Role of mercury toxicity in hypertension, cardiovascular disease, and stroke

Mercury-induced toxicity: Mechanisms, molecular pathways, and gene regulation

Mercury is a well-known neurotoxicant for humans and wildlife. The epidemic of mercury poisoning in Japan has clearly demonstrated that chronic exposure to methylmercury (MeHg) results in serious neurological damage to the cerebral and cerebellar cortex, leading to the dysfunction of the central nervous system (CNS), especially in infants exposed to MeHg in utero. The occurrences of poisoning have caused a wide public concern regarding the health risk emanating from MeHg exposure; particularly those eating large amounts of fish may experience the low-level and long-term exposure. There is growing evidence that MeHg at environmentally relevant concentrations can affect the health of biota in the ecosystem. Although extensive in vivo and in vitro studies have demonstrated that the disruption of redox homeostasis and microtube assembly is mainly responsible for mercurial toxicity leading to adverse health outcomes, it is still unclear whether we could quantitively determine the occurrence of interaction between mercurial and thiols and/or selenols groups of proteins linked directly to outcomes, especially at very low levels of exposure. Furthermore, intracellular calcium homeostasis, cytoskeleton, mitochondrial function, oxidative stress, neurotransmitter release, and DNA methylation may be the targets of mercury compounds; however, the primary targets associated with the adverse outcomes remain to be elucidated. Considering these knowledge gaps, in this article, we conducted a comprehensive review of mercurial toxicity, focusing mainly on the mechanism, and genes/proteins expression. We speculated that comprehensive analyses of transcriptomics, proteomics, and metabolomics could enhance interpretation of "omics" profiles, which may reveal specific biomarkers obviously correlated with specific pathways that mediate selective neurotoxicity.

Environmental exposure to metal(loid)s and hypertensive disorders of pregnancy: A systematic review

BACKGROUND

Environmental exposure to metal(loid)s has been associated with adverse effects on human health, but the systemic repercussion of these elements on the development of hypertensive disorders of pregnancy (HDP) is still poorly understood.

OBJECTIVE

To summarize evidence published about the influence of environmental exposure to aluminum, arsenic, barium, cadmium, lead, strontium and mercury on the development of HDP.

METHODS

We conducted a systematic literature review according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The search strategy was validated by the Peer Review of Electronic Search Strategies. We searched for articles published up to February 2023 in seven databases without language restriction. Two researchers conducted the steps for selection, data extraction and evaluation of the methodological quality of the instruments for epidemiological studies of the Joanna Briggs Institute. Any disagreements were resolved by a third researcher.

RESULTS

We obtained 5076 records, of which 37 articles met the inclusion criteria moderate to high methodological quality. Single exposure to metal(loid)s was predominant, and the leading biological matrix analyzed to detect the concentrations from exposure was maternal blood. Lead was the metal investigated the most, and had the largest number of studies showing positive association with HDP. In relation to the other metal(loid)s, higher levels were found in women with HDP in comparison with healthy women, but the finding of a cause-effect relationship was inconsistent.

CONCLUSIONS

Although we found evidence of harmful effects of the metal(loid)s studied on human health, the results were inconclusive with regard to HDP. Longitudinal studies that consider prospective investigation, adjustment of confounding factors and the interference of other contaminants in the exacerbation of oxidative stress in women from the preconception phase to the puerperal period should be encouraged.

Health-risk assessment of mercury in main market-sold foods in the Pingliang region of Gansu province, China, from 2013 to 2021

In the present study, we analyzed mercury concentrations in 742 samples across five main food categories from 2013 to 2021 using direct mercury analysis (DMA) to understand mercury pollution in major market-sold foods in the Pingliang region of Gansu Province and assess the health risks of mercury dietary exposure in adults. Health risks of adult dietary exposure were assessed through deterministic evaluation. Total mercury content ranged from non-detectable (ND) to 0.13 mg/kg, with a detection rate of 90.70% (673/742), the highest detection rates being in fresh edible mushrooms and nuts. The overall exceedance rate was 0.13% (1/742), with one sample of fresh edible mushrooms exceeding the regulatory limit for total mercury content. Additionally, we incorporated the average mercury content and consumption levels of meat and seafood from regions geographically close to Pingliang, as reported in the Fifth National Total Diet Study, to calculate the Estimated Daily Intake (EDI) by a deterministic evaluation. For adult males, the exposure was 0.120 μg/(kg BW), while for adult females, it was 0.141 μg/(kg BW). Both values are significantly lower than the provisional tolerable weekly intake (PTWI) of 4 μg/(kg BW) established by JECFA in 2010, indicating that the total mercury concentration from food intake does not pose a significant health risk to the residents of the Pingliang area. These findings offer valuable scientific data to inform food safety regulations in the region and can serve as a benchmark for future mercury pollution risk assessments in other locations.

