Thallium Use, Toxicity, and Detoxification Therapy: An Overview

Hotspots and dynamics of dissolved thallium species at oxic-anoxic interfaces in flooded soils

Thallium (Tl) is highly toxic, predominantly existing in its monovalent Tl(I) state in the environment. However, the redox "niche" of both dissolved trivalent and monovalent Tl(III/I) remain under-studied in typical oxic-anoxic interfaces. Here, we hypothesize that the behavior of dissolved Tl is constrained by manganese (Mn), iron (Fe), and sulfur (S) species. Dissolved Tl(III/I) profiles and associated redox species Fe(III/II), Mn(II), and S(VI/II) were quantified spatially (a resolution of 1.8 mm) and temporally (diurnal and seasonal) at the rice rhizosphere and the soil-water interface (SWI). The results showed that hotspots of both dissolved Tl(III) and Tl(I) were identified at the rhizosphere and SWI, with redox niche closely following Mn-reducing conditions and also supporting an oxidation mechanism from Tl(I) to Tl(III). Supporting evidence were that newly formed ferromanganese plaque strongly retained the dissolved Tl, while dissolved Tl(III/I) hotspots coincided with moderate Mn-reducing conditions in both SWI and rhizosphere. Dissolved Tl(III) prevailed at higher ratios of dissolved Fe(III)-to-Fe(II). Additionally, porewater Tl(III/I) and copper (Cu(II)) showed similar behaviors at different temporospatial scales, likely due to shared redox constraints. Collectively, the evidence suggests that Mn oxides serve as both sources and sinks of dissolved Tl(III/I) at redox fluctuated areas. Tl mobility was greatly constrained in both more reduced (Fe and S) and more oxidized conditions, highlighting implications for developing effective remediation strategies.

Pr3+ Visible to Ultraviolet Upconversion for Antimicrobial Applications

This paper addresses the upconversion of blue light to ultraviolet-C (UVC) with Pr3+-activated materials for antibacterial applications of UVC. It discusses the processes through which UV radiation provides biocidal effects on microorganisms, along with the most popular UVC sources employed in these processes. We describe the electronic and optical properties of the Pr3+ ion, emphasizing the conditions the host material must meet to obtain broad and intense emission in the UVC from parity-allowed transitions from the 4f5d levels and provide a list of materials that fulfill these conditions. This paper also delineates lanthanide-based upconversion, focusing on Pr3+ blue to UVC upconversion via the 3P0 and 1D2 intermediate states, and suggests routes for improving the quantum efficiency of the process. We review literature related to the use of upconversion materials in antimicrobial photodynamic treatments and for the blue to UVC upconversion germicidal effects. Further, we propose the spectral overlap between the UVC emission of Pr3+ materials and the germicidal effectiveness curve as a criterion for assessing the potential of these materials in antimicrobial applications. Finally, this paper briefly assesses the toxicity of materials commonly used in the preparation of upconversion materials.

Insight into selective removal of trace thallium (Tl(Ι)) by novel chitosan adsorbents encapsulating low-cost silicate mineral wastes

Recently, thallium (Tl) contamination at trace levels has gained worldwide attention, particularly in the remote ore-smelting regions of China. To effectively eliminate the residual target Tl(I) ions, one of the best strategies is to develop novel adsorbents with high selectivity. In this study, we selected silicate mineral waste (SMW) and chitosan (CTS) to synthesize a low-cost composite adsorbent for the removal of trace Tl(I). The results show that a mass ratio for SMW to CTS was optimized as 3:1 (denoted as SMW@CTS), and the preferred SMW@CTS exhibited a 37% higher removal efficiency compared to pure CTS beads (19%), underscoring the critical role of SMW in enhancing trace-level adsorption of Tl(I). Under the optimal conditions of 25 °C, pH = 5, and 6 g/L dosage, SMW@CTS achieved a Tl(I) removal efficiency of approx. 89% for an initial concentration of 100 μg/L. Moreover, the thermodynamics for the adsorption of Tl(I) onto SMW@CTS were investigated, and the structural characteristics of SMW@CTS were also characterized in detail. Furthermore, the mechanism for the high selectivity of Tl(I) onto SMW@CTS has been explored in the presence of humic acid and a series of competing ions. These findings highlight the novel SMW@CTS as a promising candidate for eliminating trace-level Tl(I) contamination from co-existing substances.

Versatility of Caenorhabditis elegans as a Model Organism for Evaluating Foodborne Neurotoxins and Food Bioactive Compounds in Nutritional Neuroscience

Epidemiological evidence has shown that the regular ingestion of vegetables and fruits is associated with reduced risk of developing chronic diseases. The introduction of the 3Rs (replacement, reduction, and refinement) principle into animal experiments has led to the use of valid, cost-effective, and efficient alternative and complementary invertebrate animal models which are simpler and lower in the phylogenetic hierarchy. Caenorhabditis elegans (C. elegans), a nematode with a much simpler anatomy and physiology compared to mammals, share similarities with humans at the cellular and molecular levels, thus making it a valid model organism in neurotoxicology. This review explores the versatility of C. elegans in elucidating the neuroprotective mechanisms elicited by food bioactive compounds against neurotoxic effects of food- and environmental-related contaminants. Several signaling pathways linked to the molecular basis of neuroprotection exerted by bioactive compounds in chemically induced or transgenic C. elegans models of neurodegenerative diseases are also discussed. Specifically, the modulatory effects of bioactive compounds on the DAF-16/FoxO and SKN-1/Nrf2 signaling pathways, stress resistance- and autophagy-related genes, and antioxidant defense enzyme activities were highlighted. Altogether, C. elegans represent a valuable model in nutritional neuroscience for the identification of promising neuroprotective agents and neurotherapeutic targets which could help in overcoming the limitations of current therapeutic agents for neurotoxicity and neurodegenerative diseases.

