Primary concept of nickel toxicity - an overview

Recent advances in biochar amendments for immobilization of heavy metals in an agricultural ecosystem: A systematic review

Over the last several decades, extensive and inefficient use of contemporary technologies has resulted in substantial environmental pollution, predominantly caused by potentially hazardous elements (PTEs), like heavy metals that severely harm living species. To combat the presence of heavy metals (HMs) in the agrarian system, biochar becomes an attractive approach for stabilizing and limiting availability of HMs in soils due to its high surface area, porosity, pH, aromatic structure as well as several functional groups, which mostly rely on the feedstock and pyrolysis temperature. Additionally, agricultural waste-derived biochar is an effective management option to ensure carbon neutrality and circular economy while also addressing social and environmental concerns. Given these diverse parameters, the present systematic evaluation seeks to (i) ascertain the effectiveness of heavy metal immobilization by agro waste-derived biochar; (ii) examine the presence of biochar on soil physico-chemical, and thermal properties, along with microbial diversity; (iii) explore the underlying mechanisms responsible for the reduction in heavy metal concentration; and (iv) possibility of biochar implications to advance circular economy approach. The collection of more than 200 papers catalogues the immobilization efficiency of biochar in agricultural soil and its impacts on soil from multi-angle perspectives. The data gathered suggests that pristine biochar effectively reduced cationic heavy metals (Pb, Cd, Cu, Ni) and Cr mobilization and uptake by plants, whereas modified biochar effectively reduced As in soil and plant systems. However, the exact mechanism underlying is a complex biochar-soil interaction. In addition to successfully immobilizing heavy metals in the soil, the application of biochar improved soil fertility and increased agricultural productivity. However, the lack of knowledge on unfavorable impacts on the agricultural systems, along with discrepancies between the use of biochar and experimental conditions, impeded a thorough understanding on a deeper level.

Trace Element Levels in Nails of Residents of Addis Ababa Are Shaped by Social Factors and Geography

The Akaki catchment in Ethiopia is home to Addis Ababa and about five million people. Its watercourses receive a variety of wastes released by the residents and industries. River water is being used for irrigation, livestock watering, and other domestic purposes. This study tested the hypothesis that the river pollution would be reflected in higher levels of trace elements in the nails of residents living in Akaki-Kality Sub-City in the downstream, as compared to those living in Gullele Sub-City in the upstream of the Akaki catchment. Samples were taken and subsequently analysed for metals using inductively coupled plasma optical emission spectrometry (ICP-OES). The mean concentrations of Fe, Zn, Cu, Mn, Ni, Cr, Pb, and As in nails from Akaki-Kality were 488 ± 49, 106 ± 10, 5.2 ± 0.3, 13 ± 1.5, 11 ± 8, 2.2 ± 0.3, 0.09 ± 0.01, and 0.16 ± 0.01 μg/g, respectively. Likewise, the concentrations of Fe, Zn, Cu, Mn, Ni, Cr, Pb, and As in nails from Gullele were 1035 ± 135, 251 ± 10, 6.6 ± 0.4, 31 ± 3.7, 7.4 ± 1.7, 2.0 ± 0.3, 0.63 ± 0.01, and 0.25 ± 0.01 μg/g, respectively. Co and Cd were not detected. Contrary to the initial hypothesis, higher metal levels were found in nails of residents living in the upstream rather than the downstream area of the catchment. In particular, the concentrations of Fe (p = 0.000), Zn (p = 0.01), and Mn (p = 0.000) were significantly elevated in nails from Gullele and also high in comparison with internationally reported values. Besides, geography and social factors, especially education level, correlated to trace metals in nails. Most of the elements were significantly lower in the nails of individuals with a university degree compared to those who were illiterate or only completed primary school.

Ferroptosis contributes to nickel-induced developmental neurotoxicity in zebrafish

Nickel (Ni) is a widely utilized heavy metal that can cause environmental pollution and health hazards. Its safety has attracted the attention of both the environmental ecology and public health fields. While the central nervous system (CNS) is one of the main targets of Ni, its neurotoxicity and the underlying mechanisms remain unclear. Here, by taking advantage of the zebrafish model for live imaging, genetic analysis and neurobehavioral studies, we reveal that the neurotoxic effects induced by exposure to environmentally relevant levels of Ni are closely related to ferroptosis, a newly-described form of iron-mediated cell death. In vivo two-photon imaging, neurobehavioral analysis and transcriptome sequencing consistently demonstrate that early neurodevelopment, neuroimmune function and vasculogenesis in zebrafish larvae are significantly affected by environmental Ni exposure. Importantly, exposure to various concentrations of Ni activates the ferroptosis pathway, as demonstrated by physiological/biochemical tests, as well as the expression of ferroptosis markers. Furthermore, pharmacological intervention of ferroptosis via deferoxamine (DFO), a classical iron chelating agent, strongly implicates iron dyshomeostasis and ferroptosis in these Ni-induced neurotoxic effects. Thus, this study elucidates the cellular and molecular mechanisms underlying Ni neurotoxicity, with implications for our understanding of the physiologically damaging effects of other environmental heavy metal pollutants.

The Impact of Long-Term Clinoptilolite Administration on the Concentration Profile of Metals in Rodent Organisms

Heavy metals are dangerous systemic toxicants that can induce multiple organ damage, primarily by inducing oxidative stress and mitochondrial damage. Clinoptilolite is a highly porous natural mineral with a magnificent capacity to eliminate metals from living organisms, mainly by ion-exchange and adsorption, thus providing detoxifying, antioxidant and anti-inflammatory medicinal effects. The in vivo efficiency and safety of the oral administration of clinoptilolite in its activated forms, tribomechanically activated zeolite (TMAZ) and Panaceo-Micro-Activated (PMA) zeolite, as well as the impact on the metallic biodistribution, was examined in healthy female rats. Concentration profiles of Al, As, Cd, Co, Pb, Ni and Sr were measured in rat blood, serum, femur, liver, kidney, small and large intestine, and brain using inductively coupled plasma mass spectrometry (ICP-MS) after a 12-week administration period. Our results point to a beneficial effect of clinoptilolite materials on the concentration profile of metals in female rats supplemented with the corresponding natural clinoptilolite materials, TMAZ and PMA zeolite. The observed decrease of measured toxicants in the kidney, femur, and small and large intestine after three months of oral intake occurred concomitantly with their most likely transient release into the bloodstream (serum) indicative of a detoxification process.

Determination of the Ni(II) Ions Sorption Mechanism on Dowex PSR2 and Dowex PSR3 Ion Exchangers Based on Spectroscopic Studies

This paper estimates the suitability of the strongly basic anion exchangers, Dowex PSR2 and Dowex PSR3, as sorbents of nickel ions in aqueous solutions. These actions are aimed at searching for new solutions due to the growing discharge of nickel into wastewaters, primarily due to its addition to steel. The nickel sorption experiments were conducted under static conditions and resulted in the optimization of pH, phase contact time, initial solution concentration, and temperature. The next step was to calculate the kinetic, isothermal, and thermodynamic parameters. Moreover, the ion exchangers were characterized by means of Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and CHN elemental analysis. It was found that the sorption process was most effective at pH 6 after 240 min and at the temperature of 293 K. The values of the thermodynamic parameters revealed that the adsorption was exothermic and spontaneous. The physicochemical analyses combined with the experimental research enabled determination of the sorption mechanism of Ni(II) ions.

Extracellular Vesicles as Mediators of Nickel-Induced Cancer Progression

Emerging evidence suggests that extracellular vesicles (EVs), which represent a crucial mode of intercellular communication, play important roles in cancer progression by transferring oncogenic materials. Nickel (Ni) has been identified as a human group I carcinogen; however, the underlying mechanisms governing Ni-induced carcinogenesis are still being elucidated. Here, we present data demonstrating that Ni exposure generates EVs that contribute to Ni-mediated carcinogenesis and cancer progression. Human bronchial epithelial (BEAS-2B) cells and human embryonic kidney-293 (HEK293) cells were chronically exposed to Ni to generate Ni-treated cells (Ni-6W), Ni-transformed BEAS-2B cells (Ni-3) and Ni-transformed HEK293 cells (HNi-4). The signatures of EVs isolated from Ni-6W, Ni-3, HNi-4, BEAS-2B, and HEK293 were analyzed. Compared to their respective untreated cells, Ni-6W, Ni-3, and HNi-4 released more EVs. This change in EV release coincided with increased transcription of the EV biogenesis markers CD82, CD63, and flotillin-1 (FLOT). Additionally, EVs from Ni-transformed cells had enriched protein and RNA, a phenotype also observed in other studies characterizing EVs from cancer cells. Interestingly, both epithelial cells and human umbilical vein endothelial (HUVEC) cells showed a preference for taking up Ni-altered EVs compared to EVs released from the untreated cells. Moreover, these Ni-altered EVs induced inflammatory responses in both epithelial and endothelial cells and increased the expression of coagulation markers in endothelial cells. Prolonged treatment of Ni-alerted EVs for two weeks induced the epithelial-to-mesenchymal transition (EMT) in BEAS-2B cells. This study is the first to characterize the effect of Ni on EVs and suggests the potential role of EVs in Ni-induced cancer progression.

