Toxic Cd Research Articles

Spatial distribution of health risk assessment of a drinking water reservoir exposed to urban agglomeration and industrial lead contamination in Istanbul, Türkiye.

The Ömerli Dam, supplied by multiple rivers that provide a major amount of Istanbul's water demands for drinking and irrigation, is experiencing toxicological threats due to rapid expansion, increased industrial activity, and population growth in light of the impending global drought. In this study, multivariate statistical analysis and spatial distribution based on geographic information system (GIS) was used to examine the status of pollution and health risk, irrigation water quality, and stochastic geo-environmental risk sources of 16 potentially toxic elements (PTEs: Na, Mg, K, Ca, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Hg, and Pb) concentrations from samples in the dam. Also, spatial analyzing of quality indices was used to assess the dam's feasibility for irrigation and drinking. As per the results of the study, the dam water has mild heavy metal (loid) pollution, which is measured at 16 PTE by the heavy metal (loid) pollution index (HPI) and heavy metal (loid) evaluation index (HEI) values. The pollution level is low during the rainy season and moderate during the dry season. The water at sampling station S3 (HPI = 146.50) is unfit for consumption and cannot be used for drinking. The majority of harmful metal species exhibited elevated concentrations (notably Pb: 51.78 μg/L, Cr: 8.55 μg/L) in the dam lake water, particularly during the dry season. The toxic metals Pb and Cd account for 15.95% of the total variance, with a high degree of loading. Lead concentrations were found to be above WHO and USEPA limit values only in S2 and S4 during the wet season, but above 0.01 mg/L in all stations except S1 during the dry. Dam water is acceptable for agricultural use, according on the results of the, sodium absorption rate, the percentage of Na and the magnesium damage index, average SAR < 0.9, Na% < 25, and MH < 50, respectively. HQingestion and HI values (all less than 1 in all PTEs) indicate that noncarcinogenic impacts might occur. PRACTITIONER POINTS: Ömerli Dam provides most of the drinking and potable water needs of a mega city like Istanbul. With this study, toxic metal pollution of dam surface water and its possible effects on human health were analyzed for the first time on a spatially wide scale.

Inhibitory effects of cadmium and hydrophilic cadmium telluride quantum dots on the white rot fungus Phanerochaete velutina.

The white rot fungus P. velutina was investigated for its ability to decolorize the reactive textile dye Reactive Black 5 (RB5) that was co-exposed to CdCl2 and quantum dots (QDs) consisting of a CdTe core capped with two different hydrophilic organic ligands (NAC and MPA). Without co-exposure, P. velutina completely decolorizes RB5 within 9 days. The highest inhibitory effect was found for soluble CdCl2 with an EC50 of 583μgl-1, followed by MPA-QDs (10,628μgl-1) and NAC-QDs (17,575μgl-1). The different EC50 values indicate that the nanoparticle coatings have a strong influence on the inhibitory effects, as the organic ligands used for surface passivation prevented the leaching of acute toxic Cd ions from the metallic QD core. Compared to CdCl2, the CdTe QDs were less inhibitory to the formation of fungal metabolites and their decolorization ability on co-exposed textile dyes. In addition, the literature comparison suggests that P. velutina is more resilient to cadmium than other microorganisms. The fungus could therefore be used for bioremediation applications of dye- or QD-contaminated wastewater from the textile or semiconductor industries.

Experimental and ANN based process optimization for bioremediation of Cr6+ and Cd2+ by green adsorbent prepared from Artocarpus Heterophyllus leaves

