Heavy metal poisoning and its laboratory investigation

Development of Lead-Free Materials for Radiation Shielding in Medical Settings: A Review

Radiation protection is an essential issue in diagnostic radiology to ensure the safety of patients, healthcare professionals, and the general public. Lead has traditionally been used as a shielding material due to its high atomic number, high density, and effectiveness in attenuating radiation. However, some concerns related to the long-term health effects of toxicity, environmental disease as well as heavy weight of lead have led to the search for alternative lead-free shielding materials. Leadfree multilayered polymer composites and non-lead nano-composite shields have been suggested as effective shielding materials to replace conventional lead-based and single metal shields. Using several elements with high density and atomic number, such as bismuth, barium, gadolinium, and tungsten, offer significant enhancements in the shielding ability of composites. This review focuses on the development and use of lead-free materials for radiation shielding in medical settings. It discusses the drawbacks of traditional lead shielding, such as toxicity, weight, and recycling challenges, and highlights the benefits of lead-free alternatives.

Engineered Extracellular Vesicles to Enhance Antigen Presentation for Boosting Light-Driven Tumor Immunotherapy

Extracellular vesicles (EVs) have emerged as potential tools for tumor-target therapy accompanied with activating anticancer immune responses by serving as an integrated platform, but usually suffered from the limited cross presentation of tumor-associated antigen by dendritic cells (DCs). Here, a straightforward engineering strategy to construct heat shock proteins 70 (HSP70) highly expressed EVs incapsulated with Te nanoparticles (Te@EVsHSP70 ) for tumor photothermal therapy triggering improved immunotherapy is proposed. Tumor cells are firstly used as bioreactors for intracellular synthesis of Te nanoparticles, and NIR irradiation is subsequently introduced to upregulate the expression of HSP70 to give engineered Te@EVsHSP70 through exocytosis. Te@EVsHSP70 exhibits excellent photothermal performance and enhanced tumor antigen capture capability, which induces significant immunogenic death of tumor cells and improves DCs maturation both in vitro and in vivo. Thus, the engineered EVs demonstrate superior antitumor efficacy through photothermal effect and following provoked antitumor immune responses. This work provides a facile method to fabricate multifunctional EVs-based drug delivery system for improving photothermal-triggered tumor immunotherapy.

Clinical and Forensic Signs Resulting from Exposure to Heavy Metals and Other Chemical Elements of the Periodic Table

Several heavy metals and other chemical elements are natural components of the Earth’s crust and their properties and toxicity have been recognized for thousands of years. Moreover, their use in industries presents a major source of environmental and occupational pollution. Therefore, this ubiquity in daily life may result in several potential exposures coming from natural sources (e.g., through food and water contamination), industrial processes, and commercial products, among others. The toxicity of most chemical elements of the periodic table accrues from their highly reactive nature, resulting in the formation of complexes with intracellular compounds that impair cellular pathways, leading to dysfunction, necrosis, and apoptosis. Nervous, gastrointestinal, hematopoietic, renal, and dermatological systems are the main targets. This manuscript aims to collect the clinical and forensic signs related to poisoning from heavy metals, such as thallium, lead, copper, mercury, iron, cadmium, and bismuth, as well as other chemical elements such as arsenic, selenium, and fluorine. Furthermore, their main sources of occupational and environmental exposure are highlighted in this review. The importance of rapid recognition is related to the fact that, through a high degree of suspicion, the clinician could rapidly initiate treatment even before the toxicological results are available, which can make a huge difference in these patients’ outcomes.

Structural–functional aberrations of erythrocytes in the northern red-backed vole (Clethrionomys rutilus Pallas, 1779) that inhabits the zone of influence of the copper smelter (the Middle Ural)

Red blood cell parameters were assessed in a natural population of the northern red-backed vole (Clethrionomys rutilus Pallas, 1779) in the zone of influence of the Kirovgrad Copper Smelter along a gradient of pollution by heavy metals (Cu, Zn, Cd, and Pb) at three catching sites (polluted [Imp] and controls [Bg-1, and Bg-2]). The difference of the smelter area (Imp group of voles) from both background groups (Bg-1 and Bg-2) was proven by means of a set of 13 parameters in univariate and multivariate analyses. Among the detected erythrocyte disturbances, we noted the following: a decrease in activities of Na⁺,K⁺-ATPase and antioxidant enzymes (SOD, GSH-Px, and CAT); an increase in the concentration of lipid peroxidation products, in osmotic fragility, and in intravascular hemolysis; interruption of carbohydrate metabolism; and lowered oxygen-carrying capacity. A higher load of Cd (p = 0.0009) and possibly Pb (p = 0.054) in the Imp animals was confirmed by quantitation of heavy metals in the liver. Most erythrocyte parameters (11 out of 13) covaried with individual Cd load by obeying a semilogarithmic dependence; such a relation was not found for Cu, Zn, and Pb. A decrease in the growth rate of structural and functional erythrocyte aberrations ("resistance improvement") with increasing cadmium load is probably due to compensatory enhancement of the synthesis of metallothioneins in the liver and kidneys and hence a greater proportion of Cd bound to metallothioneins. Problems of differences/similarities in Cd-associated reactivity among the animals are discussed too, taking into account the catching sites (polluted [Imp] and controls [Bg-1, and Bg-2]) and reproductive-age (i.e., immature underyearlings, mature underyearlings, and individuals that overwintered). The persistence of differences in erythrocyte status observed by us between the Imp and background groups after normalization to Cd load may be due to the action of other (unexamined) adverse factors and calls for further ecotoxicological studies.