Sodium Alginate/β-Cyclodextrin Reinforced Carbon Nanotubes Hydrogel as Alternative Adsorbent for Nickel(II) Metal Ion Removal

Water pollution issues, particularly those caused by heavy metal ions, have been significantly growing. This paper combined biopolymers such as sodium alginate (SA) and β-cyclodextrin (β-CD) to improve adsorption performance with the help of calcium ion as the cross-linked agent. Moreover, the addition of carbon nanotubes (CNTs) into the hybrid hydrogel matrix was examined. The adsorption of nickel(II) was thoroughly compared between pristine sodium alginate/β-cyclodextrin (SA-β-CD) and sodium alginate/β-cyclodextrin immobilized carbon nanotubes (SA-β-CD/CNTs) hydrogel. Both hydrogels were characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) spectral analysis, field emission scanning electron microscopy (FESEM), electron dispersive spectroscopy (EDX), thermogravimetric analysis (TGA) and Brunauer-Emmett-Teller (BET) surface area analysis. The results showed SA-β-CD/CNTs hydrogel exhibits excellent thermal stability, high specific surface area and large porosity compared with SA-β-CD hydrogel. Batch experiments were performed to study the effect of several adsorptive variables such as initial concentration, pH, contact time and temperature. The adsorption performance of the prepared SA-β-CD/CNTs hydrogel was comprehensively reported with maximum percentage removal of up to 79.86% for SA-β-CD/CNTs and 69.54% for SA-β-CD. The optimum adsorption conditions were reported when the concentration of Ni(II) solution was maintained at 100 ppm, pH 5, 303 K, and contacted for 120 min with a 1000 mg dosage. The Freundlich isotherm and pseudo-second order kinetic model are the best fits to describe the adsorption behavior. A thermodynamic study was also performed. The probable interaction mechanisms that enable the successful binding of Ni(II) on hydrogels, including electrostatic attraction, ion exchange, surface complexation, coordination binding and host-guest interaction between the cationic sites of Ni(II) on both SA-β-CD and SA-β-CD/CNTs hydrogel during the adsorption process, were discussed. The regeneration study also revealed the high efficiency of SA-β-CD/CNTs hydrogel on four successive cycles compared with SA-β-CD hydrogel. Therefore, this work signifies SA-β-CD/CNTs hydrogel has great potential to remove Ni(II) from an aqueous environment compared with SA-β-CD hydrogel.

Mechanistic considerations and biomarkers level in nickel-induced neurodegenerative diseases: An updated systematic review

The environment has been implicated to be a strong determinant of brain health with higher risk of neurodegeneration. The drastic rise in the prevalence of neurodegenerative diseases (NDDs) including Alzheimer's disease (AD), Parkinson's disease (PD), autism spectrum disorder (ASD), multiple sclerosis (MS) etc., supports the idea that environmental factors may play a major role in NDDs aetiology. Nickel is one of the listed environmental metals reported to pose a serious threat to human health. This paper reported available studies on nickel level in NDDs covering both animal and human studies. Different databases were searched for articles reporting the main neurotoxicity mechanisms and the concentration of nickel in fluids and tissues of NDDs patients compared to controls. Data were extracted and synthesized by ensuring the articles were related to nickel and NDDs. Various mechanisms were reported as oxidative stress, disturbances in mitochondrial membrane potential, trace elements homeostasis destabilization, etc. Nickel was found elevated in biological fluids as blood, serum/plasma and CSF and in the brain of NDDs, as a consequence of unintentional exposure thorough nickel-contaminated air, food, water, and skin contact. In addition, after exposure to nickel, the concentration of markers of lipid peroxidation were increased, while some antioxidant defence systems decreased. Thus, the reduction in the exposure to nickel contaminant may hold a promise in reducing the incidence of NDDs.

Epigenetic Regulation in Chromium-, Nickel- and Cadmium-Induced Carcinogenesis

Environmental and occupational exposure to heavy metals, such as hexavalent chromium, nickel, and cadmium, are major health concerns worldwide. Some heavy metals are well-documented human carcinogens. Multiple mechanisms, including DNA damage, dysregulated gene expression, and aberrant cancer-related signaling, have been shown to contribute to metal-induced carcinogenesis. However, the molecular mechanisms accounting for heavy metal-induced carcinogenesis and angiogenesis are still not fully understood. In recent years, an increasing number of studies have indicated that in addition to genotoxicity and genetic mutations, epigenetic mechanisms play critical roles in metal-induced cancers. Epigenetics refers to the reversible modification of genomes without changing DNA sequences; epigenetic modifications generally involve DNA methylation, histone modification, chromatin remodeling, and non-coding RNAs. Epigenetic regulation is essential for maintaining normal gene expression patterns; the disruption of epigenetic modifications may lead to altered cellular function and even malignant transformation. Therefore, aberrant epigenetic modifications are widely involved in metal-induced cancer formation, development, and angiogenesis. Notably, the role of epigenetic mechanisms in heavy metal-induced carcinogenesis and angiogenesis remains largely unknown, and further studies are urgently required. In this review, we highlight the current advances in understanding the roles of epigenetic mechanisms in heavy metal-induced carcinogenesis, cancer progression, and angiogenesis.

Review on Biocompatibility and Prospect Biomedical Applications of Novel Functional Metallic Glasses

The continuous development of novel materials for biomedical applications is resulting in an increasingly better prognosis for patients. The application of more advanced materials relates to fewer complications and a desirable higher percentage of successful treatments. New, innovative materials being considered for biomedical applications are metallic alloys with an amorphous internal structure called metallic glasses. They are currently in a dynamic phase of development both in terms of formulating new chemical compositions and testing their properties in terms of intended biocompatibility. This review article intends to synthesize the latest research results in the field of biocompatible metallic glasses to create a more coherent picture of these materials. It summarizes and discusses the most recent findings in the areas of mechanical properties, corrosion resistance, in vitro cellular studies, antibacterial properties, and in vivo animal studies. Results are collected mainly for the most popular metallic glasses manufactured as thin films, coatings, and in bulk form. Considered materials include alloys based on zirconium and titanium, as well as new promising ones based on magnesium, tantalum, and palladium. From the properties of the examined metallic glasses, possible areas of application and further research directions to fill existing gaps are proposed.

Quantitative estimation of essential/toxic elemental levels in the serum of esophagus cancer patients in relation to controls

Esophageal cancer is a very deadly disease ranking 8th most common cancer in terms of incidence and the 6th highest in terms of mortality both in the USA and around the world. A growing body of evidence indicated that changes in the concentrations of essential and toxic elements may affect/increase esophagus carcinoma risk. The aim of this study was to measure serum levels of essential and toxic (Fe, Na, Ca, K, Zn, Mg, Co, Se, Cu, Ni, Mn, Sr, Pb, Li, Sb, Cr, Ag, Cd, As, and Hg) elements in patients with esophagus carcinoma and controls. Atomic absorption spectroscopy was used to determine serum concentrations of essential and toxic elements by using nitric acid/perchloric acid-based wet digestion method. Mean levels of Cu, Ni, Cr, Cd, Pb, As, and Ag were exhibited to be significantly higher and mean Se, Co, Zn, Ca, Fe, Hg, Li, and Mg were noted lower in the serum of cancer patients than controls. The correlation coefficients among the elements in the cancerous patients revealed significantly dissimilar communal relationships than the controls. Furthermore, multivariate methods demonstrated considerably different apportionment between the elements in the cancerous patients and the controls. Significant inequalities in the elemental concentrations were also observed for esophagus cancer types (adenocarcinoma and squamous cell carcinoma) and stages (I, II, III, and IV) between the patients. Majority of the elements exposed perceptible disparities in their levels based on smoking habits, dietary habits, habitat, and gender of the esophagus cancer patients and controls. Multivariate analysis of the essential and toxic elemental data explained significantly divergent apportionment in the serum of esophagus cancer patients when compared to controls.