The effective removal of toxic pollutants from water and waste water, is a challenging issue for environmental protection. In the present work, the performance of Artocarpus Heterophyllus (jackfruit) leaves have been examined for reduction of toxic Cr (VI) and Cd (II) from synthetic wastewater. Characterization of the adsorbent was made to evaluate the surface morphology and chemical composition, by Scanning Electron Micrograph (SEM) and Energy Dispersive Spectroscopy (EDS). Characteristic surface groups [Fourier Transform Infra-Red (FTIR)], surface area and surface structure [Brunauer–Emmett–Teller, (BET)] were also determined. The influences of various factors which control the removal process were studied experimentally in batch method and optimized. High removal efficiency was obtained at pH ≤ 2 for Cr (VI); and for Cd (II) it was ≥ 6. The experimental data were tested using different kinetic and isotherm models. Artocarpus Heterophyllus leaf was found suitable to remove 99.7 % Cr (VI) and 98.4 % Cd (II) from a strength of 20 mg L-1 solution at 0.5 g L-1 adsorbent concentration, at their respective favorable pHs. The reaction followed pseudo second order kinetic model for both the cases. The calculated sorption energy of 16.16 and 12.68 kJ mol-1, suggested chemical nature for both the cases. Desorption studies showed the effective reuse of Artocarpus Heterophyllus leaf for three times. The relatively high equilibrium adsorption capacity of 32.29 and 20.37 mg g-1 for Cr (VI) and Cd (II) respectively, suggested use of Artocarpus Heterophyllus leaf as a reasonably good green bio-adsorbent. The modeling of the complex adsorption process based on artificial neural network approach exhibited reliability and high degree of proficiency (R values of 0.999) in the model’s prediction and experimental data indicated its applicability in forecasting removal efficiency for both the metal ions.

Soil environmental monitoring of repurposed railway line operated for 75 years: case study in Northeast Poland

This study examines the environmental implications of repurposing former railway infrastructure into bicycle paths in northeastern Poland. While lauding the commendable initiative for offering eco-friendly transportation alternatives, the investigation emphasises the potential environmental and consequences linked to contaminated soils resulting from the former railway line, posing risks for both users and the environment. Topsoil samples (0-25cm) were collected from eight measurement points along the Szczytno - Biskupiec Reszelski railway line (Poland), at varying distances from the railway tracks (5-30m). Concentrations of specific Potentially Toxic Elements (PTEs), notably Ni, Zn, Pb, and Cd, were analysed in 48 topsoil samples. Furthermore, the soil contamination was assessed by contamination indices, single (Igeo, PI) and integrated (RI, (IPln, MERMQ). The study revealed variations in PTE concentrations, with the highest levels recorded at the fourth and seventh sampling sites (4:34.2-57.5mg/kg; 7:18.2-42.3mg/kg). These findings were consistently supported by the MERMQ and RI indices, emphasising the significant risks for the environment and increased soil toxicity. In light of the EU's proposed Soil Monitoring Law, the research emphasises the need for robust data collection, analysis, and contamination monitoring practices to facilitate informed decision-making and sustainable environmental management in repurposed transportation infrastructure.

Energy, Aromatic, and Medicinal Plants’ Potential and Prospects for the Remediation of Potentially Toxic Element-Contaminated Agricultural Soils: A Critical Meta-Analysis

A critical meta-analysis of the past decade’s investigations was carried out with the aim of assessing the use of plant-based techniques for soil remediation. Potentially toxic element (PTE) contaminated soils were selected since these contaminants are considered hazardous and have long-term effects. Furthermore, energy, aromatic, and medicinal plants were studied as their high-value products seem to be affected by PTEs’ existence. Lead (Pb), Cu, Cd, Zn, Cr, Co, Ni, Hg, and As accumulation in different parts of plant species has been investigated using proper indices. Aromatic plants seem to provide high phytoremediation yields. Increasing toxicity levels and the coexistence of many metals enhance the accumulation capacity of aromatic plants, even of toxic Cd. In plants usable as energy sources, antagonistic effects were observed, as the simultaneous presence of Cu and Cd resulted in lower thermic capacity. Finally, in most of the plants studied, it was observed that the phytostabilization technique, i.e., the accumulation of metals mainly in the roots of the plants, was often used, allowing for the aboveground part to be almost completely free of metallic pollutants. Using plants for remediation was proven to be advantageous within a circular economy model. Such a process is a promising solution, both economically and environmentally, since it provides a useful tool for keeping environmental balance and producing safe goods.

