration in bone parameters. Growth performance of broiler chickens and Cd content in the breast meat were not affected by the inclusion rates of Cd in the GMSF. However, there was an effect of Cd in GMSF on the concentration of Cd in the skin, liver, bones, feathers, and serum; ALT; and total bilirubin. Bone flexibility had a quadratic response to increasing inclusion rates of GMSF; serum Ca concentration increased linearly and there was no effect on serum P concentration. Concentrations of Cd in GMSF above 20 mg kg-¹ caused high Cd contamination in broiler tissues. Therefore, it was concluded that Cd concentrations above 6.94 mg kg-¹ in broiler diets caused high Cd concentrations in meat and organs that are above those permitted for human consumption

Trichoderma Inoculation Alleviates Cd and Pb-Induced Toxicity and Improves Growth and Physiology of Vigna radiata (L.).

Heavy metals (HMs) pose a serious threat to agricultural productivity. Therefore, there is a need to find sustainable approaches to combat HM stressors in agriculture. In this study, we isolated Trichoderma sp. TF-13 from metal-polluted rhizospheric soil, which has the ability to resist 1600 and 1200 μg mL-1 cadmium (Cd) and lead (Pb), respectively. Owing to its remarkable metal tolerance, this fungal strain was applied for bioremediation of HMs in Vigna radiata (L.). Strain TF-13 produced siderophore, salicylic acid (SA; 43.4 μg mL-1) and 2,3-DHBA (21.0 μg mL-1), indole-3-acetic acid, ammonia, and ACC deaminase under HM stressed conditions. Increasing concentrations of tested HM ions caused severe reduction in overall growth of plants; however, Trichoderma sp. TF-13 inoculation significantly (p ≤ 0.05) increased the growth and physiological traits of HM-treated V. radiata. Interestingly, Trichoderma sp. TF-13 improved germination rate (10%), root length (26%), root biomass (32%), and vigor index (12%) of V. radiata grown under 25 μg Cd kg-1 soil. Additionally, Trichoderma inoculation showed a significant (p ≤ 0.05) increase in total chlorophyll, chl a, chl b, carotenoid content, root nitrogen (N), and root phosphorus (P) of 100 μg Cd kg-1 soil-treated plants over uninoculated treatment. Furthermore, enzymatic and nonenzymatic antioxidant activities of Trichoderma inoculated in metal-treated plants were improved. For instance, strain TF-13 increased proline (37%), lipid peroxidation (56%), catalase (35%), peroxidase (42%), superoxide dismutase (27%), and glutathione reductase (39%) activities in 100 μg Pb kg-1 soil-treated plants. The uptake of Pb and Cd in root/shoot tissues was decreased by 34/39 and 47/38% in fungal-inoculated and 25 μg kg-1 soil-treated plants. Thus, this study demonstrates that stabilizing metal mobility in the rhizosphere through Trichoderma inoculation significantly reduced the detrimental effects of Cd and Pb toxicity in V. radiata and also enhanced development under HM stress conditions.

Tradeoffs between pH, dissolved organic carbon, and mineral ions regulate cadmium uptake by Solanum hyperaccumulators in calcareous soil