Leaching experiments and risk assessment to explore the migration and risk of potentially toxic elements in soil from black shale

Black shale is rich in potentially toxic elements (PTEs) that migrate through rock weathering or rainfall, adversely affecting human health and the environment. In this study, simulated rainfall leaching experiments were used to investigate the migration patterns and leaching kinetics of PTEs in black shale from the Lower Cambrian Hetang Formation and to analyze the water quality index (WQI) of PTEs in the leachate. A comparison between the risk of PTEs in the leachate and those in the soil was also made to determine the risk sources, risk status, and distribution characteristics of PTEs in the study area. The WQI of the indoor column experimental leachate indicated the highest As contamination. The geo-accumulation index (I_geo) and potential ecological risk (Er) of soils in the entire region revealed that the risk of Cd was the highest. Furthermore, by mapping the distribution of I_geo and Er in soils, the risk level in the region where black shale is located was found to be significantly higher than that in other areas. Comparing the leaching rate of PTEs with the WQI from leaching experiments, the risk associated with As in soil can be inferred to originate mainly from the leaching of black shale. Previous studies on PTEs in black shale in the study area tended to focus on Cd; however, this study found that the risk of As was not negligible. The health risk assessment also showed that the risk at the location of black shale was beyond the accepted range. Overall, this study provided a new and important evaluation law for the level of pollution by PTEs and health risks in typical black shale regions.

Aluminum, Arsenic, Beryllium, Cadmium, Chromium, Cobalt, Copper, Iron, Lead, Mercury, Molybdenum, Nickel, Platinum, Thallium, Titanium, Vanadium, and Zinc: Molecular Aspects in Experimental Liver Injury

Experimental liver injury with hepatocelluar necrosis and abnormal liver tests is caused by exposure to heavy metals (HMs) like aluminum, arsenic, beryllium, cadmium, chromium, cobalt, copper, iron, lead, mercury, molybdenum, nickel, platinum, thallium, titanium, vanadium, and zinc. As pollutants, HMs disturb the ecosystem, and as these substances are toxic, they may affect the health of humans and animals. HMs are not biodegradable and may be deposited preferentially in the liver. The use of animal models can help identify molecular and mechanistic steps leading to the injury. HMs commonly initiate hepatocellular overproduction of ROS (reactive oxygen species) due to oxidative stress, resulting in covalent binding of radicals to macromolecular proteins or lipids existing in membranes of subcellular organelles. Liver injury is facilitated by iron via the Fenton reaction, providing ROS, and is triggered if protective antioxidant systems are exhausted. Ferroptosis syn pyroptosis was recently introduced as mechanistic concept in explanations of nickel (Ni) liver injury. NiCl2 causes increased iron deposition in the liver, upregulation of cyclooxygenase 2 (COX-2) protein and mRNA expression levels, downregulation of glutathione eroxidase 4 (GPX4), ferritin heavy chain 1 (FTH1), nuclear receptor coactivator 4 (NCOA4) protein, and mRNA expression levels. Nickel may cause hepatic injury through mitochondrial damage and ferroptosis, defined as mechanism of iron-dependent cell death, similar to glutamate-induced excitotoxicity but likely distinct from apoptosis, necrosis, and autophagy. Under discussion were additional mechanistic concepts of hepatocellular uptake and biliary excretion of mercury in exposed animals. For instance, the organic anion transporter 3 (Oat3) and the multidrug resistance-associated protein 2 (Mrp2) were involved in the hepatic handling of mercury. Mercury treatment modified the expression of Mrp2 and Oat3 as assessed by immunoblotting, partially explaining its impaired biliary excretion. Concomitantly, a decrease in Oat3 abundance in the hepatocyte plasma membranes was observed that limits the hepatic uptake of mercury ions. Most importantly and shown for the first time in liver injury caused by HMs, titanium changed the diversity of gut microbiota and modified their metabolic functions, leading to increased generation of lipopolysaccharides (LPS). As endotoxins, LPS may trigger and perpetuate the liver injury at the level of gut-liver. In sum, mechanistic and molecular steps of experimental liver injury due to HM administration are complex, with ROS as the key promotional compound. However, additional concepts such as iron used in the Fenton reaction, ferroptosis, modification of transporter systems, and endotoxins derived from diversity of intestinal bacteria at the gut-liver level merit further consideration.

Cobalt-catalyzed cross-coupling of Umpolung carbonyls with alkyl halides under mild conditions

While classical cross-couplings are dominated by palladium and nickel catalysts, cobalt-based catalysts have shown unique advantages for such cross-coupling reactions in terms of higher catalytic activity and lower toxicity. Herein, we describe a novel cobalt-catalyzed alkyl-alkyl cross-coupling reaction of hydrazone with alkyl halides under mild reaction conditions, where the use of a PNP-type pincer ligand is essential for catalysis. Both aldehyde and ketone hydrazones are compatible with this reaction, giving a series of C(sp³)-C(sp³) coupling products in moderate to good yields.

The Nickel Age in Synthetic Dual Photocatalysis: A Bright Trip Toward Materials Science

Recently, the field of dual photocatalysis has grown rapidly, to become one of the most powerful tools for the functionalization of organic molecules under mild conditions. In particular, the merging of Earth-abundant nickel-based catalytic systems with visible-light-activated photoredox catalysts has allowed the development of a number of unique green synthetic approaches. This goes in the direction of ensuring an effective and sustainable chemical production, while safeguarding human health and environment. Importantly, this relatively new branch of catalysis has inspired an interdisciplinary stream of research that spans from inorganic and organic chemistry to materials science, thus establishing itself as one dominant trend in modern organic synthesis. This Review aims at illustrating the milestones on the timeline evolution of the photocatalytic systems used, with a critical analysis toward novel applications based on the use of photoactive two-dimensional carbon-based nanostructures. Lastly, forward-looking opportunities within this intriguing research field are discussed.

Bioaerogels, the emerging technology for wastewater treatment: A comprehensive review on synthesis, properties and applications

Over the past decade use of aerogels has received much attention as an emerging technology for wastewater treatment. However, production of aerogels is not environment-friendly. Owing to its excellent properties such as porosity, three-dimensional structure, being amenable to chemical modifications, it is imperative to devise strategies for their improved production and use. Bioaerogels are non-toxic and most of their precursor compounds are biomass-derived. This review aims to present a comprehensive report on survey of existing literature published on the use of bioaerogels for removal of all major categories of water contaminants, namely, heavy metals, industrial dyes, oil, organic compounds and pharmaceuticals. It also gives critical analysis of the lacunae in the existing knowledge such as lack of studies on domestic sewage, emerging pollutants, toxicity of raw materials and adequate disposal of used adsorbents. Proposals of overcoming the limitations in the applicability of bioaerogels, like combining constructed wetlands with use of bioaerogels, among others have been discussed. In this review, emphasis has been given on production of bioaerogels, with an aim to underscore the potential of valorization of biomass waste to develop novel materials for wastewater treatment in an effort towards creating a circular and green economy.

Battery wastewater induces nephrotoxicity via disordering the mitochondrial dynamics

The rapid development of new energy battery enterprises manifolds the obsolete and scrapped batteries which are considered serious concern for the environment and ecology. Increasing trend of recycling batteries waste is public hazard throughout the world. The batteries wastes affect the various body systems but exact toxicological mechanism of battery wastewater is still unexplored. The present study was designed to observe the toxicological effects of batteries wastes on kidney functional dynamics. In this experiment, a total of 20 male mice were randomly divided into two groups including control and treatment (battery wastewater) group. The control group was provided the normal saline while the battery wastewater group were provided battery waste-water for a period of 21 days. The isolated kidneys were processed for histopathological analysis, biochemical assays, mRNA and protein estimation. The results showed that battery wastewater provision increased the mitochondrial division-related genes and proteins (Drp1, MFF, Fis1) and decreased the expression level of fusion-related nuclear proteins (MFN1, MFN2, OPA1) in kidneys. Moreover, the battery wastewater exposure significantly up-regulated the autophagy (PINK, Parkin, mTOR, ATG5, LC3-b, p62) and apoptosis (Bax, Cytc, APAF1, P53, Caspase3, Caspase8) related mRNA and proteins levels in kidneys. However, down-regulation of mRNA and proteins levels of Bcl2 and Beclin1 were also observed in kidneys after batteries wastes exposure. In conclusion, it is evident that the battery wastewater leads to renal apoptosis and autophagy by disrupting the mitochondrial dynamics in mice kidneys.