Influence of Organic Matter and Speciation on the Dynamics of Trace Metal Adsorption on Microplastics in Marine Conditions.

Dissolved organic matter (DOM), primarily in the form of humic acid (HA), plays a crucial role in trace metal (TM) speciation and their subsequent adsorption dynamics on microplastics (MP) in aquatic environments. This study evaluates the impact of environmentally relevant concentrations of HA on the adsorption behaviors of essential (Co, Cu, Ni, and Zn) and toxic (Cd and Pb) TMs onto polyethylene (PE) and polypropylene (PP) pellets, as well as PP fibers under marine conditions, during a six-week experiment. The HA concentrations were 0.1, 1, and 5 mg/L, while all metals were in the same amounts (10 µg/L). Results reveal that HA significantly influences the adsorption of Cu, Pb, and Zn on MP, particularly on PP fibers, which exhibited the greatest TM adsorption dynamics. The adsorption patterns correspond to the concentrations of these metals in seawater, with the sequence for pellets being Zn > Cu > Pb > Ni > Co~Cd, and for fibers Cu > Zn > Pb > Co~Ni > Cd. Speciation modeling supported these findings, indicating that Cu, Pb, and Zn predominantly associate with HA in seawater, facilitating their adsorption on MP, whereas Cd, Co, and Ni mainly form free ions and inorganic complexes, resulting in slower adsorption dynamics. Statistical analysis confirmed the influence of HA on the adsorption of Cd, Pb, Cu, and Ni. By investigating the dynamics of TM adsorption on plastics, the influence of DOM on these two contaminants under marine conditions was evaluated. The presented results can help in forming a better understanding of synergistic plastic and trace metal pollution in marine systems that are relevant at the global level, since both contaminants pose a serious threat to aquatic ecosystems.

Molecular and Environmental Determinants of Addictive Substances.

Knowledge about determinants of addiction in people taking addictive substances is poor and needs to be supplemented. The novelty of this paper consists in the analysis of innovative aspects of current research about relationships between determinants of addiction in Polish patients taking addictive substances and rare available data regarding the relationships between these factors from studies from recent years from other environments, mainly in Europe, and on the development of genetic determinants of physiological responses. We try to explain the role of the microelements Mn, Fe, Cu, Co, Zn, Cr, Ni, Tl, Se, Al, B, Mo, V, Sn, Sb, Ag, Sr, and Ba, the toxic metals Cd, Hg, As, and Pb, and the rare earth elements Sc, La, Ce, Pr, Eu, Gd, and Nd as factors that may shape the development of addiction to addictive substances or drugs. The interactions between factors (gene polymorphism, especially ANKK1 (TaqI A), ANKK1 (Taq1 A-CT), DRD2 (TaqI B, DRD2 Taq1 B-GA, DRD2 Taq1 B-AA, DRD2-141C Ins/Del), and OPRM1 (A118G)) in patients addicted to addictive substances and consumption of vegetables, consumption of dairy products, exposure to harmful factors, and their relationships with physiological responses, which confirm the importance of internal factors as determinants of addiction, are analyzed, taking into account gender and region. The innovation of this review is to show that the homozygous TT mutant of the ANKK1 TaqI A polymorphism rs 1800497 may be a factor in increased risk of opioid dependence. We identify a variation in the functioning of the immune system in addicted patients from different environments as a result of the interaction of polymorphisms.

Overexpression of bacterial γ-glutamylcysteine synthetase increases toxic metal(loid)s tolerance and accumulation in Crambe abyssinica.

