Search Results (552)

The increasing demand for rapid, sensitive, and eco-friendly methods for the detection of trace heavy metals in environmental samples, attributed to their serious threats to health and the environment, has spurred considerable interest in the development of sustainable sensor materials. Toxic metal ions, namely, lead (Pb²⁺), cadmium (Cd²⁺), mercury (Hg²⁺), arsenic (As³⁺), and chromium, are potential hazards due to their non-biodegradable nature with high toxicity, even at trace levels. Acute health complications, including neurological, renal, and developmental disorders, arise upon exposure to such metal ions. To monitor and mitigate these toxic exposures, sensitive detection techniques are essential. Pre-existing conventional detection methods, such as atomic absorption spectroscopy (AAS) and inductively coupled plasma-mass spectrometry (ICP-MS), involve expensive instrumentation, skilled operators, and complex sample preparation. Electrochemical sensing, which is simple, portable, and eco-friendly, is foreseen as a potential alternative to the above conventional methods. Carbon-based nanomaterials play a crucial role in electrochemical sensors due to their high conductivity, stability, and the presence of surface functional groups. Biochar (BC), a carbon-rich product, has emerged as a promising electrode material for electrochemical sensing due to its high surface area, sustainability, tunable porosity, surface rich in functional groups, eco-friendliness, and negligible environmental footprint. Nevertheless, broad-spectrum studies on the use of biochar in electrochemical sensors remain narrow. This review focuses on the recent advancements in the development of biochar-based electrochemical sensors for the detection of toxic heavy metals such as Pb²⁺, Cd²⁺, and Hg²⁺ and the simultaneous detection of multiple ions, with special emphasis on BC synthesis routes, surface modification methodologies, electrode fabrication techniques, and electroanalytical performance. Finally, current challenges and future perspectives for integrating BC into next-generation sensor platforms are outlined. Full article

In contrast to mercury, an extremely toxic element, selenium is an essential micronutrient, which by complexing with mercury can mitigate its toxicity. In this regard, we quantified mercury and selenium concentrations in samples (n = 309) of fish tissues and analyzed the Se:Hg molar ratio and HBVSe as toxicological risk biomarkers. The data indicated that mercury levels in planktivorous fish (0.630 ± 0.202 mg kg⁻¹) and carnivorous fish (1.196 ± 0.513 mg kg⁻¹) were above the Brazilian limits considered safe for daily consumption. The highest selenium concentrations were observed in planktivores (0.272 ± 0.093 mg kg⁻¹) and the lowest in herbivores (0.099 ± 0.092 mg kg⁻¹). Molar ratios greater than one and positive HBVSe values were found in 42% of the fish samples (n = 131). As a result, we found that (i) the trophic level influences the risk of mercury exposure through the intake of fish in the diet; (ii) the approach presented in our study (model II) involves greater rigor concerning intake and exposure via fish consumption, since it considers the antagonistic Se:Hg ratio; and (iii) selenium can attenuate mercury toxicity, but safe thresholds vary depending on the species. Full article

This study investigated ten potential toxic metals (PTMs) in six milk and dairy product types and evaluated food safety (TDI, RDA), human exposure (EDI), non-carcinogenic risk (THQ, HI), and contamination levels (CF, PLI). Based on total PTM load, products ranked as: children’s milk > yogurt > protein milk > milk > ayran > kefir. Aluminum (Al) showed the highest average concentration in all products except ayran, where manganese (Mn) was dominant. Cadmium (Cd), mercury (Hg), and lead (Pb) were consistently at the lowest levels. Except for chromium (Cr) exposure from children’s milk, all average and maximum EDI values stayed below TDI and RDA thresholds. Children’s milk had the highest non-carcinogenic risk, while yogurt, kefir, milk, and ayran may also pose potential risks when maximum HI values are considered. Although CF values varied across products, PLI results showed all products had high levels of PTM contamination. Given the widespread consumption of dairy across all age groups, especially by sensitive populations like children, monitoring and controlling PTM levels is crucial alongside ensuring nutritional quality. Full article

