Cd Levels Research Articles

Blood cadmium concentration and pulmonary function injury: potential mediating role of oxidative stress in chronic obstructive pulmonary disease patients

BackgroundExposure to cadmium (Cd) is associated with a reduction in lung function among patients with chronic obstructive pulmonary disease (COPD). The longitudinal relationship and mechanism underlying the link between Cd exposure and lung function changes among COPD patients are yet unknown.MethodsThe cohort study included 259 eligible patients who underwent regular professional follow-ups. Blood Cd levels and serum 8-iso-prostaglandin F2 alpha (8-iso-PGF2α) levels were assessed. Lung function was determined at baseline and follow-up research. The associations between changes in lung function and blood Cd concentration were analysed using multivariate linear and logistic regression models.ResultsEach 1-ppb elevation in blood Cd content resulted in a 0.420 L decrease in forced vital capacity (FVC), a 0.424 L decrease in forced expiratory volume in 1 s (FEV1), a 4.341% decrease in FEV1/FVC%, and a 8.418% decrease in FEV1% predicted in patients with COPD. Blood Cd concentration showed a positive correlation with serum 8-iso-PGF2α levels in a specific range. The relative contribution of increased serum levels of 8-iso-PGF2α to Cd-induced declines in FEV1, predicted FEV1%, and FEV1/FVC% were 2.08%, 8.08%, and 13.19%, respectively.ConclusionBlood Cd levels are associated with lung function changes in COPD patients. Oxidative stress is thought to be an important mediator in Cd-induced reduction of pulmonary function.

Unlocking the relationship between tourism and bivalve health: A comprehensive study of Donax trunculus as environmental and public health indicators in Morocco

This study assessed the levels of Cd, Cu and Pb in the sentinel bivalve Donax trunculus collected from two touristic Moroccan sandy beaches, namely Agadir and Taghazout, in Morocco. The results revealed higher metal contamination in D. trunculus specimens collected from Taghazout compared to those from Agadir. Among the metals analyzed, Pb was found to pose the greatest risk to human health, followed by Cd and Cu. The study also investigated the presence of the trematode parasite Bacciger bacciger in D. trunculus specimens. The parasite was found only in female D. trunculus from Taghazout, with infection rates ranging from 11% to 46%. Furthermore, significantly higher levels of oxidative stress biomarkers were observed in specimens from Taghazout, where positive correlations were observed between Cu, Cd, Glutathione S-Transferase, and parasite prevalence, as well as between Pb and Catalase. In the case of D. trunculus collected from Agadir, Malondialdehyde levels were positively correlated with Cd and negatively correlated with Pb, while Catalase levels were negatively correlated with Cu. Complex interactions emerged between metal pollution, parasitic infection, and oxidative stress biomarkers in D. trunculus from two Moroccan coastal sites. Evaluating biotic stress synergies with biomarkers shows promise for integrating biological implications of coastal contamination.

Use of Cannabis sativa L. for Improving Cadmium-Contaminated Mediterranean Soils—Effect of Mycorrhizal Colonization on Phytoremediation Capacity

Although the phytoremediation strategy has been studied worldwide, little research data are available regarding the influence of mycorrhizae on the phytoremediation capacity of various plants grown in Cd-contaminated soils in Mediterranean environments. Therefore, a pot experiment was carried out to study the possible effectiveness of hemp plant (Cannabis sativa L.) in the remediation of moderately and heavily Cd-contaminated soils and additionally to quantify the effect of Cd on Arbuscular Mycorrhizal Fungi (AMFs). For this purpose, an alkaline clay soil collected from the Farm of Institute of Plant Breeding and Genetic Resources (North Greece) was contaminated with two levels of Cd (3 and 30 mg Cd kg−1, corresponding to Levels A and B, respectively—first factor) at two incubation times (10 and 30 days—second factor) and six treatments (Control_30d, Control_10d, CdA_30d, CdB_30d, CdA_10d, CdB_10d) were created. Soil Cd concentrations, both pseudo-total and available to plants, were determined after extraction with Aqua Regia mixture and DTPA solution, respectively, before and after the cultivation of hemp plants and after the harvesting. Cd concentrations in the aboveground and underground plant parts were also estimated after digestion with Aqua Regia, while root colonization by AMFs was determined with a microscope. The highest plant’s Cd concentration, more than 50%, was observed in its underground part, at all Cd-contaminated treatments, indicating a strong capacity for cadmium to gather up in the roots. Among different Cd levels and incubation days, significant differences were recorded in the rates of root colonization by AMFs. Among different Cd levels and incubation days, 3 mg Cd Kg−1 soil promoted AMF root colonization, particularly at 10-day incubation, while 30 mg Cd Kg−1 soil diminished it. Colonization was lower with longer incubation times at both levels of Cd. Hemp appears to be a viable option for phytostabilization in Cd-contaminated soils, enabling further utilization of AMFs to assist the phytoremediation process.