Water toxicants: a comprehension on their health concerns, detection, and remediation

Water is an essential moiety for the human use since a long time. Availability of good-quality water is very essential, as it is used in almost all the industrial, agricultural, and household activities. However, several factors such as increased urbanization and industrialization, extensive use of chemicals, natural weathering of rocks, and human ignorance led to incorporation of enormous toxicants into the water. The water toxicants are broadly classified as inorganic, organic, and radiological toxicants. Inorganic toxicants include heavy metals (As, Cr, Cd, Hg, Ni, Pb) and metalloids, ammonia, nitrate, and fluoride. Uranium is included in radiological toxicants which also causes chemical toxicity. Organic pollutants include polycyclic aromatic hydrocarbons, polychlorinated biphenyls, phenolic compounds, phthalate esters, pesticides, pharmaceutical and personal care products, perchlorates, and flame retardants. These toxicants are harmful for the ecosystem as well as for the human beings causing different types of health complications like lung cancer, nasal cancer, gingivitis, severe vomiting and abdominal pain, hormonal imbalance, skeletal damage, neurotoxicity like Alzheimer and Parkinson disease, renal toxicity, nephrotoxicity, etc. The USEPA and WHO specified the permissible concentration of these pollutants in the drinking water. Determination techniques having high sensitivity, low cost, rapid onsite, and real-time detection of traces of water pollutants are discussed. This review also covers in depth about the remediation techniques, for the control of water toxicants, such as chelation of the heavy metals, intoxication of pollutants using various plants, adsorption of toxicants using different sorbent medias, and photocatalytic breakdown of persistent organic pollutants (POPs).

Turmeric (Curcuma longa L.) tends to reduce the toxic effects of nickel (II) chloride in Allium cepa L. roots

The immense protection potential of plant-derived products against heavy metal toxicity has become a considerable field of research. The goal of the present study was to evaluate the mitigative ability of turmeric against nickel (II) chloride (NiCl₂)-related toxicity in the roots of Allium cepa L. For this purpose, one control (treated with tap water) and five treatment groups (treated with 440 mg/L turmeric, 880 mg/L turmeric, 1 mg/L NiCI₂, 1 mg/L NiCI₂ + 440 mg/L turmeric, and 1 mg/L NiCI₂ + 880 mg/L turmeric, respectively) of Allium bulbs were established. Experimental conditions were maintained at room temperature for 3 days. Physiological, biochemical, cytogenetic, and meristematic integrity parameters were analyzed in all groups. NiCl₂ reduced germination percentage, root elongation, and weight gain. Following NiCl₂ application, the frequency of aberrant chromosomes and micronuclei increased, while mitotic index decreased. NiCl₂ caused an increase in oxidative stress, which was evident by increased malondialdehyde level and catalytic activities of superoxide dismutase and catalase. Epidermal and cortex cell injuries as well as deformed cell nuclei and indistinct transmission tissue were observed as a result of NiCl₂ treatment. When applied alone, turmeric, which did not cause any negative effects, led to an improvement in all parameters depending on the dose when applied together with NiCl₂. Data from the study suggests that turmeric has remarkable protection potential against NiCl₂ in Allium cepa.

Protein nanofibrils as versatile and sustainable adsorbents for an effective removal of heavy metals from wastewater: A review

Water is a valuable natural resource, which plays a crucial role in ecological survival as well as economic progress. However, the water quality has deteriorated in recent years as a result of urbanization, industrialization and human activities due to the uncontrolled release of industrial wastes, which can be extremely carcinogenic and non-degradable, in air, water and soil bodies. Such wastes showed the presence of organic and inorganic pollutants in high dosages. Heavy metals are the most obstinate contaminants, and they can be harmful because of having a variety of detrimental consequences to the ecosystem. The existing water treatment methods in many situations may not be sustainable or effective because of their high energy requirements and ecological impacts. In this review, state-of-the-art water treatment methods for the elimination of heavy metals with the help of protein nanofibrils are covered featuring a discussion on the strategies and possibilities of developing protein nanofibrils for the active elimination of heavy metals using kitchen waste as well as residues from the cattle, agriculture, and dairy industries. Further, the emphasis has been given to their environmental sustainability and economical aspects are also discussed.

Perovskite Solar Cells: A Review of the Recent Advances

Perovskite solar cells (PSC) have been identified as a game-changer in the world of photovoltaics. This is owing to their rapid development in performance efficiency, increasing from 3.5% to 25.8% in a decade. Further advantages of PSCs include low fabrication costs and high tunability compared to conventional silicon-based solar cells. This paper reviews existing literature to discuss the structural and fundamental features of PSCs that have resulted in significant performance gains. Key electronic and optical properties include high electron mobility (800 cm2/Vs), long diffusion wavelength (>1 μm), and high absorption coefficient (105 cm−1). Synthesis methods of PSCs are considered, with solution-based manufacturing being the most cost-effective and common industrial method. Furthermore, this review identifies the issues impeding PSCs from large-scale commercialisation and the actions needed to resolve them. The main issue is stability as PSCs are particularly vulnerable to moisture, caused by the inherently weak bonds in the perovskite structure. Scalability of manufacturing is also a big issue as the spin-coating technique used for most laboratory-scale tests is not appropriate for large-scale production. This highlights the need for a transition to manufacturing techniques that are compatible with roll-to-roll processing to achieve high throughput. Finally, this review discusses future innovations, with the development of more environmentally friendly lead-free PSCs and high-efficiency multi-junction cells. Overall, this review provides a critical evaluation of the advances, opportunities and challenges of PSCs.

Occupational Exposure to Hexavalent Chromium, Nickel and PAHs: A Mixtures Risk Assessment Approach Based on Literature Exposure Data from European Countries

Hexavalent chromium (Cr(VI)), nickel (Ni) and polycyclic aromatic hydrocarbons (PAHs) are genotoxic co-occurring lung carcinogens whose occupational health risk is still understudied. This study, conducted within the European Human Biomonitoring Initiative (HBM4EU), aimed at performing a mixtures risk assessment (MRA) based on published human biomonitoring (HBM) data from Cr(VI), Ni and/or PAHs occupational co-exposure in Europe. After data extraction, Risk Quotient (RQ) and Sum of Risk Quotients (SRQ) were calculated for binary and ternary mixtures to characterise the risk. Most selected articles measured urinary levels of Cr and Ni and a SRQ > 1 was obtained for co-exposure levels in welding activities, showing that there is concern regarding co-exposure to these substances. Similarly, co-exposure to mixtures of Cr(VI), Ni and PAHs in waste incineration settings resulted in SRQ > 1. In some studies, a low risk was estimated based on the single substances’ exposure level (RQ < 1), but the mixture was considered of concern (SRQ > 1), highlighting the relevance of considering exposure to the mixture rather than to its single components. Overall, this study points out the need of using a MRA based on HBM data as a more realistic approach to assess and manage the risk at the workplace, in order to protect workers’ health.

Ameliorative or corrective effects of Fig "Ficus carica" extract on nickel-induced hepatotoxicity in Wistar rats

Many heavy metals and metalloids (e.g., Pb, Cd, and Ni) can contaminate the environment and cause severe health problems. Through this study, investigated the possible corrective effects of Ficus carica extract (FCE) against nickel (Ni) induced stress response and damage on the liver of rats. Male Wistar rats were divided into four groups (8 rats per group) and co-treated with FCE (350 mg/kg) and exposed to Nickel chloride (10 mg/kg) for 4 weeks. The volatile compounds of FCE were characterized by solid phase micro-extraction (SPME) coupled with GC-MS, and the biochemical parameters of stress were determined. The SPME-GC/MS analysis of FCE indicated the presence of thirty (30) phyto-bioactive compounds including alcohols, aldehydes, organic acids, ketones, furans, terpenes, ester and others. The best capacity for scavenging DPPH free radicals and metal chelating were found with the IC50 values of 0.49 and 2.91 mg/mL, respectively. Ni induced damage to various macromolecules. Malondialdehyde, protein carbonyls, alanine aminotransferase and gamma glutamyl transferarse levels were significantly increased in Ni exposed group compared to control group and co-treatment with FCE reduced the levels of these parameters. In conclusion, current findings showed that Ni-induced oxidative damage and the administration of FCE can improve correct and restore the alteration in the rat liver.