Associations of serum lead, cadmium, and mercury concentrations with all-cause and cause-specific mortality among individuals with cardiometabolic multimorbidity

Epidemiological evidence indicates an association between exposure to toxic metals and the occurrence of cardiometabolic diseases (CMDs). However, the impact of exposure to harmful metallic elements, such as lead (Pb), cadmium (Cd), and mercury (Hg), on mortality in individuals with cardiometabolic multimorbidity (CMM) remains uncertain. Therefore, in this study, we analyzed data from 4139 adults diagnosed with CMM from the National Health and Nutrition Examination Survey 1999-2016. CMM was defined as the presence of at least two CMDs (hypertension, diabetes, stroke, and coronary artery disease). Over an average follow-up period of 9.0 years, 1379 deaths from all causes, 515 deaths related to cardiovascular disease (CVD), and 215 deaths attributable to cancer were recorded. After adjusting for potential covariates, serum Pb concentrations were not associated with all-cause, CVD, or cancer mortality. Participants exposed to Cd had an elevated risk of all-cause mortality (hazard ratio [HR], 1.23; 95 % CI, 1.16-1.30), CVD-related mortality (HR, 1.23; 95 % CI, 1.12-1.35), and cancer-related mortality (HR, 1.29; 95 % CI, 1.13-1.47). Participants with serum Hg levels in the highest quantile had lower risks of all-cause (HR, 0.64; 95 % CI, 0.52-0.80) and CVD-related (HR, 0.62; 95 % CI, 0.44-0.88) mortality than did those in the lowest quantile. Stratified analyses revealed significant interactions between serum Cd concentrations and age for CVD-related mortality (P for interaction =0.011), indicating that CMM participants aged < 60 years who were exposed to Cd were at a greater risk of CVD-related mortality. A nonlinear relationship was observed between serum Cd concentrations and all-cause (P for nonlinear relationship = 0.012) and CVD-related (P for nonlinear relationship < 0.001) mortality. Minimizing Cd exposure in patients with CMM may help prevent premature death.

Current status of advancement in remediation technologies for the toxic metal mercury in the environment: A critical review

Currently, pollution due to heavy metals, in particular dissolved mercury, is a major concern for society and the environment. This work aims to evaluate the current scenario regarding the removal/elimination of mercury. Mercury removal through adsorption is mainly done through artificial resins and metallic-organic frameworks. In the case of the zinc organic framework, it was able to adsorb Hg2+, reaching an adsorption capacity of 802 mg g-1. As for the Hg(0) the coconut husk was found to have the lowest equilibrium time, 30 min, and the highest adsorption capacity of 956.2 mg g-1. Experimental reports and molecular simulation indicate that the adsorption of mercury and other chemical forms occurs due to electrostatic interactions, ion exchange, precipitation, complexation, chelation, and covalent bonds, according to the material nature. The reported thermodynamic results show that, in most cases, the mercury adsorption has an endothermic nature with enthalpy levels below 40 kJ mol-1. Thermal and chemical regeneration methods lead to a similar number of 5 cycles for different materials. The presence of other ions, in particular cadmium, lead, and copper, generates an antagonistic effect for mercury adsorption. Regarding the other current technologies, it was found that mercury removal is feasible through precipitation, phytoremediation, and marine microalgae; all these methods require constant chemicals or a slow rate of removal according to the conditions. Advanced oxidative processes have noteworthy removal of Hg(0); however, Fenton processes lead to mineralization, which leads to Fe2+ and Fe3+ in solution; sonochemical processes are impossible to scale up at the current technology level; and electrochemical processes consume more energy and require constant changes of the anode and cathode. Overall, it is possible to conclude that the adsorption process remains a more friendly, economical, and greener process in comparison with other processes.

