High Cadmium Research Articles

The Effect of Soil and Foliar Nitrogen Applications On Cd Toxicity of Durum Wheat (Triticum turgidum L.) Grown in Low and High Cadmium Contaminated Soils

The Effect of Soil and Foliar Nitrogen Applications On Cd Toxicity of Durum Wheat (Triticum turgidum L.) Grown in Low and High Cadmium Contaminated Soils

New complete genome insights into Enterobacter roggenkampii FACU2: a potential player in cadmium bio-removal.

Industrial workplaces, particularly those involved in ore processing or smelting, pose a high risk of exposure to cadmium, a highly toxic metal. This study isolated and identified eight cadmium-resistant strains from industrial wastewater for their ability to resist cadmium. Enterobacter roggenkampii FACU2 demonstrated exceptional cadmium removal capabilities during our analysis, successfully eliminating 62% of the cadmium. Additionally, transmission electron microscopy (TEM) was utilized to examine the morphological change between the most and least efficient strains that responded to cadmium stress at the cellular level. Compared to the control bacteria, the treated bacteria exhibited notably higher levels of cadmium adsorption and accumulation within their cells. A complete genome analysis revealed that E. roggenkampii FACU2 has one chromosome and one plasmid with a size of 4,856,454bp and 80,926bp, respectively, in addition to harboring numerous heavy metal-resistant genes related to cadmium and other heavy metals. Moreover, the gene expression of four cadmium-resistant genes (czcA, cadA, czcC and czcD) showed that the high cadmium concentration led to a significant increase in czcA and cadA mRNA levels, thus indicating the activation of cadmium-resistant genes in the E. roggenkampii FACU2 compared to Enterobacter sp. strain FACU. Due to its ability to remove cadmium and other heavy metals, this strain holds promise as a source of genes for biological treatment methods. This application could contribute to environmental purification, ultimately benefiting human health.

Spatial Prediction of Soil Total Phosphorus in a Karst Area: Comparing GWR and Residual-Centered Kriging

Accurate soil total phosphorus (TP) prediction is essential to support sustainable agricultural practices and formulate ecological conservation protection policies, particularly in complex karst landscapes with high spatial variability and high phosphorus and cadmium content and interactions, complicating nutrient management. This study uses GIS and geostatistical methods to analyze the spatial distribution, influencing factors, and predictive modeling of soil TP in the karst region of northern Mashan County, Guangxi, China. Using 427 surface soil samples, we developed five predictive models: ordinary kriging (OK), regression kriging (RK) and geographically weighted regression kriging (GWRK) combined with environmental variables such as land uses, soil types, and topographic factors; residual mean-centered kriging (MM_OK), and residual median-centered kriging (MC_OK). Our results indicate that higher TP levels were observed in agricultural lands (paddy fields and dry land, at 766 and 913 mg·kg−1, respectively) may due to fertilization, while forests and shrublands showed lower TP levels (383 and 686 mg·kg−1, respectively), reflecting natural phosphorus cycling. The high-value areas of soil TP concentration are in the karst areas in the west and east of the study area, and the low-value area is in the Hongshui River valley in the north of Mashan. The spatial distribution of soil TP is affected by land use, soil type, and topography. The GWRK model exhibited superior accuracy (80.6%), with predicted concentration of TP closely aligning with observed TP values, effectively capturing fine spatial variations, and showing the lowest mean standardized error, average standard error, and mean absolute error. GWRK also achieved the highest R2 (0.67), demonstrating robust predictive capability. MM_OK and MC_OK models performed well and showed smoother spatial transitions, while the OK model displayed the lowest predictive accuracy (62%). By utilizing spatially adaptive weighting, GWRK and its residual-centered kriging method improve soil TP’s prediction accuracy and smoothness in karst areas, providing a reference for targeted soil conservation and sustainable agricultural practices in spatially complex karst environments.

Nanoparticles for treatment of cadmium-contaminated cocoa-growing soils and beans: Performance on metal immobilization and removal.