Soil solution pH and dissolved organic carbon (DOC) influence cadmium (Cd) uptake by hyperaccumulators but their tradeoff in calcareous soils is unclear. This study investigated the mechanisms of Solanum nigrum L. and Solanum alatum Moench in calcareous soil using a combination of concentration gradient experiments (0.6–100 mg Cd kg−1) and soil solution composition analysis. The results showed that the soil solution pH of S. nigrum remained stable despite Cd stress. On average, the soil solution pH of S. alatum was 0.23 units higher than that of S. nigrum, although pH decreased significantly under high Cd stress. In addition, the concentrations of potassium (K) and calcium (Ca) in the soil solution of S. nigrum increased and decreased under low and high levels of Cd stress, respectively. In S. alatum, the K and Ca concentrations in the soil solution generally increased with increasing Cd stress levels. Moreover, the level of DOC in the soil solution of both plants was higher under Cd stress compared to the control, and a gradually increasing trend with Cd stress level was observed in S. alatum. Consequently, the bioconcentration factors of the roots (2.62–19.35) and shoots (1.20–9.59) of both plants were >1, while the translocation factors were <1, showing an obstacle of Solanum hyperaccumulators in transferring Cd into their aboveground parts. Redundancy analysis revealed that the Cd concentration in S. nigrum roots was significantly negatively correlated with the soil solutions of K and Ca. In contrast, Cd concentrations in S. alatum roots and shoots were significantly positively correlated with soil solution DOC, K, and Ca but negatively correlated with pH. Our results suggest that calcareous soil neutralizes the acidity of released protons but does not affect cation exchange, inhibiting DOC in assisting the translocation of Cd within plants.

Screening for the Presence of Some Heavy Metals, Total Soluble Solids and Caffeine Contents in Some Energy Drinks Sold in Jordanian Market

Energy drinks (EDs) are beverages that are devoid of alcohol containing high amounts of caffeine and sugar. Energy drinks are available in the Jordanian market and consumed by Jordanian youth. There is no Jordanian standard for EDs. Establishing a standardization for a certain contaminant requires assessing the heavy metal content in the EDs available in the market. This research aimed to screen the 10 most consumed energy drinks sold in the Jordan market for total soluble solids, caffeine contents, and the presence of some heavy metals. This study, thus, will serve as an initial step for setting a standard for heavy metals in EDs in Jordan. The analyzed EDs didn’t contain detectable amounts of Pb. On the other hand, the analyzed samples contained 0.1 to 2.8, 1.8 to 6.5, 0.01, and 0.2 to 3.5 mg kg-1 Cu, Ni, Cd, and Fe respectively. The total soluble solids content of the studied samples ranged between 4.8 to 15.4 g/100 g. On the other hand, the caffeine content of the analyzed samples ranged between 24.7 to 32 mg/100 mL. It is recommended to establish a Jordanian standards specification for energy drinks including heavy metal, total dissolved solids, and caffeine.

DETERMINAÇÃO MULTIELEMENTAR EM AMOSTRAS DE BIODIESEL EMPREGANDO ESPECTROMETRIA DE FLUORESCÊNCIA DE RAIOS-X POR DISPERSÃO DE ENERGIA APÓS EXTRAÇÃO INDUZIDA POR QUEBRA DE EMULSÃO

MULTI-ELEMENT DETERMINATION IN BIODIESEL SAMPLES USING ENERGY DISPERSIVE X-RAY FLUORESCENCE SPECTROMETRY AFTER EXTRACTION INDUCED BY EMULSION BREAKING. A method for determining Cd, Cr, Cu, and Fe in biodiesel samples is proposed using energy dispersive X-ray fluorescence spectrometry (EDXRF) after extraction induced by emulsion breaking (EIEB). A volume of 7.0 mL of biodiesel and an aliquot of 500 µL of Triton X-100 solution (2%, v v-1) prepared in nitric acid were used to prepare the emulsion. After 5 min of manual agitation, phase separation was performed by centrifugation for 5 min at 2000 rpm. A 100 µL aliquot of the enriched aqueous phase was collected and applied to the center of a filter paper. After drying, the analysis was performed directly on the paper using EDXRF. The detection limits were 60, 20, 30, and 60 μg kg-1 for Cd, Cr, Cu, and Fe, respectively. Recovery tests were performed by adding 450 μg kg-1 of the analytes in biodiesel samples, and the results varied between 87 and 113%. The procedure was applied to biodiesel samples, and the concentrations obtained for the four analytes were compared with those obtained by inductively coupled plasma optical emission spectrometry (ICP OES) after sample digestion.

Physiological tolerance of black locust (Robinia pseudoacacia L.) and changes of rhizospheric bacterial communities in response to Cd and Pb in the contaminated soil.