Preliminary insight into the intracellular behaviour of rare earths and other technology-critical elements (TCEs) in northern pike liver: study of TCE-binding biomolecules via size-exclusion HPLC-ICP-MS

Technology-critical elements (TCEs) refer to the elements that play an important role in many emerging technologies and the production of advanced materials, and these include lanthanides, tungsten and vanadium. Actinides, Tl, and Pb, which also belong to TCEs, are abundantly used in power generation, industrial applications, and modern agricultural practices. The information on the influence of these elements on the aquatic environment and biota is still rather scarce. Thus, the distributions of the above-mentioned metals among cytosolic biomolecules of different molecular masses in the liver of the northern pike (Esox lucius) from the Mrežnica River (Croatia) were studied to obtain an insight into their intracellular behaviour and potential for toxicity. The applied method was a hyphenated system of size-exclusion high-performance liquid chromatography and inductively coupled plasma mass spectrometry. In the samples with lower cytosolic concentrations, the obtained distributions of several TCEs (lanthanides, W, Th, and U) and Pb, among biomolecules of a wide range of molecular masses, which covered the entire column separation range (<10 to >600 kDa), indicated their nonspecific binding to various intracellular components. In the sample with the highest cytosolic concentration, a shift towards the highest molecular masse (>600 kDa) was observed for lanthanides and actinides, which is a sign of their possible binding to protein aggregates. In contrast, W and Pb showed a preference for medium molecular mass biomolecules (30-100 kDa). Moreover, it was hypothesized that prominent elution of U and Pb observed in the low molecular mass region (<10 kDa) possibly indicated their partial detoxification. Potential Pb associations with metallothionein-like proteins were also recorded (∼6-7 kDa). The remaining two elements, V and Tl, exhibited more specific intracellular binding, as they were eluted within one/two narrow peaks in the high molecular mass region (575 kDa/100-400 kDa). The tendency of the studied TCEs and other potentially toxic elements to bind to medium and high molecular mass intracellular proteins necessitates further research of their specific targets.

Increased atmospheric thallium threats to populated areas: A mini review

Air pollutants combined with Hg, Cd, Cr, Pb, etc. in many global populated areas were studied comprehensively, while our understanding towards thallium (Tl), an extremely toxic heavy metal, remains very limited. Further, the knowledge on atmospheric emissions, distribution, and the hidden risks associated with Tl is of great scarcity. Hence, this work aims to review recent data on significant sources of ambient Tl resulting from industrial activities, including Pb/Zn/Cu/Fe sulfide ore smelting, steel-making, coal burning, and cement production that involves the use of Tl-bearing wastes. Through the examination of Tl emissions and transfer pathways in the atmosphere, it is found that Tl is present at lower than ng/m3 in aerosols and air particulates but can increase to much higher levels even at 1000 μg/m3 in atmospheric fine particulate matters near the mining and smelting industrialized zones located near populated areas. This study highlights the importance of creating a comprehensive emission inventory for Tl, particularly in developing countries where this data is currently lacking. The time has come to develop a precise national emission inventory for Tl in order to prevent and mitigate the risks associated with ambient exposure to this element. This review offers novel insights for the scientific community and policy-makers in establishing effective control and management strategies to curb hidden Tl hazards derived from industrial activities.

Dissociation of mitochondrial and ribosomal biogenesis during thallium administration in rat kidney

Thallium (Tl) is a heavy metal with toxicity comparative to other heavy metals such as As, Cd, and Hg. Nevertheless, fewer studies have been reported concerning the molecular mechanism of Tl toxicity as compared to other heavy metals. To obtain insight into Tl toxicity in the kidney, rats were intraperitoneally administered Tl2SO4 (30 mg/kg), and the kidneys were removed 2 or 5 days later to examine the effects of Tl. Transcriptome analysis using DNA microarray of the rat kidney 2 and 5 days after Tl administration showed that cytoplasmic ribosomal proteins are the most upregulated category; many of the genes involved in ribosome biosynthesis were upregulated by Tl administration. This upregulation was associated with the activation of eukaryotic transcription initiation factor 2α (eIF2α), implying that increased ribosome biogenesis was linked to the subsequent activation of protein translation. In contrast, decreased mitochondrial biogenesis was revealed via proteomic analysis. Although we found an increase in Myc, a positive regulator of both ribosomal and mitochondrial biogenesis, decreased levels of NRF1 and TFAM, positive regulators of mitochondrial biogenesis whose gene expression is directory activated by Myc, were paradoxically observed. Taken together, differing responses of ribosomes and mitochondria to Tl toxicity were observed. Failure of transmission of the Myc signal to NRF1/TFAM might be involved in the observed disruption of coordinated responses in mitochondria and ribosomes during Tl administration in rat kidney.