In Situ Measurements of Domestic Water Quality and Health Risks by Elevated Concentration of Heavy Metals and Metalloids Using Monte Carlo and MLGI Methods

The domestic water (DW) quality of an island province in the Philippines that experienced two major mining disasters in the 1990s was assessed and evaluated in 2021 utilizing the heavy metals pollution index (MPI), Nemerow’s pollution index (NPI), and the total carcinogenic risk (TCR) index. The island province sources its DW supply from groundwater (GW), surface water (SW), tap water (TP), and water refilling stations (WRS). This DW supply is used for drinking and cooking by the population. In situ analyses were carried out using an Olympus Vanta X-ray fluorescence spectrometer (XRF) and Accusensing Metals Analysis System (MAS) G1 and the target heavy metals and metalloids (HMM) were arsenic (As), barium (Ba), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), nickel (Ni), and zinc (Zn). The carcinogenic risk was evaluated using the Monte Carlo (MC) method while a machine learning geostatistical interpolation (MLGI) technique was employed to create spatial maps of the metal concentrations and health risk indices. The MPI values calculated at all sampling locations for all water samples indicated a high pollution. Additionally, the NPI values computed at all sampling locations for all DW samples were categorized as “highly polluted”. The results showed that the health quotient indices (HQI) for As and Pb were significantly greater than 1 in all water sources, indicating a probable significant health risk (HR) to the population of the island province. Additionally, As exhibited the highest carcinogenic risk (CR), which was observed in TW samples. This accounted for 89.7% of the total CR observed in TW. Furthermore, all sampling locations exceeded the recommended maximum threshold level of 1.0 × 10⁻⁴ by the USEPA. Spatial distribution maps of the contaminant concentrations and health risks provide valuable information to households and guide local government units as well as regional and national agencies in developing strategic interventions to improve DW quality in the island province.

Nickel Isotope Fractionation As an Indicator of Ni Sulfide Precipitation Associated with Microbially Mediated Sulfate Reduction

Microbially mediated sulfate reduction is a promising cost-effective and sustainable process utilized in permeable reactive barriers (PRB) and constructed wetlands to treat mine wastewater. Laboratory batch experiments were performed to evaluate nickel (Ni) isotope fractionation associated with precipitation of Ni-sulfides in the presence of the sulfate-reducing bacterium (SRB) Desulfovibrio desulfuricans^T (DSM-642). Precipitates were collected anaerobically and characterized by synchrotron powder X-ray diffraction (PXRD), scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDS), and transmission electron microscopy (TEM). Solid-phase analyses showed that the precipitates associated with bacteria attached to the serum bottle walls were characterized by enhanced size and crystallinity. Lighter Ni isotopes were preferentially concentrated in the solid phase, whereas the solution was enriched in heavier Ni isotopes compared to the input solution. This fractionation pattern was consistent with closed-system equilibrium isotope fractionation, yielding a fractionation factor of Δ⁶⁰Ni_solid-aq = -1.99‰. The Ni isotope fractionation measured in this study indicates multiple Ni reaction mechanisms occurring in the complex SRB-Ni system. The results from this study offer insights into Ni isotope fractionation during interaction with SRB and provide a foundation for the characterization and development of Ni stable isotopes as tracers in environmental applications.

Ferroptosis as a mechanism of non-ferrous metal toxicity

Ferroptosis is a recently discovered form of regulated cell death, implicated in multiple pathologies. Given that the toxicity elicited by some metals is linked to alterations in iron metabolism and induction of oxidative stress and lipid peroxidation, ferroptosis might be involved in such toxicity. Although direct evidence is insufficient, certain pioneering studies have demonstrated a crosstalk between metal toxicity and ferroptosis. Specifically, the mechanisms underlying metal-induced ferroptosis include induction of ferritinophagy, increased DMT-1 and TfR cellular iron uptake, mitochondrial dysfunction and mitochondrial reactive oxygen species (mitoROS) generation, inhibition of Xc-system and glutathione peroxidase 4 (GPX4) activity, altogether resulting in oxidative stress and lipid peroxidation. In addition, there is direct evidence of the role of ferroptosis in the toxicity of arsenic, cadmium, zinc, manganese, copper, and aluminum exposure. In contrast, findings on the impact of cobalt and nickel on ferroptosis are scant and nearly lacking altogether for mercury and especially lead. Other gaps in the field include limited studies on the role of metal speciation in ferroptosis and the critical cellular targets. Although further detailed studies are required, it seems reasonable to propose even at this early stage that ferroptosis may play a significant role in metal toxicity, and its modulation may be considered as a potential therapeutic tool for the amelioration of metal toxicity.

Assessment of the Enrichment of Heavy Metals in Coal and Its Combustion Residues

Coal-fired thermal power plants remain one of the main sources of electricity generation in Turkey. Combustion of coal creates coal ash and slag, which are often stored in landfills located near residential and agricultural fields, increasing the potential for high environmental contamination and health risks. This study investigates the content and enrichment factor (EF) of heavy metals in pulverized lignite coal and its combustion residues from the Kangal lignite coal-fired thermal power plant situated in the Central Anatolian Region of Turkey. The concentration of heavy metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Zr, Cd, Hg, and Pb) in lignite coal, slag, and fly ash samples were analyzed using an energy dispersive X-ray fluorescence technique. The concentration of Fe is highest while Hg concentration is lowest in the samples. The concentrations of heavy metals are higher in slag and fly ash samples than in lignite coal. Average values of EF (related to Earth's crust average) revealed that extreme enrichment has been shown by arsenic and mercury in lignite coal and fly ash samples while very high enrichment has been shown in slag samples.

Nitinol Release of Nickel under Physiological Conditions: Effects of Surface Oxide, pH, Hydrogen Peroxide, and Sodium Hypochlorite

Nitinol is a nickel-titanium alloy widely used in medical devices for its unique pseudoelastic and shape-memory properties. However, nitinol can release potentially hazardous amounts of nickel, depending on surface manufacturing yielding different oxide thicknesses and compositions. Furthermore, nitinol medical devices can be implanted throughout the body and exposed to extremes in pH and reactive oxygen species (ROS), but few tools exist for evaluating nickel release under such physiological conditions. Even in cardiovascular applications, where nitinol medical devices are relatively common and the blood environment is well understood, there is a lack of information on how local inflammatory conditions after implantation might affect nickel ion release. For this study, nickel release from nitinol wires of different finishes was measured in pH conditions and at ROS concentrations selected to encompass and exceed literature reports of extracellular pH and ROS. Results showed increased nickel release at levels of pH and ROS reported to be physiological, with decreasing pH and increasing concentrations of hydrogen peroxide and NaOCl/HOCl having the greatest effects. The results support the importance of considering the implantation site when designing studies to predict nickel release from nitinol and underscore the value of understanding the chemical milieu at the device-tissue interface.

“For Asia Market Only”: A Green Tattoo Ink between Safety and Regulations

Due to the increasing tattoo practicing in Eastern countries and general concern on tattoo ink composition and safety, the green tattoo inks Green Concentrate by Eternal, for European and “for Asia Market Only” were analyzed, under the premise that only the former falls under a composition regulation. A separation of the additives from the pigment was carried out by successive extraction in solvents of different polarities, i.e., water, acetone and dichloromethane. The solid residues were analyzed by IR and Raman spectroscopies, the liquid fractions by GC/mass spectrometry. The relative pigment load and element traces were also estimated. We found that the European and the Asian inks are based on the same pigment, PG7, restricted in Europe, though at different loads. They have a similar content of harmful impurities, such as Ni, As, Cd and Sb and both contain siloxanes, including harmful D4. Furthermore, they have different physical-chemical properties, the European ink being more hydrophilic, the Asian more hydrophobic. Additionally, the Asian ink contains harmful additives for the solubilization of hydrophobic matrices and by-products of the phthalocyanine synthesis. Teratogenic phthalates are present as well as chlorinated teratogenic and carcinogenic compounds usually associated to the laser treatment for removal purposes, to a larger extent in the European ink. The composition of the inks does not seem to reflect regulatory restrictions, where issued.