Water, Soil, Noise, and Light Pollution: JACC Focus Seminar, Part 2

Various forms of pollution carry a substantial burden with respect to increasing the risk of causing and exacerbating noncommunicable diseases, especially cardiovascular disease. The first part of this 2-part series on pollution and cardiovascular disease provided an overview of the impact of global warming and air pollution. This second paper provides an overview of the impact of water, soil, noise, and light pollution on the cardiovascular system. This review discusses the biological mechanisms underlying these effects and potential environmental biometrics of exposure. What is clear from both these pollution papers is that significant efforts and redoubled urgency are needed to reduce the sources of pollution in our environment, to incorporate environmental risk factors into medical education, to provide resources for research, and, ultimately, to protect those who are particularly vulnerable and susceptible.

A new Eosin Y-based 'turnon' fluorescent sensor for ratiometric sensing of toxic mercury ion (Hg2+) offering unaided eye detection and its antibacterial activity

A unique fluorescent molecule (ND-S) was obtained from Eosin Y in two simple yet high yielding steps (1). ND-S has special metal ion sensing ability, such that it can selectively detect toxic Hg2+ present in very low concentration in aqueous solutions in the presence of other competing metal ions. The host-guest complexation is ratiometric and is associated with significant increase in fluorescence during the process. Isothermal titration calorimetry (ITC) experiments provided thermodynamic parameters related to interaction between ND-S and Hg2+. Using inductively coupled plasma mass spectrometry (ICP-MS), the Hg2+(aq) removal efficiency of ND-S was estimated to be 99.88%. Appreciable limit of detection (LOD = 7.4 nM) was observed. Other competing ions did not interfere with the sensing of Hg2+ by ND-S. The effects of external stimuli (temperature and pH) were studied. Besides, the complex (ND-M), formed by 1:1 coordination of ND-S and Hg2+ was found to be effective against the survival of Gram-positive bacteria (S. aureus and B. subtilis) with a high selectivity index. Moreover, bacterial cell death mechanism was studied systematically. Overall, we have shown the transformation of a toxic species (Hg2+), extracted from polluted water by a biocompatible sensor (ND-S), into an effective and potent antibacterial agent (ND-M).

Heavy Metal Exposure and Cardiovascular Disease

Heavy metals are harmful environmental pollutants that have attracted widespread attention due to their health hazards to human cardiovascular disease. Heavy metals, including lead, cadmium, mercury, arsenic, and chromium, are found in various sources such as air, water, soil, food, and industrial products. Recent research strongly suggests a connection between cardiovascular disease and exposure to toxic heavy metals. Epidemiological, basic, and clinical studies have revealed that heavy metals can promote the production of reactive oxygen species, which can then exacerbate reactive oxygen species generation and induce inflammation, resulting in endothelial dysfunction, lipid metabolism distribution, disruption of ion homeostasis, and epigenetic changes. Over time, heavy metal exposure eventually results in an increased risk of hypertension, arrhythmia, and atherosclerosis. Strengthening public health prevention and the application of chelation or antioxidants, such as vitamins and beta-carotene, along with minerals, such as selenium and zinc, can diminish the burden of cardiovascular disease attributable to metal exposure.

In vivo chronic exposure to inorganic mercury worsens hypercholesterolemia, oxidative stress and atherosclerosis in the LDL receptor knockout mice

Heavy metal exposure leads to multiple system dysfunctions. The mechanisms are likely multifactorial and involve inflammation and oxidative stress. The aim of this study was to evaluate markers and risk factors for atherosclerosis in the LDL receptor knockout mouse model chronically exposed to inorganic mercury (Hg) in the drinking water. Results revealed that Hg exposed mice present increased plasma levels of cholesterol, without alterations in glucose. As a major source and target of oxidants, we evaluated mitochondrial function. We found that liver mitochondria from Hg treated mice show worse respiratory control, lower oxidative phosphorylation efficiency and increased H2O2 release. In addition, Hg induced mitochondrial membrane permeability transition. Erythrocytes from Hg treated mice showed a 50% reduction in their ability to take up oxygen, lower levels of reduced glutathione (GSH) and of antioxidant enzymes (SOD, catalase and GPx). The Hg treatment disturbed immune system cells counting and function. While lymphocytes were reduced, monocytes, eosinophils and neutrophils were increased. Peritoneal macrophages from Hg treated mice showed increased phagocytic activity. Hg exposed mice tissues present metal impregnation and parenchymal architecture alterations. In agreement, increased systemic markers of liver and kidney dysfunction were observed. Plasma, liver and kidney oxidative damage indicators (MDA and carbonyl) were increased while GSH and thiol groups were diminished by Hg exposure. Importantly, atherosclerotic lesion size in the aorta root of Hg exposed mice were larger than in controls. In conclusion, in vivo chronic exposure to Hg worsens the hypercholesterolemia, impairs mitochondrial bioenergetics and redox function, alters immune cells profile and function, causes several tissues oxidative damage and accelerates atherosclerosis development.