Transgenic Crambe abyssinica lines overexpressing γ-ECS significantly enhance tolerance to and accumulation of toxic metal(loid)s, improving phytoremediation potential and offering an effective solution for contaminated soil management. Phytoremediation is an attractive environmental-friendly technology to remove metal(loid)s from contaminated soils and water. However, tolerance to toxic metals in plants is a critical limiting factor. Transgenic Crambe abyssinica lines were developed that overexpress the bacterial γ-glutamylcysteine synthetase (γ-ECS) gene to increase the levels of non-protein thiol peptides such as γ-glutamylcysteine (γ-EC), glutathione (GSH), and phytochelatins (PCs) that mediate metal(loid)s detoxification. The present study investigated the effect of γ-ECS overexpression on the tolerance to and accumulation of toxic As, Cd, Pb, Hg, and Cr supplied individually or as a mixture of metals. Compared to wild-type plants, γ-ECS transgenics (γ-ECS1-8 and γ-ECS16-5) exhibited a significantly higher capacity to tolerate and accumulate these elements in aboveground tissues, i.e., 76-154% As, 200-254% Cd, 37-48% Hg, 26-69% Pb, and 39-46% Cr, when supplied individually. This is attributable to enhanced production of GSH (82-159% and 75-87%) and PC2 (27-33% and 37-65%) as compared to WT plants under AsV and Cd exposure, respectively. The levels of Cys and γ-EC were also increased by 56-67% and 450-794% in the overexpression lines compared to WT plants under non-stress conditions, respectively. This likely enhanced the metabolic pathway associated with GSH biosynthesis, leading to the ultimate synthesis of PCs, which detoxify toxic metal(loid)s through chelation. These findings demonstrate that γ-ECS overexpressing Crambe lines can be used for the enhanced phytoremediation of toxic metals and metalloids from contaminated soils.

Exploring 32 % efficiency of eco-friendly kusachiite-based solar cells: A numerical study

Recently, solar cells have appeared as a promising solution to meet the increasing energy demand. However, their large-scale commercial use is limited by issues such as toxicity (Cd, Pb, etc), high manufacturing costs, lower stability, and low efficiency. In this perspective, kusachiite solar cells (KSCs) are environmentally friendly, long-term stable, and easy to manufacture. Thus, in this work, kusachiite (CuBi2O4) is used as an absorber layer, with NiO and SrTiO3 serving as the hole transport material (HTM) and an electron transport layer (ETL), respectively. The KSCs, with a structure of FTO/SrTiO3/CuBi2O4/NiO/Au, are numerically simulated. Maximum power conversion efficiency is achieved by optimizing several photovoltaic parameters, such as the thickness and doping density of the ETL, absorber, and HTM. The optimized thicknesses for the HTL, absorber layer, and ETL are 1.5 μm, 2.28 μm, and 0.02 μm, respectively. The designed KSCs exhibit an efficiency eta (η) of 31.89 %, an open-circuit voltage (Voc) of 1.31 V, a short-circuit current (Jsc) of 28.58 mA/cm2, and a fill factor (FF) of 84.99 %.

Nutritional Analysis of Wheat Flour at Hyderabad for Detection of Essential and Toxic Metals

Wheat flour is basic diet in Asian countries. Quality of wheat flour and milling process has been changing day by day which have profound impact on nutrition value of wheat flour. Objective: To carry out Nutritional assessment of whole and refined wheat flour grinded locally at 13 mills of Hyderabad to determine presence of essential and toxic metals. Methods: Whole and refined wheat flour were randomly collected from 13 flour mills of Hyderabad for determination of moisture, ash, fat, fiber, carbohydrates, proteins, essential (Fe, Zn and Mn) and Toxic (Cd, Cr, Pb and Cu) metals with standard scientific methods. Results: High moisture has been recorded in F.M.13 mill in whole and refined flour as 12.5% and 11.8% respectively where as low moisture 7.1% has been found in whole flour in F.M.10 mill and 7.4% in refined flour in F.M.01 mill. F.M.04 contains high Iron in whole and refined wheat flour as 0.91±1.1 and 0.74±0.5mg/kg respectively. Zinc content has been high in F.M.10 and F.M.11 as 9.95±5.6mg/kg and 8.66±5.1mg/kg respectively. Cadmium has been high in F.M.09 as 0.06±0.01mg/kg in refined flour whereas Lead has been high in F.M.09 as 0.28±0.13mg/kg in whole wheat flour. Conclusions: Carbohydrates have been high whereas fiber and protein has been low in refined flour. Fe, Zn and Mn has been significantly low whereas Cd, Pb, Cr and Cu has been significantly high in refined wheat flour. It is concluded that consumption of whole wheat flour is better than refined wheat flour.