Woody plants possess great potential for phytoremediation of heavy metal-contaminated soil. A pot trial was conducted to study growth, physiological response, and Cd and Pb uptake and distribution in black locust (Robinia pseudoacacia L.), as well as the rhizosphere bacterial communities in Cd and Pb co-contaminated soil. The results showed that R. pseudoacacia L. had strong physiological regulation ability in response to Cd and Pb stress in contaminated soil. The total chlorophyll, malondialdehyde (MDA), soluble protein, and sulfhydryl contents, as well as antioxidant enzymes (superoxide dismutase, peroxidase, catalase) activities in R. pseudoacacia L. leaves under the 40mg·kg-1 Cd and 1000mg·kg-1 Pb co-contaminated soil were slightly altered. Cd uptake in R. pseudoacacia L. roots and stems increased, while the Pb content in the shoots of R. pseudoacacia L. under the combined Cd and Pb treatments decreased in relative to that in the single Pb treatments. The bacterial α-diversity indices (e.g., Sobs, Shannon, Simpson, Ace, and Chao) of R. pseudoacacia L. rhizosphere soil under Cd and Pb stress were changed slightly relative to the CK treatment. However, Cd and Pb stress could significantly (p < 0.05) alter the rhizosphere soil microbial communities. According to heat map and LEfSe(Linear discriminant analysis Effect Size) analysis, Bacillus, Sphingomonas, Terrabacter, Roseiflexaceae, Paenibacillus, and Myxococcaceae at the genus level were notably (p < 0.05) accumulated in the Cd- and/or Pb-contaminated soil. Furthermore, the MDA content was notably (p < 0.05) negatively correlated with the relative abundances of Isosphaeraceae, Gaiellales, and Gemmatimonas. The total biomass of R. pseudoacacia L. was positively (p < 0.05) correlated with the relative abundances of Xanthobacteraceae and Vicinamibacreraceae. Network analysis showed that Cd and Pb combined stress might enhance the modularization of bacterial networks in the R. pseudoacacia L. rhizosphere soil. Thus, the assembly of the soil bacterial communities in R. pseudoacacia L. rhizosphere may improve the tolerance of plants in response to Cd and/or Pb stress.

Influence of heavy metal ions and storage time on hydroxymethylfurfural formation in honey collected from Ilu Woreda, Oromia Regional State, Ethiopia

The effect of heavy metals on the formation of hydroxymethyl furfural (HMF) from degradation of reducing sugars in honey collected from Ilu Woreda, West Shewa Zone of Oromia Regional State, Ethiopia were studied. The concentration level of Pb, Cd, Cr and Ni in honey sample was determined using AOAC Official Method. The concentration of HMF in honey was determined using international honey commission standards. The concentrations of heavy metals in fresh honey were 11 ± 0.001, 454 ± 0.002, 630 ± 0.001 and 1 ± 0.001 µg kg-1 for Pb, Cr, Ni and Cd, respectively. The influence of heavy metals on the formation of HMF in honey samples was studied on 5, 30 and 60 days after spiking at concentration level of 10,000 µg kg-1 of each heavy metal. The concentration of HMF for untreated honey samples was ranged 1380-2200 µg kg-1 for the storage time of 5, 30 and 60 days. The concentration of HMF in honey samples spiked with Pb, Ni, Cr and Cd were found to be in the range of 2100-2150, 1900-2430, 2100-2270 and 2050-2330 µg kg-1, respectively. The results of this study indicate that contamination of honey with heavy metal facilitate the formation of HMF.&#x0D; KEY WORDS: Fresh honey, HMF, Heavy metal ions, HPLC-DAD and Honey quality&#x0D; Bull. Chem. Soc. Ethiop. 2024, 38(1), 1-10. DOI: https://dx.doi.org/10.4314/bcse.v38i1.1

United States Grown and Imported Rice on Sale in Las Vegas: Metal(loid)s Composition and Geographic Origin Discrimination.