What does scientometry tell us about mercury toxicology and its biological impairments?

Mercury is a toxic pollutant that poses risks to both human and environmental health, making it a pressing public health concern. This study aimed to summarize the knowledge on mercury toxicology and the biological impairments caused by exposure to mercury in experimental studies and/or diagnosis in humans. The research was conducted on the main collection of Web of Science, employing as a methodological tool a bibliometric analysis. The selected articles were analyzed, and extracted data such as publication year, journal, author, title, number of citations, corresponding author's country, keywords, and the knowledge mapping was performed about the type of study, chemical form of mercury, exposure period, origin of exposure, tissue/fluid of exposure measurement, mercury concentration, evaluation period (age), mercury effect, model experiments, dose, exposure pathway, and time of exposure. The selected articles were published between 1965 and 2021, with Clarkson TW being the most cited author who has also published the most articles. A total of 38% of the publications were from the USA. These studies assessed the prenatal and postnatal effects of mercury, emphasizing the impact of methylmercury on neurodevelopment, including motor and cognitive evaluations, the association between mercury and autism, and an evaluation of its protective effects against mercury toxicity. In observational studies, the blood, umbilical cord, and hair were the most frequently used for measuring mercury levels. Our data analysis reveals that mercury neurotoxicology has been extensively explored, but the association among the outcomes evaluated in experimental studies has yet to be strengthened. Providing metric evidence on what is unexplored allows for new studies that may help governmental and non-governmental organizations develop guidelines and policies.

Cardioprotective Effect of Eugenol Against Cd-Induced Inflammation, Oxidative Stress, and Dyslipidemia in Male Rats: An In Vivo and Molecular Docking Study

Cadmium, a highly toxic heavy metal, can cause severe damage to several vital organs including the kidney, liver, and brain. Many of the natural compounds found in aromatic plants have beneficial pharmacological properties. Eugenol is one such compound reported to have anti-inflammatory and antioxidant properties. The aim of this study is to investigate whether eugenol, a natural compound found in aromatic plants known for its anti-inflammatory and antioxidant properties, can mitigate the detrimental effects of cadmium exposure on cardiac inflammation, oxidative stress, and dyslipidemia. Male albino rats were subjected to randomization into four groups, each comprising six animals, to investigate the potential of eugenol in mitigating cadmium-induced toxicity. All groups received oral gavage treatment for 21 days. Following the treatment regimen, cardiac tissue specimens were collected for analysis. The assessment of cardiac antioxidant status entailed the determination of enzymatic activities including catalase, SOD, GST, and GPx. Additionally, levels of lipid peroxidation, reduced glutathione, protein carbonyl oxidation, and thiol levels were quantified in the cardiac tissue samples. To evaluate cardiac damage, marker enzymes such as LDH and CK-MB were measured. Furthermore, the inflammatory response in the cardiac tissue induced by cadmium exposure was assessed through the quantification of NO, TNF-α, and IL-6 levels. Additionally, molecular docking and dynamics studies were conducted utilizing autodock and GLIDE methodologies. Cadmium administration markedly enhanced the activities of LDH and CK-MB, prominent cardiac markers. Furthermore, cadmium treatment also demonstrated a significant decrease in the reduced glutathione levels and antioxidant enzyme activities. Significant elevation of the inflammatory markers was also observed in the cadmium-treated group. Eugenol treatment effectively ameliorates cadmium-induced biochemical changes. This study underscores the potent anti-inflammatory and antioxidant attributes of eugenol. Co-administration of eugenol alongside cadmium exhibited remarkable protective efficacy against cadmium-induced cardio-toxicity. Eugenol demonstrated the capability to reinstate the cellular redox equilibrium of rats subjected to cadmium treatment to levels akin to those of the normal control group.