How tree species have modified the potentially toxic elements distributed in the developed soil–plant system in a post-fire site in highly industrialized region

The biogeochemical cycles of trace elements are changed by fire as a result of the mineralization of organic matter. Monitoring the accumulation of trace elements in both the environment and the tree biomass during the post-fire (PF) forest ecosystem regeneration process is important for tree species selection for reforestation in ecosystems under anthropogenic pressure. We analyzed the soil concentrations of different groups of potentially toxic elements (PTEs), including beneficial (Al), toxic (Cd, Cr, Pb), and microelements (Cu, Mn, Ni, Zn), and their bioaccumulation in the tree species (Pinus sylvestris, Betula pendula, Alnus glutinosa) biomass introduced after a fire in a forest weakened by long-term emissions of industrial pollutants. The results indicated no direct threat from the PTEs tested at the PF site. The tree species introduced 30 years ago may have modified the biogeochemical cycles of the PTEs through different strategies of bioaccumulation in the belowground and aboveground biomass. Alder had relatively high Al concentrations in the roots and a low translocation factor (TF). Pine and birch had lower Al concentrations in the roots and higher TFs. Foliage concentrations and the TF of Cd increased from alder to pine to birch. However, the highest concentration and bioaccumulation factor of Cd was found in the alder roots. The concentrations of Cr in the foliage and the Cr TFs in the studied species increased from pine to birch to alder. Higher concentrations of Cu and Ni were found in the foliage of birch and alder than of pine. Among the species, birch also had the highest Pb and Zn concentrations in the roots and foliage. We found that different tree species had different patterns of PTE phytostabilization and ways they incorporated these elements into the biological cycle, and these patterns were not dependent on fire disturbance. This suggests that similar patterns might also occur in more polluted soils. Therefore, species-dependent bioaccumulation patterns could also be used to design phytostabilization and remediation treatments for polluted sites under industrial pressure.

Excellent adsorption of toxic Cd (II) ions from water with effective antibacterial activity by novel GO-ZnO-curcumin composite.

A significant health risk arises from the bioaccumulation of harmful Cd (II) in drinking water. Here, we report the unique Cd (II) remediation from drinkingwater by using novel GO-ZnO-curcumin composite. The composites were tailored by varying the ratio of GO-ZnO and curcumin. The composites followed Langmuir adsorption isotherm and pseudo-second-order kinetics. ZnO nano-rods were more effective in Cd (II) than ZnO nano-disks. A maximum adsorption capacity of 4580 ± 40mg/gm was achieved for 21G-B with a removal efficiency of 87.5% at neutral pH under optimized conditions. The removal process was governed by ion exchange and electrostatic attraction, followed bycation exchange capacity (CEC). The lattice parameter increase was detected after adsorption of Cd (II) ions. The regeneration and reusability of the composite was studied. Also, the effect of presence of dyes such as methylene blue on Cd (II) adsorption was noted. The latter had negligible effect on Cd (II) removal efficiency from water. The composite showed high antibacterial activity against B. subtilis and P. aeruginosa with minimum inhibitory concentration (MIC) of 10 ± 0.75µg/ml and 5 ± 1µg/ml respectively due to the presence of zinc. Composite stability was confirmed through leaching and thermal gravimetric analysis (TGA) analysis. The study establishes the nanocomposite as a potential material for remediation of hazardous Cd (II) ions from real water samples under neutral conditions.