Bangladeş'in Chattogram ve Cox's Bazar bölgesindeki çamur yengeci (Scylla serrata) ve ortam çamurundaki ağır metal konsantrasyonu

Heavy metal levels have increased due to increased industrialization, which has a negative impact on crab, an essential source of protein. This study aimed to measure the level of certain heavy metals (Pb, Cd, and Hg) in edible tissue from mud crab (Scylla serrata) and related soil collected from Chattogram and Cox's Bazar in Bangladesh. The concentration of heavy metals in mud crab and the soil were determined using an Atomic Absorption Spectrophotometer (AAS) (Model ICE 3300). While the mean values of heavy metals in crab tissue samples from Chattogram were 0.06 mg/kg for Cd and 0.45 mg/kg for Pb, in the related soil samples these values were determined as 0.52 mg/kg for Cd and 7.24 mg/kg for Pb. In Cox's Bazar, the mean Pb content was 4.1 mg/kg in related soil, but the levels of Cd and Hg were below the detection limit. In S. serrata tissues, all heavy metal concentrations were below the detection limit. The heavy metal values obtained in the study were compared with the Food and Agriculture Organization (FAO), World Health Organization (WHO), European Union (EU) and Food and Drug Administration (FDA). Results concluded that metal concentrations were within permissible limits and did not pose an immediate risk to public health or human consumption. Specifically, the measured concentration levels are considered poor when compared to national and international requirements.

Estimating Cadmium Concentration in Agricultural Soils with ZY1-02D Hyperspectral Data: A Comparative Analysis of Spectral Transformations and Machine Learning Models

The accumulation of cadmium (Cd) in agricultural soils presents a significant threat to crop safety, emphasizing the critical necessity for effective monitoring and management of soil Cd levels. Despite technological advancements, accurately monitoring soil Cd concentrations using satellite hyperspectral technology remains challenging, particularly in efficiently extracting spectral information. In this study, a total of 304 soil samples were collected from agricultural soils surrounding a tungsten mine located in the Xiancha River basin, Jiangxi Province, Southern China. Leveraging hyperspectral data from the ZY1-02D satellite, this research developed a comprehensive framework that evaluates the predictive accuracy of nine spectral transformations across four modeling approaches to estimate soil Cd concentrations. The spectral transformation methods included four logarithmic and reciprocal transformations, two derivative transformations, and three baseline correction and normalization transformations. The four models utilized for predicting soil Cd were partial least squares regression (PLSR), support vector machine (SVM), bidirectional recurrent neural networks (BRNN), and random forest (RF). The results indicated that these spectral transformations markedly enhanced the absorption and reflection features of the spectral curves, accentuating key peaks and troughs. Compared to the original spectral curves, the correlation analysis between the transformed spectra and soil Cd content showed a notable improvement, particularly with derivative transformations. The combination of the first derivative (FD) transformation with the RF model yielded the highest accuracy (R2 = 0.61, RMSE = 0.37 mg/kg, MAE = 0.21 mg/kg). Furthermore, the RF model in multiple spectral transformations exhibited higher suitability for modeling soil Cd content compared to other models. Overall, this research highlights the substantial applicative potential of the ZY1-02D satellite hyperspectral data for detecting soil heavy metals and provides a framework that integrates optimal spectral transformations and modeling techniques to estimate soil Cd contents.