Chemical contaminants in blood and their implications in chronic diseases

Artificial chemical products are widely used and ubiquitous worldwide and pose a threat to the environment and human health. Accumulating epidemiological and toxicological evidence has elucidated the contributions of environmental chemical contaminants to the incidence and development of chronic diseases that have a negative impact on quality of life or may be life-threatening. However, the pathways of exposure to these chemicals and their involvements in chronic diseases remain unclear. We comprehensively reviewed the research progress on the exposure risks of humans to environmental contaminants, their body burden as indicated by blood monitoring, and the correlation of blood chemical contaminants with chronic diseases. After entering the human body through various routes of exposure, environmental contaminants are transported to target organs through blood circulation. The application of the modern analytical techniques based on human plasma or serum specimens is promising for determining the body burden of environmental contaminants, including legacy persistent organic pollutants, emerging pollutants, and inorganic elements. Furthermore, their body burden, as indicated by blood monitoring correlates with the incidence and development of metabolic syndromes, cancers, chronic nervous system diseases, cardiovascular diseases, and reproductive disorders. On this basis, we highlight the urgent need for further research on environmental pollution causing health problems in humans.

Protective effects of oral administration of lactic acid bacteria strains against methylmercury-induced intestinal toxicity in a murine model

The utilization of lactic acid bacteria has been proposed to mitigate the burden of heavy metal exposure through processes probably involving chelation and reduced metal bioaccessibility. We evaluated the effects of daily intake of two strains of lactobacilli (Lactobacillus intestinalis LE1 or Lactobacillus johnsonii LE2) on intestinal toxicity during methylmercury (MeHg) exposure through drinking water (5 mg/L) for two months in mice. MeHg exposure resulted in inflammation and oxidative stress at the colon, as well as an increase in intestinal permeability accompanied by decreased fecal short-chain fatty acids (SCFA). The administration of the strains resulted in a differential protective effect that, based on their chelation capacity, supported the existence of additional mechanisms of action besides chelation. Both strains reduced IL-1β levels and oxidative stress, while LE1 lowered TNF-α, diminished MeHg-induced mucus over-secretion triggered by the IL-4/IL-13/STAT6 pathway, reduced intestinal permeability, and ameliorated inflammation and oxidative stress, probably by acting on the Keap1/Nrf2/ARE pathway. Administration of LE1 partially restored SCFA contents, which could be partly responsible for the positive effects of this strain in alleviating MeHg toxicity. These results demonstrate that lactobacilli strains can be useful tools in reducing the intestinal toxicity of MeHg, the main mercurial form conveyed by food.

Microfluidics in environmental analysis: advancements, challenges, and future prospects for rapid and efficient monitoring

Microfluidic devices have emerged as advantageous tools for detecting environmental contaminants due to their portability, ease of use, cost-effectiveness, and rapid response capabilities. These devices have wide-ranging applications in environmental monitoring of air, water, and soil matrices, and have also been applied to agricultural monitoring. Although several previous reviews have explored microfluidic devices' utility, this paper presents an up-to-date account of the latest advancements in this field for environmental monitoring, looking back at the past five years. In this review, we discuss devices for prominent contaminants such as heavy metals, pesticides, nutrients, microorganisms, per- and polyfluoroalkyl substances (PFAS), etc. We cover numerous detection methods (electrochemical, colorimetric, fluorescent, etc.) and critically assess the current state of microfluidic devices for environmental monitoring, highlighting both their successes and limitations. Moreover, we propose potential strategies to mitigate these limitations and offer valuable insights into future research and development directions.

Associations between patterns of blood heavy metal exposure and health outcomes: insights from NHANES 2011-2016

BACKGROUND

Extensive research has explored the association between heavy metal exposure and various health outcomes, including malignant neoplasms, hypertension, diabetes, and heart diseases. This study aimed to investigate the relationship between patterns of exposure to a mixture of seven heavy metals and these health outcomes.

METHODS

Blood samples from 7,236 adults in the NHANES 2011-2016 studies were analyzed for levels of cadmium, manganese, lead, mercury, selenium, copper, and zinc. Cluster analysis and logistic regression identified three distinct patterns of mixed heavy metal exposure, and their associations with health outcomes were evaluated.