Super-stable mineralization of arsenic contaminated water using industrialized layered double hydroxides and derivatives

The issue of arsenic contamination, specifically in the form of As(III), is progressively escalating, so presenting a substantial danger to human well-being and security. In this study, commercially industrially produced CaAl-layered double hydroxides (CaAl-LDH) and MgAl-LDH were processed by calcination to produce a series of LDH-based mixed metal oxides (CaAl-x, MgAl-x) at calcination temperatures (x) ranging from 200 to 1000 °C. The resulting CaAl-900 exhibited a remarkable capacity for removing high concentrations of As(III), with a removal capacity of 612.5 mg/g. Besides, MgAl-500 demonstrated effective removal of low levels of As(III) to meet industrial emission standards, specifically below 0.5 mg/L. Furthermore, MgAl-500 was employed to simultaneously stabilize mixed toxic metals (As(III), Pb(II), and Cd(II) ions) in the treatment process of contaminated water, meeting standard levels. The comprehensive analysis of the characterization data indicated that the key determinant for the remarkable capacity of CaAl-900 to remove As(III) was its surface adsorption and memory effect. MgAl-500 also formed complex compounds through formation of As-O-Mg bond. This research showcases the capacity of LDHs produced from the industry for efficient remediation of As(III) ions in water.

Assessment of Essential and Toxic Element Levels in the Toenails of Children with Autism Spectrum Disorder.

Autism spectrum disorder (ASD) has become a global public health concern, impacting the quality of life. The question of gene-environment interaction in the emergence of ASD remains a subject of ongoing debate, and exploring its pathophysiology is thoroughly related to metals as a risk factor. Therefore, this study aims to assess the levels of toxic (Al, Cd, Hg, and Pb) and essential (Cr, Mn, Fe, Ni, Cu, Zn, and Se) elements in toenail samples collected in children with ASD and neurotypical children, by ICP-MS. Parallelly, we will discuss the use of toenails as an exposure indicator. The study involved 208 children aged 3 to 14 from Marrakech, Morocco. One hundred two were diagnosed with ASD and 106 were neurotypical children. Significant statistical differences in the concentration of Cr, Mn, and Fe were documented between the two groups. Higher levels of Pb in toenails compared to reference values have been reported. No association was established between concentrations of elements and age. Spearman correlation coefficients revealed a significantly different pattern of mutual dependence for toxic and essential elements between the two groups. The strongest positive correlations were found in the neurotypical group (Fe-Mn (ρ = 0.750), and Se-Zn (ρ = 0.800)). These results provide additional, although inconclusive, evidence on the probable role of element disturbance in the pathogenesis of ASD. Further studies should be performed to explore other nutritional, cultural, sociodemographic, environmental, and methodological factors that may impact the levels of these elements in the nails and their possible correlation with the incidence of ASD.

Evaluating the environmental effects of open dumps and waste farming: A case study

Dhapa, the landfill situated in Kolkata, is a very active site for municipal dumping. A humongous amount of municipal solid waste is added in this dump daily and the nearby farmlands produce a significant yield for the local population. The current study seeks to examine the environmental associated with leachate migration due to open dumping of unsorted solid waste in Dhapa, Kolkata, India. Also, the second goal of the study is to assess the risk to public health associated with the consumption of agricultural products possibly contaminated with heavy metals through soil and groundwater. The seasonal soil and groundwater sample, and samples of products grown near the landfill were collected around the periphery of Dhapa. The presence of heavy metals in the samples was determined using classical methods in a specialized laboratory. The soil and groundwater results compared to FAO/WHO, and BIS/WHO was found that toxic metal Cd, Cr, Zn, Pb &amp; Hg were present in high concentrations. For the vegetables grown at the site fields, multiple samples were collected as multiple different vegetables are grown around the year, it was found that mainly Cd, Cr, Zn, Pb and Hg exceeding Indian permissible standards of consumptions many fold. Finally by the use of multiple indices like Average Daily Dose (ADD) &amp; Chronic Daily Intake (CDI) along with Hazard Quotient (HQ) it was found that carcinogenic risk, on human health, was highest in the ground water and vegetables. The current study fills the gap associated with the scientific substantiation of actively developing environmental hazards at the regional level.

