High Levels Of Cd Research Articles

Total contents, fractionation and bioaccessibility of nine heavy metals in household dust from 14 cities in China

The potential health risk caused by long-term exposure to heavy metals in household dust is not only depended on their total content, but also bioaccessibility. In this study, twenty-one dust samples were collected from residential buildings, schools, and laboratories in 14 provincial-capital/industrial cities of China, aiming to evaluate the total contents, fractionation, bioaccessibility and health risks of nine heavy metals (As, Cd, Cr, Ni, Pb, Mn, Zn, Fe, and Cu). Results showed that the highest levels of Cd, Cr, Ni and Zn were found in laboratory dust, As, Pb and Mn in school dust, and Fe and Cu in residential dust, indicating different source profiles of the heavy metals. The mean bioaccessibility of the heavy metals across all samples as evaluated using SBRC (Solubility Bioavailability Research Consortium), IVG (In Vitro Gastrointestinal), and PBET (Physiologically Based Extraction Test) assays was 58.4%, 32.4% and 17.2% in gastric phase (GP), and 24.9%, 21.9% and 9.39% in intestinal phase (IP), respectively. Cadmium had the highest content in the fractions of E1+C2 (43.7%), as determined by sequential extraction, and Pb, Mn, and Zn had a higher content in E1+C2+F3 (64.2%, 67.2%, 78.8%), resulting in a higher bioaccessibility of these heavy metals than others. Moreover, the bioaccessibility of most heavy metals was inversely related to dust pH (R = −0.18 in GP; −0.18 in IP; P < 0.01) and particle size, while a positive correlation was observed with total organic carbon (R = 0.40 in GP; 0.38 in IP; P < 0.01). The exposure risk calculated by the highest bioaccessibility was generally lower than that calculated by the total content. However, Pb in one school dust sample had an unacceptable carcinogenic risk (adult risk = 1.19 × 10−4; child risk = 1.08 × 10−4). This study suggests that bioaccessibility of heavy metals in household dust is likely related to geochemical fractions and physical/chemical properties. Further research is needed to explore the sources of bioaccessible heavy metals in household dust.

Effects of selenium on biogeochemical cycles of cadmium in rice from flooded paddy soil systems in the alluvial Indus Valley of Pakistan

This study delves into the pollution status, assesses the effects of Se on Cd biogeochemical pathways, and explores their interactions in nutrient-rich paddy soil-rice ecosystems through 500 soil-rice samples in Pakistan. The results showed that 99.6 % and 12.8 % of soil samples exceeded the World Health Organization (WHO) allowable Se and Cd levels (7 and 0.35 mg/kg). In comparison, 23 % and 6 % of the grain samples exceeded WHO's allowable Se and Cd levels (0.3 and 0.2 mg/kg), respectively. Geographically Weighted Regression (GWR) model results further revealed spatial nonstationarity, confirming diverse associations between dependent variables (Se and Cd in rice grain) and independent variables from paddy soil and plant tissues (root and shoot), such as Soil Organic Matter (SOM), pH, Se, and Cd concentrations. High Se:Cd molar ratios (>1) and a negative correlation (r = −0.16, p < 0.01) between the Cd translocation factor (Cd in rice grain/Cd in root) and Se in roots suggest that increased root Se levels inhibit the transfer of Cd from roots to grains. The inverse correlation between Se and Cd in paddy grains was further characterized as Se deficiency, no risk, high Cd risk, Se risk, Cd risk, and Se–Cd co-exposure risk. There was no apparent risk for human co-consumption in 42.6 % of grain samples with moderate Se and low Cd. The remaining categories indicate differing degrees of risk. In the study area, 31 % and 20 % of grain samples with low Se and Cd indicate Se deficiency and risk, respectively. High Se and low Cd levels in rice samples suggest a potential hazard for severe Se exposure due to frequent rice consumption. This study not only systematically evaluates the pollution status of paddy-soil systems in Pakistan but also provides a reference to thoroughly contemplate the development of a scientific approach for evaluating human risks and the potential dangers associated with paddy soils and rice, specifically in regions characterized by low Se and low Cd concentrations, as well as those with moderate Se and high Cd concentrations. SynopsisThis study is significant for understanding the effects of Se on Cd geochemical cycles and their interactions in paddy soil systems in Pakistan.