Background and purpose: Indigenous people in the Brazilian Amazon are exposed to mercury by eating methylmercury-contaminated fish. The lack of information on the health effects of prolonged exposure to mercury hinders the implementation of mitigation programs offered by the Brazilian government. This article aims to evaluate the studies that have investigated mercury exposure in indigenous people living in the Brazilian Amazon. Methods: A scoping review of the literature was conducted from studies published between 1995 and 2024 in Portuguese, English, and Spanish that evaluated mercury (Hg) concentrations in hair samples in indigenous people from the Brazilian Amazon. Results: Using total mercury (TotalHg) values in hair samples, we analyzed exposure levels, prevalence, and toxic effects. We found 15 epidemiological studies with a cross-sectional design and sample sizes ranging from 31 to 910 participants. Four studies involved children and mothers, four of which were associated with clinical outcomes and three of which analyzed genetic polymorphism. Most of the communities evaluated had a high prevalence of mercury exposure, showing levels ranging from 0.8 to 83.89 µg/g, and the highest average TotalHg concentration was found among the Kayabi. Mercury was associated with hypertension, cognitive disorders, worse mental health indicators and central and peripheral neurological disorders. Conclusions: It is concluded that indigenous people in the Brazilian Amazon experience exposure levels that are causing damage to their health, and control measures must be adopted to prevent the situation from worsening. Full article

The Amazon faces significant challenges related to mercury contamination, including naturally elevated concentrations and gold mining activities. Due to mercury’s toxicity and the importance of fish as a protein source for local populations, assessing mercury levels in regional fish is crucial. However, there are gaps in knowledge regarding mercury concentrations in many areas of the Amazon basin. This study aims to synthesize the existing literature on mercury concentrations in fish and the exposure of urban and traditional social groups through fish consumption. A systematic review (1990–2022) was conducted for six fish genera (Cichla spp., Hoplias spp. and Plagioscion spp., Leporinus spp., Semaprochilodus spp., and Schizodon spp.) in the Web of Science (Clarivate Analytics) and Scopus (Elsevier) databases. The database consisted of a total of 46 studies and 455 reports. The distribution of studies in the region was not homogeneous. The most studied regions were the Madeira River sub-basin, while the Paru–Jari basin had no studies. Risk deterministic and probabilistic assessments based on Joint FAO/WHO Expert Committee on Food Additives (JECFA, 2007) guidelines showed high risk exposure, especially for traditional communities. Carnivorous fish from lakes and hydroelectric reservoirs, as well as fish from black-water ecosystems, exhibited higher mercury concentrations. In the Amazon region, even if mercury levels in fish muscle do not exceed regulatory limits, the high fish consumption can still elevate health risks for local populations. Monitoring mercury levels across a broader range of fish species, including both carnivorous and non-carnivorous species, especially in communities heavily reliant on fish for their diet, will enable a more accurate risk assessment and provide an opportunity to recommend fish species with lower mercury exposure risk for human consumption. The present study emphasizes the need to protect regions that already exhibit higher levels of mercury—such as lakes, hydroelectric reservoirs, and black-water ecosystems—to ensure food safety and safeguard public health. Full article

Mercury (Hg) pollution is a widespread ecological threat with sublethal effects on wildlife. Birds, due to their ecological diversity and sensitivity, serve as effective models for evaluating the behavioural impacts of Hg exposure. This review applies Tinbergen’s four questions: causation, ontogeny, function, and evolution, as an integrative framework. Mechanistically, Hg disrupts neuroendocrine pathways, gene expression, immune function, and hormone regulation, leading to behavioural changes such as reduced foraging, altered parental care, and impaired predator avoidance. Early-life exposure affects neural development, learning, and social behaviour into adulthood. Functionally, these changes reduce fitness by compromising reproduction and survival. Phylogenetic comparisons show interspecific variability, with piscivorous and insectivorous birds exhibiting high Hg burdens and sensitivity, linked to ecological roles and exposure. Behavioural responses often precede physiological or demographic effects, highlighting their value as early indicators. Both field and laboratory studies show that even low Hg concentrations can alter behaviour, though outcomes vary by species, life stage, and exposure route. Integrating behavioural endpoints into ecotoxicological risk assessments is essential to improve conservation strategies and understanding of sublethal pollutant effects on wildlife. Full article