Thallium reabsorption via NKCC2 causes severe acute kidney injury with outer medulla-specific calcium crystal casts in rats

Thallium (Tl) is one of the most toxic heavy metals, associated with accidental poisoning and homicide. It causes acute and chronic systemic diseases, including gastrointestinal and cardiovascular diseases and kidney failure. However, few studies have investigated the mechanism by which Tl induces acute kidney injury (AKI). This study investigated the toxic effects of Tl on the histology and function of rat kidneys using biochemical and histopathological assays after intraperitoneal thallium sulfate administration (30 mg/kg). Five days post-administration, rats exhibited severely compromised kidney function. Low-vacuum scanning electron microscopy revealed excessive calcium (Ca) deposition in the outer medulla of Tl-loaded rats, particularly in the medullary thick ascending limb (mTAL) of the loop of Henle. Tl accumulated in the mTAL, accompanied by mitochondrial dysfunction in this segment. Tl-loaded rats showed reduced expression of kidney transporters and channels responsible for Ca2+ reabsorption in the mTAL. Pre-administration of the Na-K-Cl cotransporter 2 (NKCC2) inhibitor furosemide alleviated Tl accumulation and mitochondrial abnormalities in the mTAL. These findings suggest that Tl nephrotoxicity is associated with preferential Tl reabsorption in the mTAL via NKCC2, leading to mTAL mitochondrial dysfunction and disrupted Ca2+ reabsorption, culminating in mTAL-predominant Ca crystal deposition and AKI. These findings on the mechanism of Tl nephrotoxicity may contribute to the development of novel therapeutic approaches to counter Tl poisoning. Moreover, the observation of characteristic Ca crystal deposition in the outer medulla provides new insights into diagnostic challenges in Tl intoxication.

Thallium Toxicity and its Interference with Potassium Pathways Tested on Various Cell Lines

Thallium (Tl) is a highly toxic heavy metal whose mechanism of toxicity is still not completely understood. The aim of this study was to test Tl cytotoxicity on several cell lines of different tissue origin in order to clarify specific Tl toxicity to a particular organ. In addition, possible interference of Tl with cell potassium (K) transport was examined. Human keratinocytes (HaCaT), human hepatocellular carcinoma (HepG2), porcine kidney epithelial cells (PK15), human neuroblastoma (SH-SY5Y) and Chinese hamster lung fibroblast cells (V79) were treated with thallium (I) acetate in a wide concentration range (3.9-500 µg/mL) for 24 h, 48 and 72 h. To assess competitive interaction between Tl and K, the cells were treated with four Tl concentrations close to IC50 (15.63, 31.25, 62.50, 125 µg/mL) in combination with/or without potassium (I) acetate (500 µg/mL). The cells' morphology was monitored, and cytotoxic effect was assessed by 3-(4, 5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) test. The most sensitive to Tl exposure were SH-SY5Y cells, while HepG2 were the most resistant. The combined exposure to thallium (I) acetate and potassium (I) acetate for every cell line, except V79 cells, resulted in higher cell viability compared to thallium (I) acetate alone. The results of our study indicate that cell sensitivity to Tl treatment is largely affected by tissue culture origin, its function, and Na+/K+-ATPase activity.

Public health and economic burden of heavy metals in Ethiopia: Review

Heavy metals pose a significant threat to public health and economic stability in Ethiopia, contaminating various environmental media, including water, soil, and air. This paper aimed to provide an overview of the public health and economic burden of heavy metals in Ethiopia. Exposure to heavy metals such as lead, mercury, cadmium, and arsenic has been linked to numerous adverse health effects, including neurological disorders, renal failure, cardiovascular diseases, and cancer. In Ethiopia, populations are particularly vulnerable to heavy metal exposure due to various factors, such as artisanal mining, industrial activities, agricultural practices, and inadequate waste management systems. The economic burden of heavy metal contamination manifests through increased healthcare costs, loss of productivity, and environmental remediation expenses. Furthermore, the impact extends to sectors such as agriculture and tourism, affecting national development goals and exacerbating poverty levels. Efforts to mitigate the public health and economic burdens of heavy metals in Ethiopia require multidisciplinary approaches, including policy interventions, regulatory enforcement, public awareness campaigns, and investment in sustainable development practices. Strengthening monitoring systems, implementing pollution control measures, and promoting research on alternative technologies for waste management are essential steps toward addressing this pressing issue. In conclusion, addressing the public health and economic challenges posed by heavy metal contamination in Ethiopia necessitates concerted efforts from the government, industry, academia, and civil society to safeguard human health, preserve the environment, and promote sustainable development.

