Source Of Cadmium Research Articles

Preparation of water-soluble CdSeS alloy quantum dots with small particle size and high fluorescence lifetime by using hydrodynamic cavitation technology and their application in Ag+ detection

In this study, hydrodynamic cavitation (HC) is used as a novel and simple large-scale preparation technique. Water-soluble CdSeS alloy quantum dots (QDs) were successfully prepared by using Cd(NO3)2·4H2O, Na2S·9H2O and selenium powder as cadmium, sulfur and selenium sources. The effects of cycle time, reaction temperature, inlet pressure and Se/S molar ratio on the morphology, size and optical properties of CdSeS QDs were investigated. The prepared CdSeS QDs were characterized by X-ray diffractometer, X-ray photoelectron spectroscopy, transmission electron microscopy, UV–vis absorption spectra, fluorescence emission spectra and fluorescence attenuation curves. Finally, under the conditions of 12 h cycle time, 3.0 bar inlet pressure, 60 °C reaction temperature and 0.5/0.5 Se/S molar ratio, the ternary alloy CdSeS QDs with 2.62 nm average particle size and 482.62 ns fluorescence lifetime was obtained. Furthermore, a mechanism of preparing CdSeS QDs by using the HC method was proposed to explain the process of CdSeS precipitates conversion to CdSeS QDs. In addition, it is also found that Ag+ has a quenching effect on the prepared CdSeS QDs, which means that CdSeS QDs can be used as a fluorescence probe to specifically detect Ag+. This work not only provides a new possibility for large-scale preparation of high-performance QDs but also helps to understand the mechanism of CdSeS QDs as a metal ion selective fluorescence probe.

Soil application of FeCl3 and Fe2(SO4)3 reduced grain cadmium concentration in Polish wheat (Triticum polonicum L.)

BackgroundWheat is one of major sources of human cadmium (Cd) intake. Reducing the grain Cd concentrations in wheat is urgently required to ensure food security and human health. In this study, we performed a field experiment at Wenjiang experimental field of Sichuan Agricultural University (Chengdu, China) to reveal the effects of FeCl3 and Fe2(SO4)3 on reducing grain Cd concentrations in dwarf Polish wheat (Triticum polonicum L., 2n = 4x = 28, AABB).ResultsSoil application of FeCl3 and Fe2(SO4)3 (0.04 M Fe3+/m2) significantly reduced grain Cd concentration in DPW at maturity by 19.04% and 33.33%, respectively. They did not reduce Cd uptake or root-to-shoot Cd translocation, but increased Cd distribution in lower leaves, lower internodes, and glumes. Meanwhile, application of FeCl3 and Fe2(SO4)3 up-regulated the expression of TpNRAMP5, TpNRAMP2 and TpYSL15 in roots, and TpYSL15 and TpZIP3 in shoots; they also downregulated the expression of TpZIP1 and TpZIP3 in roots, and TpIRT1 and TpNRAMP5 in shoots.ConclusionsThe reduction in grain Cd concentration caused by application of FeCl3 and Fe2(SO4)3 was resulted from changes in shoot Cd distribution via regulating the expression of some metal transporter genes. Overall, this study reports the physiological pathways of soil applied Fe fertilizer on grain Cd concentration in wheat, suggests a strategy for reducing grain Cd concentration by altering shoot Cd distribution.

The metal tolerance protein OsMTP11 facilitates cadmium sequestration in the vacuoles of leaf vascular cells for restricting its translocation into rice grains