Heavy metals (lead [Pb], cadmium [Cd], arsenic [As], mercury [Hg], manganese [Mn], copper [Cu], zinc [Zn], and iron [Fe]) might be risk factors for pre-eclampsia (PE), whereas their joint effect remains unclear. To address this issue, we conducted a nested case–control study consisting of 49 PE cases and 329 controls from a Chinese prospective birth cohort and divided the participants into low/high and quartile groups based on hair metal concentrations. We used logistic regression models and a weighted quantile sum (WQS) model to investigate the independent and mixed associations between these eight heavy metals in maternal hair and the risk of PE. After multivariable adjustment, high hair Pb was associated with a 2.53-fold increased risk of PE, and significantly higher risks of PE were also observed in quartiles 2 to 4 of Pb and quartiles 3 to 4 of Fe. The WQS model revealed a statistically significant association between maternal co-exposure to all eight heavy metals and the risk of PE, with Pb, As, and Fe presenting the biggest risk. Therefore, high maternal exposure to heavy metals may increase the risk of PE. It is crucial to consider co-exposure to multiple heavy metals throughout pregnancy in future research endeavors. Full article

Background/Objectives: Trace minerals (TMs), both essential and toxic, are integral to human physiology, participating in enzymatic reactions, oxidative balance, immune function, and the modulation of chronic disease risk. Despite their importance, imbalances due to deficiencies or toxic exposures are widespread globally. While low-income countries often face overt deficiencies and environmental contamination, middle- and high-income populations increasingly deal with subclinical deficits and chronic toxic metal exposure. This review aims to explore the relevance of serum as a matrix for evaluating TM status across diverse clinical and epidemiological, geographic, and demographic settings. Methods: A narrative literature review was conducted focusing on the physiological roles, health impacts, and current biomarker approaches for key essential (e.g., zinc, copper, selenium) and toxic (e.g., lead, mercury, cadmium, arsenic) trace elements. Particular emphasis was placed on studies utilizing serum analysis and on recent advances in multi-element detection using inductively coupled plasma mass spectrometry (ICP-MS). Results: Serum was identified as a versatile and informative matrix for TM assessment, offering advantages in terms of clinical accessibility, biomarker reliability, and capacity for the simultaneous quantification of multiple elements. For essential TMs, serum levels reflect nutritional status with reasonable accuracy. For toxic elements, detection depends on instrument sensitivity, but serum can still provide valuable exposure data. The method’s scalability supports applications ranging from public health surveillance to individualized patient care. Conclusions: Serum trace mineral analysis is a practical and scalable approach for nutritional assessment and exposure monitoring. Integrating it into clinical practice and public health strategies can improve the early detection of imbalances, guide interventions such as nutritional supplementation, dietary modifications, and exposure mitigation efforts. This approach also supports advanced personalized nutrition and preventive care. Full article

Climate change, mining activities, pollution and other human impacts on the natural environment cause significant changes in the concentrations and mixtures of metallic elements found in different ecosystems. Metals such as cadmium, copper, lead and mercury affect multiple aspects of host–pathogen interactions, influencing the risk of infectious diseases caused by various classes of pathogens. Notably, exposure to metals in doses and combinations toxic to the immune system can favor the dissemination of pathogens in natural environments, threatening the reproduction, well-being and survival of varied animal species. However, these problems remain neglected, since the influences of metals on infectious diseases are studied with a primary focus on human medicine. Therefore, this article aims to review the influence of metals/metalloids (e.g., arsenic, cadmium, chromium, copper, iron, lead, mercury, nickel, zinc) on infectious and parasitic diseases in animals living in natural environments. The potential impact of metals on the risk of zoonotic spillover events is also discussed. Metal pollution tends to increase as the demand for elements used in the manufacture of industrial products, batteries, and electronic devices increases globally. This problem can aggravate the biodiversity crisis and facilitate the emergence of infectious diseases. Considering the interconnections between pollution and immunity, measures to limit metal pollution are necessary to protect human health and biodiversity from the risks posed by pathogens. This review helps fill the gap in the literature regarding the connections between metal pollution and various aspects of infectious diseases. Full article