Some areas of tropical soils where cocoa grows contain high cadmium (Cd) concentrations. The cocoa plant's need for nutrition causes the reticular system to uptake the toxic metal, translocate it, and accumulate it in roots, stems, and other edible parts such as cocoa beans and shells, threatening the health of cocoa consumers. To cope with this difficulty, different treatments have been applied to cadmium-contaminated soils, but they showed limited success. In this study, we prepared multicomponent nanoparticles (MCNPs) to treat cocoa soils in fixed-bed columns and field tests. Also, MCNPs were mixed with two varieties of cocoa beans, CNN51 and Fino de Aromain, during the fermentation, aiming to capture the cadmium. Our field investigations began by collecting soil samples from three Ecuadorian cocoa-producing farms to determine their physicochemical properties, cadmium, and iron contents. A few weeks later, a home-built prototype was installed in a cocoa plantation to fabricate the nanomaterials using commercial-grade chemicals and rainwater. Scanning Electron Microscope (SEM) images showed MCNPs with an average size of 65.21 nm and the formation of chain-like aggregates. In contrast, MCNPs size was 76.6 nm, measured with Dispersed Light Scattering (DLS). The chemical composition of MCNPs was 90.7% Fe0 and 1.81% sulfur (S), analyzed by energy dispersal X-ray (EDX) and confirmed by X-ray diffraction (XRD) spectrometer measurements. Regarding the treatments, for the fixed-bed column tests, 0.28-1.08 L/kg was dosed into the soil, while for field treatments, 250, 500, and 835 mL/min MCNPs were injected in soil areas of 5 m2 surrounding each cocoa tree (0.5-4.5 mg MCNPs/kg soil) at depths between 0 and 5 cm. Test results revealed that the procedure applied in the field did not reproduce the metal’s immobilization (∼22%) as in the fixed-bed columns (∼80%). Moreover, cadmium removal was ∼ 20% and ∼75% after treating CCN51 and Fino de Aroma cocoa beans with 0.112 kg MCNPs/kg in the fermentation on-site and 0.034 kg MCNPs/kg in the laboratory. In this study, the size and chain-like aggregates of MCNPs notably influenced the field treatments as they precluded the filtration of MCNPs downwards. However, immobilizing cadmium could be more effective in soils with higher concentrations of the metal and multicomponent nanoparticles of smaller size, expanding our research scope and offering a practical solution to pollution issues in cocoa-growing regions.

Enhancing soil quality in soybean cultivation: Mycorrhizal technology combined with intercropping under high cadmium stress

Enhancing soil quality in soybean cultivation: Mycorrhizal technology combined with intercropping under high cadmium stress

High dense cadmium lead-borate glasses: fabrication, physical properties and capability for γ-ray and neutron shields

High dense cadmium lead-borate glasses: fabrication, physical properties and capability for γ-ray and neutron shields

Geospatial clustering of auto-antibodies against apolipoprotein A-1, heavy metals, cardiovascular and liver diseases in the general population

Abstract Aims Heavy metals (HM) are combustion-related environmental factors predisposing to cardiovascular (CVD), autoimmune and liver diseases, even below regulatory concentrations. Pro-atherogenic and pro-steatotic auto-antibodies against apolipoprotein A1 (AAA1) are prevalent in the general population for unclear reasons. We explored a putative interplay between HM exposure, AAA1, CVD risk factors and a non-alcoholic fatty liver disease (NAFLD) risk score, using a geospatial clustering approach at the general population level. Methods Getis-Ord, Moran I2 clustering and geographically weighted regression (GWR) geosptatial analyses were carried out on 6361 individuals recruited in the CoLaus/PsyCoLaus general population cohort. Geospatial dependences between serum AAA1, urinary HM (cadmium, arsenic, cobalt) concentrations, SCORE2 CVD risk, and fatty liver index (FLI) were assessed. Results Cadmium and cobalt were found to be associated with higher SCORE2 risk (p<0.04). AAA1 were associated with higher cadmium, cobalt, and cigarette consumption, independently of SCORE2 (p<0.04). AAA1 hotspots overlapped significantly with those of cadmium and FLI, independently of SCORE2. According to GWR, correlations between cadmium and AAA1 were the highest in railways proximity regions, increasing up to 10-fold compared to global associations. AAA1 were not associated with other HM. Conclusions These geospatial footprints highlight independent associations between Cadmium, AAA1, and NAFLD risk score in the general population. We hypothesize that environmental cadmium exposure may facilitate the occurrence of AAA1 in humans. Ongoing experimental studies will confirm/refute a possible causal link. Whether AAA1 could represent an early biological signature of cadmium exposure and subsequent health hazards remains to be shown.