The effect of Ulva rigida (C. Agardh, 1823) against cadmium-induced apoptosis and oxidative stress

Cadmium (Cd) is known as a pollutant source in recent years with the increase in industrialization. Algae have secondary metabolites with high biological activity, used for pharmaceutical agents. The liver and kidney are the primary organs involved in the elimination of systemic cadmium and the main targets of cadmium toxicity. In the previous research, it was determined the ameliorative effects of the extract obtained from Ulva rigida in the liver tissue of rats induced by cadmium. 35 female Wistar rats between 225-240 g were used. The subjects were injected subcutaneously with 1 mg/kg cadmium chloride (CdCl2) four times a week for four weeks. The study was carried out by groups as control (G1), Cadmium group (1 mg/kg CdCl2-G2), Algae group (100 mg/kg-G3), Cd+algae group (1 mg/kg CdCl2+50 mg/kg algae extract-G4) and Cd+algae group (1 mg/kg CdCl2+100 mg/kg algae extract -G5). The subjects were sacrificed by cervical dislocation. Liver tissue and cardiac blood were collected. It was determined that oxidative stress with iNOS, inflammation and apoptosis with TNF-α increased with cadmium induction, while there was a statistically significant decrease in the groups that were given algae extract. In addition, biochemical changes in SOD, CAT and MDA values were found to be significant (p<0.05). As a result, it was determined that algae extract could play a protective role with its antioxidant and antiapoptotic properties in experimentally induced cadmium toxicity in rats.

Quantitative evaluation of mercury adsorption and removal efficacy of Spirulina (Arthrospira platensis) powder in mice

Spirulina is a blue-green alga, grown in alkaline water and used for detoxification of several toxic metal ions. Apart from its nutritional value, it is also used for the decontamination of toxic metal ions. Therefore, present study was envisaged to evaluate the adsorption and removal efficiency of Spirulina powder for mercury. The adsorption efficiency of Spirulina was evaluated in terms of weight of adsorbent, contact time, simulated gastric (SGF) and intestinal (SIF) fluid, and mercury concentration. In vivo removal efficacy of Spirulina for mercury was evaluated in mice. The mercury content in major tissues, urine and feces was estimated. The whole tissue retention and excretion of mercury after treatment with Spirulina were taken as a measure of its metal ions removal efficacy. Activated charcoal was taken as a standard adsorbent for comparative study. The maximum adsorption capacity of Spirulina and charcoal for mercury was found to be 66.667 and 158.730 mg g^-1 in water, 83.33 and 94.340 mg g^-1 in SGF and 125.0 and 133.33 mg g^-1 in SIF, respectively. In mice, Spirulina and activated charcoal were significantly reduced the mercury deposition in tissues and facilitated their excretion through feces. Spirulina has shown good adsorption and removal efficacy like activated charcoal. Therefore, Spirulina can be used as a potential adsorbent to remove mercury from the body.

Evaluation of metallic trace elements contents in some major raw foodstuffs in Burkina Faso and health risk assessment

Diet based on cereal, vegetables, oleaginous and dried fish are providing essential metallic elements. It can be also a source of exposure to toxic metallic elements. The aims of this study were to evaluate the contents on nine metallic trace elements (Fe, Zn, Mn, Co, Cd, Pb, Cu, Ni, Cr) in some major raw foodstuffs including rice, maize, peanut, tomato and dried fish in Burkina Faso and assess the health risk of these elements. Two hundred twenty-two samples were collected and analyzed by atomic absorption spectrometry. The health risk assessment was based on the United States Environment Protection Agency (USEPA) model. Iron and Zinc were the elements with the highest concentrations in the investigated foodstuffs. The iron highest median value (68.80 mg/kg) was observed in dried fish followed by maize (43.09 mg/kg) and peanuts (28.92 mg/kg). Rates of 77.95%, 66.66% and 32.5% obtained respectively fro tomato, maize and rice samples were above the maximum limit of lead set by Codex Alimentarius while 47.6%, 71.16% and 0% of maize, tomato and rice samples respectively have shown concentration above the maximum limit of cadmium. Chromium had shown higher contribution rate to the maximum daily intake of 167.11%, 34%, 2% and 8.53% for rice, maize and peanut respectively. A non-cancer risk situation has been observed on rice, maize and peanut consumption. None of the index risk values was above the threshold set by USEPA.

Sustainable Amelioration of Heavy Metals in Soil Ecosystem: Existing Developments to Emerging Trends

The consequences of heavy metal contamination are progressively degrading soil quality in this modern period of industry. Due to this reason, improvement of the soil quality is necessary. Remediation is a method of removing pollutants from the root zone of plants in order to minimize stress and increase yield of plants grown in it. The use of plants to remove toxins from the soil, such as heavy metals, trace elements, organic chemicals, and radioactive substances, is referred to as bioremediation. Biochar and fly ash techniques are also studied for effectiveness in improving the quality of contaminated soil. This review compiles amelioration technologies and how they are used in the field. It also explains how nanoparticles are becoming a popular method of desalination, as well as how they can be employed in heavy metal phytoremediation.

Urban sediment pollutants alternate human cell essential behaviour through promoting oxidative damage

The main objective of this study was to establish a human cell-based platform to assess the effects of sediment toxicity on oxidative damage and cell essential behaviour. Since sediment pollution has increased as a consequence of including but not limited to industrialisation, the contaminants accumulated in sediments have already led to human health concerns. The Hsinchu Science Park is one of the most prominent semiconductor manufacturing centres in the world, and the Ke-Ya River flows through Hsinchu Science Park and the Hsinchu urban district. Because semiconductor wastes potentially contribute to higher-than-normal rates of cancers, birth defects, and serious diseases, the quality assessment of the Ke-Ya River has prompted widespread concerns. While previous studies have shown an association between the degradation of fish populations and sediment pollutants, very little is known about the issues on human health. Herein, the effects of sediment from three sediment sampling sites of the Ke-Ya River on 11 different human cell lines were directly evaluated. The upstream represents the undeveloped zone, the middle-stream represents the household/industrial wastewater zone, and the downstream represents the accumulation zone. Our results indicated that the sediment pollution of the downstream Ke-Ya River was more cytotoxic than that of the middle stream and upstream. Downstream sediment extract (DSE) significantly increased reactive oxygen species (ROS) levels across all cell types. Accordingly, oxidative stress can trigger redox-sensitive pathways and alter essential biological processes such as cell viability, cell adhesion, and cell motility. Importantly, the MTT assay indicated that DSE significantly decreased the viability of brain, oral, lung, breast, liver, pancreatic, cervical, prostate, and colorectal cells. Furthermore, the adhesive ability and wound healing ability of most cells were greatly reduced in the presence of DSE compared to other conditions. Thus, this study shows the results of the first analyses completed on the sediment cytotoxicity in human cells, and stimulated ROS levels are crucial for cellular life. In future research, the detailed cause and effect mechanisms of the abundant ROS generated in DSE will be further investigated. We sincerely hope that our study provides a scientific basis for further investigations with a global perspective on public health challenges.