Fertilized soils enhance the efficiency of phytoremediation by tropical grasses in cadmium-contaminated soils

The effectiveness of phytoremediation in Cd-contaminated soils is crucial for enhancing nutrient availability and plant tolerance to Cd. We simulated soil contamination with varying textures and fertilization conditions. Two experiments were conducted: one without liming and fertilization and another with soil fertilization for grasses. The soil types used were Oxisol and Entisol, and the grasses tested were Megathyrsus maximus and Urochloa brizantha at three Cd levels: 0 mg kg−1 (Control), 2 mg kg−1 (Low), and 12 mg kg−1 (High). Soil amendments and fertilization did not significantly change Cd availability. Soil chemical attributes were unaffected by Cd contamination but were influenced by fertilization, which kept the pH below optimal levels. Cd availability was higher in more contaminated soils, with Entisol showing greater concentrations than Oxisol. Dry matter production of the grasses decreased with higher contamination, with U. brizantha being more productive than M. maximus in fertilized soils. Cd accumulation was higher in highly contaminated soils, particularly for U. brizantha. The bioconcentration factor was higher in Entisol, while the translocation factor exceeded 1.0 only for M. maximus in low-contamination Oxisol. Fertilization can mitigate Cd contamination effects, with U. brizantha showing greater tolerance and accumulation capacity in fertilized soils.

Assessment of heavy metal levels in cow's milk and associated health risks in the vicinity of the MIDROC Laga Dambi gold mine in Ethiopia

IntroductionThe possible health effects of consuming milk contaminated with heavy metals have been the subject of considerable concern worldwide. ObjectiveThe aim of this study was to determine the level of heavy metals in cow's milk in the vicinity of MIDROC Laga Dambi gold mine and to assess their possible health risks for consumers. MethodsNine composite samples were formed by aggregating 243 milk samples obtained in triplicates from 81 domestic milk-producing households. Inductively coupled plasma-optical emission spectroscopy was used to measure the amount of heavy metals after samples digestion under optimal conditions. ResultsThe heavy metals concentrations obtained were 13.913˗7.843, 9.505˗3.589, 5.972˗3.147, 2.288˗1.851, 0.403˗0.143, 0.436˗0.128, 0.26˗0.153, 0.143˗0.048, 0.160˗ND (not detected), and 0.140˗ND mgkg−1for Fe, Zn, Pb, Mn, Hg, Cr, Cd, As, Ni, and Co, respectively. Of the heavy metals identified, the levels of Pb, As, Cd, and Hg exceeded the recommended value. Based on the estimated daily intake (EDI), the total health quotient (THQ) is higher than unity even for Pb alone. It has been found that the consumption of cow milk increases the health index (HI) by 2.972. Ninety five percent of the HI in the study area was explained by the toxic heavy metals (Pb, Cd, As, and Hg) in the cow milk, which were found to be beyond the safe limit. ConclusionThis demonstrates that there is a health risk to the population who consume cow’s milk sourced from the vicinity of MIDROC Laga Dambi gold mine. To safeguard the public’s health, we advised strict monitoring and legislative control for the safety of cow’s milk originating from study area.

Screening nitrogen-fixing cyanobacteria that can alleviate cadmium toxicity to rice and reduce cadmium accumulation in brown rice

Among food crops, rice is the most serious food crop contaminated with cadmium (Cd). It is critical to reduce Cd bioavailability in the soil and prevent its accumulation in brown rice. The use of microorganisms to lessen Cd toxicity in rice has been the subject of numerous studies carried out in recent years. The nitrogen-fixing cyanobacterium (NFC) is a potent biofertilizer and heavy metal biosorbent. However, there is a dearth of research on the impact of NFC supplementation on rice's susceptibility to Cd poisoning. This study screened for Cd-tolerant NFCs and assessed how well they might promote growth and lower the amount of Cd in rice. Four NFCs with tolerance to 1 mg L−1 Cd were selected from ten NFCs. The results of seedling experiment showed that SCAU-10 treatment increased plant height and biomass while reducing Cd levels in seedlings by 62.0 %. The pot experiment also demonstrated that SCAU-10 was effective in lowering Cd content in brown rice by 85.3 %. Reducing the bioavailability of soil Cd, shielding rice roots, preventing Cd transfer from below to above ground, generating phytohormones, and enhancing the photochemical electron quantum yield of rice leaves are a few possible action mechanisms of the NFC. It indicates that Trichormus sp. SCAU-10 has a great deal of promise for use as a biofertilizer in the safe management of Cd-contaminated rice fields. This is the first report on using Trichormus sp. biofertilizer for relieving the toxicity of Cd to rice and reducing Cd accumulation in brown rice.