An endophytic fungus interacts with the defensin-like protein OsCAL1 to regulate cadmium allocation in rice

Defensin-like proteins are conserved in multicellular organisms and contribute to innate immune responses against fungal pathogens. In rice, defensins play a novel role in regulating cadmium (Cd) efflux from the cytosol. However, whether the antifungal activity of defensins correlates with Cd-efflux function remains unknown. In this study, we isolated an endophytic Fusarium, designed Fo10, by a comparative microbiome analysis of rice plants grown in a paddy contaminated with Cd. Fo10 is tolerant to high levels of Cd, but is sensitive to the defensin-like protein OsCAL1, which mediates Cd efflux to the apoplast. We found that Fo10 symbiosis in rice is regulated by OsCAL1 dynamics, and Fo10 coordinates multiple plant processes, including Cd uptake, vacuolar sequestration, efflux to the environment, and formation of Fe plaques in the rhizosphere. These processes are dependent on the salicylic acid signaling pathway to keep Cd levels low in the cytosol of rice cells and to decrease Cd levels in rice grains without any yield penalty. Fo10 also plays a role in Cd tolerance in the poaceous crop maize and wheat, but has no observed effects in the eudicot plants Arabidopsis and tomato. Taken together, these findings provide insights into the mechanistic basis underlying how a fungal endophyte and host plant interact to control Cd accumulation in host plants by adapting defense responses to promote the establishment of a symbiosis that permits adaptation to high-Cd environments.

A comparative study on the pollution status of heavy metals in soils and sediment from farmlands in Askira Uba, Nigeria

Heavy metals may enter the food chain from soil through mineralization by crops or environmental contamination, as in application of agricultural inputs such as pesticides and fertilizers or in the treatment of soils with sewage sludge cupper content of normal plant tissue. Atomic Absorption Spectroscopic (AAS) method is one of the most commonly used instrument in metal analysis due to its reproducibility of results, short analysis time, lower level of detection. Soil and sediments samples were collected at three distinct stations each, designated as A1, B1, C1 and A2, B2, C2 respectively from Askir/Uba local government area of Borno State, Nigeria. The concentrations of six heavy metals of environmental concern which includes Cd, Cu, Cr, Pb, Ni and Zn were determined by Atomic Absorption Spectrophotometer; Buck scientific model 210GP. The mean concentration of Cd in soil and sediment were (10.7±2.32 mg/kg and 9.62±2.32 mg/kg) and are of toxicological concern. The decrease in concentrations of the metals across sampling locations followed this order Cd &gt; Cu &gt; Cr &gt; Pb &gt; Ni &gt; Zn. The geoaccumulation index of the sediment by each metals are in the following increasing order: B2 &lt; A2 &lt; C2 for Cd and Pb, B2 &lt; C2 &lt; A2 for Cr, A2 &lt; B2 &lt; C2 for Cu, A2 &lt; B2 &lt; C2 for Zn respectively. In general, the order of metal contamination were Zn &lt; Ni &lt; Cu &lt; Pb &lt; Cr &lt; Cd. The results of the findings revealed that the soil and sediment were contaminated with Cadmium, the high level of Cd in the soil were above the recommended values. However, Independent-samples t-test (statically significant at p&lt;0.05) was used to compared the average metal composition in soil and sediment which showed that there was no significant difference on the composition in soil and sediment for all the metals p-value = 0.8939 The aim of the study was to compare the mean level of the soil and sediment with WHO permissible limit, hence evaluate their pollution status by the application of geoaccumulation index.

Roots recruited distinct rhizo-microbial communities to adapt to long-term Cd and As co-contaminated soil in wheat-maize rotation