Rice (Oryza sativa) provides >20% of the consumed calories in the human diet. However, rice is also a leading source of dietary cadmium (Cd) that seriously threatens human health. Deciphering the genetic network that underlies the grain-Cd accumulation will benefit the development of low-Cd rice and mitigate the effects of Cd accumulation in the rice grain. In this study, we identified a QTL gene, OsCS1, which is allelic to OsMTP11 and encodes a protein sequestering Cd in the leaf during vegetative growth and preventing Cd from being translocated to the grain after heading in rice. OsCS1 is predominantly expressed in leaf vascular parenchyma cells, where it binds to a vacuole-sorting receptor protein OsVSR2 and is translocated intracellularly from the trans-Golgi network to pre-vacuolar compartments and then to the vacuole. In this trafficking process, OsCS1 actively transports Cd into the endomembrane system and sequesters it in the vacuoles. There are natural variations in the promoter of OsCS1 between the indica and japonica rice subspecies. Duplication of a G-box-like motif in the promoter region of the superior allele of OsCS1 from indica rice enhances the binding of the transcription factor OsIRO2 to the OsCS1 promoter, thereby promoting OsCS1 expression. Introgression of this allele into commercial rice varieties could significantly lower grain-Cd levels compared to the inferior allele present in japonica rice. Collectively, our findings offer new insights into the genetic control of leaf-to-grain Cd translocation and provide a novel gene and its superior allele for the genetic improvement of low-Cd variety in rice.

A Systematic Review on Phytoremediation of Cadmium-Contaminated Soils: Identifying Hyperaccumulator Plants, Assessing Soil Quality, Analyzing Contamination Sources and Determining Health Risks

Cadmium is a highly toxic heavy metal found in soils due to various anthropogenic and natural sources, posing significant environmental and health risks. This systematic review aimed to identify plant species that can effectively accumulate cadmium, assess soil quality and contamination sources in cadmium- affected areas, and evaluate potential health risks within affected communities. Relevant studies and articles were methodically selected from databases such as PubMed, Science Direct, Google Scholar, Research Gate, and Zendy, following Prisma Guidelines. The reviewed studies, both local and international, were published after 2000. The review found that several plant species can accumulate high levels of cadmium, with Athyrium wardii (Hook.) (Makino) achieving a 55% removal rate, Linum usitatissimum L. (Flax) achieving 32-49% removal, and T. caerulescens (Alpine Pennycress) achieving 19-36% removal. These plants showed the highest cadmium concentrations in their roots, followed by stems and leaves. Anthropogenic sources of cadmium in farm soil include agricultural activities and emissions from fuel combustion, with petrochemical industries significantly contributing through oil and gas flares, leading to elevated levels of nickel and cadmium. The review highlighted that higher cadmium accumulation poses substantial health risks, with risk concentrations higher in agricultural lands than in urban areas, implying a higher carcinogenic risk for people in these regions.

Uptake and translocation of cadmium and trace metals in common rice varieties at different growth stages.

Rice (Oryza sativa) is an important nutritional grain for the majority of Asian countries, but it is also a major source of cadmium (Cd) accumulation. A pot experiment was carried out to investigate the Cd uptake and translocation of high Cd (IR-50) and low Cd (White Ponni) rice cultivars in Cd-contaminated soils. The findings revealed that Cd impacts on rice development and growth differed depending on rice cultivars. Soil Cd levels in the seedling stage exceeded the critical levels (3-6mgkg-1) only 5.0mgkg-1 Cd treatment for the IR-50 (7.47mgkg-1). At higher Cd treatments (1.0 and 5.0mgkg-1), morphometric characteristics and yield of grains showed a declining and increasing trend in both rice varieties, respectively. The accumulation of Cd was higher in soil and roots during seedling and tillering stages, whereas in booting and maturity stages increased in stems and leaves in IR-50 and WP rice varieties. Cd levels in rice grains above the maximum allowable limit (0.4mgkg-1) only in IR-50 (0.51mgkg-1) rice cultivar at maturity stage. The EF of Cd were classified as minor enrichment to 'moderate enrichment' in both rice cultivars. TF values exhibited > 1 in booting and maturity stages in both rice cultivars at higher Cd treatments. The study concluded that the IR-50 rice variety exhibited increased Cd intake and transported to various parts of rice plants, particularly grains. The findings indicate that WP rice cultivar is more resistant to Cd toxicity, reducing health hazards for persons who preferred the staple food rice.