High cadmium exposure impairs adult hippocampal neurogenesis via disruption of store-operated calcium entry

Cadmium (Cd) is a neurotoxicant that gradually accumulates in the human body with age. High Cd burden is correlated with adult hippocampal neurogenesis (AHN) and memory deficits in mammals. However, little knowledge is known about the mechanism by which Cd exposure impairs neurogenesis and cognition. Here, we investigated the roles of store-operated calcium entry (SOCE)-mediated calcium dyshomeostasis in Cd-induced AHN and memory deficits as well as therapeutic potential for the prevention of Cd-induced neurotoxicity. To achieve this goal, 8 weeks-old C57BL/6 J mice were subjected to different concentrations of cadmium chloride (0, 5, 10, 20 ppm) in drinking water for 8 weeks, we then examined the AHN, calcium homeostasis, SOCE channel and memory in Cd-exposed mice by using immunohistochemistry, calcium imaging, Y-maze and fear conditioning test. Our results indicated that chronic Cd exposure markedly increased Cd levels in serum and cerebrospinal fluid by almost 10-fold, and inhibited the proliferation and differentiation of hippocampal adult neural stem cells in a dose-dependent manner. Additionally, Cd exposure impaired the maturation of hippocampal neural stem cells without inducing gliosis. Transcriptome analysis revealed that Cd exposure inhibited the proliferation of neuroblastoma via alteration of calcium signaling pathway, and attenuated SOCE channels played a pivotal role in mediating Cd-induced cytoplasmic calcium overload and depletion of endoplasmic reticulum calcium stores. Activation of SOCE by hyperforin, a natural derivative from medicinal plant, restored intracellular calcium homeostasis and improved AHN and memory in Cd-exposed mice. Together, this study provided novel insights into the mechanism that Cd exposure impaired AHN and memory by prompting neuronal SOCE-mediated calcium dyshomeostasis, and offered a new therapeutic approach for prevention of Cd-induced neurotoxicity.

Combined Effects of Heavy Metal and Simulated Herbivory on Leaf Trichome Density in Sunflowers

Trichomes play a key role in both heavy metal tolerance and herbivory defense, and both stressors have been shown to induce increased trichome density. However, the combined effect of these stressors on trichome density in general, and specifically on metal-hyperaccumulating plants, has yet to be examined. The aim of this study was to test the effect of cadmium availability and herbivory on leaf trichome density and herbivore deterrence in the metal hyperaccumulator Helianthus annuus. To test this, H. Annuus plants were grown in control pots or pots inoculated with 10 mg/kg cadmium and were subjected to either no herbivory or simulated herbivory using mechanical damage and foliar jasmonic acid application. Herbivore deterrence was tested in a feeding assay using Spodoptera littoralis caterpillars. Interestingly, while the trichome density of H. annuus increased by 79% or 53.5% under high cadmium availability or simulated herbivory, respectively, it decreased by 26% when the stressors were combined. Furthermore, regardless of cadmium availability, simulated herbivory induced a 40% increase in deterrence of S. littoralis. These findings suggest that the combination of metal availability and herbivory might present excessive stress to hyperaccumulators. Moreover, they suggest that the risk of metal bioaccumulation in phytoremediation can be reduced by simulated herbivory.

In-situ induced formation of Fe-OM association in soil: Theory and practice of remediation of cadmium contaminated paddy fields in high cadmium geological background areas

Cadmium (Cd) pollution in rice paddies, attributable to high geological Cd backgrounds, has emerged as a global concern. This study leverages the passivation mechanism of bioavailable Cd by iron-organic matter associations (Fe-OM) to explore a novel strategy for Cd immobilization. We examined the adsorptive capacity and removal efficiency of Cd by laccase-mediated Fe-OM association and assessed their natural stability using 57Fe isotopic tracing. Additionally, we conducted in-situ remediation trials in a Cd-enriched paddy soil. Our results indicate that the theoretical maximum adsorption capacity for Cd by the laccase-mediated Fe-OM is 100.0 mg/g, which is a 15% improvement over the common Fe-OM and a 150% enhancement over inorganic iron oxides (ferrihydrite). The 57Fe isotope tracing test showed that the affinity of laccase-modified organic matter for iron increased by 55.6%, and it exhibited better stability than common Fe-OM under anaerobic conditions. The field-scale remediation, predicated on the in situ synthesis of Fe-OM association, effectively reduced the bioavailable Cd concentration in the soil from 0.91 mg/kg to 0.40 mg/kg. Concurrently, the Cd concentration in rice grains was lowered from 0.63 mg/kg to 0.15 mg/kg, thus falling beneath the national safety threshold. This study represents a significant advancement in the safe reclamation and utilization of agricultural soils with elevated geological Cd burdens.