Cd and As accumulation in staple crops poses potential risks to food safety and human health. Rhizo-microbial communities are involved in their behaviors from soil to crops. However, the responses of rhizo-microbial communities to different Cd and As co-contaminated soils in wheat‒maize rotation are still unclear. This study explored whether wheat or maize could recruit distinct rhizo-microbial communities to adapt to long-term co-contaminated soils with low or high levels of Cd and As (LS or HS). It was apparent that the average wheat grain-Cd/As concentrations were 17.96-fold/4.81-fold in LS and 5.64-fold/7.70-fold in HS higher than those in maize grains, significantly depending on the mobility of Cd/As in soil–crop system, especially from soil to root and from straw to grain. Meanwhile, wheat or maize roots recruited specific bacteria and fungi in LS and HS, which were substantially associated with Cd/As bioavailability in rhizosphere. Wheat roots recruited specific bacterial genera norank_c__MB-A2-108 (Actinobacteria), norank_f__JG30-KF-CM45 (Chloroflexi), and norank_o__Rokubacteriales (Methylomirabilota) and fungal genera Metarhizium and Olpidium under HS, and their relative abundances were positively correlated with soil Cd/As bioavailability and were resistant to Cd and As co-contamination. However, bacterial genera Arthrobacter, Nocardioides, Devosia, Skermanella, and Pedobacter were sensitive to Cd and As co-contamination and were specifically enriched in wheat rhizospheres under LS. Meanwhile, the bacterial genus norank_c__KD4-96 (Chloroflexi) was resistant to Cd and As co-contamination under HS and was distinctly enriched in maize rhizosphere. Furthermore, the roots of wheat and maize recruited the bacterial genus Marmoricola in LS, which was sensitive to Cd and As co-contamination, and recruited specific fungal genus Fusicolla in HS, which was tolerant to Cd and As co-contamination. These results confirmed that HS and LS shifted the composition and structure of the rhizo-microbial communities in the wheat-maize rotation to promote crops survival in different long-term Cd and As co-contaminated soils.

Elemental profiling of red seaweed Neopyropia yezoensis used in fast authenticating the geographical origin and food safety assessment

The red seaweed Neopyropia yezoensis is one of the predominant seaweeds cultivated and consumed in China. Its quality characteristics and economic value are closely influenced by the environmental conditions. So developing a fast method to trace the geographical origins of N. yezoensis is urgent because it concerns consumers knowing the origin of the product, nutritional value and safety. In present work, the elemental profiling in a total of 132 subsamples of N. yezoensis collected from five areas along the eastern and northern coast of China was established. Results showed that the content of K was the highest among the analyzed elements, and the Na/K ratio in N. yezoensis was 0.37. The consumption of N. yezoensis was confirmed to be a good source of essential dietary elements. However, high levels of Cd must attract consumers’ attention, because about 20.5% of the samples was not compliant with the current European regulations. The influence of the geographical origin have a great difference on element profile. The linear discriminant analysis (LDA) with the stepwise method showed that the samples from Liaoning Province and Shandong Province could be well distinguished from those from Jiangsu Province. Based on the leave-one-out cross-validation method, the predictive ability was 80.3%, indicating a good performance of elemental fingerprints in fast authenticating of the origin of N. yezoensis in China. This discrimination made it possible to simultaneously characterize the samples according to their nutritional value and human consumption safety levels.

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.

Does cadmium cause cascading effects on the development and reproduction of the striped stem borer, Chilo suppressalis (Walker)?

The heavy metal, cadmium (Cd), causing growth retardation and yield reduction on rice and impacting the fitness of organisms inhabiting on rice through bottom-up effects, has become a great challenge to rice production. However, the effect of Cd-exposure on the development of an economically important and destructive rice pest, Chilo suppressalis remains unexplored. By exposing the larvae of C. suppressalis to different Cd-exposed artificial diets (0, 0.2, 1.0, 2.5, 5.0, and 10.0 mg/kg), we found that Cd exposure did not affect the larval duration or pupation rate of C. suppressalis, but caused negative effects on pupal weight at high Cd levels (5.0 and 10.0 mg/kg) and on adult deformity rate from 2.5 and 5.0 mg/kg treatments. Although Cd significantly increased the female pupae ratio, C. suppressalis did not oviposit when Cd treatment was more than 2.5 mg/kg. Meanwhile, Cd transferred to pupae, females, exuviae of pupa and eggs of C. suppressalis from Cd treated larvae, and exhibited a dose-dependent response on Cd accumulation. Our results indicated that Cd had a negative effect on rice stem borer and can be transferred to eggs of C. suppressalis, but more work is needed to further assess the bottom-up effect on third tropic levels in Cd-polluted fields.