Decorporation dilemma: Interplay of prussian blue and potassium iodide in radioactive contamination

The expansion of the nuclear industry has led to various radioactive effluents, originating from routine operations or catastrophic incidents such as those at Three Mile Island (USA), Chernobyl (Ukraine), and Fukushima (Japan). Research conducted after these events emphasizes Cesium-137 (137Cs) and iodine 131 (131I) as major contributors to harmful airborne dispersion and fallout. These isotopes infiltrate the human body via inhalation, ingestion, or wounds, posing significant health risks. Understanding contamination mechanisms and devising effective countermeasures are crucial in mitigating nuclear incident consequences. We propose that concurrent administration of Pru-Decorp™/Pru-Decorp-MG and potassium iodide (KI) could synergistically reduce the levels of 137Cs and block uptake of 131I, respectively, in nuclear incident scenarios. Pru-Decorp™ capsules contain insoluble ferric hexacyanoferrate(II) and are equivalent to USFDA-approved Radiogardase®-Cs, offering radiation exposure mitigation for Cs and Tl contamination. Pru-Decorp-MG capsules consist of insoluble PB and magnesium hydroxide, serving as a prophylactic measure to reduce the risk of internal Cs and Tl contamination for rescue responders. Pru-Decorp™/Pru-Decorp-MG binds Cs/Tl ions in the gastrointestinal tract, hindering absorption and promoting excretion, while KI saturates the thyroid gland with stable iodine, decreasing the uptake of radioactive iodine isotopes. Our hypothesis is supported by studies demonstrating the effectiveness of combination therapies, such as calcium alginate, iron(III) ferrocyanide, and KI, in decreasing the retention of radioisotopes in vital organs. To test this hypothesis, we propose a comprehensive research plan, including in vitro studies simulating gastrointestinal conditions, animal studies to evaluate the efficacy of both drugs simultaneously, and safety clinical trials comparing Pru-Decorp™/Pru-Decorp-MG alone, KI alone, and their combination. Expected outcomes include insights into the synergistic effects of Pru-Decorp™/Pru-Decorp-MG and KI, guiding the development of optimized treatment protocols for simultaneous administration during radioactive contamination incidents. This research aims to address significant critical gaps in nuclear incident preparedness by providing evidence-based recommendations for concurrent antidote use in scenarios involving multiple isotope contamination. Ultimately, this will enhance public health and safety during nuclear emergencies.

The determination of thallium in the environment: A review of conventional and advanced techniques and applications

Thallium (Tl) is a potential toxicity element that poses significant ecological and environmental risks. Recently, a substantial amount of Tl has been released into the environment through natural and human activities, which attracts increasing attention. The determination of this hazardous and trace element is crucial for controlling its pollution. This article summarizes the advancement and progress in optimizing Tl detection techniques, including atomic absorption spectroscopy (AAS), voltammetry, inductively coupled plasma (ICP)-based methods, spectrophotometry, and X-ray-based methods. Additionally, it introduces sampling and pretreatment methods such as diffusive gradients in thin films (DGT), liquid-liquid extraction, solid phase extraction, and cloud point extraction. Among these techniques, ICP-mass spectrometry (MS) is the preferred choice for Tl detection due to its high precision in determining Tl as well as its species and isotopic composition. Meanwhile, some new materials and agents are employed in detection. The application of novel work electrode materials and chromogenic agents is discussed. Emphasis is placed on reducing solvent consumption and utilizing pretreatment techniques such as ultrasound-assisted processes and functionalized magnetic particles. Most detection is performed in aqueous matrices, while X-ray-based methods applied to solid phases are summarized which provide non-destructive analysis. This work improves the understanding of Tl determination technology while serving as a valuable resource for researchers seeking appropriate analytical techniques.

Domestic dogs as environmental sentinel in comparative toxicologic pathology: Assessment of metals and rare earth elements concentrations in healthy and neoplastic mammary glands

Quantification of trace element concentrations in human and animal tissues has acquired great importance in the last few years, considering the pivotal role of these elements in several physiological and pathological processes. Variations in their concentrations appear to have a role in the development and advancement of diseases in both humans and animals, for example, cancer. The purpose of this study was to investigate the concentration of rare earth elements and metals in healthy and neoplastic Formalin-Fixed Paraffin-Embedded (FFPE) mammary gland tissue of dogs. All samples were processed to have a quantitative determination of inorganic elements including metals of known toxicological interest such as Pb, Cd, Tl, As, Hg, the trace elements Mn, Fe, Co, Cu, Zn, Se, and other elements including Cr, V, Mo, Ni, Sb, W, Sn. Moreover, rare earth elements (REEs) (Sc, Y, Lu, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb) were also investigated. Cu and Mo concentrations in mammary cancerous tissue were greater than those in normal mammary glands (p < 0.05). In non-neoplastic tissue increased concentrations of Cd, Co, Ni, Tl, and V were also reported (p < 0.05). The mammary tissue of healthy individuals had greater concentrations of REEs than the neoplastic mammary glands (p < 0.05). The results of our study confirmed differences in mammary inorganic element concentrations between healthy and neoplastic groups, highlighting the potential relevance of these fluctuations in toxicologic pathology.