Design of rice with low cadmium accumulation in grain using single segment substitution line

Rice (Oryza sativa L.) is a major dietary source of cadmium (Cd). Developing rice varieties with reduced Cd levels in the grain is a cost-effective and practical approach to enhance food safety, particularly in regions with high Cd contamination. However, the genetic mechanisms underlying Cd accumulation in rice grains are not fully understood. In this study, we identified eight quantitative trait loci (QTLs) associated with Cd accumulation in rice grains through substitution mapping using single segment substitution lines (SSSLs). These QTLs, named qCd‐2‐1, qCd‐3‐1, qCd‐3‐2, qCd‐5‐1, qCd‐6‐1, qCd‐7‐1, qCd‐8‐1, and qCd‐11‐1, are distributed across seven chromosomes. Notably, the qCd‐5‐1 and qCd‐6‐1 loci are reported for the first time. We performed a detailed haplotype analysis of candidate genes related to heavy metal metabolism, specifically focusing on Cd accumulation. All SSSLs carrying alleles from donor parents exhibited a significant reduction in Cd accumulation, with additive effects ranging from −0.061 to −0.105. To further develop rice varieties with lower Cd accumulation in the grain, we developed six pyramided lines through crossing and marker-assisted selection. These pyramided lines showed significantly reduced Cd content in the grain compared to the elite indica recurrent parent, Huajingxian74 (HJX74). Importantly, most agronomic characteristics of the pyramided lines were similar to those of HJX74. In conclusion, this study demonstrates that identifying and pyramiding QTLs associated with reduced Cd accumulation is an effective strategy for developing rice varieties with lower Cd content in the grain.

Associations of environmental cadmium exposure with kidney damage: Exploring mediating DNA methylation sites in Chinese adults

Environmental exposure is widely recognized as the primary sources of Cadmium (Cd) in the human body, and exposure to Cd is associated with kidney damage in adults. Nevertheless, the role of DNA methylation in Cd-induced kidney damage remains unclear. This study aimed to investigate the epigenome-wide association of environmental Cd-related DNA methylation changes with kidney damage. We included 300 non-smoking adults from the China in 2019. DNA methylation profiles were measured with Illumina Infinium MethylationEPIC BeadChip array. Linear mixed-effect model was employed to estimate the effects of urinary Cd with DNA methylation. Differentially methylated positions (DMPs) associated with urinary Cd were then tested for the association with kidney damage indicators. The mediation analysis was further applied to explore the potential DNA methylation based mediators. The prediction model was developed using a logistic regression model, and used 1000 bootstrap resampling for the internal validation. We identified 27 Cd-related DMPs mapped to 20 genes after the adjustment of false-discovery-rate for multiple testing among non-smoking adults. 17 DMPs were found to be associated with both urinary Cd and kidney damage, and 14 of these DMPs were newly identified within the Chinese. Mediation analysis revealed that DNA methylation of cg26907612 and cg16848624 mediated the Cd-related reduced kidney damage. In addition, ten variables were selected using the LASSO regression analysis and were utilized to develop the prediction model. It found that the nomogram model predicted the risk of kidney damage caused by environmental Cd with a corrected C-index of 0.779. Our findings revealed novel DMPs associated with both environmental Cd exposure and kidney damage among non-smoking adults, and developed an easy-to-use nomogram-illustrated model using these novel DMPs. These findings could provide a theoretical basis for formulating prevention and control strategies for kidney damage from the perspective of environmental pollution and epigenetic regulation.

Revealing the Sources of Cadmium in Rice Plants under Pot and Field Conditions from Its Isotopic Fractionation.