Efficient mineralization of cadmium and arsenic by poorly crystalline CaFe-layered double hydroxide in soil: Performance and mechanism

The co-contamination of arsenic (As) and cadmium (Cd) in the environment is of most concern. In this work, poorly crystalline CaFe-layered double hydroxide (CaFe-LDH) was synthesized with a Ca-to-Fe molar ratio of 4 to ensure effective immobilization of Cd and As in soil. The application of Ca4Fe-LDH in soil remediation demonstrated that the targeted heavy metals gradually mineralized into a relatively stable oxidizable and residual state. At a soil remediation dosage of 1.6%, the availability levels of Cd and As decreased significantly, achieving stabilization efficiencies of 99% and 85.2% respectively. Cd is trapped through isomorphic substitution and dissolution-reprecipitation of calcium (Ca) laminate, resulting in the formation of CdCaFe-LDH mineralization products. As is immobilized through ion exchange with interlayer anions, redox with Fe(III), and Fe-Cd-As complexation. Moreover, the results of the characterization and density functional theoretical (DFT) calculations demonstrate that the CdCaFe-LDH formed by isomeric substitution of Ca for Cd enhanced the adsorption of As on the (110) plane of LDH, indicating that the trap mechanism of Cd and As by Ca4Fe-LDH is synergistically promoted. Overall, the above results prove that mineralization using Ca4Fe-LDH is a promising method to remediate soils combined contaminated by both Cd and As.

Interplay between fluorine and cadmium on intestinal accumulation, oxidative stress, permeability and inflammatory response in rats

Fluorine (F) and Cadmium (Cd) have given rise to public concern regarding their adverse impacts on the environment and human beings. Yet, the toxic interplay between F and Cd on the intestine is still vague. Aiming to investigate the role of F on Cd-damaged intestine, a total of five groups of 30 SD rats were picked at random to be gavaged for 90 days: Control group (Ultra-pure water), Cd (Cd 1 mg/kg), Cd+LF (Cd 1 mg/kg+F 15 mg/kg), Cd+MF (Cd 1 mg/kg+F 45 mg/kg), and Cd+HF (Cd 1 mg/kg+F 75 mg/kg). It demonstrated that Cd enriched in the intestine and disordered intestinal barrier of rats. Interestingly, two side effects of F were observed resisting to the Cd toxicity. The Cd levels in colon contents were attenuated by 45.45 %, 28.11 %, and 19.54 % by F supplement, respectively. In the Cd+LF group, SOD, GSH-Px, and CAT activities elevated by 0.93, 1.76, and 1.78 times, respectively, and the MDA content reduced 0.67 times; the expressions of NQO1, SOD2, and GSH-Px mRNA markedly enhanced, as well as the Keap1 mRNA significantly decreased. Nevertheless, all indexes above in the Cd+HF group showed the opposite trends. Furthermore, LPS levels decreased by 45.93 % for the Cd+LF group and increased by 12.70 % in that the Cd+HF group. The ZO-1 expression in the Cd+LF group increased, whereas the Cd+HF group's expressions of Claudin-1, Occludin, and ZO-1 were all diminished by 35.46 %, 27.23 %, and 16.32 %, respectively. Moreover, the levels of TNF-α, IL-1β and TLR-4 decreased and IL-10 level promoted, while all showed opposite trends in the Cd+HF group. Collectively, it indicated there is a twofold interplay between F and Cd on intestinal damage and mainly depends on F dosages.