Association of heavy metals and trace elements in renal cell carcinoma: A case-controlled study

PURPOSE

Trace elements and/or heavy metals are important for various biological activities. However, excess amount of these elements is associated with a variety of diseases, including cancer. We aimed to analyse the alterations of trace elements levels in renal cell carcinoma (RCC) patients.

MATERIALS AND METHODS

In this observational study, patients with biopsy proven RCC were taken as study group while age- and sex-matched healthy volunteers were taken as control. Blood and urine samples were compared for Arsenic (As), Copper (Cu), Manganese (Mn), Selenium (Se), Cadmium (Cd), Lead (Pb) and Mercury (Hg) levels measured by inductively coupled plasma mass-spectroscopy. Serum glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) antioxidant enzymes and lipid peroxidation (LPO) levels were assessed to know the redox status between 2 groups.

RESULTS

A total of 76 RCC cases and 64 controls were recruited in the study. A significantly higher concentration of As, Cu, Mn, Cd, Pb and Hg were observed in the blood of RCC patients as compared to controls. However, blood Se level was significantly lower in RCC patients. In 33 (43.4%) patients, one or more heavy metals were higher in the blood above their permitted level as compared to 10 (15.6%) subjects in control group. RCC patients had a higher urinary Mn and Se levels compared to controls. A significantly lower GSH-Px (182.08 ± 132.91 vs. 236.95 ± 132.94, P = 0.04) and a higher LPO levels (26.02 ± 20.79 vs. 14.06 ± 8.44, P = 0.003) were noted in RCC patients than controls. SOD levels were comparable between two groups.

CONCLUSIONS

A significantly altered heavy metals concentration is noted in the blood and urine in RCC patients as compared to healthy controls. An associated lower levels of GSH-Px antioxidant enzyme and increased LPO in RCC patients signifies an imbalance in the redox status.

Interaction of copper with titanium dioxide nanoparticles induced hematological and biochemical effects in Clarias gariepinus

The increasing demand for engineered nanomaterials induces potential harmful impact into aquatic ecosystems and is a great concern for freshwater biodiversity. The present study showed that enhancing toxic property of titanium dioxide nanoparticles (TiO₂ NPs) with copper (Cu) was responsible for the disruption of hormonal, hematological, and biochemical activities, in Clarias gariepinus. The study revealed that C. gariepinus intravenously injected with safe concentrations of TiO₂ NPs (3μg g) and Cu (2.5 μg g) alone and binary mixtures (TiO₂ NPs (3μg g) + Cu (2.5μg g)) for a period of 96h remarkably changed hormonal activities and hematological and biochemical indices of the fish. Our findings indicated that both chemicals accumulated in vital organs (the brain, serum, heart, gonad, liver, gills, serum, and kidney) and the presence of TiO₂ NPs enhanced the bioavailability of copper. Fish exposed to TiO₂ NPs alone significantly increased thyroxine (T₄) and further decreased triidothyronine (T₃). In addition, the binary mixtures showed antagonistic effects on both hormones. The hematological indices (WBC, RBC, HGt, MCV, MCH, MCHC, and Hct) were altered in all treatment groups. Decrease in WBC, RBC, HGt, Hct, and MCV were observed. Furthermore, the co-exposure further decreased WBC (60.28%), RBC (47.10%), HGt (75.99%), Hct (25.34%), and MCV (16.18%), in contrast, MCH and MCHC increased by of 2 folds, respectively. Metabolic enzymes alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) showed significant (p<0.05) increase, with additive effect in co-exposure. However, the alkaline phosphatase (ALP) activity decreased significantly in co-exposure. Significant (p<0.05) decrease of antioxidants, superoxide dismutase (SOD), glutathione transferase (GST), catalase (CAT), and metallothionein (Met) was observed in all the treatments with additive effect of 64.9%, 30.77%, and 91.31% in SOD, GST, and CAT, respectively. However, there was an increase in lipid peroxidation (MDA) in all treated fish. The results indicate that combined mixture influences the accumulation, hormonal, hematological, and biochemical factors which could affect the health of the fish.

Evaluation of essential and non-essential elemental composition of commonly used medicinal plants from district Peshawar, Khyber Pakhtunkhwa, Pakistan

This study illustrates a profile of some essential and non-essential elements (Na, K, Mg, Ca, Cu, Zn, Mn, Fe, Pb, Cr, Cd, Co, Al, and Sn) in the aerial parts of six medicinal plants, i.e. Coriandrum sativum L., Mentha spicata L., Papaver somniferum L., Calotropis gigantean (L.) Dryand., Withania coagulans (Stock) Dunal, and Fagonia arabica L. widely consumed in district Peshawar, the capital city of Khyber Pakhtunkhwa, Pakistan. The samples were converted into liquid state via wet digestion method and analyzed for elemental composition by using atomic absorption spectrometry. After determining the concentration, hazard quotient (HQ) was calculated for the elements having available maximum permissible limit set by FAO/WHO or any other agency for 50 mg daily intake of the herbal plants by a person of body mass 70 kg. K/Na ratio for the studied plants varied between 14.88:1 and 113.75:1 which was in agreement with the reported permissible range. The amount of Mg, Ca, Cu, and Co was within the permissible limit in all the enlisted plants. However, the HQ value for Mg and Ca was greater than the safe limit for some of the plants. The concentration and HQ value of Zn, Mn, Fe, Pb, Cr, and Cd was beyond the permissible and unsafe limits for almost all the plants. This study suggests that the plants of this area must be pretreated for lessening the concentration of some elements before consumption.

Element Rich Area Associated with Human Health Disorders: A Geomedical Science Approach to Potentially Toxic Elements Contamination

(1) Background: Geomedical science focuses on the relationship between environmental impact and human health. The abundance of elements in a geographic area is reflected accumulation of these elements in humans. This study aims to describe the relationship between concentrations of geologic elements and accumulations in the human body as well as element-related symptoms. (2) Methods: Geogenic sampling was conducted in an Artisanal and Small-Scale Gold Mining (ASGM) area and around residential areas in Indonesia, and samples were analyzed using particle-induced X-ray Emission (PIXE). Head hair was sampled, and health assessments were performed to determine heavy metal exposure, especially to copper and mercury. (3) Results: Results show that potentially toxic elements' accumulation in the human body follows the abundance of these elements in the geographic area, which then affect health and manifest with specific signs and symptoms. East Tulabolo is an area rich in copper (hazard quotient (HQ) in dust = 152.8), and most of the population shows the sign of Kayser-Fleischer rings. Likewise, the Dunggilata area has the highest concentration of mercury, especially in the dust (HQ = 11.1), related to ASGM activity in residential areas. (4) Conclusions: This study concludes that the geogenic concentration of elements parallels the accumulation of human tissue and manifests with element-related signs and symptoms.