The highly excessive uptake of cadmium (Cd) by rice plants is well known, but the transfer pathway and mechanism of Cd in the paddy system remain poorly understood. Herein, pot experiments and field investigation were systematically carried out for the first time to assess the phytoavailability of Cd and fingerprint its transfer pathway in the paddy system under different treatments (slaked lime and biochar amendments), with the aid of a pioneering Cd isotopic technique. Results unveiled that no obvious differences were displayed in the δ114/110Cd of Ca(NO3)2-extractable and acid-soluble fractions among different treatments in pot experiments, while the δ114/110Cd of the water-soluble fraction varied considerably from -0.88 to -0.27%, similar to those observed in whole rice plant [Δ114/110Cdplant-water ≈ 0 (-0.06 to -0.03%)]. It indicates that the water-soluble fraction is likely the main source of phytoavailable Cd, which further contributes to its bioaccumulation in paddy systems. However, Δ114/110Cdplant-water found in field conditions (-0.39 ± 0.05%) was quite different from those observed in pot experiments, mostly owing to additional contribution derived from atmospheric deposition. All these findings demonstrate that the precise Cd isotopic compositions can provide robust and reliable evidence to reveal different transfer pathways of Cd and its phytoavailability in paddy systems.

Ultralong Nanowires of Cadmium Phosphate Hydroxide Synthesized Using a Cadmium Oleate Precursor Hydrothermal Method and Sulfidation Conversion to Ultralong CdS Nanowires.

Ultralong nanowires with ultrahigh aspect ratios exhibit high flexibility, and they are promising for applications in various fields. Herein, a cadmium oleate precursor hydrothermal method is developed for the synthesis of ultralong nanowires of cadmium phosphate hydroxide. In this method, water-soluble cadmium salt is used as the cadmium source, water-soluble phosphate is used as the phosphorus source, and sodium oleate is adopted as a reactant to form cadmium oleate precursor and as a structure-directing agent. By using this method, ultralong nanowires of cadmium phosphate hydroxide are successfully synthesized using CdCl2, sodium oleate, and NaH2PO4 as reactants in an aqueous solution by hydrothermal treatment at 180 °C for 24 h. In addition, a new type of flexible fire-resistant inorganic paper with good electrical insulation performance is fabricated using ultralong nanowires of cadmium phosphate hydroxide. As an example of the extended application of this synthetic method, ultralong nanowires of cadmium phosphate hydroxide can be converted to ultralong CdS nanowires through a convenient sulfidation reaction. In this way, ultralong CdS nanowires are successfully synthesized by simple sulfidation of ultralong nanowires of cadmium phosphate hydroxide under mild conditions. The as-prepared ultralong nanowires of cadmium phosphate hydroxide are promising for applications as the precursors and templates for synthesizing other inorganic ultralong nanowires and have wide applications in various fields.

Effect of Cadmium on flag leaf morpho-physiological traits in three Mediterranean hulless barley varieties

In Morocco, the use of phosphate fertilizer in farming system represents a source of cadmium that accumulates in soil and would affect negatively the growth and yield. Cadmium toxicity decreases nutrients and water translocation and absorption, it leads to an increase in oxidative harm, affects the metabolism of plants, and inhibits plant morpho-physiology as well. This experiment was conducted to examine the impacts of various concentrations of Cd (0, 15, 30 mg leg-1) in the flag leaf of three hulless barley varieties: Assiya (Morocco), Tombari (Tunisia), and Gizal30 (Egypt). Several morpho-physiological parameters were measured at vegetative stage encompassing measurements like Flag leaf length (FLL), Flag leaf area (FLA), Flag leaf width (FLW), and Flag leaf dry weight (FLDW), water relative content (RWC), total chlorophyll content (SPAD), and Fluorescence (Fv/Fm). ANOVA analysis showed that all morphological traits (except for FLDW) were primarily affected by the variety effect (>62% of total variance). In contrast, the treatment of Cd largely influenced physiological traits (>90% of total variance). Moreover, the interaction between the two factors was in general of lower importance. Comparison among varieties showed significant differences for all traits. In fact, the Moroccan variety (Assiya) displayed the highest values for physiological and morphological parameters.