Metal content, bioaccumulation, translocation, and health risk assessment of root vegetables grown in KwaZulu-Natal small-scale farms of South Africa.

Metal uptake by vegetables is becoming a threat to the life of consumers. Therefore, continuous monitoring of metals in vegetables and soils is becoming a necessity. In this study, the occurrence of 18 metals in amadumbe (Colocasia esculenta L.), sweet potatoes (Ipomoea batatas L.), potatoes (Solanum tuberosum L.), and carrots (Daucus carrota L.) grown in small-scale South African agricultural farms was monitored using inductively coupled plasma-optical emission spectroscopy. All the 18 investigated elements were detected in soils and different vegetative plants parts. Bioaccumulation factors indicated the transfer of selected metals from soils into the plant roots. Toxic metals Cd, Cr, and Pb had their concentrations exceeding the maximum permissible levels set by the World Health Organization in the edible parts of all root vegetables. Cd and Pb varied between 18.89 and 19.19mgkg-1 and 10.46 and 11.46mgkg-1, respectively, while Cr remained constant at 16.78mgkg-1. The exact metals together with As and Ni had their total hazard quotients exceeding the threshold value of 1, which indicated that the daily consumption of the investigated root vegetables is likely to pose health risks to both adults and children. Therefore, this study points out to a possibility of toxic health effects that could arise when these vegetables are consumed daily.

Comparative biomonitoring of airborne potentially toxic elements using mosses (Hypnum cupressiforme, Brachythecium spp.) and lichen (Evernia prunastri) over remote areas.

The selection of the appropriate biomonitor species is a crucial criterion for biomonitoring on a broad spatial scale. Mosses Hypnum cupressiforme and Brachythecium spp. and lichen Evernia prunastri were sampled at 22 remote sites over Serbia aiming interspecies comparison of their bioconcentration capacities. The concentration of 16 potentially toxic elements (PTEs), Al, Ba, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, P, Pb, S, Sr, V, and Zn, was measured in the samples. Between the co-located mosses, linear regression analysis (type II) showed significant determination coefficients only for a couple of the elements (Cd and S), while for H. cupressiforme vs. lichen, significant regression lines were obtained for a broader set of elements (Ba, Cd, Fe, Hg, Mn, Ni, Sr). The ratio of the PTEs in the mosses discovered higher concentrations in H. cupressiforme than in another moss at some sites and vice versa at other sites. According to the PTE ratios, H. cupressiforme accumulated much more element content than the lichen, but followed a similar spatial pattern. In addition, principal component analysis (PCA) pointed out a different grouping of the PTEs depending on the species tested. The poor correlation of the moss-moss data is perhaps because several species of the genus Brachythecium were sampled, which possibly influenced the average genus accumulation capacity. In addition, morphological features of the mosses (concave vs. flat leaflets, creeping vs. cushiony life form) presumably delegate differences in PTE accumulation. To conclude, it should be careful with using more biomonitor species, even of the same genus, within the same study.

Assessment of essential and toxic trace element levels in erythrocytes of hemodialysis patients with end-stage renal disease

BackgroundChronic kidney disease (CKD) is a global public health problem, resulting in end-stage kidney disease, cardiovascular disease, and premature death. AimThe aim of the study was to determine the profile of essential and toxic trace elements in erythrocytes of patients with end-stage renal disease (ESRD) and their relationship with selected anthropometric and biochemical parameters. MethodsThe present study compared the profiles of trace elements, including toxic sub-stances, in the erythrocytes of 80 hemodialysis patients with CKD with 40 healthy subjects. All patients had stage 5 CKD. The levels of Cd and Pb were determined by graphite furnace atomic absorption spectrometry and levels of Fe, Mn, Zn, Cu Cr, Ni, and Li by inductively coupled plasma atomic emission spectrometry. ResultsThe ESRD patients demonstrated significantly lower Fe and Zn concentrations and significantly higher Mn and Li and toxic Pb and Cd concentrations in erythrocytes compared to those of the healthy controls. Negative correlations were observed, among others, between the concentrations of Cu, Li, and creatinine; Cu and phosphates; Mn, Pb, and transferrin saturation while positive correlations were noted between Cu, Cr, and transferrin and Pb, Cr, and the normalized protein catabolism rate. ConclusionsThe higher concentrations of toxic elements present in the erythrocytes of CKD patients might have resulted from the reduced ability of the kidneys to excrete them. Moreover, differences in the concentrations of essential elements (Fe, Mn, Zn) between the two groups indicated that their resorption in the kidneys of CKD patients was impaired. Patients with CKD might benefit from interventions intended to reduce high, toxic concentrations of Pb and Cd and Li and Mn as an alternative supportive treatment. Iron and zinc supplementation should be a component for the treatment of anemia in CKD patients.