Environmental concentrations of cadmium and zinc and associating metabolomics profile alternations in urine of pregnant women in the first trimester: A prospective cohort study in Taiyuan, North China

especially to pregnant women. In recent years, zinc (Zn) supplementation has attracted increasing attention among pregnant women. Thus, understanding the effects and interactions of Cd and Zn in pregnant women is critical. This study aimed to assess the urinary levels of Cd and Zn in pregnant women during early pregnancy, examine associated alterations in urine metabolomics, and identify potential metabolic biomarkers among distinct Cd and Zn groups. Urine samples from 185 pregnant women were collected, and inductively coupled plasma mass spectrometry (ICP-MS) was used to detect Cd and Zn contents. The women were then divided into four groups according to median contents of Cd and Zn. Alterations in the metabolite profile were assessed using a liquid chromatograph mass spectrometer (LC-MS). The results showed that the gravidity of pregnant women was closely related to urinary Cd levels and that the urinary Zn contents of pregnant women with morning sickness in the first trimester were lower than that of non-morning-sick pregnant women. A total of 51 metabolites exhibited significant differential expression in the high level of Cd and Zn (HCdHZn) compared with low level of Cd and Zn (LCdLZn), the diagnostic performance of these 51 metabolites were assessed using receiver operating characteristic curve analysis and revealed that octadecylamine was a promising diagnostic indicator for evaluating the combined effects of Zn and Cd. Metabolomics analysis showed that the arginine and proline pathways were upregulated in HCdHZn compared with that in LCdLZn, suggesting a potential risk of obesity. Although higer levels of bovinic acid in HCdHZn vs. HCdLZn (high level of Cd and low level of Zn) indicated that Zn has antioxidant and anti-inflammatory properties, excessive Zn may still cause harmful effect to the human health and should be supplemented with caution. The study findings may be valuable for potential risk ahissessment of the combined effects of Cd-Zn and their interactions in pregnant women.

Co-occurrence of toxic metals, bacterial communities and metal resistance genes in coastal sediments from Bohai bay

Sediment heavy metal contamination poses substantial risks to microbial community composition and functional gene distribution. Bohai Bay (BHB), the second-largest bay in the Bohai Sea, is subject to severe anthropogenic pollution. However, to date, there have been no studies conducted to evaluate the distribution of metal resistance genes (MRGs) and bacterial communities in the coastal sediments of BHB. In this study, we employed high-throughput sequencing based on 16S rRNA genes and real-time quantitative PCR (qPCR) to provide a comprehensive view of toxic metals, MRGs, and bacterial communities in BHB's coastal sediment samples across two seasons. We detected high levels of Cd in the summer samples and As in the autumn samples. The metal content in most autumn samples and all summer samples, based on ecological indices, indicated low ecological risk. Proteobacteria dominated all samples, followed by Desulfobacterota, Bacteroidota and Campilobacterota. Bacterial community variability was higher between autumn sampling sites but more stable in summer. We detected 9 MRG subtypes in all samples, with abundances ranging from 4.58 × 10−1 to 2.25 copies/16S rRNA copies. arsB exhibited the highest relative abundance, followed by acr3, czcA and arrA. The efflux mechanism is a common mechanism for sediment resistance to metal stress in Bohai Bay. Procrustes analysis indicated that bacterial community composition may be a determinant of MRGs composition in BHB sediments. Network analysis suggested that eight classes could be potential hosts for six MRGs. However, this type of correlation requires further validation. To summarize, our study offers preliminary insights into bacterial community and MRG distribution patterns in heavy metal-exposed sediments, laying the groundwork for understanding microbial community adaptations in multi-metal polluted environments and supporting ecological restoration efforts.

Exploring the association of metal mixture in blood to the kidney function and tumor necrosis factor alpha using machine learning methods

This research aimed to approach relationships between metal mixture in blood and kidney function, tumor necrosis factor alpha (TNF-α) by machine learning. Metals levels were measured by Inductively Couple Plasma Mass Spectrometry in blood from 421 participants. We applied K Nearest Neighbor (KNN), Naive Bayes classifier (NB), Support Vector Machines (SVM), random forest (RF), Gradient Boosting Decision Tree (GBDT), Categorical boosting (CatBoost), eXtreme Gradient Boosting (XGBoost), Whale Optimization-based XGBoost (WXGBoost) to identify the effect of plasma metals, TNF-α, and estimated glomerular filtration rate (eGFR by CKD-EPI equation). We conducted not only toxic metals, lead (Pb), arsenic (As), cadmium (Cd) but also included trace essential metals, selenium (Se), copper (Cu), zinc (Zn), cobalt (Co), to predict the interaction of TNF-α, TNF-α/white blood count, and eGFR. The high average TNF-α level group was observed among subjects with higher Pb, As, Cd, Cu, and Zn levels in blood. No associations were shown between the low and high TNF-α level group in blood Se and Co levels. Those with lower eGFR group had high Pb, As, Cd, Co, Cu, and Zn levels. The crucial predictor of TNF-α level in metals was blood Pb, and then Cd, As, Cu, Se, Zn and Co. The machine learning revealed that As was the major role among predictors of eGFR after feature selection. The levels of kidney function and TNF-α were modified by co-exposure metals. We were able to acquire highest accuracy of over 85% in the multi-metals exposure model. The higher Pb and Zn levels had strongest interaction with declined eGFR. In addition, As and Cd had synergistic with prediction model of TNF-α. We explored the potential of machine learning approaches for predicting health outcomes with multi-metal exposure. XGBoost model added SHAP could give an explicit explanation of individualized and precision risk prediction and insight of the interaction of key features in the multi-metal exposure.