In Situ Growth of CdS Nanoparticles Between g‐C3N4 Layers for Photocatalytic Reduction of Nitrobenzene

AbstractPhotocatalysis technology is green and sustainable for reduction of nitrobenzene to aniline. However, the photocatalytic activity of pure carbon nitride is limited by the high photogenerated carrier recombination rates. Carbon nitride nanosheets (CNN) were prepared by prepolymerization and high temperature calcination and cadmium sulfide (CdS) nanoparticles were in situ grown between the layers of carbon nitride for facilitating the separation and transfer of charges. As a result, the optimal composite catalyst (CdS/CNN‐2) exhibited superior photocatalytic activity with nitrobenzene reduction rate of 83 % within 60 min. This work presents an effective strategy for designing catalysts for the photocatalytic reduction of nitrobenzene.

Co-expression analyses reveal key Cd stress response-related metabolites and transcriptional regulators in Kentucky bluegrass

Kentucky bluegrass (Poa pratensis) is known for its high cadmium (Cd) tolerance and accumulation, and it is therefore considered to have the potential for phytoremediation of Cd-contaminated soil. However, the mechanisms underlying the accumulation and tolerance of Cd in Kentucky bluegrass are largely unknown. In this study, we examined variances in the transcriptome and metabolome of a Cd-tolerant variety (Midnight, M) and a Cd-sensitive variety (Rugby II, R) to pinpoint crucial regulatory genes and metabolites associated with Cd response. We also validated the role of the key metabolite, l-phenylalanine, in Cd transport and alleviation of Cd stress by applying it to the Cd-tolerant variety M. Metabolites of the M and R varieties under Cd stress were subjected to co-expression analysis. The results showed that shikimate-phenylpropanoid pathway metabolites (phenolic acids, phenylpropanoids, and polyketides) were highly induced by Cd treatment and were more abundant in the Cd-tolerant variety. Gene co-expression network analysis was employed to further identify genes closely associated with key metabolites. The calcium regulatory genes, zinc finger proteins (ZAT6 and PMA), MYB transcription factors (MYB78, MYB62, and MYB33), ONAC077, receptor-like protein kinase 4, CBL-interacting protein kinase 1, and protein phosphatase 2A were highly correlated with the metabolism of phenolic acids, phenylpropanoids, and polyketides. Exogenous l-phenylalanine can significantly increase the Cd concentration in the leaves (22.27%–55.00%) and roots (7.69%–35.16%) of Kentucky bluegrass. The use of 1 mg/L of l-phenylalanine has been demonstrated to lower malondialdehyde levels and higher total phenols, flavonoids, and anthocyanins levels, while also significantly enhancing the uptake of Cd and its translocation from roots to shoots. Our results provide insights into the response mechanisms to Cd stress and offer a novel l-phenylalanine-based phytoremediation strategy for Cd-containing soil.

Nebulized spray pyrolysis deposited CdO thin films for liquefied petroleum gas and ethanol gas sensor

High quality cadmium oxide (CdO) thin films were prepared through an inexpensive and simple nebulized Spray Pyrolysis (neb-SP) technique. The transparent conducting CdO thin films deposited at different substrate temperatures (TS) for the ethanol and liquefied petroleum gas (LPG) sensor application. XRD, SEM, UV–vis Spectroscopy and Hall Effect were done to study the structural, morphological, optical and electrical properties respectively. Polycrystalline nature thin films shows (1 1 1) cubic structure as the prominent peak. Surface morphology studies reveal that the grain size and roughness of the films are increased with increase in the substrate temperature. The average transmittance of the yellowish transparent CdO thin films is about 57%, thus the films are transparent in the visible region. The optical band gap (Eg) value of the CdO films increased from 2.16 to 2.28 eV with increase in the TS from 225 °C to 300 °C. The minimum value of electrical resistivity of the films is 1.40 × 10−3 Ωcm obtained at 275 °C. The neb-SP deposited CdO thin film (275 °C) shows maximum response to the ethanol and LPG gas sensitivity of 31.87% and 16.4% respectively at operating temperature of 573 K. Thus the results authenticate that the CdO thin films deposited low substrate temperature with high quality can be achieved via neb-SP technique compared to other wet chemical or physical method.