RESULTS

Pattern 1 exhibited higher odds ratios (ORs) for malignancy during NHANES 2011-2012 (OR = 1.33) and 2015-2016 (OR = 1.29) compared to pattern 2. Pattern 3 showed a lower OR for malignancy during NHANES 2013-2014 (OR = 0.62). For hypertension, pattern 1 displayed higher ORs than pattern 2 for NHANES 2011-2012 (OR = 1.26), 2013-2014 (OR = 1.31), and 2015-2016 (OR = 1.41). Pattern 3 had lower ORs for hypertension during NHANES 2013-2014 (OR = 0.72) and 2015-2016 (OR = 0.67). In terms of heart diseases, pattern 1 exhibited higher ORs than pattern 2 for NHANES 2011-2012 (OR = 1.34), 2013-2014 (OR = 1.76), and 2015-2016 (OR = 1.68). Pattern 3 had lower ORs for heart diseases during NHANES 2013-2014 (OR = 0.59) and 2015-2016 (OR = 0.52). However, no significant trend was observed for diabetes. All three patterns showed the strongest association with hypertension among the health outcomes studied.

CONCLUSIONS

The identified patterns of seven-metal mixtures in NHANES 2011-2016 were robust. Pattern 1 exhibited higher correlations with hypertension, heart disease, and malignancy compared to pattern 2, suggesting an interaction between these metals. Particularly, the identified patterns could offer valuable insights into the management of hypertension in healthy populations.

Emerging evidence on selenoneine and its public health relevance in coastal populations: a review and case study of dietary Se among Inuit populations in the Canadian Arctic

Selenium is an essential mineral yet both deficiency and excess are associated with adverse health effects. Dietary intake of Se in humans varies greatly between populations due to food availability, dietary preferences, and local geological and ecosystem processes impacting Se accumulation into agricultural products and animal populations. We argue there is a need to evaluate and reconsider the relevance of public health recommendations on Se given recent evidence, including the metabolic pathways and health implications of Se. This argument is particularly pertinent for Inuit populations in Northern Canada, who often exceed dietary tolerable upper intake levels and exhibit very high whole blood Se concentrations due to their dependence on local country foods high in the newly discovered Se compound, selenoneine. Since selenoneine appears to have lower toxicity compared to other Se species and does not contribute to the circulating pools of Se for selenoprotein synthesis, we argue that total dietary Se or total Se in plasma or whole blood are poor indicators of Se adequacy for human health in these populations. Overall, this review provides an overview of the current evidence of Se speciation, deficiency, adequacy, and excess and implications for human health and dietary recommendations, with particular reference to Inuit populations in the Canadian Arctic and other coastal populations consuming marine foods.

Non-essential heavy metal effects in cardiovascular diseases: an overview of systematic reviews

Introduction

Cardiovascular diseases (CVDs) are the most important cause of premature death and disability worldwide. Environmental degradation and cardiovascular diseases are two keys to health challenges, characterized by a constant evolution in an industrialized world that exploits natural resources regardless of the consequences for health. The etiological risk factors of CVDs are widely known and include dyslipidemia, obesity, diabetes, and chronic cigarette consumption. However, one component that is often underestimated is exposure to heavy metals. The biological perspective explains that different metals play different roles. They are therefore classified into essential heavy metals, which are present in organisms where they perform important vital functions, especially in various physiological processes, or non-essential heavy metals, with a no biological role but, nonetheless, remain in the environment in which they are absorbed. Although both types of metal ions are many times chemically similar and can bind to the same biological ligands, the attention given today to nonessential metals in several eukaryotic species is starting to raise strong concerns due to an exponential increase in their concentrations. The aim of this systematic review was to assess possible correlations between exposure to nonessential heavy metals and increased incidence of cardiovascular disease, reporting the results of studies published in the last 5 years through March 2023.

Methods

The studies includes reviews retrieved from PubMed, Medline, Embase, and Web of Science databases, in accordance with the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement and following the PICO (Population Intervention Comparison Outcome Population) framework.

Results

Eight reviews, including a total of 153 studies, were identified. Seven of these review enlighted the association between CVDs and non-essential heavy metals chronic exposure.

Discussion

It is evident that exposure to heavy metals represent a risk factor for CVDs onset. However, further studies are needed to better understand the effects caused by these metals.