Metal concentrations in the whole blood of farmers in southeast Brazil

In this study, we measured Ni, Co, Cd, and Pb concentrations in the whole blood of farmers from southeast Brazil to address the factors influencing human exposure in this population. The factors included smoking, alcohol consumption, aging, body composition, gender, and feeding preferences, which were measured through carbon and nitrogen isotopic composition. We also calculated and compared the reference values (RVs) of the measured elements to evaluate ongoing exposure levels. We observed the influence of lifestyle habits on metal exposure; Cd levels were statistically higher in smokers, and alcohol consumption affected only Pb concentrations, with an association also observed with the frequency of alcohol ingestion. The metal levels were positively associated with both isotope values, indicating that feeding may be the dominant source of these elements in this population. We also observed the effect of endogenous sources measured through age, as increased Pb concentrations in both genders and higher Cd levels in older women, which is related to bone, kidney, and liver accumulation. The body mass index was negatively associated with Ni, Co, and Cd in women and positively in men. The negative associations may indicate that body fat may act as a reservoir for metals, reducing their availability in the blood in individuals with higher body mass and possibly influencing the assessment of exposure levels. The evaluated population presented elevated RVs for all elements: Ni 36, Co 3.3, Cd 16, and Pb 149 μg L−1. These values point to higher exposure in this population compared to other studies in Brazil and worldwide. These results emphasize an urgent need for monitoring programs for toxic substances in Brazil and evaluating possible health effects, given the ongoing environmental exposure associated with endogenous exposure and lifestyle habits that promote higher metal levels in this population.

Cadmium contamination in cacao farms of Piura, North Peru: A comprehensive assessment of geogenic and anthropogenic sources and implications for future production

Cadmium (Cd) is a heavy metal that poses a threat to food safety via the ingestion of food products with Cd. The uptake of Cd by the cacao tree (Theobroma cacao) has gained attention after the European Union set limits for Cd in chocolate products, the main commodity produced from cacao beans. In this study, we analyzed levels of Cd in soils and plant tissues across five cacao farms in the Piura region of Peru to identify the origins of Cd accumulation, and the natural and human factors controlling its concentration. Our results show that Cd levels varied in the order: leaves (1.25 mg kg−1) > beans (0.78 mg kg−1) > soils at 5 cm (0.68 mg kg−1) > soils at 20 cm (0.6 mg kg−1). Our findings suggest that the higher concentration of Cd in plant tissues and surface soils can be explained by readily available Cd from fertilizers and a litter layer being absorbed, cycled, and accumulated by the plant. Moreover, even when fertilizers are within regulatory limits, their continuous application, combined with the biocycling of Cd, may lead to high Cd concentrations in beans and leaves. Conversely, farms on alluvial soils and more stable topographic positions display higher soil and plant Cd concentrations. Likewise, farms located at lower altitudes, with higher contributing areas are more likely to receive Cd transported through sediments and water in the river network. Our results also suggest that variations in the underlying geology and soil mineralogy may be a source of potentially Cd bearing sediments. Overall, this study indicates that the high levels of Cd in plants in the study area are the result of a combined mechanism involving plant bioaccumulation and high Cd in fertilizers for the most part, with a minor contribution from potential Cd bearing minerals in sediments of alluvial soils.