Effects of Reaction Temperature and Cadmium Source on the Optical, Morphological and Cytotoxic Properties of CdSe/ZnSe Quantum Dots

AbstractThe colloidal synthesis of CdSe/ZnSe core/shell quantum dots (QDs) under nitrogen gas flow is presented in this study. The optical, morphology and structural properties of CdSe/ZnSe core/shell QDs are varied by changing the growth temperature and the cadmium source (Cd2+). The Fourier transform infra‐red studies validate that CdSe/ZnSe QDs capped with functional −COOH groups were formed. The morphological and composition studies conducted using high resolution transmission microscope, selected area electron diffraction andenergy dispersive spectroscope confirmed the formation of pure and mono‐disperse QDs while photoluminescence and ultra‐violet visible spectroscopy displayed their improved fluorescent properties. Caco‐2 cell line was cultured from colon cancer and cytotoxic studies were conducted to test for cell viability of various capped 3‐MPA CdSe/ZnSe QDs at various concentrations. The formed CdSe/ZnSe QDs prominently bear the zinc‐blende structure with their particle size lying well below the Bohr excitation radii. Their hydrophilic nature and the availability of functional groups on the CdSe/ZnSe QDs makes them excellent potential labeling and therapeutic agents for the colon cancer disease diagnosis.

Manufacturing practices as potential sources of cadmium and other relevant metals in processed meat products. Risk and nutritional assessment

Processed meat products could constitute a relevant source of cadmium (Cd) and other toxic elements in the diet as they could contain organ meats (e.g. kidneys, liver) known to accumulate metals. Additionally, these products could be contaminated due to metal transfer from the machinery during processing and, in the case of canned meats, metal migration from the container could also occur. We analyzed Cd together with arsenic (As), chromium (Cr), copper (Cu), iron (Fe), nickel (Ni), lead (Pb), tin (Sn) and zinc (Zn) in heavily processed meat products from low, medium, and high-cost US supermarkets (n = 75). These elements were analyzed using inductively coupled plasma mass spectrometry (ICP-MS) and the results were expressed on a wet weight basis. The limits of detection (LOD) for the elements analyzed were: 2.8 μg/kg for As, 0.46 μg/kg for Cd, 2.3 μg/kg for Cr, 7.0 μg/kg for Cu, 41 μg/kg for Fe, 2.4 μg/kg for Ni, 0.83 μg/kg for Pb and 4.3 μg/kg for Sn and 5.6 μg/kg for Zn. Cd was detected in the vast majority of the samples presenting an overall median (IQR) concentration of 3.71 (2.10, 5.34) μg/kg. The products with the highest median Cd concentrations were beef franks and pork cheese sausages from the low-cost supermarket, while spam (from the low and medium-cost supermarkets) presented the lowest. The elements As, Sn and Pb were mainly undetectable. Cr and Ni were detected in most of the samples displaying overall median (IQR) concentrations of 18.39 (8.26, 36.18) μg/kg and 22.25 (12.66, 54.85) μg/kg, respectively. Cu, Fe and Zn were detectable in all the samples with overall median (IQR) concentrations of 312 (235, 493) μg/kg, 10.84 (7.36, 13.57) mg/kg and 13.73 (11.42, 18.12) mg/kg, respectively. Metal composition of these products does not evidence addition of organ meat nor Cd contamination during processing. Metal migration in canned meat (spam) is also unlikely. All processed meat samples presented metal concentrations below the maximum levels set by the Food and Agriculture Organization of the United Nations/World Health Organization (FAO/WHO) and the European Union (EU). The estimated Cd intake due to the consumption of these products represented a minimal percentage of the tolerable weekly intake (TWI). Processed meat products from the low and medium-cost supermarkets generally had higher levels of Cd and, in similar products, lower levels of Fe and Zn than those from the high-cost supermarket.