Ecological risk assessment of the riverine and deltaic environments (Rozechai River, Urmia Lake, Iran), using sediment quality indices

Rozechai River is one of the tributaries of Urmia Lake (the nrthwest of Iran), which has experienced severe pollution and water level fluctuations in the coastal zone over the past four decades. The present study aimed to assess the ecological risk for aquatic life and human health. Research methods were designed for applying the sediment quality guidelines (LEL, PEL, SEL), sediment quality indices (C_f, C_d, E_r, RI), and enrichment factor (EF) based on the concentration of toxic metals in sediments. Event-based geochronology of the sediment column showed that the high stands in the water level of the Urmia Lake (> 1274 m) occurred in 1983, 1989, and 1995. Thus, As, Pb, Zn, Cd, Cr, and Ni reached a moderate to considerable enrichment under the oxidation and alkaline condition. Consequently, a moderated level of ecological risk index (RI) was predominant between 1983 and 1999. The uppermost 35 cm of the sediment column was deposited during a severe drought period to which H₂S bearing water and reducing status contributed. In such conditions, the low ecological risk was resulted in the basin due to the lower rate of the toxic metal influx. The industrial, urban, and agricultural wastewaters contributed to the release of toxic metals and the dominance of moderate to considerable enrichment, which led to a moderate ecological risk at the coastal zone of the Rozechai River. The sediment column of the deltaic area has experienced a mean sedimentation rate of 1.66 cm year^-1 since 1982.

Laser Cutting Technologies and Corresponding Pollution Control Strategy

In conjunction with the increasing demand for material cutting, such as the decommissioning and dismantling of nuclear facilities, advanced cutting technologies need be developed to increase precision and cost-effectiveness. As compared with other cutting technologies, laser cutting offers advantages of greater cutting precision, accuracy, and customization. In this work, we investigated the constitution, classification, and current status of this technology. Pollutant emission during laser cutting, corresponding pollution control methods and apparatus were proposed as well. Laser cutting equipment mainly comprises an automated system integrating a fiber laser, industrial computer, servo motor control, electrical control, and detection technology. It mainly consists of mechanical and electrical control parts. Laser cutting equipment is distinguished by light source, power, and cutting dimensions. Known variants of laser cutting technology involve vaporization, fusion, reactive fusion, and controlled fracture cutting. During the cutting process, dust, smoke, and aerosols can be released, which is an environmental concern and poses a threat to public health. The selection of the dedusting method and design of apparatus should take into account the dust removal rate, initial capital cost, maintenance cost, etc. Multi-stage filtration such as bag filtration combined with activated carbon filtration or electrostatic filtration is accepted.

Facile synthesis and adsorption characteristics of a hybrid composite based on ethyl acetoacetate modified chitosan/calcium alginate/TiO2 for efficient recovery of Ni(II) from aqueous solution

In this study, chemical modification of chitosan has been carried out using epichlorohydrin as crosslinking agent and ethyl acetoacetate as a modifier to graft acetoacetyl moiety. The said organo-functionalization on chitosan and sodium alginate not only offered a novel support for TiO2 immobilization but also enhanced sorption performance for Ni(II) recovery from aqueous medium. So, a composite consisting of acetoacetyl moiety grafted chitosan, sodium alginate and titanium oxide (EAA-MCS/TiO2) was prepared and characterized by fourier transform-infra red (FT-IR) spectroscopy and scanning electron microscopy (SEM). The hybrid composite (3EAA-MCS/TiO2) which had TiO2 to EAA-MCS mass ratio of 20.0% by weight showed maximum sorption efficiency. The formulated sorbent was conditioned in the form of hydrogel beads for operation. Isothermal sorption and kinetics studies were performed at pH = 6.0 to configure the nature of sorption. Pseudo-2nd order rate expression better explained the sorption kinetics and chemisorption is the predominant mode of uptake. Langmuir adsorption model better explained the sorption process (R 2 ∼ 0.99) and maximum monolayer sorption capacity (q m ) at sorption/desorption dynamic equilibrium was computed as 403 mg/g at optimized pH.

A comprehensive review on the sources, essentiality and toxicological profile of nickel

This review contains up-to-date knowledge and recent advancements on the essentiality, sources, and toxicological profile of nickel and its different compounds. Nickel is a recognized essential element for several important biological processes like the healthy growth of plants, animals, and soil/water microbes; though an excess amount of nickel intoxicates flora and fauna. Nickel is found to affect the photosynthetic function of higher plants; it can severely degrade soil fertility and causes many chronic diseases in humans. Due to the huge growth in the nickel industry and consumption of nickel-containing products, environmental pollution has become inevitable by the element nickel and also varieties of its by-products through all the phases of making, utilization and dumping. We have focused on the importance of agenda 2030 (UN 17 SDGs) during the preparation of the write-up and have highlighted goals 3, 6, 8, 9, 11, 12, 13, 14, and 15 by elaborately discussing associated points. The plausible molecular mechanism of nickel toxicity is presented in simple diagrams. The article elaborates on possible methods for remediation of nickel toxicity and the treatment of nickel dermatitis and nickel cancer. Recent advancements in the understanding of the dual aspects of nickel as beneficial and a carcinogen are the key subject of this article.

This review contains up-to-date knowledge and recent advancements on the essentiality, sources, and toxicological profile of nickel and its different compounds.

The distribution and structural fingerprints of metals from particulate matters (PM) deposited in human lungs

This work investigated the distribution and chemical fingerprints of 24 metals in particulate matter (PM) deposited in nonoccupational human lungs. Metals in the pulmonary PM can be grouped by the mean concentration as > 5 × 10³ μg/g (Al/Fe/Ca/Mg/Zn), 1-5 × 10³ μg/g (Ti/Ba/Pb/Mn), 0.2-1 × 10³ μg/g (Cu/Cr/As/V) and < 100 μg/g (Ni/Sn/Cd/Sb). Three parameters (LF_L, LR, EF_P) were defined to predict different metal leaching behaviors. The leaching factor (LF_L) of metals was 10-60 for Pb/Sb/Cd/Co/Cu and decreased to 1-2 for Ni/Cr/Mg/Al/Fe. Metals showed a divergent extent of lung retention (LR), including high retention (LR>10, Al/Cd/Cr/Ba/Ni/Ti/Sn/V/Sb), moderate retention (2 <LR<10, Pb/Mn/Fe), minor retention (1 < LR <2, Cu/Co), and negligible retention (LR<1, Ca/Mg/Zn). V and Ti were found to be mainly from indoor PM sources and deserve a close attention in healthy individuals. C-, Al- and Ti-rich fine particles were the most common pulmonary particles imaged by spherical aberration-corrected scanning transmission electron microscopy (Cs-STEM). These data establish a foundation for classification and further risk assessment of the metal species in pulmonary PM.

Hematobiochemical, Oxidative Stress, and Histopathological Mediated Toxicity Induced by Nickel Ferrite (NiFe2O4) Nanoparticles in Rabbits

From the past few decades, attention towards the biological evaluation of nanoparticles (NPs) has increased due to the persistent and extensive application of NPs in various fields, including biomedical science, modern industry, magnetic resonance imaging, and the construction of sensors. Therefore, in the current study, magnetic nickel ferrite (NiFe2O4) nanoparticles (NFNPs) were synthesized and evaluated for their possible adverse effects in rabbits. The crystallinity of the synthesized NFNPs was confirmed using X-ray diffraction (XRD) technique. The saturation magnetization (46.7 emug-1) was measured using vibrating sample magnetometer (VSM) and 0.35-tesla magnetron by magnetic resonance imaging (MRI). The adverse effects of NFNPs on blood biochemistry and histoarchitecture of the liver, kidneys, spleen, brain, and heart of the rabbits were determined. A total of sixteen adult rabbits, healthy and free from any apparent infection, were blindly placed in two groups. The rabbits in group A served as control, while the rabbits in group B received a single dose (via ear vein) of NFNPs for ten days. The blood and visceral tissues were collected from each rabbit at days 5 and 10 of posttreatment. The results on blood and serum biochemistry profile indicated significant variation in hematological and serum biomarkers in NFNP-treated rabbits. The results showed an increased quantity of oxidative stress and depletion of antioxidant enzymes in treated rabbits. Various serum biochemical tests exhibited significantly higher concentrations of different liver function tests, kidney function tests, and cardiac biomarkers. Histopathologically, the liver showed congestion, edema, atrophy, and degeneration of hepatocytes. The kidneys exhibited hemorrhages, atrophy of renal tubule, degeneration, and necrosis of renal tubules, whereas coagulative necrosis, neutrophilic infiltration, and severe myocarditis were seen in different sections of the heart. The brain of the treated rabbits revealed necrosis of neurons, neuron atrophy, and microgliosis. In conclusion, the current study results indicated that the highest concentration of NPs induced adverse effects on multiple tissues of the rabbits.