Cotransport of aged biochar colloids and thallium(I) in water-saturated porous media: Impact of the ionic strength, pH and aging degree

Biochar colloids entering the soil undergo aging over time and exhibit strong capabilities in adsorbing and transporting pollutants. Therefore, investigating the cotransport of aged biochar colloids and thallium (Tl(I)) in quartz sand media is crucial for understanding Tl(I) migration in underground environments. This study investigated the migration of biochar colloids with two different aging degrees and Tl(I) in quartz sand media at various pH and ionic strengths (ISs). The results revealed that under all ISs and pH, 30%AWB (biochar aged with 30 % (w/w) HNO3) inhibited Tl(I) migration in media. This inhibition primarily arose from the introduction of hydroxyl and carboxyl groups during aging, which significantly enhanced colloid adsorption onto Tl(I). At lower ISs, 30%AWB colloids exhibited greater inhibition of Tl(I) migration due to their increased adsorption capacity. Additionally, aging promoted the migration of biochar colloids in the media. Greater biochar aging notably enhanced this promotion, potentially owing to reduced colloidal particle size and the formation of biochar derivatives. Moreover, 50%AWB (biochar aged with 50 % (w/w) HNO3) inhibited Tl(I) migration under low ISs but had almost no impact under high ISs. Nonetheless, at high pH, 50%AWB colloids facilitated Tl(I) migration. This phenomenon might be attributed to the inhibitory effect of aged biochar colloids on Tl(I) adsorption onto media at a high pH, as well as the stable binding between Tl(I) and aged biochar colloids. This study discusses the cotransport of biochar with various degrees of aging and Tl(I) in media, providing insights into remediating soils contaminated with Tl.

Cryptic footprint of thallium in soil-plant systems; A review

The current review highlights the complex behavior of thallium (Tl) in soil and plant systems, offering insight into its hazardous characteristics and far-reaching implications. The research investigates the many sources of Tl, from its natural existence in the earth crust to its increased release through anthropogenic activities such as industrial operations and mining. Soil emerges as a significant reservoir of Tl, with diverse physicochemical variables influencing bioavailability and entrance into the food chain, notably in Brassicaceae family members. Additionally, the study highlights a critical knowledge gap concerning Tl influence on legumes (e.g., soybean), underlining the pressing demand for additional studies in this crucial sector. Despite the importance of leguminous crops in the world food supply and soil fertility, the possible impacts of Tl on these crops have received little attention. As we traverse the ecological complexity of Tl, this review advocates the collaborative research efforts to eliminate crucial gaps and provide solutions for reducing Tl detrimental impacts on soil and plant systems. This effort intends to pave the path for sustainable agricultural practices by emphasizing the creation of Tl-tolerant legume varieties and revealing the complicated dynamics of Tl-plant interactions, assuring the long-term durability of our food systems against the danger of Tl toxicity.

The Impact of Thallium Exposure in Public Health and Molecular Toxicology: A Comprehensive Review

This review offers a synthesis of the current understanding of the impact of low-dose thallium (Tl) on public health, specifically emphasizing its diverse effects on various populations and organs. The article integrates insights into the cytotoxic effects, genotoxic potential, and molecular mechanisms of thallium in mammalian cells. Thallium, a non-essential heavy metal present in up to 89 different minerals, has garnered attention due to its adverse effects on human health. As technology and metallurgical industries advance, various forms of thallium, including dust, vapor, and wastewater, can contaminate the environment, extending to the surrounding air, water sources, and soil. Moreover, the metal has been identified in beverages, tobacco, and vegetables, highlighting its pervasive presence in a wide array of food sources. Epidemiological findings underscore associations between thallium exposure and critical health aspects such as kidney function, pregnancy outcomes, smoking-related implications, and potential links to autism spectrum disorder. Thallium primarily exerts cellular toxicity on various tissues through mitochondria-mediated oxidative stress and endoplasmic reticulum stress. This synthesis aims to shed light on the intricate web of thallium exposure and its potential implications for public health, emphasizing the need for vigilant consideration of its risks.

Splenic Elemental Composition of Breast Cancer-Suffering Rats Supplemented with Pomegranate Seed Oil and Bitter Melon Extract

The aim of this study was to investigate how dietary modifications with pomegranate seed oil (PSO) and bitter melon aqueous extract (BME) affect mineral content in the spleen of rats both under normal physiological conditions and with coexisting mammary tumorigenesis. The diet of Sprague-Dawley female rats was supplemented either with PSO or with BME, or with a combination for 21 weeks. A chemical carcinogen (7,12-dimethylbenz[a]anthracene) was applied intragastrically to induce mammary tumors. In the spleen of rats, the selected elements were determined with a quadrupole mass spectrometer with inductively coupled plasma ionization (ICP-MS). ANOVA was used to evaluate differences in elemental composition among experimental groups. Multivariate statistical methods were used to discover whether some subtle dependencies exist between experimental factors and thus influence the element content. Experimental factors affected the splenic levels of macroelements, except for potassium. Both diet modification and the cancerogenic process resulted in significant changes in the content of Fe, Se, Co, Cr, Ni, Al, Sr, Pb, Cd, B, and Tl in rat spleen. Chemometric analysis revealed the greatest impact of the ongoing carcinogenic process on the mineral composition of the spleen. The obtained results may contribute to a better understanding of peripheral immune organ functioning, especially during the neoplastic process, and thus may help develop anticancer prevention and treatment strategies.