Possible enrichment process of Cd in the Se-rich soil area of Lanshan District, Shandong Province, China.

High cadmium (Cd) concentrations widely occured in selenium (Se)-rich soils, which has been an important obstacle in the usage of Se-rich soils. There is still no special information detailing the enrichment process and mechanism of Cd in Se-rich soils. 4474 soils and 21 rocks in Lanshan District were sampled to detect its enrichment process. The surface soils have Cd concentrations of 0.01-9.41mg·kg-1 (an average of 0.16mg·kg-1). The soil Cd concentrations were significantly correlated with soil Se concentrations. The relatively higher-Cd surface soils are distributed in Lower-middle Ordovician carbonate areas with Se-rich soils and Quaternary areas with typical anthropic activities. Surface soils in Ordovician carbonate area have the highest Cd concentrations. Soil Cd concentrations are significantly correlated with sulfophil elements (Zinc (Zn), Copper (Cu), Molybdenum (Mo), Lead (Pb) and Arsenic (As) etc.), Ca (Calcium) concentrations and soil organic carbon (SOC). The soil and rock samples from different geological units also confirmed soil Cd concentrations developing from Ordovician carbonates were higher than those from other rocks. The results indicate the soil Cd concentrations were the complex consequences of bedrock, soil-forming processes and anthropogenic activities. Higher Ca concentrations and more reduction environments result in high-Cd bedrock. CaCO3 leaching and alkaline pH, which are the special soil-forming process of carbonates, enrich Cd in soils. Agricultural and industrial activities also affect soil Cd concentrations. An enrichment model of Cd in Se-rich soils is forwarded.

Ecological and human health risk of heavy metals in Nubui River: a case of rural remote communities

IntroductionThe Nubui River is a primary source of water for drinking purposes and other domestic activities in the rural communities dotted along its riparian zone, with agriculture being the major activity occurring in this important ecotone. The river has become a potential sink for agrochemical residue, including heavy metals, and has apparent aesthetic water quality issues, with associated health consequences. This study, therefore, assessed the health risks of heavy metals within the rural populations in the catchment areas, who have limited sources of improved water supply.MethodsThe concentration of iron (Fe), lead (Pb), cadmium (Cd), mercury (Hg), and zinc (Zn) was assessed on cumulatively 275 water samples, using a Perkin Elmer PINAAcle 900 T atomic absorption spectrophotometer for 11 months. A cross-sectional survey was conducted amongst 338 community members, following field observations on utilisation types, aesthetic appeal, and perceived quality of water from the Nubui River. To determine the potential human and ecological risks of heavy metals, the hazard quotient, chronic daily intake, contamination factor, and health pollution indices of heavy metals were computed. STATA version 16 was used to analyse the survey results.ResultsDescriptive statistics of average concentrations of heavy metals in surface water at all sampling stations showed the pattern Hg < Pb < Cd < Zn < Fe, with relatively low concentrations, between 0.001 and 0.004 mg/L for Hg, 0.0011 and 0.0019 mg/L for Pb, 0.0461 and 0.0739 mg/L for Zn, and 0.2409 and 0.377 mg/L for Fe. The findings, however, showed relatively high cadmium levels between 0.0215 mg/L and 0.0383 mg/L in two of five sampling stations in comparison with the World Health Organisation (WHO) drinking water guideline values in some months. Hazard quotient values indicate that the population is safe from the non-carcinogenic health risks of exposure to heavy metals through oral routes. The contamination factor and heavy metal pollution indices for cadmium exceed recommended guideline values of 1 and 100, respectively. Meanwhile, 73.1% of community members evidently preferred the Nubui River for various domestic activities with 86.1% of them utilising it for drinking purposes. This occurrence results in exposure to associated health risks.