To be, or not to be… Guillain-Barré Syndrome

Guillain-Barré Syndrome (GBS) is currently the most frequent cause of acute flaccid paralysis on a global scale, being an autoimmune disorder wherein demyelination of the peripheral nerves occurs. Its main clinical features are a symmetrical ascending muscle weakness with reduced osteotendinous reflexes and variable sensory involvement. GBS most commonly occurs after an infection, especially viral (including COVID-19), but may also transpire after immunization with certain vaccines or in the development of specific malignancies. Immunoglobulins, plasmapheresis, and glucocorticoids represent the principal treatment modalities, however patients with severe disease progression may require supportive therapy in an intensive care unit. Due to its symptomology, which overlaps with numerous neurological and infectious illnesses, the diagnosis of GBS may often be misattributed to pathologies that are essentially different from this syndrome. Moreover, many of these require specific treatment methods distinct to those recommended for GBS, in lack of which the prognosis of the patient is drastically affected. Such diseases include exposure to toxins either environmental or foodborne, central nervous system infections, metabolic or serum ion alterations, demyelinating pathologies, or even conditions amenable to neurosurgical intervention. This extensive narrative review aims to systematically and comprehensively tackle the most notable and challenging differential diagnoses of GBS, emphasizing on the clinical discrepancies between the diseases, the appropriate paraclinical investigations, and suitable management indications.

The Mediation Effects of Aluminum in Plasma and Dipeptidyl Peptidase Like Protein 6 (DPP6) Polymorphism on Renal Function via Genome-Wide Typing Association

Aluminum (Al) toxicity is related to renal failure and the failure of other systems. Although there were some genome-wide association studies (GWAS) in Australia and England, there were no GWAS about Han Chinese to our knowledge. Thus, this research focused on using whole genomic genotypes from the Taiwan Biobank for exploring the association between Al concentrations in plasma and renal function. Participants, who underwent questionnaire interviews, biomarkers, and genotyping, were from the Taiwan Biobank database. Then, we measured their plasma Al concentrations with ICP-MS in the laboratory at Kaohsiung Medical University. We used this data to link genome-wide association (GWA) tests while looking for candidate genes and associated plasma Al concentration to renal function. Furthermore, we examined the path relationship between Single Nucleotide Polymorphisms (SNPs), Al concentrations, and estimated glomerular filtration rates (eGFR) through the mediation analysis with 3000 replication bootstraps. Following the principles of GWAS, we focused on three SNPs within the dipeptidyl peptidase-like protein 6 (DPP6) gene in chromosome 7, rs10224371, rs2316242, and rs10268004, respectively. The results of the mediation analysis showed that all of the selected SNPs have indirectly affected eGFR through a mediation of Al concentrations. Our analysis revealed the association between DPP6 SNPs, plasma Al concentrations, and eGFR. However, further longitudinal studies and research on mechanism are in need. Our analysis was still be the first study that explored the association between the DPP6, SNPs, and Al in plasma affecting eGFR.

Long-term misdiagnosis and neurologic outcomes of thallium poisoning: A case report and literature review

INTRODUCTION

Thallium poisoning is a rare occurrence. Therefore, thallium poisoning is easily misdiagnosed and is often accompanied by a series of serious sequelae and can even result in death in severe cases. Here, we report long-term follow-up of a case of a patient who was poisoned with thallium on two separate occasions.

METHODS

A 43-year-old man was initially misdiagnosed as gastroenteritis, diabetic peripheral neuropathy, and Guillain-Barré Syndrome (GBS) within 21 months. The correct diagnosis was confirmed by blood and urine thallium assays. After Prussian blue treatment, thallium was undetectable in the blood by day 60. Following this investigation, a criminal suspect confessed to two instances of adulterating thallium sulfate in the patient's beverage. A 6-year follow-up was performed after discharge, and a comprehensive literature was review.

RESULTS

We found that the original gastrointestinal symptoms, skin lesions, and hair loss were reversed and had recovered, except for residual neurologic damage, even with long-term rehabilitation.

DISCUSSION

Thallium intoxication may have been initially identified if neurologic symptoms had occurred concurrently with gastrointestinal and cutaneous symptoms. Neurologic damage represented the main sequelae of thallium poisoning in our present case report.

Natural and Anthropogenic Origin of Metals in Lacustrine Sediments; Assessment and Consequences—A Case Study of Wigry Lake (Poland)

The contamination of aquatic sediments by metals is a worldwide phenomenon and its assessment is a fairly complex issue, as numerous factors affect the distribution of particular contaminants in the environment, as well as their bioavailability. Wigry Lake, as the object of this study, is almost a perfect water body for such considerations. It has been well investigated and densely sampled (up to 459 sediment samples). The quantities of seven metals were determined using the atomic absorption spectrometry (AAS) or inductively coupled plasma (ICP)-MS methods, following previous extraction in a microwave oven. The levels of concentration of the examined elements were as follows (min–max (mg·kg−1)): Cd—0.003–3.060; Cr—0.20–22.61; Cu—0.02–59.70; Fe—80–32,857; Mn—18–1698; Pb—7.0–107.5; Zn—3.1–632.1. Significant differences were also registered in terms of particular metal concentrations in different sediment types found at the lake bottom. Five different geochemical backgrounds and sediment quality guidelines implemented in the study enabled a very scrupulous contamination assessment of the lake sediments’ condition, as well as the evaluation of the natural and anthropogenic contribution to the enrichment of examined sediments in metals. Although Wigry Lake is situated in a pristine region, it is still subject to anthropopressure, which seems to be the lowest in respect to Cr and Mn, while the highest in the case of Pb. The chemoecological state of the lake was ultimately assessed as good. The study highlighted the necessity of an integrated approach to the assessment of contamination or pollution in the course of an environmental research.