Thallium - poisoner's poison: An overview and review of current knowledge on the toxicological effects and mechanisms

Thallium (Tl) is one of the most toxic metals and its historic use in homicides has led it to be known as "the poisoner's poison." This review summarizes the methods for identifying Tl and determining its concentrations in biological samples in recently reported poisoning cases, as well as the toxicokinetics, toxicological effects, toxicity mechanisms, and detoxication methods of Tl. Recent findings regarding Tl neurotoxicological pathways and toxicological effects of Tl during pregnancy are also presented. Confirmation of elevated Tl concentrations in blood, urine, or hair is indispensable for diagnosing Tl poisoning. The kidneys show the highest Tl concentration within 24 h after ingestion, while the brain shows the highest concentration thereafter. Tl has a very slow excretion rate due to its large distribution volume. Following acute exposure, gastrointestinal symptoms are observed at an early stage, and neurological dysfunction is observed later: Tl causes the most severe damage in the central nervous system. Alopecia and Mees' lines in the nails are observed within 1 month after Tl poisoning. The toxicological mechanism of Tl is considered to be interference of vital potassium-dependent processes with Tl+ because its ionic radius is similar to that of K+, as well as inhibition of enzyme reactions by the binding of Tl to -SH groups, which disturbs vital metabolic processes. Tl toxicity is also related to reactive oxygen species generation and mitochondrial dysfunction. Prussian blue is the most effective antidote, and metallothionein alone or in combination with Prussian blue was recently reported to have cytoprotective effects after Tl exposure. Because Tl poisoning cases are still reported, early determination of Tl in biological samples and treatment with an antidote are essential.

Molecular fingerprint of gilthead seabream physiology in response to pollutant mixtures in the wild

The increase in trace element concentrations in the aquatic environment due to anthropogenic activities, urges the need for their monitoring and potential toxicity, persistence, bioaccumulation, and biomagnification at different trophic levels. Gilthead seabream is a species of commercial importance in the Mediterranean Sea, both for the aquaculture and fisheries sectors, however very little is known about their trace element contamination accumulation and the resulting effect on their health status. In the present study, 135 juveniles were collected from seven coastal lagoons known to be essential nursery areas for this species. We measured seventeen different inorganic contaminants at the individual level in fish muscle (namely Al, As, Be, Bi, Cd, Cr, Cu, Hg, Li, Ni, Pb, Rb, Sb, Sr, Ti, Tl and Zn). Our results revealed the accumulation of multiple trace elements in individuals and distinct contamination signatures between lagoons which might lead to contrasted quality as nurseries for juveniles of numerous ecologically and economically relevant fish species in addition to seabreams. We further evaluated the potential adverse effect of these complex contamination mixtures on the liver (the main organ implicated in the metabolism of xenobiotics) and red muscle (a highly metabolic organ) using a proteomic approach. Alterations in cellular organization pathways and protein transport were detected in both tissues (albeit they were not similarly regulated). Chromosome organization and telomere maintenance in the liver appeared to be affected by contaminant mixture which could increase mortality, age-related disease risk and shorter lifetime expectancy for these juveniles. Red muscle proteome also demonstrated an upregulation of pathways involved in metabolism in response to contamination which raises the issue of potential energy allocation trade-offs between the organisms' main functions such as reproduction and growth. This study provides new insights into the cellular and molecular responses of seabreams to environmental pollution and proposed biomarkers of health effects of trace elements that could serve as a starting point for larger-scale biomonitoring programs.

Prevalence of Cobalt in the Environment and Its Role in Biological Processes

Cobalt (Co) is an essential trace element for humans and other animals, but high doses can be harmful to human health. It is present in some foods such as green vegetables, various spices, meat, milk products, seafood, and eggs, and in drinking water. Co is necessary for the metabolism of human beings and animals due to its key role in the formation of vitamin B12, also known as cobalamin, the biological reservoir of Co. In high concentrations, Co may cause some health issues such as vomiting, nausea, diarrhea, bleeding, low blood pressure, heart diseases, thyroid damage, hair loss, bone defects, and the inhibition of some enzyme activities. Conversely, Co deficiency can lead to anorexia, chronic swelling, and detrimental anemia. Co nanoparticles have different and various biomedical applications thanks to their antioxidant, antimicrobial, anticancer, and antidiabetic properties. In addition, Co and cobalt oxide nanoparticles can be used in lithium-ion batteries, as a catalyst, a carrier for targeted drug delivery, a gas sensor, an electronic thin film, and in energy storage. Accumulation of Co in agriculture and humans, due to natural and anthropogenic factors, represents a global problem affecting water quality and human and animal health. Besides the common chelating agents used for Co intoxication, phytoremediation is an interesting environmental technology for cleaning up soil contaminated with Co. The occurrence of Co in the environment is discussed and its involvement in biological processes is underlined. Toxicological aspects related to Co are also examined in this review.