Combined toxicity of multiwall carbon nanotubes and cadmium on rice (Oryza sativa L.) growth in soil

The comprehensive effects of nanoparticles and coexisting heavy metals on plant growth are still unclear, especially in soil medium. The single and combined effects of multiwall carbon nanotubes (MWCNTs) and cadmium (Cd) on rice (Oryza sativa L.) growth were examined in this study through a 4 months pot experiment in 2022. Rice plants were exposed to different concentrations of MWCNTs (100 and 500 mg kg−1) in the presence of 5.0 mg kg−1 Cd stress. At the tillering stage, the 500 mg kg−1 MWCNTs addition reduced plant height by 8.0% and increased soluble protein content in the leaves by 13.7%, demonstrating that a single MWCNTs had a slight negative impact on rice growth. When exposed to Cd stress, the inclusion of 500 mg kg−1 MWCNTs led to a 6.7%–9.0% decrease in bioavailable Cd level in soil, resulting in considerable reductions in Cd content in roots (23.4%–29.9%), shoots (24.5%–28.3%) and grains (28.3%–66.2%). Compared to the single Cd treatment, the O. sativa L. leaves treated with Cd and MWCNTs (500 mg kg−1) had considerably reduced levels of malondialdehyde (MDA), soluble protein, and activities of antioxidant enzymes (POD, CAT, and SOD). The findings of this study indicated that appropriate concentrations of MWCNTs application in soil could alleviate Cd-induced toxicity on rice growth.

Pollution Assessment and Source Apportionment of Heavy Metals in the Surrounding Soil of Typical Mining Areas in Tongling, Anhui Province

To study the level of heavy metal pollution and ecological risks in the soil around typical mining areas in Tongling, a total of 150 soil samples were collected from the study area. The content characteristics of 10 elements, namely, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, Fe, and Zn, in the soils were analyzed. Methods including enrichment factor, the geo-accumulation index, single-factor pollution index, Nemero comprehensive pollution index, and potential ecological risk index were used to evaluate the pollution status of heavy metals in the soil of the study area. The pollution sources of heavy metals in the soil were also analyzed using correlation analysis, cluster analysis, and principal component analysis. The results showed that except for Cr and Fe, the average contents of the other eight heavy metal elements were higher than the soil background values in the study area. Pb, Zn, As, Cu, and Cd had a high degree of variation and were significantly affected by external interference. The spatial distribution showed that both Cr and Ni showed a decreasing trend from the edge to the central region, whereas the other eight heavy metals showed a decreasing trend from the central region to the surrounding areas. The pollution level of Cd and Cu in the soil of the research area was relatively severe. The overall ecological risk was at a medium to low level. Cd and Hg were the main contributing factors. As, Cd, Cu, Fe, Mn, Pb, and Zn mainly came from agricultural, industrial, and transportation sources, whereas Cr and Ni were mainly from natural sources. However, the sources of Hg were relatively complex. The research results can provide a scientific basis for the prevention and control of soil heavy metal pollution in metal mining areas, as well as the remediation of mine pollution.

Cadmium distribution in rice: Understanding the role of plant nodes and growth stages

Cadmium (Cd) contamination in farmland poses a significant threat to food security in staple crops, especially rice. Using a mix of hydroponic and soil culture methods, stable isotope tracers, and advanced analytical techniques, this study elucidated the mechanisms of Cd uptake, translocation, and accumulation in rice throughout different growth stages. Despite a notable linear correlation between soil DTPA (diethylene-triaminepentaacetic acid)-Cd and the total Cd concentration of rice, our findings showed that the influence of soil Cd level on the proportion of Cd in grain was negligible. The study highlighted the dynamic response of Cd distribution within plant nodes to changes in DTPA-extractable Cd. Heading stage (HS) and mature stage (MS) were critical for Cd uptake and upward transport in rice, and the contribution of Cd absorption in brown rice was 28.61% and 40.16%, respectively. Moreover, the distribution of Cd in nodes showed how important nodes are for controlling and redistributing Cd in rice. In the HS, the lower node had a function in re-transporting, whereas in the MS, there was a considerable redistribution of Cd in the upper node.These insights can help us understand rice Cd dynamics and develop agronomic techniques and rice cultivars that minimize Cd accumulation.