Phytoremediation of toxic metals present in soil and water environment: a critical review

Heavy metals are one of the most hazardous inorganic contaminants of both water and soil environment composition. Normally, heavy metals are non-biodegradable in nature because of their long persistence in the environment. Trace amounts of heavy metal contamination may pose severe health problems in human beings after prolonged consumption. Many instrumental techniques such as atomic absorption spectrophotometry, inductively coupled plasma-mass spectrometry, X-ray fluorescence, neutron activation analysis, etc. have been developed to determine their concentration in water as well as in the soil up to ppm, ppb, or ppt levels. Recent advances in these techniques along with their respective advantages and limitations are being discussed in the present paper. Moreover, some possible remedial phytoremediation approaches (phytostimulation, phytoextraction, phyotovolatilization, rhizofiltration, phytostabilization) have been presented for the removal of the heavy metal contamination from the water and soil environments.

A portable microfluidic device-based Fe3O4-urease nanoprobe-enhanced colorimetric sensor for the detection of heavy metals in fish tissue

A portable microfluidic device with highly sensitive enzyme nanoprobe (Fe₃O₄ MNPs-urease, average size 34.6 nm) was demonstrated for the analysis of heavy metals ions (Hg²⁺, Cd²⁺ and Pb²⁺) in fish gill and muscle tissue. The immobilized urease nanoprobe (K_m = 0.05 mM) exhibited twofold sensitivity over the free enzyme assay (apparent K_m = 0.1 mM). The nanoprobe was characterized using SEM, EDAX, PSA and FT-IR. The inhibition measurements were carried out for individual as well as the mixture of metal ions (CRM standards of 9 elements (CRM_mix-9)). The lower limit of quantification (LOQ) (0.5, 0.1, and 0.1 ng L^-1 for Hg²⁺, Cd²⁺, and Pb²⁺) and lower limit of detection (LOD) was achieved at 0.1 ng L^-1 with sensitivity 8-14% per decade for Hg²⁺, Cd²⁺, and Pb²⁺ ions. A visual result can be observed by the naked eye through the microfluidic device as well as with 96 transparent microwell plates. The order of relative inhibition was found to be CRM_mix-9 > (Hg²⁺ + Cd²⁺ + Pb²⁺) > (Cd²⁺ + Pb²⁺) > (Pb²⁺ + Hg²⁺) > (Hg²⁺ + Cd²⁺) > Pb²⁺ > Cd²⁺ > Hg²⁺, respectively. The recovery % in fish tissues were found to be 88-98% for Hg²⁺, Cd²⁺ and Pb²⁺ ions.

Graphene based adsorbents for remediation of noxious pollutants from wastewater

The contamination of water resources with noxious pollutants is a serious issue. Many aquatic systems are contaminated with different toxic inorganic and organic species; coming to wastewater from various anthropogenic sources such as industries, agriculture, mining, and domestic households. Keeping in view of this, wastewater treatment appears to the main environmental challenge. Adsorption is one of the most efficient techniques for removing all most all types of pollutants i.e. inorganics and organics. Nowadays, graphene and its composite materials are gaining importance as nano adsorbents. Graphene; a two-dimensional nanomaterial having single-atom graphite layer; has attracted a great interest in many application areas (including wastewater treatment) due to its unique physico-chemical properties. The present paper is focused on the remediation of noxious wastes from wastewater using graphene based materials as adsorbents, and it contains all the details on materials - i.e., from their synthesis to application in the field of wastewater treatment (removal of hazardous contaminants of different chemical nature - heavy and rare-earth metal ions, and organic compounds - from wastewater effluents. The efficiency of the adsorption and desorption of these substances is considered. Certainly, this article will be useful for nano environmentalist to design future experiments for water treatment.

Risk assessment and source identification of heavy metal contamination by multivariate and hazard index analyses of a pipeline vandalised area in Lagos State, Nigeria

Petroleum contamination is a significant contributor of elevated level of toxic heavy metals, which are of great concern to human health, due to their non-biodegradable nature. Agaye community has experienced frequent gasoline spills due to pipeline vandalisation, resulting in the contamination of soil and water sources. The concentrations of metals (Cd, Cr, Cu, Mn, Ni, Pb, V and Zn) in groundwater, surface-water and soil were determined from a total of 216 samples acquired bi-monthly for two years by Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) to evaluate the impact of oil spills. Multivariate analyses using principal component analysis (PCA) and cluster analysis (CA) were also used to study the interactions between metals and identify the possible sources of contamination. The concentrations of heavy metals in soil and water samples (surface and groundwater) were in decreasing order of Mn > Ni > Zn > Cu > V > Cr > Pb > Cd and Ni > Zn > V > Cu > Mn > Pb > Cr > Cd respectively. Ni concentration ranged from 0.42-8.05 mg kg^-1 and 0.10-2.85 mg L^-1 for soil and groundwater respectively. Ni and V were more enhanced (P < 0.05) in soil samples. This study showed that there was significant relationship between elevated levels of Cr, Cu, Ni and Zn and oil spillage, due to petroleum spills and that residents were vulnerable to and at greater risk of non-carcinogenic hazards if they consumed groundwater. Multivariate analyses showed significant anthropogenic intrusions of two diagnostic heavy metals (Ni and V) for petroleum contamination in the soils and water sources.

Chromosomal expression of CadR on Pseudomonas aeruginosa for the removal of Cd(II) from aqueous solutions

Genetically engineered bacteria for pollution control of heavy metal have been widely studied, however, using Pseudomonas aeruginosa (P. aeruginosa) that can adapt to various circumstances to remediate heavy metal pollution is rarely reported. In this study, we employed CadR, a cadmium (Cd)-specific binding protein, displaying on the surface of P. aeruginosa with chromosomal expression. The genetically engineered (GE) P. aeruginosa still flourished in the 30th generation in the LB broth which contained 100 μM Cd(II), exhibiting an excellent genetic stability. Chromosomally expressed P. aeruginosa showed an adsorption capacity of up to 131.9 μmol/g of Cd(II). In addition, the low concentration of the coexisting two valence ions has no significant effect on adsorption capacity of Cd(II). This study provides a direction for application of P. aeruginosa in environment remediation.