A hair-ball heterostructure of MnS-MnS2/CdS with compact linking interface for ultrasensitive photoelectrochemical bioanalysis of carcinoembryonic antigen

The heterostructured photoelectric material is supposed to markedly promote the photoelectrochemical (PEC) property. Herein, the species heterostructured MnS/CdS and MnS-MnS2/CdS(1∼2) composites derived from Mn-ZIF MOFs via a sulfofication reaction using Cd(NO3)2, CdC12 cadmium source, respectively. Under irradiation, the PEC tests showed that the photocurrent response of MnS-MnS2/CdS(1∼2) signally enhanced compared to globose MnS/CdS heterostructure and pure MnS or CdS. It was ascribed to the matching band-gap to form type II heterojunction in MnS-MnS2/CdS(1∼2) which dramatically facilitated photo-induced electron/hole (e−/h+) separation and transfer. The hair-ball morphologies structure of MnS-MnS2/CdS(1∼2) with large number of pores was beneficial to improve penetrating efficiency of the electrolyte liquid. Meanwhile, the well-synergistic effect on the MnS, MnS2, CdS components and with tight connecting heterojunction interface among MnS-MnS2/CdS(1∼2) which also led to violently photocurrent output. Besides, the chitosan (CS) was covalently coupled with glutaraldehyde (GLD) to obtain steady composite film, and the cross-linker of GLD can achieve the high efficiency to graft the Apt-CEA (aptamer) biomolecules, which resulting in the promotion of hybridization reaction efficiency of the CEA target. Hence, this created biosensor of Apt-CEA/GLD-CS/MnS-MnS2/CdS(1)/ITO for the CEA detection displayed a wide linear range from 0.001 to 18 ng mL−1 and with ultralow detection limit of 0.313 pg mL−1. This research innovatively prepared a contact heterojunction interface with special porosities structure, which had superior PEC nature for the fabrication of high-performance biosensor.

Design and simulation of a source of cold cadmium for atom interferometry

We present a novel optimised design for a source of cold atomic cadmium, compatible with continuous operation and potentially quantum degenerate gas production. The design is based on spatially segmenting the first and second-stages of cooling with the strong dipole-allowed 1S0-1P1 transition at 229 nm and the 326 nm 1S0-3P1 intercombination transition, respectively. Cooling at 229 nm operates on an effusive atomic beam and takes the form of a compact Zeeman slower (∼5 cm) and two-dimensional magneto-optical trap (MOT), both based on permanent magnets. This design allows for reduced interaction time with the photoionising 229 nm photons and produces a slow beam of atoms that can be directly loaded into a three-dimensional MOT using the intercombination transition. The efficiency of the above process is estimated across a broad range of experimentally feasible parameters via use of a Monte Carlo simulation, with loading rates up to 108 atoms s−1 into the 326 nm MOT possible with the oven at only 100 ∘C. The prospects for further cooling in a far-off-resonance optical-dipole trap and atomic launching in a moving optical lattice are also analysed, especially with reference to the deployment in a proposed dual-species cadmium-strontium atom interferometer.

Influence of dietary patterns on urinary excretion of cadmium in an Italian population: A cross-sectional study