Contamination by potentially toxic metals from urban rivers located in an area covered by the Guarani Aquifer in Southern Brazil

The present study aimed to evaluate the concentration of heavy metals considered globally alarming, such as cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb) and zinc (Zn), in the surface water and in the sediment of urban rivers located in an area covered by the Guarani Aquifer, in Lages, southern Brazil. The water and sediment samples were collected in September and October 2016 in three urban rivers. The quantification of the metals was performed through an atomic absorption spectrometer. The levels of Cd, Cr, Cu, Pb and Zn in the control points (P1 and P7) presented a concentration below the level I proposed by Brazilian legislation 344/2004 of the National Environment Council (CONAMA), while the other points presented concentrations higher and above level I, evidencing an increase of metals in the rivers from upstream to downstream of the urban area of ​​Lages. Cr concentrations above level II proposed by Brazilian legislation at the mouth of the Carahá River were also found, and this value may have adverse effects on aquatic biota. The results show that urban rivers in the area covered by the Guarani Aquifer in Lages have been contaminated by toxic elements associated with anthropogenic activities.

Analysis of Cadmium (Cd) Levels in Tilapia Fish (Oreochromis mossambicus) from Ponds in Palibelo

Fish are oceanic biota that are frequently utilized as signs of weighty metal contamination in waters. The purpose of this study was to determine the levels of cadmium (Cd) in tilapia from ponds in Palibelo and whether or not it is safe for consumption based on the Regulation of the Food and Drug Supervisory Agency (BPOM) No. 9 of 2022 concerning Requirements for Heavy Metal Contamination in Processed Food. Sampling was carried out by purposive sampling, at each station two fish samples were taken using floating nets. Samples were analyzed at the Health Laboratory, Testing and Calibration Center (BLKPK) of NTB Province. Data analysis was carried out by taking body parts, namely tilapia meat, then analyzing cadmium (Cd) levels using AAS. The results showed that cadmium levels in tilapia were still below the standard quality standards ranging from 0.0033-0.0057 mg/kg, with an average cadmium of 0.00465 mg/kg. Cadmium comes from household waste and modern waste carried by river currents. Environmental factors obtained temperature, pH, and salinity are in ideal conditions for the life of Tilapia fish. The conclusion is that Tilapia fish from fish farming in Palibelo is still suitable for consumption because it is still below the standard quality of 0.30 mg/kg.

Effect of pH on growth and Cd accumulation in different rice varieties under hydroponics

ABSTRACT Currently, applying lime to cadmium (Cd)-contaminated paddy fields to increase pH and reduce Cd availability is an effective method to control excessive Cd levels in rice grain. However, under hydroponic conditions, the impact of increased pH on Cd accumulation in different rice varieties remains unclear. This study employed three rice varieties (Yuzhenxiang, Shaoxiang 100, Xiangwanxian 12) with different Cd accumulation characteristics under different pH and long-term treatment with 1 μM CdCl2, to study the effect of pH on growth and Cd accumulation in different rice varieties. The result showed that as pH shifted from 5 to 8, the SPAD values, shoot dry weight, and plant height of the three rice varieties significantly decreased. The main root length, root volume, and root dry weight of Yuzhenxiang, and Shaoxiang100 significantly decreased. Conversely, the root architecture indicators of Xiangwanxian 12 did not change significantly. As for element accumulation, increasing the pH significantly increased the content of Mn in both the shoots and roots of all three varieties. Yuzhenxiang significantly reduced Cd content in both the shoots and roots of rice, while Shaoxiang100 significantly increased Cd content in both parts. Xiangwanxian 12 showed a significant increase in Cd content in the shoots but a decrease in the roots. In terms of subcellular distribution, Yuzhenxiang significantly reduced Cd concentrations in the cell wall and organelles of root cells, resulting in lower Cd concentrations in the root tissue. Conversely, Shaoxiang100 significantly increased Cd concentrations in the cell wall, organelles, and soluble fractions of root cells, leading to higher Cd concentrations in the root tissue. Xiangwanxian 12 also exhibited a decrease in Cd concentrations in the cell wall, organelles, and soluble fraction of root cells, resulting in lower Cd concentrations in the root tissue. Additionally, the expression of the OsNRAMP5 and OsHMA3 gene was significantly increased in Shaoxiang 100, while no significantly change in Yuzhenxiang and Xiangwanxian 12. These results provide important guidance on the impact of pH on Cd accumulation during the vegetative growth stage of different rice varieties.