Metals in Callitriche cophocarpa from small rivers with various levels of pollution in SW Poland

The anthropogenic impact of metals on aquatic environments is a risk for biota, and thus their levels must be controlled. Callitriche cophocarpa Sendtn. belongs to a genus with a potential for accumulation of elevated metal levels. Thus, it may provide consolidated evidence of contamination. Therefore, the aim of this investigation was to determine Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in this species collected together with water and bottom sediments from rivers with various levels of pollution. Of these rivers, one less polluted and one more polluted was selected for the collection of C. cophocarpa for an experiment to compare its Cu and Zn concentration potential. Both metals were supplemented at concentrations 0.01, 0.02, 0.03, 0.05, 0.08 and 0.14 mg L-1 of Cu as CuSO4 × 5H2O and 0.4, 0.6, 0,9, 1,35, 2.03 and 3.04 mg L-1 of Zn as ZnSO4 × 7H2O, and in the binary design containing (mg·L-1) 0.01Cu + 0.4Zn, 0.02Cu + 0.6Zn, 0.03Cu + 0.9Zn, 0.05Cu + 1.4Zn, 0.08Cu + 2.03 Zn and 0.14Cu + 3.04Zn. The upper concentrations of Cr, Cu, Mn and Zn in C. cophocarpa shoots from both types of rivers as well as of Ni and Pb in shoots from more polluted rivers were higher than the values typical for toxicity thresholds with no visible harmful effects, which may indicate accumulation abilities of C. cophocarpa for these metals. Both roots and shoots of C. cophocarpa may be included in the group of macroconcentrators for bottom sediments with respect to Cd, Co, Cr, Cu, Fe, Mn, Ni and Zn and deconcentrators of Pb. Greater accumulation of most metals in roots than in shoots indicates their restricted mobility and translocation by C. cophocarpa to shoots. C. cophocarpa from the less polluted river and exposed to all experimental solutions contained significantly higher levels of Cu and Zn than that from the more polluted river exposed to identical experimental solutions. The plants collected from the more polluted river influenced by surplus of metals and living under chemical stress could probably limit further accumulation by developing a resistance mechanism. Cu and Zn contents in C. cophocarpa were higher when treated with separate metals than for binary treatment both in the more and less polluted river. Such research presenting the impact of a combination of metals could be important for understanding and explaining the interactions of these elements which may influence their bioavailability in nature as well as importance in the evaluation of the risk of environmental toxicity.

A novel application of thallium isotopes in tracing metal(loid)s migration and related sources in contaminated paddy soils

Thallium (Tl) is a highly toxic heavy metal, which is harmful to plants and animals even in trace amounts. Migration behaviors of Tl in paddy soils system remain largely unknown. Herein, Tl isotopic compositions have been employed for the first time to explore Tl transfer and pathway in paddy soil system. The results showed considerably large Tl isotopic variations (ε²⁰⁵Tl = -0.99 ± 0.45 ~ 24.57 ± 0.27), which may result from interconversion between Tl(I) and Tl(III) under alternative redox conditions in the paddy system. Overall higher ε²⁰⁵Tl values of paddy soils in the deeper layers were probably attributed to abundant presence of Fe/Mn (hydr)oxides and occasionally extreme redox conditions during alternative dry-wet process which oxidized Tl(I) to Tl(III). A ternary mixing model using Tl isotopic compositions further disclosed that industrial waste contributed predominantly to Tl contamination in the studied soil, with an average contribution rate of 73.23%. All these findings indicate that Tl isotopes can be used as an efficient tracer for fingerprinting Tl pathway in complicated scenarios even under varied redox conditions, providing significant prospect in diverse environmental applications.

Release and mobility characteristics of thallium from polluted farmland in varying fertilization: Role of cation exchange

Batch and column leaching tests were used to study thallium's release and migration behaviour and evaluate its potential toxicity risks in soil. The results indicated that leaching concentrations of Tl using TCLP and SWLP were much higher than the threshold, indicating a high risk of thallium pollution in the soil. Furthermore, the intermittent leaching rate of Tl by Ca²⁺ and HCl reached its maximum value, demonstrating the easy release of Tl. After HCl leaching, the form of Tl in the soil has changed, and ammonium sulfate has increased its extractability. Additionally, the extensive application of calcium promoted the release of Tl, increasing its potential ecological risk. Spectral analysis showed that Tl was mainly present in minerals such as Kaolinite and Jarosite, and exhibited significant adsorption capacity for Tl. HCl and Ca²⁺ damaged the crystal structure of the soil, greatly enhancing the migration and mobility of Tl in the environment. More importantly, XPS analysis confirmed that the release of Tl (I) in the soil was the leading cause of increased mobility and bioavailability. Therefore, the results revealed the risk of Tl release in the soil, providing theoretical guidance for its pollution prevention and control.

A unique investigation of thallium, tellurium, osmium, and other heavy metals in recurrent pregnancy loss: A novel approach

OBJECTIVE

To study the impact of heavy metals especially tellurium, thallium, and osmium, in recurrent pregnancy loss (RPL) and to study their association with antioxidant status and DNA damage.

METHODS

This case-control study included women with RPL (n = 30) and healthy pregnant women as control (n = 30). Following blood collection, serum levels of thallium, tellurium, osmium, lead, mercury, and cadmium were estimated by inductively coupled plasma mass spectrophotometer.