Effects of Cadmium Toxicity on Chemical Contents and Leaf Yield of Three Sun-Cured Tobacco Varieties

ABSTRACT Tobacco plants grown in cadmium (Cd)-contaminated soils accumulate high concentration of Cd in leaves and the Cd in leaves can readily be transferred to the human body through smoking of cigarettes. This study was conducted to investigate the effects of four soil Cd concentrations (0, 5, 10, and 20 mg kg−1) on leaf Cd, zinc (Zn), and nitrogen (N) concentrations and nicotine, reducing sugar and phenolic compounds of sun-cured Canik 190/5, Xanthi 81, and Birlik 124 varieties grown in a semi-arid condition of Turkey. Increasing doses of Cd did not significantly decrease leaf yield of tobacco cultivars, while significant (p < .05) increase and decrease were recorded in leaf Cd and Zn concentrations, respectively. The highest leaf Cd concentration was accumulated in Birlik 124 (60.5 mg kg−1), and the lowest in Canik 190/5 (55.35 mg kg−1) variety. Nicotine concentration of Xanthi 81 and Birlik 124 cultivars in the highest Cd dose (Cd20) increased compared to the nicotine in control application, while nicotine concentration of Canik 190/5 cultivars decreased in Cd20 dose. The results revealed that all three tobacco varieties were able to accumulate Cd in their leaves under high soil Cd levels. The effects of Cd on N uptake and nicotine, reducing sugar and phenolic compounds were different among the tobacco varieties. The result may be associated with differences in responses of tobacco cultivars to soil Cd concentration.

Manganese (II) sulfate affects the formation of iron-manganese oxides in soil and the uptake of cadmium and arsenic by rice

Rice (Oryza sativa L.) consumption represents a major route of human exposure to cadmium (Cd) and arsenic (As), especially in Asia. This study investigated the effects of adding MnSO4 (0, 200, 400, and 800 mg kg‐1−1) on the formation of soil Fe/Mn oxides and Cd and As uptake in rice. The application of MnSO4 reduced soil pH, increased Eh, increased the contents of Fe/Mn oxides in the soil, and decreased the total Fe and Mn2+ contents in the porewater. It also led to lower contents of available Cd and As, higher levels of Cd and As bound to Fe/Mn oxides, and higher abundances of Thiobacillus and Syntrophobacter. Furthermore, Mn application increased the Fe and Mn contents in the root Fe/Mn plaque and decreased the grain Cd and As contents. Therefore, Mn application may modify the microbial community and porewater composition in soil, resulting in higher levels of Fe/Mn oxides in soil and Fe/Mn plaque at the root surface and in a lower accumulation of Cd and As in rice grains. Thus, Mn application can be a promising strategy for Cd and As stabilization in soils.

Exposure Assessment of Heavy Metals and Microplastic-like Particles from Consumption of Bivalves.

The aim of this study was to determine the contamination of lead (Pb), cadmium (Cd) and microplastic (MP)-like particles in bivalves and estimate the exposure of the Thai population to these contaminants due to bivalve consumption. Clams, mussels and cockles were purchased from five wholesale seafood markets located on the upper Gulf of Thailand during the period 2017-2019. Determinations of Cd and Pb in the bivalves were conducted using a graphite furnace atomic absorption spectrometer (GFAAS). Visualization was conducted using a stereomicroscope to investigate the morphology and content of MP-like particles in the bivalve samples. The average Pb contents in clams, mussels and cockles were 112, 64 and 151 µg/kg wet wt., respectively. The average Cd contents were 126, 107 and 457 µg/kg wet wt. for clams, mussels and cockles, respectively. The average number of MP-like particles in bivalve samples varied from not detected to 1.2 items/g wet wt. and not detected to 4.3 items/individual. The exposure to Pb, Cd and MP-like particles due to bivalve consumption varied between 0.005 and 0.29 µg/kg bw/day, 0.017 and 28.9 µg/kg bw/month and 0.015 and 27.5 items/person/day, respectively. There was no potential health risk of exposure to Pb and Cd due to bivalve consumption in any age group. However, a high consumption of cockles with high Cd levels (the worst-case scenario) in children may be of concern.