Effects of titanium oxide nanoparticles and 24-epibrassinosteroid to mitigate the toxicity of cadmium (Cd) and improve physio-morphological traits of soybean (Glycine max L.) cultivated under Cd-contaminated soil

Cadmium (Cd) toxicity is a serious environmental threat to living organisms. Nanoparticles (NPs) and plant growth regulators are able to mitigate Cd toxicity and restore crop growth in heavy metals-contaminated soils. However, the synergistic potential of combining 24-epibrassinosteroid (24-epiBRs) and titanium oxide nanoparticles (TiO2-NPs) to alleviate Cd toxicity and restore soybean (Glycine max L.) production remains unexplored. Thus, a pot-based experimental trial was conducted to assess the effects of applying TiO2-NPs (15 mg L−1) and 24-epiBRs (10−7 M), individually and in combination, on soybean growth in soil cultivated with 30 ppm of Cd. The study revealed that Cd toxicity significantly inhibited soybean root length (11.0 %), root dry biomass (63.5 %), root fresh biomass (84.9 %), shoot length (11.7 %), shoot dry biomass (49.0 %), and shoot fresh biomass (27.3 %), compared to the control. Additionally, the toxicity of Cd enhanced the oxidative stress and lowered the photosynthetic efficiency, gas exchange characteristics, and antioxidant defense system of soybeans. Interestingly, the combined application of TiO2-NPs and 24-epiBRs ameliorated the Cd toxic effects and improved the agronomic traits, photosynthesis efficiency, and antioxidant activity in soybeans by lowering oxidative stress. Specifically, the dual application of 24-epiBRs and TiO2-NPs effectively lowered the Cd levels in roots, shoots, and leaves of soybean plants by 62.5, 162.7, and 87.1 %, respectively, relative to the control soybean plants grown under Cd stress. Overall, the combined treatment of TiO2-NPs and 24-epiBRs synergistically reduced Cd uptake and restored soybean physiology in Cd-contaminated soils. Moving forward, further research should include field trials to assess the effectiveness and economic viability of this novel method.

Antagonistic effects of Bacillus subtilis-derived chitosan nanoparticles on growth performance, stress biomarkers, and histological alterations of cadmium-intoxicated Nile tilapia fingerlings

Heavy metals including cadmium (Cd) are one of the major persistent and non-biodegradable wastewater pollutants. However, Cd reaches the aquatic ecosystem via industrial and agricultural waste discharges and causes serious deterioration in the welfare status of aquatic animals. The use of feed supplements with immune-stimulants to mitigate the toxic influences of heavy metals including Cd is a much more intriguing point. Thus, the current experiment used the bio-synthetized chitosan nanoparticles derived from Bacillus subtilis (Bs-CNPs) as a feed supplement and evaluated its ameliorative impacts on the growth and welfare status of Cd-intoxicated Nile tilapia (Oreochromis niloticus). Bifactorial design (3 Bs-CNPs levels × 3 Cd levels) was used in the current study where Nile tilapia fingerlings (58–63 g) were fed on 0.0, 2, and 4 g Bs-CNPs/kg feed alongside with exposing to 0.0, 0.392, and 0.784 mg Cd/L for 60 days to represent nine treatments as follows: T1: control group (no Cd exposure; no Bs-CNPs supplement); T2 and T3: fish were intoxicated with 0.784 and 0.392 mg Cd/L, respectively; T4 and T5: fish fed on 2 and 4 g Bs-CNPs/kg feed, respectively; T6 and T7: fish were fed on 2 g Bs-CNPs/kg feed along with exposure to 0.784 and 0.392 mg Cd/L, respectively; and T8 and T9: fish were fed on 4 g Bs-CNPs/kg feed along with exposure to 0.784 and 0.392 mg Cd/L, respectively. It is noted that the Cd-intoxicated fish exhibited significant retardation in growth performance and digestive enzyme activities with a decline in their survival rate compared to the control group (T1). The results also revealed that exposing fish to Cd toxicity alone with no feed supplement (T2 and T3) experienced abnormal clinical signs and behavioral changes. Compared with the control group (no Cd with no Bs-CNPs), highest values of cortisol, glucose, aspartate and alanine aminotransferase, and acetylcholine esterase activity were found in fish fed on the control diet along with exposure to 0.784 mg Cd/L. Higher Cd restudies in liver, intestine, gills, kidney, and muscles tissues were detected in fish exposed to 0.784 mg Cd/L alone and the sequence order of Cd levels in different fish organs is intestine > gills > liver > kidney > muscles. Remarkable pathological alterations in hepatic and intestinal tissues were also observed. On the other hand, feeding Nile tilapia on Bs-CNPs-enriched diets alone with no Cd exposure enhanced their growth performance, digestive enzyme activities, and hematological parameters with no Cd residues in fish organs. Interestingly, feeding the Cd-intoxicated fish on diets with Bs-CNPs (4 g/kg feed) returned their growth, digestive enzymes, hematological, and biochemical parameters to approximate those of the control group. Furthermore, these treatments showed histopathological alteration recovery in the intestine and liver tissues is similar to those in the control group (no Cd with no Bs-CNPs). Fish fed on Bs-CNPs levels with no Cd exposure showed no Cd residues in different fish organs. The Cd levels in different organs of fish exposed to 0.392 mg Cd/L along with feeding on Bs-CNPs (4 g/kg feed) were lower than those in Cd-exposed fish treatments. Consequently, the current study evoked that feeding Nile tilapia fingerlings on Bs-CNPs (4 g/kg feed) could enhance their growth performance and protect the fish from the Cd toxicity that may occur in the aquatic ecosystem.