RESULTS

Women with RPL exhibited significantly higher levels of heavy metals (P < 0.001) when compared with control women. Intriguingly, increased levels of serum thallium, tellurium, osmium, and lead were negatively correlated with total antioxidant status (P < 0.05). Further, the RPL group demonstrated strong positive correlation between heavy metals (thallium, tellurium, osmium, lead) and DNA damage (P < 0.05). No significant correlation between other heavy metals and markers of cellular damage was noted.

CONCLUSION

Enhanced levels of heavy metals in women with RPL and correlation of thallium, tellurium, osmium, and lead with markers of cellular damage reflect the role of heavy metal poisoning, especially thallium, tellurium, and osmium, as potential risk factor in the etiology underlying recurrent miscarriage.

A rhodamine based chemodosimeter for the detection of Group 13 metal ions

A new rhodamine derivative, HL-CIN, derived from a reaction between N-(rhodamine-6G)lactam-ethylenediamine (L1) and trans-cinnamaldehyde, is reported here for the colorimetric and fluorogenic sensing of Group 13 trivalent cations, namely Al³⁺, Ga³⁺, In³⁺ and Tl³⁺. The absorption intensity of the probe increases significantly at 530 nm whereas the fluorescence intensity enhances massively at 558 nm upon interaction with these metal ions. Other relevant metal ions could not impart any noticeable color change or fluorescence enhancement. The quantum yield or fluorescence life time of HL-CIN increases considerably in the presence of these Group 13 metal ions. Different spectral studies such as ESI-mass, FT-IR, ¹H and ¹³C NMR spectra, establish that HL-CIN undergoes hydrolysis in the presence of the trivalent cations and a rhodamine species in its ring opened form (i.e. N-(2-aminoethyl)-2-((6Z)-3-(ethylamino)-6-(ethylimino)-2,7-dimethyl-6H-xanthen-9-yl)benzamide, (L2)) along with cinnamaldehyde are produced. The rhodamine species in its ring opened form (L2) is responsible for the color change and strong increment in the absorbance and fluorescence of HL-CIN with Group 13 cations. Interaction between L1 and these metal ions could not produce the same outcome. It has been used in test paper strips and to detect these cations in real samples.

Arsenic: A Review on a Great Health Issue Worldwide

Arsenic intoxication represents a worldwide health problem and occurs mainly through drinking water. Arsenic, a metalloid and naturally occurring element, is one of the most abundant elements in the earth’s crust, whose toxicity depends on the reduction state. The trivalent arsenicals are more toxic than the pentavalent arsenicals. In the trivalent state, inorganic and organic arsenic may react with thiol groups in proteins inhibiting their activity, whereas inorganic arsenic in the pentavalent state may replace phosphate ions in several reactions. Arsenic induces various epigenetic changes in mammalian cells, both in vivo and in vitro, often leading to the development of various types of cancers, including skin, lung, liver, urinary tract, prostate, and hematopoietic cancers. Potential mechanisms of arsenic toxicity in cancer include genotoxicity, altered DNA methylation and cell proliferation, co-carcinogenesis, tumor promotion, and oxidative stress. On the other hand, the FDA-certified drug arsenic trioxide provides solutions for various diseases, including several types of cancers. Detoxification from arsenic includes chelation therapy. Recently, investigations of the capability of some plants, such as Eucalyptus camadulensis L., Terminalia arjuna L. and Salix tetrasperma L., to remove arsenic from polluted soil and water have been studied. Moreover, nanophytoremediation is a green technology including the nanoscale materials used for absorption and degradation of organic and inorganic pollutants, such as arsenic compounds. This brief review represents an overview of arsenic uses, toxicity, epigenetics, and detoxification therapies.

Thallium isotopic compositions as tracers in environmental studies: A review

Thallium is a highly poisonous heavy metal. Since Tl pollution control has been neglected worldwide until the present, countless Tl pollutants have been discharged into the environment, endangering the safety of drinking water, farmland soil, and food chain, and eventually posing a great threat to human health. However, the source, occurrence, pathway and fate of Tl in the environment remains understudied. As Tl in non-contaminated systems and from anthropogenic origin exhibits generally different isotopic signatures, which can provide fingerprint information and a novel way for tracing the anthropogenic Tl sources and understanding the environmental processes. This review summarizes: (i) the state-of-the-art development in highly-precise determination analytical method of Tl isotopic compositions, (ii) Tl isotopic fractionation induced by the low-temperature surface biogeochemical process, (iii) Tl isotopic signature of pollutants derived from anthropogenic activities and isotopic fractionation mechanism of Tl related to the high-temperature industrial activities, and (iv) application of Tl isotopic composition as a new tracer emerging tracer for source apportionment of Tl pollution. Finally, the limitations and possible future research about Tl isotopic application in environmental contamination is also proposed: (1) Tl fractionation mechanism in different environmental geochemistry processes and industrial activities should be further probed comprehensively; (2) Tl isotopes for source apportionment should be further applied in other different high Tl-contaminated scenarios (e.g., agricultural systems, water/sediment, and atmosphere).