IntroductionCadmium is a toxic heavy metal with detrimental effects on human health. Apart from smoking and occupational factors, diet is the main source of cadmium. However, the relation between adherence to so-called “healthy” dietary patterns and cadmium exposure has not been investigated in detail. In this study, we aimed at assessing such association in a Northern Italian population. MethodsUsing a cross-sectional study design, we investigated a population of non-smokers aged 30–60 years in the period 2017–2019. Each subject completed a validated food frequency questionnaire (FFQ) in order to estimate adherence to four dietary patterns, namely the Dietary Approach to Stopping Hypertension-DASH diet, Greek Mediterranean Index-GMI, the Italian Mediterranean Index-IMI, and the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet. We collected a fasting morning urinary sample to measure urinary levels of cadmium and cotinine. The association between increasing adherence to dietary patterns and cadmium exposure was evaluated using a cubic spline regression non-linear model and adjusting for relevant confounders (age, sex, body mass index, urinary cotinine levels, intake of fiber, and alcohol). ResultsWe recruited 137 participants (males/females: 62/75) with median (interquartile range-IQR) age of 47 (IQR: 43–53) years. Median scores for the investigated dietary patterns were 24 (IQR: 21–28), 4 (IQR: 3–6), 4 (IQR: 3–5), and 7.5 (IQR: 6.5–8.5) for DASH, GMI, IMI and MIND diets, respectively. The median urinary cadmium level was 0.21 μg/L (IQR: 0.11–0.34 μg/L). Spline regression analysis showed an inverse linear association between increasing adherence to the DASH and MIND diets and urinary cadmium levels, reaching a plateau at high adherence scores, approximately > 25 and > 9 for DASH and MIND diets, respectively. An increase of cadmium exposure with increasing MIND score also emerged. Conversely, the association was almost null for IMI, and slightly positive for GMI. ConclusionsThe present findings suggest that increasing adherence to the DASH and MIND diets are associated with decreased cadmium levels only at moderate level. Overall, these results indicate that public health strategies, including the decrease of cadmium contamination in healthy foods should be implemented.

Blood and Urinary Metal Levels among Exclusive Marijuana Users in NHANES (2005-2018).

Marijuana is the third most used drug in the world. Because the cannabis plant is a known scavenger of metals, we hypothesized that individuals who use marijuana will have higher metal biomarker levels compared with those who do not use. We combined data from the National Health and Nutrition Examination Survey (2005-2018) for participants, classified by use: non-marijuana/non-tobacco, exclusive marijuana, exclusive tobacco, and dual marijuana and tobacco use. Five metals were measured in blood and 16 in urine using inductively coupled plasma mass spectrometry; urinary metals were adjusted for urinary creatinine. Participants reporting exclusive marijuana use compared with non-marijuana/non-tobacco use had statistically significantly higher mean cadmium levels in blood [ (95% CI: 1.11, 1.34); ] and urine [ (95% CI: 1.0, 1.31); ] and statistically significantly higher mean lead levels in blood [ (95% CI: 1.07, 1.50); ] and urine [ (95% CI: , 1.50); ]. Our results suggest marijuana is a source of cadmium and lead exposure. Research regarding cannabis use and cannabis contaminants, particularly metals, should be conducted to address public health concerns related to the growing number of cannabis users. https://doi.org/10.1289/EHP12074.

Breastmilk cadmium levels and estimated infant exposure: a multicenter study of associated factors in a resource-limited country

BackgroundDespite the undisputed benefits of breastfeeding, infants might become exposed to xenobiotics that could be excreted into breast milk following maternal exposure. This study was conducted to assess breastmilk cadmium levels among lactating women in Palestine, a resource-limited country. Estimated daily intake (EDI) of cadmium via breastmilk was also calculated and predictors of high breastmilk cadmium levels and high infant exposure via breastmilk were identified.MethodsThis multicenter study was conducted using a descriptive-analytical design. The lactating women were recruited from different maternity and public health clinics in all regions of Palestine. Demographic variables and exposure to sources of cadmium were collected in an interviewer-administered questionnaire. Foremilk samples (about 5 mL) were collected in polyethylene tubes using the hand-expression technique. The breast milk samples were collected in the period between December 2020 and March 2021. A pre-validated method using inductively coupled plasma mass spectrometry (ICP-MS) was used to quantify breastmilk cadmium levels. EDI values were calculated from the quantified breastmilk cadmium levels.ResultsBreastmilk samples were obtained from 256 lactating women. The mean breastmilk cadmium level was 0.34 (SD: 0.33) μg / L and the mean EDI of cadmium via breastmilk was 0.059 (SD: 0.058) µg / kg per body weight / day. Breastmilk cadmium levels were quantified in 92.6% of the breastmilk samples. Of the breastmilk samples, 13 (5.1%) had cadmium levels above those reported as “normal” by the World Health Organization (WHO). Multiple linear regression showed that higher breastmilk cadmium levels and higher EDI were predicted by being a smoker, living in a refugee camp, living close to an industrial area, living close to disposal of wastes, living close to paint shops, living in a house with peeling / chipping paint, frequent use of cosmetics, frequent use of hair dyes, and not using vitamins.ConclusionThe breastmilk cadmium levels and infant exposure were predicted by maternal exposure to sources of cadmium. The findings reported in this study are valuable to antenatal and postnatal healthcare service providers. More studies are needed to plan and implement measures to reduce breastmilk cadmium levels and infants’ exposure to cadmium via breastmilk.