Comparative Study of Potentially Toxic Nickel and Their Potential Human Health Risks in Seafood (Fish and Mollusks) from Peninsular Malaysia

Human exposure to highly nickel (Ni)-polluted environments through oral ingestion pathways may cause various pathological effects. This biomonitoring study aimed to assess the human health risk of potentially toxic Ni in 19 species of marine fishes from Setiu (Terengganu) and two popular seafood molluscs (mangrove snail Cerithidea obtusa and cockle Anadara granosa) from the coastal area of Peninsular Malaysia. The Ni levels of the three seafood types were found below the maximum permissible limit for Ni. The Ni target hazard quotient values of all seafood were lower than 1.00 for average and high-level (AHL) Malaysian consumers, indicating no Ni's non-carcinogenic risk of seafood consumption. It was also found that the calculated values of estimated weekly intake were below than established provisional tolerable weekly intake of Ni for both AHL consumers. It can be concluded that both the AHL consumption of seafood would not pose adverse effects of Ni to the consumers. This study provided a scientific basis for the food safety assessment of Ni and suggestions for risk management of potentially toxic Ni of seafood consumption in Malaysia.

Modified alginate-chitosan-TiO2 composites for adsorptive removal of Ni(II) ions from aqueous medium

In this study, organo-funtionalization of sodium-alginate has been carried out using phenylsemicarbazide as modifier to graft N, O-donor atoms containing functional groups (amino-carbamate moieties) to offer novel support for TiO₂ immobilization. Hybrid composite made of aminocarbamated alginate, carboxymethyl chitosan (CMC) and titanium oxide TiO₂ (MCA-TiO₂) was prepared for the promising adsorptive remediation of Ni(II). FT-IR, SEM-EDX were employed to characterize MCA-TiO₂. The optimization of TiO₂ to modified alginate mass ratio was carried out and hydrogel beads with TiO₂/MCA mass ratio of 10.0% (2MCA-TiO₂) revealed highest sorption efficiency. The produced sorbents were adapted in the form of hydrogel beads for operation. Organic functionalization based on aminocarbamate (OCONHNH₂) moieties on linear chains of alginate embedded additional chelating functional sites which enhanced sorption and selectivity. Batch mode experiments were conducted for optimization of pH and sorbent dose. Equilibrium sorption, kinetic and thermodynamic studies were performed to pattern the nature of sorption. Kinetic data was found in close agreement with pseudo-second order rate expression (PSORE). Isothermal equilibrium sorption data was well fitted with Langmuir adsorption model. Maximum sorption capacity was evaluated as 229 mg/g at 298 K and pH = 6.0.

Effect of Resveratrol, L-Carnitine, and Aromatic Amino Acid Supplements on the Trace Element Content in the Organs of Mice with Dietary-Induced Obesity

Given environmental contamination with toxic metals, diets that promote the elimination of these metals from the body of individuals, including those suffering from obesity, are urgently needed. The aim of this study was to determine the effects of supplementation with resveratrol (Res), L-carnitine (L-Car), tyrosine (Tyr), and tryptophan (Trp) on the content of trace elements in the organs of mice. DBA/2J mice and DBCB tetrahybrid mice received diets high in carbohydrate and fat supplemented with Res, L-Car, Tyr, or Trp for 65 days. In the liver, kidneys, and brain, the contents of 18 elements, including Al, As, Cu, Fe, Mn, Pb, Se, and Zn, were determined by inductively coupled plasma mass spectrometry. Res, L-Car, Tyr, and Trp had minimal or no effect on the essential elements (Fe, Mg, Cu, Zn, Se) in all organs studied. The Mn content notably increased in the organs of mice consuming L-Car and Trp. Mn accumulation was stimulated by Res in organs exclusively in DBCB mice and by Tyr exclusively in livers and brains of DBA/2J mice. Al levels were significantly reduced by L-Car and Trp in all organs of the mice, by Res in only DBCB mice, and by Tyr in only kidneys and livers of DBA/2J mice. In addition, L-Car and Trp decreased Pb accumulation in most organs of mice. Res and Tyr also inhibited Pb accumulation in some cases. Thus, the studied supplements affected the metabolism of trace elements, which may contribute to dietary treatments for obese individuals.

Current trends and future prospective in nanoremediation of heavy metals contaminated soils: A way forward towards sustainable agriculture

Heavy metals (HMs) contamination in agricultural soils is a major concern for global food safety and human health. Although, various in-situ and ex-situ remediation methods have been used for the treatment of HMs contaminated soils, however, they also have many drawbacks viz., capital investment, toxicity, and environmental health hazards. Consequently, there is an urgent need to develop a novel method to ameliorate the toxicity of HMs in agricultural soils. In recent years, nanoparticles (NPs) have gained significant attention due to their potential applications in the environment and agriculture fields. Nanoremediation employs NPs that effectively reduce the contents of toxic HMs in the soil-plant system. Several studies have reported that the application of NPs in HMs-polluted soils, which reduced plant-available HMs concentration soils. However, the long-term efficiency of NPs immobilization is still unclear. Here, we provide details about the toxicity of HMs to environmental systems and potential applications NPs to alleviate the accumulation of HMs in agricultural soils. Finally, we present the mechanistic route of HMs-toxicity alleviation in plants by NPs application as well as their long-term efficiency and future prospects.

Tracing the toxic ions of an endodontic tricalcium silicate-based sealer in local tissues and body organs

BACKGROUND

This study aimed to track the toxic ions released by MTA Fillapex, BioRoot RCS, and an experimental tricalcium silicate-based sealer (CEO) into local and distant tissues as well as to investigate their potential adverse effects. In addition, the chemical constituents of the sealers were also evaluated. The main components of the dry powders, pastes, and mixed sealers were characterized.

MATERIAL AND METHODS

Dry powder and sealer discs were each set for 72 h and their main components were characterized by energy dispersive X-ray spectroscopy. Polyethylene tubes filled with sealers were used to measure silicon and calcium ions. Polyethylene tubes filled with sealers or empty tubes were implanted into the dorsal connective tissue of Wistar rats. On days 7, 15, 30, and 45, the animals were euthanized and their brains, livers, kidneys, and subcutaneous tissues were removed and processed to determine the concentrations of chromium, cobalt, copper, lead, iron, magnesium and nickel using an inductively coupled plasma optical emission spectrometer.

RESULTS

The main compounds in all sealers were carbon, oxygen, silicon, and calcium. MTA Fillapex release more Si while highest levels of Si were found in presence of BioRoot. The release of Si and Ca ions promoted by MTA Fillapex raise by time. No traces of cobalt, chromium, or magnesium were detected in any tissue. Irrespective of the sealer, no traces of copper and lead were found in the subcutaneous tissue; however, they were observed in the organs. The highest concentration of iron was identified in the liver. All sealers exhibited similar nickel traces in the brain, kidney, and liver except for MTA Fillapex, which demonstrated levels higher than CEO in the subcutaneous tissue on day 7. Tracing nickel ions over time revealed that lowest concentrations were found in subcutaneous tissue.

CONCLUSION

Taken together, our data demonstrate that CEOs have chemical compositions similar to those of other commercial sealers. Furthermore, none of them exhibited a threat to systemic health. Moreover, the minimal amounts of iron and nickel detected were not related to the sealers.