Heavy metal pollution causes mass mortality of fish in a tropical estuary in the southwestern Bay of Bengal

A massive fish mortality of the major species, viz., Mugil cephalus, Chanos chanos, and Oreochromis mossambicus, occurred on November 27, 2017 in the Adyar estuary. This catastrophe followed a spell of heavy rainfall and flash floods. A detailed study of water quality parameters (pH, water temperature, salinity, total suspended matter, dissolved oxygen, biochemical oxygen demand, and nutrients) and heavy metals, i.e., chromium (Cr), copper (Cu), cadmium (Cd), nickel (Ni), lead (Pb), and zinc (Zn), in the sediment and fish tissues were analyzed. Pollution indices like the enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), potential ecological risk index (PERI), and biota sediment accumulation factor (BSAF) were used to measure heavy metals. The pollution indices revealed that metals were significantly enriched in the sediments. The Igeo indicates that there was moderate contamination by Cd (2.27–3.25), whereas CF shows high contamination by Cd (7.22–9.72) and moderate contamination by Pb (2.5–3.25). The PLI (1.04–1.13) suggests that heavy metal contamination of sediments has occurred. Results showed that high concentrations of the toxic metals Pb and Cd were found in the sediment as well as in fish tissues. Length and weight of fish are significantly correlated (r2 = 0.98, p < 0.05). The study revealed that the mass fish kill was due to impulsive changes in the water quality and heavy metal pollution from untreated urban sewage discharges in this region.

Facile and economic preparation of graphene hydrothermal nanocomposite from sunflower waste: Kinetics, isotherms and thermodynamics for Cd(II) and Pb(II) removal from water

Keeping the need for good water quality and the demand of climatic issues, the sunflower waste was converted into graphene hydrothermal nanocomposite absorbents for the removal of toxic Cd(II) and Pb(II) metal ions from water. The graphene composite materials were studied by scanning (SEM) and transmission electron microscopy (TEM), XRD analysis, TG and DSC, Raman and IR spectroscopy. According to SEM and TEM analysis, the decarbonized materials had a disordered structure with amorphous carbon with a small pore content. During the carbonization process, the pores space was opened due to the removal of amorphous organic matter and the formation of defects; providing a significant number of meso- and micropores. The prepared graphene composite showed 133.33 and 222.22 mg/g Langmuir adsorption of Cd(II) and Pb(II) at pH 6.0, dose 0.33 g/30 mL, initial concentration 300 mg/L, time 30 min and at 45 °C temperature using hydrothermal nanocomposite HTC/graphene oxide absorbent. The obtained results followed the sorption of heavy metal ions in a mixed-diffusion mode with the contribution of a second-order reaction between the active center of the sorbent and the metal ions. The Temkin and Dubinin-Radushkevich model’s parameters and thermodynamic results confirmed endothermic physical interactions among adsorbent and metal ions. This paper is highly useful for managing sunflower waste and purifying water; leading to the present demand for clean water and climatic issues. The production of the effective low-cost nanocomposite using green synthesis technologies (hydrothermal carbonization of raw materials) is highly useful for the removal of Cd(II) and Pb(II) toxic metal ions from water.