Artisanal small-scale gold mining (ASGM) is the largest source of global mercury (Hg) emissions. This study investigated Hg contamination in water, soil, sediment, fish, and cassava plants around ASGM sites in Gunung Pongkor, West Java, Indonesia. Hg concentration ranged from 0.06 to 4.49 µg/L in water; 0.420 to 144 mg/kg dw in soil; 0.920 to 150 mg/kg dw in sediment; 0.259 to 1.23 mg/kg dw in fish; 0.097 to 5.09 mg/kg dw in cassava root; and 0.350 to 8.84 mg/kg dw in cassava leaf. Geo-accumulation index (Igeo) analysis revealed moderate to heavy soil contamination upstream, likely due to direct ASGM input. In contrast, sediment Igeo values indicated heavy contamination downstream, suggesting Hg transport and sedimentation. Bioconcentration factors (BCFs) in fish were predominantly high in downstream and midstream areas, indicating enhanced Hg bioavailability. Bioaccumulation factors (BAFs) in cassava were higher in upstream areas. Health risk assessment, based on the Hazard Quotient (HQ) and Hazard Index (HI), identified ingestion as the primary exposure route, with children exhibiting significantly higher risks than adults. These findings highlight the significant Hg contamination associated with ASGM in Gunung Pongkor and emphasize the need for targeted mitigation strategies to protect human and environmental health. Full article

The metalloid arsenic (As) and the metals lead (Pb) and mercury (Hg), which together we call the “Toxic Triad”, are among the pollutants of greatest global concern, harming the health of millions of people and contributing to biodiversity loss. The widespread distribution of As, Pb and Hg facilitates the exposure of humans and other species to these elements simultaneously, potentially amplifying their individual toxic effects. While As, Pb and Hg are well established as toxic elements, the mechanisms by which they interact with genetic material and impact the health of various species remain incompletely understood. This is particularly true regarding the combined effects of these three elements. In this context, the objective of this work was to perform a toxicogenomic analysis of As, Pb and Hg to highlight multiple aspects of element-gene interactions, in addition to revisiting information on the genotoxicity and carcinogenicity of the Toxic Triad. By using The Comparative Toxicogenomics Database, it was possible to identify that As interacts with 7666 genes across various species, while Pb influences 3525 genes, and Hg affects 692 genes. Removing duplicate gene names, the three elements interact with 9763 genes across multiple species. Considering the top-20 As/Pb/Hg-interacting genes, catalase (CAT), NFE2 like bZIP transcription factor 2 (NFE2L2), caspase 3 (CASP3), heme oxygenase (HMOX1), tumor necrosis factor (TNF), NAD(P)H quinone dehydrogenase 1 (NQO1) and interleukin 6 (IL6) were the most frequently observed. In total, 172 genes have the potential to interact with the three elements. Gene ontology analysis based on those genes evidenced that the Toxic Triad affects several cellular compartments and molecular functions, highlighting its effect on stimulation of toxic stress mechanisms. These 172 genes are also associated with various diseases, especially those of the urogenital tract, as well as being related to biological pathways involved in infectious diseases caused by viruses, bacteria and parasites. Arsenic was the element with the best-substantiated genotoxic and carcinogenic activity. This article details, through a toxicogenomic approach, the genetic bases that underlie the toxic effects of As, Pb and Hg. Full article

Deciduous teeth accumulate toxic metals until fully mineralized, making them a stable biological matrix for assessing chronic exposure during fetal and early postnatal life. Their metal content is influenced by environmental factors (e.g., industrial areas, mining sites) and individual factors (e.g., maternal diet, early nutrition, passive smoking). The aim of this study was to evaluate the toxic metal content in deciduous teeth and to identify factors contributing to its accumulation, as well as possible health implications. A systematic review was conducted in accordance with the PRISMA guidelines and following the PICO framework. Quality assessment was assessed using the Joanna Briggs Institute (JBI) checklist for quasi-experimental studies. The literature search was carried out in the PubMed, Scopus, and Web of Science databases using the following keywords: deciduous, milk, primary, decidua, teeth, dentition, heavy metal, toxic metals. A total of 134 articles were initially identified, with 95 remaining after duplicate removal. After screening, 75 articles were excluded: 71 did not meet the inclusion criteria, 3 were not available in English, and 1 lacked full-text access. Ultimately, 20 studies were included in the review. Toxic metal concentrations were determined using various analytical techniques, mainly inductively coupled plasma mass spectrometry (ICP-MS) and atomic absorption spectrometry (AAS). Higher levels of metals, especially lead, were observed in the teeth of children residing in industrial areas, near mines, or in regions affected by armed conflict. Although two out of five studies indicated a possible link between fathers’ smoking habits and elevated lead concentrations, no definitive relationship was established between secondhand smoke exposure and the levels of lead and cadmium found in dental tissue. Similarly, no definitive relationship was identified between mercury and lead content and the prevalence of autism. However, lower manganese levels were associated with the presence of autistic traits, weaker verbal performance, and reduced memory capacity. In conclusion, deciduous teeth represent a valuable biological material for assessing chronic prenatal and early postnatal exposure to toxic metals, which may serve as a starting point for further research into diseases of unknown etiology, such as autism, and in the future may have clinical significance in their prevention and treatment. And it is also important for monitoring environmental pollution levels. Full article