Bioaccessibility and bioavailability assessment of cadmium in rice: In vitro simulators with/without gut microbiota and validation through in vivo mouse and human data

Assessing the bioaccessibility and bioavailability of cadmium (Cd) is crucial for effective evaluation of the exposure risk associated with intake of Cd-contaminated rice. However, limited studies have investigated the influence of gut microbiota on these two significant factors. In this study, we utilized in vitro gastrointestinal simulators, specifically the RIVM-M (with human gut microbial communities) and the RIVM model (without gut microbial communities), to determine the bioaccessibility of Cd in rice. Additionally, we employed the Caco-2 cell model to assess bioavailability. Our findings provide compelling evidence that gut microbiota significantly reduces Cd bioaccessibility and bioavailability (p<0.05). Notably, strong in vivo-in vitro correlations (IVIVC) were observed between the in vitro bioaccessibilities and bioavailabilities, as compared to the results obtained from an in vivo mouse bioassay (R2 = 0.63–0.65 and 0.45–0.70, respectively). Minerals such as copper (Cu) and iron (Fe) in the food matrix were found to be negatively correlated with Cd bioaccessibility in rice. Furthermore, the results obtained from the toxicokinetic (TK) model revealed that the predicted urinary Cd levels in the Chinese population, based on dietary Cd intake adjusted by in vitro bioaccessibility from the RIVM-M model, were consistent with the actual measured levels (p > 0.05). These results indicated that the RIVM-M model represents a potent approach for measuring Cd bioaccessibility and underscore the crucial role of gut microbiota in the digestion and absorption process of Cd. The implementation of these in vitro methods holds promise for reducing uncertainties in dietary exposure assessment.

Assessing health hazards of dried fish consumption from coastal markets in a developing nation

Dried fish is a crucial protein source for coastal populations in developing countries, but it is becoming increasingly contaminated with heavy metals due to the use of traditional drying methods. This study assessed Cd, Cr, Pb, and Mn levels and their health risks in four commonly consumed dried fish species (Harpodon nehereus, Trichiurus lepturus, Penaeus affinis, and Amblypharyngodon mola) from the central coast of Bangladesh. Results showed Mn levels (17.47 ± 4.69 mg/kg) exceeded FAO limits (4.35 mg/kg), with the highest concentrations in H. nehereus. Cd levels (0.24 ± 0.16 mg/kg) in A. mola were also above safety thresholds. Lead was found in all species except P. affinis, with the highest concentration in A. mola (0.432 ± 0.06 mg/kg), which was within safe limits. Risk assessments revealed higher health risks for children, with elevated Target Hazard Quotient (THQ) and Hazard Index (HI) values compared to adults. H. nehereus had the highest THQ values for Cr (0.0014 mg/kg) and Mn (0.00044 mg/kg). Multivariate analyses indicated contamination from both anthropogenic and natural sources. The study stressed the need for better monitoring and mitigation to ensure the safety and nutritional value of dried fish.