Siloxane-Based Nanoporous Polymers with Narrow Pore-size Distribution for Cell Imaging and Explosive Detection

Porous polymers are among the most promising porous materials for various application because they show the combined advantages of fluorescent porous materials and polymers. This study developed a cell imaging technique based on luminescent porous organosilicon polymers (LPOPs) that were synthesized via Friedel-Crafts reaction of octaphenylcyclotetrasiloxane with octavinylsilsesquioxanes. The porous organosilicon polymers possessed narrow pore-size distribution, high surface area, and monomodal nanopores centered at approximately 0.59 nm. The excellent properties to the porous polymers can be attributed to the fine structures of LPOPs. LPOP-2 owned the highest fluorescence intensity and micropore volume ratio in LPOPs and showed high selectivity for Fe³⁺ detection and excellent sensitivity to nitroaromatic compound detection. Interestingly, these porous polymers still exhibited excellent responsiveness to Fe³⁺ ion even when inside of living cells. We also fabricated a paper-based sensor using LPOP-2 to develop a simple method for visual detection of explosives. This rapid and visual paper sensor demonstrates promising application for explosive detection and can be expanded for the detection of other analytes.

An Investigation of Protective Effects of Litium Borate on Blood and Histopathological Parameters in Acute Cadmium-Induced Rats

This study was carried out to determine the protective effects of lithium borate (LTB) on blood parameters and histopathological findings in experimentally induced acute cadmium (Cd) toxicity in rats. Twenty-eight male Wistar albino rats were used, weighing 200-220 g, and they were randomly divided into four groups, including one control and the following three experimental groups: a Cd group (0.025 mmol/kg), a LTB group (15 mg/kg/day orally for 5 days), and a LTB + Cd group (15 mg/kg/day orally for 5 days and Cd 0.025 mmol/kg by intraperitoneal injection on the fifth day). All the rats in the study were anesthetized with ketamine at the end of the sixth day, blood was taken from their hearts, and then the rats were decapitated. The values in the control and LTB group were usually close to each other. White blood cell (WBC), neutrophil %, and C-reactive protein (CRP) levels increased in the Cd and LTB + Cd groups while lymphocyte and monocyte levels decreased in a statistically significant manner, in comparison to the other groups. It was determined that the levels of red blood cells (RBCs), hematocrit (Htc), and hemoglobin (Hb) did not change in the groups. The levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in the Cd and LTB + Cd groups significantly increased, in comparison to the other groups, while the glucose, alkaline phosphatase (ALP), albumin (ALB), and total protein (TP) levels decreased. According to histopathological findings in the control and LTB groups, the liver and kidney tissues were found to have normal histological structures. In the Cd group, severe necrotic hemorrhagic hepatitis, mild steatosis, and mononuclear cell infiltration were detected in the liver. In the LTB + Cd group, degeneration and mild mononuclear cell infiltration were found in the liver. Regarding the kidney tissue in the Cd group, severe intertubular hyperemia in both kidney cortex and medulla, as well as degeneration and necrosis in the tubulus epithelium, was observed. In the LTB + Cd group, mild interstitial hyperemia and mononuclear cell infiltration was detected. Resultantly, it can be said that LTB at this dose has non-toxic effects and some beneficial effects for liver and kidney damage caused by acute Cd toxicity.

Adsorption of heavy metals on conventional and nanostructured materials for wastewater treatment purposes: A review

The problem of water pollution is of a great concern. Adsorption is one of the most efficient techniques for removing noxious heavy metals from the solvent phase. This paper presents a detailed information and review on the adsorption of noxious heavy metal ions from wastewater effluents using various adsorbents - i.e., conventional (activated carbons, zeolites, clays, biosorbents, and industrial by-products) and nanostructured (fullerenes, carbon nanotubes, graphenes). In addition to this, the efficiency of developed materials for adsorption of the heavy metals is discussed in detail along with the comparison of their maximum adsorption capacity in tabular form. A special focus is made on the perspectives of further wider applications of nanostructured adsorbents (especially, carbon nanotubes and graphenes) in wastewater treatment.

Bio-prospectus of cadmium bioadsorption by lactic acid bacteria to mitigate health and environmental impacts

Foodstuffs and water are the key sources of cadmium biomagnifiaction. The available strategies to mitigate this problem are unproductive and expensive for practical large-scale use. Biological decontamination of metals through environmental microbes has been known since long time, whereas lactic acid bacteria (LAB) have not been extensively studied for this purpose. The LAB are known for maintaining homeostasis and suppression of pathogens in humans and animals. They also play a vital role in bioremediation of certain heavy metals. Recently in-vivo research findings strongly complement the in-vitro results in relation to decreased total body cadmium burden in animal model. This review summarizes the currently available information on impact of toxic metal (Cd) on human and animal health as well as cadmium sequestration through microbes placed broadly, whereas preeminent attention grabbed on LAB-cadmium interaction to explore their possible role in bioremediation of cadmium from foods and environment to safeguard human as well as environment health.

Alopecia and Associated Toxic Agents: A Systematic Review

Importance/Objective

There are a number of toxic agents that can cause alopecia. In this review we summarize the known substances that cause alopecia as one of the clinical signs of overdose or toxicity.

Evidence Review

A search was conducted using PubMed, EMBASE, and Cochrane for studies describing hair loss of any type as a result of exposure to or ingestion of a toxic agent. The search yielded 856 articles, with 47 studies included in this review.

Findings

Agents with the strongest evidence of association to alopecia include thallium, mercury, selenium, and colchicine. Agents with described incidents include boric acid, arsenic, vitamin A, botulinum toxin, Podostroma cornu-damae, and the synthetic opioid MT-45.

Conclusions and Relevance

Numerous toxic agents have been implicated in alopecia, and the strength of evidence behind each agent varies. Toxic levels of thallium and colchicine have long been established to cause alopecia, as compared to agents such as botulinum toxin A and synthetic recreational drugs which have less literature describing their links to alopecia and will need further investigation to characterize their relationships to hair loss. Knowledge of typical presentations of hair loss will aid in the development of a differential diagnosis for patients presenting with alopecia.