Background and objective: Environmental and occupational exposure to toxic metals poses a significant risk to neurological health, particularly affecting motor-related brain structures. Essential metals like manganese, copper, and iron become neurotoxic when homeostasis is disrupted, while non-essential metals such as lead, mercury, and cadmium are inherently toxic, even at low exposure levels. We aimed to investigate the state of the art on neuroimaging evidence of the effects of exposure to toxic metals on motor related brain structures and functions. Methods: PRISMA guidelines were followed. We included studies that reported neuroimaging studies exploring the link between metal exposure and neural changes in motor areas. Results: We identified 518 papers, but only 20 articles were included. Our findings indicate that manganese is the most extensively studied metal in relation to the motor system using neuroimaging, but studies have also investigated the effects of other metals, including lead, mercury, and copper. Across these studies, the brain regions most consistently affected by metal exposure include the globus pallidus, caudate nucleus, frontal cortex, and cerebellum. Some studies exhibit structural or functional reductions in these areas that correlate with increased levels of metal exposure, suggesting a dose-dependent neurotoxic effect. Conclusions: This review synthesizes current neuroimaging evidence on metal-induced neurotoxicity, emphasizing its impact on motor function and highlighting critical gaps to guide future research and public health strategies. Full article

The administration of nutraceutical substances to fish diet can help to control disease outbreaks in aquaculture practices, thereby promoting sustainability and food safety. In particular, some substances have the potential to alleviate the effects of trace metals toxicity in fish also by reducing metal accumulation in tissues. This study evaluates, for the first time, the effect of nutraceutical substances on bioaccumulation mechanisms of mercury (Hg) in tissues and organs of farmed gilthead seabream (Sparus aurata) by mesocosm experimentation. The kinetics of bioaccumulation in muscle, gills, gut, liver and kidney and the detoxification efficiency were also assessed. Fish were fed with three different diets: a commercial diet used as control (CD); a diet enriched with short chain fatty acids (SCFA) and extract of Castanea sativa (D1); a diet enriched with yeast Saccharomyces cerevisiae and extract of Schinopsis balansae (D2). All groups were exposed to sub-lethal concentrations of mercury. After 20 days of exposure, mercury levels in different organs and tissues clearly revealed the effectiveness of yeast and plant extracts in limiting the metal bioaccumulation in fish fed with D2 through mercury absorption and then elimination by feces. In contrast, the D1 seems to not reduce the Hg bioaccumulation in fish tissues. This can be attributed to the high affinity of SCFA for mercury, leading to the formation of organometallic compounds absorbed by the fish tissues. This mechanism potentially counteracts the efficiency of tannins contained in the extract plant on mercury removal. This study clearly demonstrates that the use of diets enriched with yeast and/or plant extracts rich in tannins are a useful bioremediation strategy to reduce trace metals bioaccumulation in farmed fish, thus preserving their health status from intoxication, their commercial values, and consequently the health of consumers. Full article

Environmental exposure to heavy metals seriously threatens children’s health, potentially impacting the cardiovascular system. Mechanisms such as oxidative stress, inflammation, and lipid metabolism disturbances play a significant role in this process. Although cardiovascular diseases typically manifest in adulthood, an increasing number of studies suggest that their origins trace back to childhood and result from long-term pathophysiological changes. Therefore, early identification of modifiable risk factors is crucial for effective preventive measures and reducing future health risks. Full article