Assessing the status of Ichkeul Lake and its catchment through identifying potentially toxic cyanobacteria, simultaneously extracted metals and use of acid-volatile-sulfide model

Lake Ichkeul is considered one of the most significant wetlands in the Mediterranean basin. It serves as a crucial wintering area for numerous western Palearctic birds. A notable decline in species diversity has been observed in the past decade, attributed to excessive water usage for irrigation and the effects of climate change. This study aimed to assess the status of Ichkeul Lake and its catchment through identifying potentially toxic cyanobacteria, and sediment quality. Our first striking finding was that Lyngbya majuscula the dominant potentially toxic cyanobacterium in the lake originated from the Tinja channel. Trace element concentrations in lake sediments exceeded SQG standards which is indicative of rare detrimental effects to biological life. However, the sediment in front of the Tinja channel exhibited high contamination levels of Zn and Cd. These findings call for an urgent need to ensure the ongoing management and conservation of this world heritage site.

Effect of cadmium exposure on body composition deterioration: A propensity score-matched cohort study.

This propensity score-matched cohort study investigated the effects of blood cadmium (Cd) levels on body composition. Body composition was assessed by multifrequency bioelectrical impedance analysis and categorized into three groups: metabolically healthy obesity (MHO), adiposity obesity (AO), and sarcopenic obesity (SO). At baseline, 85 and 101 participants had MHO and AO, respectively (mean age, 51 ± 7years; male-to-female ratio, 1.0:1.3). During the 14-year follow-up, the body composition of 40 MHO and 6 AO participants deteriorated to AO and SO, respectively. The incidence of AO and SO differed according to age, sex, and blood Cd level. High blood Cd level increased the risk of body composition deterioration, particularly among those aged 60-69years (hazard ratio [HR] = 2.14), women (HR = 1.46), and those with AO at baseline (HR = 1.63; all p < 0.05). Cd exposure deteriorates body composition in older and female individuals, particularly from AO to SO.

Evaluating the Efficacy of Activated Carbon in Minimizing the Risk of Heavy Metals Contamination in Spinach for Safe Consumption.

Toxicity induced by heavy metals is a major concern in agriculture as it decreases crops' growth and yield and leads to the deterioration of food quality. Recently, activated carbon has been identified as a possible solution. It can potentially improve crop nutrition and immobilize heavy metals in soil. That is why a glasshouse trial was conducted to investigate the effects of sugarcane bagasse-derived biochar on spinach growth and the availability of cadmium (Cd) and chromium (Cr) in artificially contaminated soil. The soil was placed in pots and contaminated with Cd and Cr at a rate of 10 mg kg-1. Biochar was added to the soil at concentrations of 0 (control), 0 (contaminated control), 100, 150, and 200 g, and 10-day-old nursery spinach plants were transplanted to the pots. The results showed that applying 200 g of biochar significantly increased shoot weight (235 g), soil pH, electrical conductivity, and organic matter. The highest levels of Cd (27.71 mg kg-1) and Cr (20.44 mg kg-1) were observed in the contaminated control pots, while the lowest levels of Cd (16.80 mg kg-1) and Cr (9.80 mg kg-1) were found in pots treated with 200 g of biochar (2%). Similarly, the highest levels of Cd (35.80 mg kg-1) and Cr (40.24 mg kg-1) in the roots were found in the contaminated control pots, while the lowest levels of Cd (19.26 mg kg-1) and Cr (21.34 mg kg-1) were observed in pots treated with 200 g of biochar. Biochar application at a rate of 2% can immobilize Cd and Cr in the soil and improve chlorophyll contents, carotenoids, photosynthetic rate, transpiration rate, and stomatal conductance in spinach in Cd- and Cr-contaminated soils. Further long-term field studies will be necessary to determine the feasibility of applying biochar as an organic amendment for enhancing spinach growth and reducing Cd and Cr bioavailability in contaminated soil.

Determination of Lead and Cadmium level in cattle offals, water and feed in Omdurman locality –Sudan

This study was carried out to determine the level of Cadmiuum (Cd) and Lead (Pb) in cattle meat, offals, water and feed samples. The samples were obtained from Al Muwalih area (Omdurman locality- Sudan). Laboratory analysis was carried out using Atomic Absorption Spectroscopy. Usually, animals are transported from theWestern region of Sudan to the capital city Khartoum, were after few months will be slaughtered for consumption. The highest concentration of Cd and Pb was observed in kidney and liver with a mean of 0.0302 ±0.003mg/g and 0.259± 0.008mg/g respectively. High levels of Cd and Pb were also detected in water and feed samples. It is thus important to supply safe feed for animals to safeguard animal health and reduce the risk of exposure of consumers to heavy metals.