Concentrations of metal(loid)s, Ag, Al, As, Cd, Co, Cr, Cu, Fe, Mn, Ni, Se, Sr, V and Zn, were determined in rice on sale in Las Vegas. The rice samples were grown in five different countries, the USA, Thailand, India, Pakistan, and Bangladesh. The elemental concentrations in rice grain were determined using inductively coupled plasma mass spectrometry (ICP-MS) following hot block-assisted digestion. The accuracy of the laboratory procedure was verified by the analysis of rice flour standard reference material (NIST SRM 1568b). The mean metal(loid) contents in rice of various geographic origins were 3.18-5.91 mg kg-1 for Al, 0.05-0.12 mg kg-1 for As, 3.64-41 μg kg-1 for Cd, 5.11-12 μg kg-1 for Co, 0.12-0.14 mg kg-1 for Cr, 1.5-1.91 mg kg-1 for Cu, 3.04-4.98 mg kg-1 for Fe, 4.2-10.4 mg kg-1 for Mn, 0.21-0.41 mg kg-1 for Ni, 0.02-0.07 mg kg-1 for Se, 0.68-0.88 mg kg-1 for Sr, 3.64-5.26 μg kg-1 for V, and 16.6-19.9 mg kg-1 for Zn. respectively. The mean concentration of As in US rice was significantly higher than in Indian, Pakistani, and Bangladeshi rice. On the other hand, it was found a significantly low mean level of Cd in US-grown rice. It was also found that the concentrations of metal(loid)s in black and brown rice on sale in Las Vegas were statistically similar, except for Mn and Se. The geographic origin traceability of rice grain involved the use of ICP-MS analysis coupled with chemometrics that allowed their differentiation based on the rice metal(loid) profile, thus confirming their origins. Data were processed by linear discriminant analysis, and US and Thai rice samples were cross-validated with higher accuracy (100%). This authentication quickly discriminates US rice from the other regions and adds verifiable food safety measures for consumers.

Interaction and Transport Characteristics of Lead and Cadmium in Different Soil-wheat Systems

In this study, four groups of lead(Pb) and cadmium(Cd) combined treatments with different concentration ratios were set up in Hailun black soil, Xianning brown-red soil, and Changwu Heilu soil, and wheat(Zhengmai 9023) was planted for a five-month pot experiment to analyze the Pb-Cd interaction behavior on heavy metal bioaccumulation in wheat under three soil-wheat systems. The low pH brown-red soil had the highest water-soluble Cd and Pb contents with significant Pb-Cd interactions in the soil, whereas the black soil with high organic matter and Heilu soil with high calcium carbonate content exhibited lower Cd and Pb activities. Among the three soils, wheat height and dry weight showed the poorest growth performance in the Heilu soil, but the wheat height increased by 2.68-8.49 cm compared with that in the control under the Pb-Cd combined treatment, whereas Pb-Cd interaction had the least effect on wheat height and dry weight in black soil and inhibited the growth of wheat in the brown-red soil. In the transport process of Cd or Pb in wheat, Pb-Cd interaction showed quite different effects in the three soil-wheat systems. Under the 125 mg·kg-1 and 250 mg·kg-1 Pb treatments, the Pb content in wheat grain planted in brown-red soil significantly increased by 73.2% and 19.1% with the addition of Cd, respectively, and therefore there was a synergistic effect between Pb and Cd. Under the 0.3 mg·kg-1 and 0.6 mg·kg-1 Cd treatments, the Cd content in wheat grains planted in black soil decreased by 51% and 33% with the addition of Pb, respectively; therefore, there was an antagonist effect between Pb and Cd. In the Heilu soil, a synergistic effect of Cd on Pb transport in wheat leaves was only observed under high Pb treatment. Therefore, pH and organic matter content were the key factors that determined the interaction behavior of Pb and Cd. The wheat food security risk of Pb and Cd combined pollution was higher than that of single metal pollution in acidic brown-red soil and lower in high organic matter black soil, whereas the interaction of Pb and Cd had little impact on the wheat food security risk of alkaline Heilu soil.