Assessment of toxic elements in selected fish species in the marine water at Jamestown, Ghana

Fish is an excellent source of low-fat protein. Fish contains a lot of omega-3 fatty acids, as well as vitamins D and B2 (riboflavin). The daily consumption of contaminated food, especially fish, is among the primary cause of heavy metals pollution to human health. The aim of the research was to determine the concentration of heavy metals in selected species of fish from the Gulf of Guinea at James Town in Ghana. In tandem with the study's objective, samples of different forms of fish, Cassava fish, Flatfish, Redfish, Kingfish, and Silverfish, and sediment were obtained and analyzed for the presence of heavy metals using atomic absorption spectrometer (PerkinElmer®, PinAAcle 900T). The analysis indicated a high concentration of Pb, Cd, and Cr concentrations in fish gills, muscles, and sediment. High lead concentration in Silverfish gills (5.9 mg/kg) and Flatfish gills (2.29 mg/kg) above WHO levels. Cadmium was found in all fish species and sediment except Kingfish. Chromium concentrations were high n Cassava fish (3.10 mg/kg) and Silverfish (4.01 mg/kg) and copper concentrations were absent in the fish species. Arsenic and mercury were also not detected in all fish species and sediment. Manganese concentrations were found in fish and sediment. High cadmium target hazard quotient (0.17–11.60 for adults and 0.24 to 16.24 for children) and cancer risk (0.00–0.04) values in fish samples indicated potential health concerns. The Hazard Index (HI) for the analyzed samples ranged from 0.00 to 12.48 for adults and 0.00 to 17.47 for children. The study suggests that eliminating pollution and other sources of waterbody pollution is crucial to protecting the marine environment and the health of seafood consumers.

The Effect of Two Siderophore-Producing Bacillus Strains on the Growth Promotion of Perennial Ryegrass under Cadmium Stress.

Cadmium (Cd) is a highly toxic and cumulative environmental pollutant. Siderophores are heavy metal chelators with high affinity to heavy metals, such as Cd. Ryegrass (Lolium perenne L.) has a potential remediation capacity for soils contaminated by heavy metals. Consequently, using ryegrass alongside beneficial soil microorganisms that produce siderophores may be an effective means to remediate soils contaminated with Cd. In this study, the Bacillus strains WL1210 and CD303, which were previously isolated from the rhizospheres of Nitraria tangutorum in Wulan and Peganum harmala L. in Dachaidan, Qinghai, China, respectively, both arid and sandy environments, were evaluated for heavy metal pollution mitigation. Our quantitative analyses have discerned that the two bacterial strains possess commendable attributes of phosphorus (P) solubilization and potassium (K) dissolution, coupled with the capacity to produce phytohormones. To assess the heavy metal stress resilience of these strains, they were subjected to a cadmium concentration gradient, revealing their incremental growth despite cadmium presence, indicative of a pronounced tolerance threshold. The subsequent phylogenetic analysis, bolstered by robust genomic data from conserved housekeeping genes, including 16S rDNA, gyr B gene sequencing, as well as dnaK and recA, delineated a species-level phylogenetic tree, thereby confirming the strains as Bacillus atrophaeus. Additionally, we identified the types of iron-carrier-producing strains as catechol (WL1210) and carboxylic acid ferrophilin (CD303). A genomic analysis uncovered functional genes in strain CD303 associated with plant growth and iron carrier biosynthesis, such as fnr and iscA. Ryegrass seed germination assays, alongside morphological and physiological evaluations under diverse heavy metal stress, underscored the strains' potential to enhance ryegrass growth under high cadmium stress when treated with bacterial suspensions. This insight probes the strains' utility in leveraging alpine microbial resources and promoting ryegrass proliferation.

Associations among global long interspersed nuclear element-1 DNA methylation, metal exposure, and chronic kidney disease.

Long interspersed nuclear element-1 (LINE-1) methylation serves as an indicator of global DNA methylation. This study explored the correlation between LINE-1 methylation and chronic kidney disease (CKD). We also evaluated whether LINE-1 methylation could modify the association between CKD and metal exposure. A total of 213 patients with clinically defined CKD, without hemodialysis and 416 age and sex matched controls were recruited. Levels of LINE-1 methylation, total urinary arsenic, blood lead, blood cadmium, and plasma selenium were assessed. The results reveal a positive association between LINE-1 methylation and CKD, with an odds ratio (OR) of 5.30 (95% confidence interval: 2.81 to 9.99). Total urinary arsenic and blood cadmium concentrations were positively related with LINE-1 methylation. This study was the first to observe that low plasma selenium, high blood cadmium, and high blood lead levels significantly and additively interact with increased LINE-1 methylation to increase the OR of CKD. Additionally, high LINE-1 methylation interacted multiplicatively with low plasma selenium to increase the OR of CKD (p < 0.001). This study highlighted the significant association between LINE-1 hypermethylation and CKD. Furthermore, the results demonstrate that LINE-1 methylation can interact with high blood cadmium or low plasma selenium to affect CKD risk.