Selective and reversible adsorption of cationic dyes by mixed ligand Zn(ii) coordination polymers synthesized by reactant ratio modulation

2D/3D luminescent Zn(ii)-based coordination polymers CP1 and CP2 have been synthesized by reactant ratio modulation. Photoluminescence studies of both CPs; selective and reversible adsorption/separation of cationic dyes by CP1 in the aqueous medium has been investigated.

Synthesis and characterization of new 1-hydroxy-2-pyridinethione derivatives: Their lead complexes and efficacy in the treatment of acute lead poisoning in rats

A number of new mono- and dihydroxypyridinethione ligands have been synthesized via reaction of dimethylamine and amino acid esters with the active amide obtained from the reaction of 1-hydroxy-2-pyridinethione-4-carboxylic acid (1) and 1,1'-carbonyldiimidazole in DMF. Moreover, the lead complexes of these new ligands were also prepared. Structures of the newly synthesized compounds have been confirmed by different spectroscopic methods such as IR, ¹H NMR, and ¹³C NMR, and by elemental analysis. The effect of these synthesized ligands on the excretion of lead, iron, and zinc, and their distribution in kidneys, liver, and bones in acutely intoxicated rats was investigated and results, for lead, were compared with those of the known drug meso-2,3-dimercaptosuccinic acid (DMSA). Results obtained revealed that compound 5 exhibits remarkable ability in total fecal and urinary excretion of lead and was superior to DMSA. In addition, results show that the concentration of lead in soft tissues and bones was lower in rats treated with HTPL than those treated with DMSA. Furthermore, the concentration of lead in liver tissues obtained from sub-chronic lead-intoxicated rats treated with HTPL was lower than those treated with DMSA and calcium disodium ethylenediaminetetraacetic acid (CaNa₂EDTA).

Effect of hydroxypropyl cellulose (HPC), polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) on Nd-TiO2/graphene oxide nanocomposite for removal of lead(II) and copper(II) from aquatic media

In order to investigate the effect of hydroxypropyl cellulose (HPC), polyvinylpyrrolidone (PVP) and polyethylene glycol (PEG) on adsorbing capacity of nanosorbent Nd-TiO₂/GO, Nd-TiO₂/HPC/GO, Nd-TiO₂/PVP/GO and Nd-TiO₂/PEG/GO nanocomposites were synthesized. Studies by Fourier transform infrared spectroscopy confirmed the expected structure and X-ray diffraction results confirmed the formation of crystalline phase of anatase titania and also graphene oxide (GO). Scanning electron microscopy pictures and energy dispersive X-ray spectroscopy analysis showed the formation of Nd-TiO₂ nanoparticles. These nanocomposites were used for removal of lead(II) and copper(II) from water and the effective factors on removal were optimized. The results showed that the maximum removal for all three nanocomposites was at pH = 7. The amount of adsorbent and contact time for Nd-TiO₂/HPC/GO and Nd-TiO₂/PVP/GO nanocomposites was equal to 0.02 g and 20 minutes respectively, but they were equal to 0.01 g and 15 minutes for Nd-TiO₂/PEG/GO nanocomposite. Investigating the effect of interfering ions showed they had no considerable effect on removal efficiency. In order to investigate the effect of photocatalytic activity in optimal conditions and in the presence of visible-ultraviolet light, the removal process was performed. The results showed an increase in removal efficiency. Furthermore, the ability of synthesized nanosorbents to decompose organic compounds available in water was confirmed and their energy band gaps were calculated.

Ameliorative effect of two Ayurvedic herbs on experimentally induced arsenic toxicity in calves

ETHNOPHARMACOLOGICAL RELEVANCE

Chronic arsenic poisoning due to contaminated subsoil water is a threat to society in West Bengal, India and in Bangladesh. The human being may also be affected by the exposed cattle from the affected area by consuming milk, egg, meat and others. In Ayurveda, several herbs like Haridra (turmeric), Shunthi (dried ginger root) and others are used for the management of arsenic poisoning.

AIM OF THE STUDY

The study was conducted to find out the ameliorative effect of turmeric and ginger powder against experimentally induced arsenic toxicity in calves.

MATERIALS AND METHODS

Twenty four calves were divided into four groups (group I, II, III and IV) having six animals in each group. Animals of group I, II and III were orally administered with sodium arsenite at 1mg/kg body weight for 90 days and in addition group II and group III animals were treated orally with turmeric and ginger powder respectively at 10mg/kg body weight from 46th day onwards. Group IV animals were given food and water without drug and served as control. Arsenic content was estimated in faeces, hair, urine and plasma in every 15 days. Bio-chemical, haematological and anti-oxidant parameters were also assessed.

RESULTS

Turmeric and ginger powder significantly (P<0.05) reduced the plasma and hair arsenic levels through increased excretion via faeces and urine. Haemoglobin level, TEC and TLC were decreased in groups I, II and III, however these were improved significantly (P<0.05) from 75th day onwards in turmeric and ginger treated groups. Increased activity of AST and ALT were significantly decreased (P<0.05) from 75th day onwards in group II and III. Blood urea nitrogen and plasma creatinine were also significantly decreased (P<0.05) in group II and III than group I from 60th day onwards. The SOD and catalase activity were significantly (P<0.05) reduced in groups I, II and III, but these were restored at the end of the experiment in turmeric and ginger treated groups.

CONCLUSION

The test drugs are found significantly effective not only to eliminate arsenic from the body but also give protection from possible damage caused by arsenic exposure, it may be concluded from the present study that turmeric and ginger can be helpful in the therapy of chronic arsenic toxicity in calves.