Evaluation of Trace Element Contamination and Health Risks of Medicinal Herbs Collected from Unpolluted and Polluted Areas in Sichuan Province, China

Trace element contamination in Chinese herbal medicines has been recognized as a potential health concern for consumers. To assess the health risk to the herb-consuming population, nine trace elements (Cu, Cd, Cr, Mo, Ni, Pb, Sr, Zn, and As) were investigated based on their concentrations in three common medicinal plants (Astragalus membranaceus, Codonopsis tangshen, and Paris polyphylla var. chinensis) and soils from unpolluted and polluted areas in the Sichuan Province, China. The results showed that the metal content differed significantly in medicinal plants and soils from unpolluted versus polluted areas. No significant differences in metal accumulation were observed for these CHMs grown in either unpolluted or polluted areas. Evaluation of the health risk index suggested that soil ingestion and medicated diet represented the dominant exposure routes, indicating that trace metal(loids) in local soil might pose potential risks through soil-food chain transfer. Hazard quotient values for AM (1.473) and CT (1.357) were higher than the standard value (HQ > 1), whereas the hazard indices for PC, AM, and CT were 13.18, 14.33, and 14.01 times higher than the safe limit (HI > 1) in the polluted area, indicating non-cancer-related health hazards. Ingestion of soil was responsible for 36.39 to 91.06% of the total cancer risk and medicated diet accounted for 6.35 to 62.71%, compared with inhalation and dermal contact, suggesting carcinogenic health risks in herbs from polluted soils. In this study, Pb showed relatively higher non-carcinogenic risks, while Cr and Ni posed the highest cancer risks. Therefore, we propose more effective measures, which should be considered for Cr, Ni, and Pb remediation in soil to reduce their pollution in the studied areas.

Analysis of essential and non-essential trace elements in the organs of a mother-fetus pair of spotted seals (Phoca largha) from the Sea of Japan

Concentrations of 22 essential and non-essential trace elements (Be, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Ag, Cd, Sb, Ba, Tl, Pb, Th, U, and Hg) were measured in the organs of a mother-fetus pair (at the last trimester of pregnancy) of spotted seals from the Sea of ​Japan. The concentrations of eleven elements are reported for the first time. Eight organs of the pair were examined: lungs, heart, liver, kidneys, intestines, spleen, muscles, and bones. All trace elements detected in the organs of the mother were found also in the organs of the fetus at various concentrations. Placenta is not an effective barrier to prevent non-essential elements from getting into the fetus, but can control entry of some of them, e.g., aluminum, cadmium, and mercury. In most organs of the fetus, the concentrations of toxic trace elements (beryllium, antimony, thorium, and uranium) were noticeably higher than in the same organs of the mother, which indicates that during pregnancy female removes excess of non-essential trace elements by transferring them to the fetal body through the placental barrier.

Variation of soil properties with sampling depth in two different light-textured soils after repeated applications of urban sewage sludge

Semi-arid agricultural soils have increasingly been subjected to urban sewage sludge (USS) applications due to accelerated soil depletion and shortages in manure supply. Research studies addressing USS reuse have mostly been conducted in cropping systems and focused on changes in topsoil properties of a given texture. Therefore, sludge-soil interactions could be largely influenced by the presence of plants, soil particle composition and depth. In this field study, two agricultural soils (sandy, S and sandy loam, SL) received simultaneously four annual USS applications of 40, 80, and 120 t ha^-1 year^-1 in absence of vegetation. Outcomes showed the increase of carbon and macronutrients in both soils proportionally to USS dose especially in the topsoil profile (0-20 cm). Subsoil (20-40 cm) was similarly influenced by sludge rates, showing comparable variations of fertility parameters though at significant lower levels. The depth-dependent improvement of soil fertility in both layers enhanced the microbiological properties accordingly, with significant variations in soil SL characterized by a higher clay content than soil S. Besides, positive correlations between increases in sludge dose, salinity, trace metals, and enzyme activities in both soils indicate that excessive sludge doses did not cause soil degradation or biotoxic effects under the described experimental conditions. In particular and despite high geoaccumulation indices of Ni in both soils and profiles, the global concentrations of Cu, Ni, Pb, and Zn were still below threshold levels for contaminated soils. In addition, the maintenance of pH values within neutral range and the increase of organic matter content with respect to control would have further reduced metal availability in amended soils. Therefore, we could closely investigate the effects of texture and depth on the intrinsic resilience of each soil to cope with repetitive USS applications.

Electrospun Polyacrylonitrile/Lignin/Poly(Ethylene Glycol)-Based Porous Activated Carbon Nanofiber for Removal of Nickel(II) Ion from Aqueous Solution

The issue of heavy metal contamination has caused a great deal of concern among water quality experts today, as it contributes to water pollution. Activated carbon nanofibers (ACNFs) showed a significant ability in removing heavy metals from the wastewater. In this study, polyacrylonitrile (PAN) was blended and electrospun with an abundant and inexpensive biopolymer, lignin and a water soluble polymer, poly(ethylene glycol) (PEG), by using an electrospinning technique to form nanofibers. The electrospun nanofibers were then investigated as a precursor for the production of porous ACNFs to study the removal of nickel(II) ions by adsorption technique. PEG was added to act as a porogen and to create the porous structure of carbon nanofibers (CNFs). CNFs were prepared by thermal treatment of the electrospun nanofibers and followed by activation of CNFs by thermal and acid treatment on CNFs. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) spectral analysis of the ACNFs showed a strong absorption peak of the C-O functional group, indicating the increase in the oxygenated compound. Field emission scanning electron microscopy (FESEM) images concluded that the ACNFs have more porous and compact fibers with a smaller fiber diameter of 263 ± 11 nm, while the CNFs are less compact and have slightly larger fiber diameter of 323 ± 6 nm. The adsorption study showed that the ACNFs possessed a much higher adsorption capacity of 18.09 mg/g compared with the CNFs, which the amount adsorbed was achieved only at 2.7 mg/g. The optimum adsorption conditions that gave the highest percentage of 60% for nickel(II) ions removal were 50 mg of adsorbent dosage, 100 ppm of nickel(II) solution, pH 3, and a contact time of 60 min. The study demonstrated that the fabrication of ACNFs from PAN/lignin/PEG electrospun nanofibers have potential as adsorbents for the removal of heavy metal contaminants.

Probiotics and gut microbiome - Prospects and challenges in remediating heavy metal toxicity

The gut microbiome, often referred to as "super organ", comprises up to a hundred trillion microorganisms, and the species diversity may vary from person to person. They perform a decisive role in diverse biological functions related to metabolism, immunity and neurological responses. However, the microbiome is sensitive to environmental pollutants, especially heavy metals. There is continuous interaction between heavy metals and the microbiome. Heavy metal exposure retards the growth and changes the structure of the phyla involved in the gut microbiome. Meanwhile, the gut microbiome tries to detoxify the heavy metals by altering the physiological conditions, intestinal permeability, enhancing enzymes for metabolizing heavy metals. This review summarizes the effect of heavy metals in altering the gut microbiome, the mechanism by which gut microbiota detoxifies heavy metals, diseases developed due to heavy metal-induced dysbiosis of the gut microbiome, and the usage of probiotics along with advancements in developing improved recombinant probiotic strains for the remediation of heavy metal toxicity.

Nickel induces autophagy via PI3K/AKT/mTOR and AMPK pathways in mouse kidney

Nickel (Ni), a widely distributed metal, is an important pollutant in the environment. Although kidney is a crucial target of Ni toxicity, information on autophagy and the potential mechanisms of Ni-induced renal toxicity are still poorly described. As we discovered, NiCl₂ could induce renal damage including decrease in renal weight, renal histological alterations, and renal function injury. According to the obtained results, NiCl₂ could obviously increase autophagy, which was characterized by increase of LC3 expression and decrease of p62 expression. Meanwhile, the result of ultrastructure observation showed increased autolysosomes numbers in the kidney of NiCl₂-treated mice. In addition, NiCl₂ increased mRNA and protein levels of autophagy flux proteins including Beclin1, Atg5, Atg12, Atg16L1, Atg7, and Atg3. Furthermore, NiCl₂ induced autophagy through AMPK and PI3K/AKT/mTOR pathways which featured down-regulated expression levels of p-PI3K, p-AKT and p-mTOR and up-regulated expression levels of p-AMPK and p-ULK1. In summary, the above results indicate involvement of autophagy in renal injury induced by NiCl₂, and NiCl₂ induced autophagy via PI3K/AKT/mTOR and AMPK pathways in mouse kidney.