Association of dietary selenium intake and all-cause mortality of Parkinson’s disease and its interaction with blood cadmium level: a retrospective cohort study

BackgroundParkinson’s disease (PD) is a slowly progressive neurodegenerating disease that may eventually lead to disabling condition and pose a threat to the health of aging populations. This study aimed to explore the association of two potential risk factors, selenium and cadmium, with the prognosis of Parkinson’s disease as well as their interaction effect.MethodsData were obtained from the National Health and Nutrition Examination Survey (NHANES) 2005–2006 to 2015–2016 and National Death Index (NDI). Participants were classified as Parkinson’s patients by self-reported anti-Parkinson medications usage. Cox regression models and restricted cubic spline models were applied to evaluate the association between PD mortality and selenium intake level as well as blood cadmium level. Subgroup analysis was also conducted to explore the interaction between them.ResultsA total of 184 individuals were included. In full adjusted cox regression model (adjusted for age, gender, race, hypertension, pesticide exposure, smoking status and caffeine intake), compared with participants with low selenium intake, those with normal selenium intake level were significantly associated with less risk of death (95%CI: 0.18–0.76, P = 0.005) while no significant association was found between low selenium intake group and high selenium group (95%CI: 0.16–1.20, P = 0.112). Restricted cubic spline model indicated a nonlinear relationship between selenium intake and PD mortality (P for nonlinearity = 0.050). The association between PD mortality and blood cadmium level was not significant (95%CI: 0.19–5.57, P = 0.112). However, the interaction term of selenium intake and blood cadmium showed significance in the cox model (P for interaction = 0.048). Subgroup analysis showed that the significant protective effect of selenium intake existed in populations with high blood cadmium but not in populations with low blood cadmium.ConclusionModerate increase of selenium intake had a protective effect on PD mortality especially in high blood cadmium populations.

Geoenvironmental Assessment of the Impacts of Ewu-Elepe Dumpsite on Soil and Groundwater Resources at Ikorodu, Lagos State, Nigeria

The environmental status of the municipal solid waste dumpsite at Ewu-Elepe, Ikorodu Local Government Area of Lagos State was investigated. A total of seventeen (17) samples consisting of twelve (12) soils, three (3) groundwater and two (2) leachate samples were collected and analyzed for different parameters using Atomic Absorption Spectrophotometer (AAS). The results revealed that in the leachate samples, all the heavy metals, Cl- , COD, salinity, and conductivity contents showed significant increase. The physicochemical results for the groundwater samples agreed with the international standards for drinking water, except for high cadmium content (0.009mg/l) recorded in the groundwater sample W1 which exceeded the NSDWQ and WHO permissible limits of 0.003 and 0.005mg/l respectively for drinking water, and high manganese content (0.09mg/l) recorded also in W1. The results of soil samples from the dumpsite showed that the concentration of all the heavy metals, Zn (23.5mg/kg), Cu (10.8mg/kg), Cr (14.2mg/kg), Ni (3.47mg/kg) and Pb (19.0mg/kg) fall below the Sediment Quality Criteria ISQG-Low level and the Lowest Effect Range of the New York Sediment Criteria except for Cd (16.60mg/kg) which is even higher than the High Effect Range of both the New York sediment Criteria and the Sediment Quality Criteria that the soil within the dumpsite have been moderately impacted is further demonstrated by the application of environmentric parameters treatment such as Contamination Factor (CF), Geo-accumulation Index, Enrichment Factor (EF) and Ecological Risk Factor Analyses. The results of the sediment quality assessment are good evidence to confirm that the soil of the dumpsite is highly polluted with cadmium (Cd), and moderately contaminated with lead (Pb). This study reveals that the solid waste dumpsite is affecting the natural quality of the ambient environment. Therefore, indiscriminate dumping of solid waste at the dumpsite should be prohibited.