Efficacy of indigenous probiotic Lactobacillus strains to reduce cadmium bioaccessibility - An in vitro digestion model

The toxic heavy metal cadmium (Cd) appears as one of the major global threats to human and animal health. Human being and aquatic life are exposed to Cd by breathing, eating, or drinking when industrial effluents released into environment. The study was aimed to identify cadmium-binding Lactobacillus strain to reduce its bioaccessibility in in vitro digestion model. In this context, forty-eight lactobacilli strains isolated and characterized from fermented dairy products and human origin were screened for their Cd biosorption potential using Flame Atomic Absorption Spectroscopy (FAAS). The present study revealed that Cd biosorption potential of 48 lactobacilli strains ranged from 1.0832 ± 0.012 to 3.562 ± 0.03 mg Cd g^-1 of cells from initial 10 mg L^-1 cadmium chloride (CdCl₂) aqueous solution. Lactobacillus plantarum strain HD 48 demonstrated highest biosorption of 3.562 ± 0.03 mg Cd g^-1 of cells. Lactobacilli-Cd complex stability indicated its strong stability as even after three washes with Milli-Q water metal desorption was nonsignificant (p < 0.05) and further studies to delineate the influence of Cd (100 mg L^-1 CdCl₂) on their growth. Moreover, these strains were able to reduce Cd bioaccessibility in the in vitro digestion model in the range of 24.71 to 41.62 %. Transmission electron microscopy (TEM) investigations on Cd bioadsorption also revealed its surface associated bioadsorption phenomenon. These findings depicted that probiotic strain L. plantarum HD 48 was found to be endowed with remarkable Cd biosorption ability as well as reduction in its bioaccessibility. These results suggest that probiotic strain L. plantarum HD 48 has immense potential to sequester Cd from aqueous solution which could be further explored as a potent source to diminish body Cd burden.

Levels of heavy metals in the raw and processed Ethiopian tobacco leaves

Tobacco (Nicotiana tabacum L.) is a commercial plant. Tobacco leaves naturally accumulate and concentrate relatively high levels of heavy metals and particular cadmium in leaves. Tobacco is one of the basic agricultural products, in Ethiopia, with social and economic importance. However, there is no report in the literature on the determination of levels of heavy metals in Ethiopian tobacco leaves. Hence this research is intended to determine the levels of heavy metals in the raw and processed Ethiopian Virginia tobacco leaves. Samples of raw Virginia tobacco leaves were collected from two different regions of Ethiopia (Billate and Shewa Robit). The three processed tobacco samples were collected from National Tobacco Enterprise, Addis Ababa, Ethiopia. The samples were wet-digested using 3 mL HNO₃ (69–72 %) and 3 mL HClO₄ (70 %) at 350 °C for 3.5 h and concentrations of heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) in the samples were determined by flame atomic absorption spectrometer. The mean metals concentrations (in µg/g dry weight) in the raw Virginia tobacco leaves from Billate and Shewa Robit, respectively, were: Cu (4.38, 7.30), Zn (53.7, 33.2), Cd (1.20, 1.30), Cr (ND, 1.45), Ni (ND, 1.90). The mean metals concentrations (in µg/g dry weight) in the processed tobacco from Billate and Shewa Robit, respectively, were: Cu (9.80, 12.8), Ni (2.35, 2.20) Cd (1.45, 1.90), Cr (1.65, 1.75), Zn (101, 83.8). The mean metals concentrations (in µg/g dry weight) in the processed tobacco Nyala (Ethiopian cigarette leaves) were: Cu (8.95), Cd (1.55), Cr (1.62), Ni (4.70), Zn (79.3). The concentrations of Cr and Ni in tobacco leaves from Billate and Pb in all the tobacco samples were below the detection limits. This study showed that the metal contents of tobacco leaves varied with the geographical origin in which the tobacco plant grows. The metal contents of processed tobacco were higher than the corresponding raw leaves. Pb was not detected in both the raw and processed Ethiopian tobacco leaves.

Thiol-Functionalized Mesoporous Silica for Effective Trap of Mercury in Rats

The chance of exposure to heavy metal for human being rises severely today due to the increasing water contamination and air pollution. Here, we prepared a series of thiol-functionalized mesoporous silica as oral formulation for the prevention and treatment of heavy metal poisoning. The successful incorporation of thiol was verified by the FTIR spectra. SBA15-SH-10 was used for the study as it is of uniform mesopores and fine water dispersibility. In simulated gastrointestinal fluid, the thiol-functionalized mesoporous silica can selectively capture heavy metal, showing a very high affinity for inorganic mercury (II). The blood and urine mercury levels of rats fed with a diet containing Hg (II) and material were significantly lower than those of rats fed with the metal-rich diet only. On the contrary, the mercury content in fecal excretion of the treatment group increased more than twice as much as that of the control group. This result indicated that SBA15-SH-10 could effectively remove mercury (II)in vivoand the mercury loaded on SBA15-SH-10 would be excreted out. Hence, SBA15-SH-10 has potential application in preventing and treating heavy metal poisoningviadigestive system.

Effect of propolis on erythrocyte rheology in experimental mercury intoxication in rats

In the present study, changes in erythrocyte rheology in association with mercury toxicity and the role of propolis were analyzed in rats. Forty male Wistar Albino rats that were 4-5 months old were used in the study. The control group was administered normal saline intraperitoneal (ip) injections; the mercury chloride group was administered HgCl2 (4 mg/kg, ip); the propolis group was administered propolis (200 mg/kg, by gavage); and the HgCl2+ propolis group was administered HgCl2 (4 mg/kg, ip) + propolis (200 mg/kg, by gavage) for 3 days. The following parameters were analyzed: hematological parameters, plasma potassium (K) levels, methemoglobin, 2,3-DPG, erythrocyte deformability, and hemolysis as a percentage. The results revealed that leukocyte count significantly increased, and a significant decline occurred in the platelet count (p < 0.01). Serum K(+), MetHb, 2, 3-DPG, and hemolysis percentage significantly increased in the rats exposed to mercury (p < 0.01). However, the values of rats administered only with propolis were close to the values of the control group and the changes were avoided by the administration of propolis as protection in the rats exposed to mercury chloride.

Pattern-based detection of toxic metals in surface water with DNA polyfluorophores

Heavy metal contamination of water can be toxic to humans and wildlife; thus the development of methods to detect this contamination is of high importance. Here we describe the design and application of DNA-based fluorescent chemosensors on microbeads to differentiate eight toxic metal ions in water. We developed and synthesized four fluorescent 2'-deoxyribosides of metal-binding ligands. A tetramer-length oligodeoxy-fluoroside (ODF) library of 6561 members was constructed and screened for sequences responsive to metal ions, of which seven sequences were selected. Statistical analysis of the response patterns showed successful differentiation of the analytes at concentrations as low as 100 nM. Sensors were able to classify water samples from 13 varied sites and quantify metal contamination in unknown specimens. The results demonstrate the practical potential of bead-based ODF chemosensors to analyze heavy metal contamination in water samples by a simple and inexpensive optical method.