Evidences for the augmented Cd(II) biosorption by Cd(II) resistant strain Candida tropicalis XTA1874 from contaminated aqueous medium

Cadmium is one of the most dreadful heavy metals and is becoming a major toxicant in ground water with increasing concentration above the WHO Guidelines in drinking water (0.003 mg/L). The potential sources of cadmium include sewage sludge, phosphate fertilizers and ingredients like Ni–Cd batteries, pigments, plating and plastics. Cadmium levels are increased in water owing to the use and disposal of cadmium containing ingredients. Water draining from a landfill may contain higher cadmium levels. The authors have tried to evaluate the optimized nutritional conditions for the optimal growth and Cd(II) remediation capacity for a developed Cd(II) resistant yeast strain named Candida tropicalis XTA 1874 isolated from contaminated water-body in West Bengal. By analyzing the optimization conditions, a synthetic medium was developed and the composition has been given in the main text. The strain showed much better Cd(II) adsorption capacity under the optimized nutritional conditions (Mean removal = 88.077 ± 0.097%).

English

Heavy metal cycles in horticultural systems in areas supplying vegetables to Mbare Musika were characterized with reference to the soil, water, fertilizers used and crops grown from different ecological zones of Zimbabwe. Apart from inherent soil heavy metal properties, anthropogenic sources contributed through irrigation water and fertilizers. Different areas specialized in growing peculiar vegetables through influence of environmental traits within the horticultural system. The soil in Mutoko, Rusape and Seke had high levels of cadmium and lead unlike in other study areas. The water was a major source of cadmium, cobalt and lead. Most soils within the study area had an acidic pH noted to promote heavy metals solubility hence makes vegetables contamination inevitable. Irrigation water is the challenge in most of the study areas. Generally, soil pH, irrigation water quality and fertilizers need to be regulated together with other soil amendment programs to break the cycle of heavy metals in the horticultural systems. Key words:  Heavy metal, pH, cadmium, lead, maximum threshold, route, Mbare  Musika, horticultural system.

A vacuolar transporter plays important roles in zinc and cadmium accumulation in rice grain.

Rice grain is a poor dietary source of zinc (Zn) but the primary source of cadmium (Cd) for humans; however, the molecular mechanisms for their accumulation in rice grain remain incompletely understood. This study functionally characterized a tonoplast-localized transporter, OsMTP1. OsMTP1 was preferentially expressed in the roots, aleurone layer, and embryo of seeds. OsMTP1 knockout decreased Zn concentration in the root cell sap, roots, aleurone layer and embryo, and subsequently increased Zn concentration in shoots and polished rice (endosperm) without yield penalty. OsMTP1 haplotype analysis revealed elite alleles associated with increased Zn level in polished rice, mostly because of the decreased OsMTP1 transcripts. OsMTP1 expression in yeast enhanced Zn tolerance but did not affect that of Cd. While OsMTP1 knockout resulted in decreased uptake, translocation and accumulation of Cd in plant and rice grain, which could be attributed to the indirect effects of altered Zn accumulation. Our results suggest that rice OsMTP1 primarily functions as a tonoplast-localized transporter for sequestrating Zn into vacuole. OsMTP1 knockout elevated Zn concentration but prevented Cd deposition in polished rice without yield penalty. Thus, OsMTP1 is a candidate gene for enhancing Zn level and reducing Cd level in rice grains.