DNA barcoding continues to identify endangered species of shark sold as food in a globally significant shark fin trade hub

Shark fins are a delicacy consumed throughout Southeast Asia. The life history characteristics of sharks and the challenges associated with regulating fisheries and the fin trade make sharks particularly susceptible to overfishing. Here, we used DNA barcoding techniques to investigate the composition of the shark fin trade in Singapore, a globally significant trade hub. We collected 505 shark fin samples from 25 different local seafood and Traditional Chinese Medicine shops. From this, we identified 27 species of shark, three species are listed as Critically Endangered, four as Endangered and ten as Vulnerable by the International Union for Conservation of Nature (IUCN). Six species are listed on CITES Appendix II, meaning that trade must be controlled in order to avoid utilization incompatible with their survival. All dried fins collected in this study were sold under the generic term "shark fin"; this vague labelling prevents accurate monitoring of the species involved in the trade, the effective implementation of policy and conservation strategy, and could unwittingly expose consumers to unsafe concentrations of toxic metals. The top five most frequently encountered species in this study are Rhizoprionodon acutus, Carcharhinus falciformis, Galeorhinus galeus, Sphyrna lewini and Sphyrna zygaena. Accurate labelling that indicates the species of shark that a fin came from, along with details of where it was caught, allows consumers to make an informed choice on the products they are consuming. Doing this could facilitate the avoidance of species that are endangered, and similarly the consumer can choose not to purchase species that are documented to contain elevated concentrations of toxic metals.

Specific dietary fibers prevent heavy metal disruption of the human gut microbiota in vitro

Heavy metal exposure is a growing concern due to its adverse effects on human health, including the disruption of gut microbiota composition and function. Dietary fibers have been shown to positively impact the gut microbiota and could mitigate some of the heavy metal negative effects. This study aimed to investigate the effects of different heavy metals (As, Cd and Hg in different concentrations) on gut microbiota in the presence and absence of different dietary fibers that included fructooligosaccharides, pectin, resistant starch, and wheat bran. We observed that whereas heavy metals impaired fiber fermentation outcomes for some fiber types, the presence of fibers generally protected gut microbial communities from heavy metal-induced changes, especially for As and Cd. Notably, the protective effects varied depending on fiber types, and heavy metal type and concentration and were overall stronger for wheat bran and pectin than other fiber types. Our findings suggest that dietary fibers play a role in mitigating the adverse effects of heavy metal exposure on gut microbiota health and may have implications for the development of dietary interventions to reduce dysbiosis associated with heavy metal exposure. Moreover, fiber-type specific outcomes highlight the importance of evidence-based selection of prebiotic dietary fibers to mitigate heavy metal toxicity to the gut microbiota.

Estimation of mercury uptake and distinction of corn cultivation in China

Corn cultivation potentially plays a vital role in the global mercury (Hg) biogeochemical cycle. Nevertheless, there have been limited studies quantifying the Hg mass flow during corn cultivation. This study focuses on Hg uptake by corn plants in China, integrating data from both sample collection and prior studies, resulting in 400 datasets. The findings reveal that the Hg in corn plants is mainly incorporated in leaves (45.5 %-47.5 %) and husks (14.5 %-15.7 %). Despite a decrease in total gaseous Hg (TGM) concentrations in the atmosphere over time, annual Hg uptake by corn cultivation in China has risen from 72.0 (ranging from 47.6 to 96.3) tons (2009-2014) to 84.3 (ranging from 51.9 to 109.6) tons (2015-2020) due to the increasing in corn kernel production. Spatial analysis demonstrates regional disparities in Hg uptake, primarily influenced by corn kernel production, TGM levels, and soil Hg content. Furthermore, temporal analysis reveals a shift in the fate of Hg in corn plants, which can be attributed to variations in corn straw treatment policy or methods. From 2009 to 2014, a substantial amount of absorbed Hg by corn plants was re-released into the atmosphere (48.9 %) due to corn residues burning, whereas, between 2015 and 2020, a greater proportion of Hg ended up accumulating in the soil (51.1 %) after the imposition of the straw burning ban in China. Prior to the ban (2009-2014), corn cultivation contributed approximately 7.7 tons of Hg input to soil annually, with a range from 1.7 to 13.5. However, following the ban (2015-2020), Hg input into the soil increased by approximately 4.5 times, reaching 34.5 (ranging from 17.5 to 52.6) tons per year. These findings emphasize the significant risks associated with soil Hg pollution caused by corn cultivation due to the straw burning ban.

An Unusual Cause of Complete Heart Block

Mercury poisoning is most frequently associated with multiorgan toxicity involving the brain, lungs, and kidneys. Cardiotoxic effects of mercury are rare and often overlooked. We demonstrate mercury poisoning-induced cardiotoxicity through a case study and then provide a review of the incidence, pathophysiology, and associated management plans. This case illustrates the importance of thorough history-taking to promote early recognition of toxicity.

The Impact of Environmental Toxins on Cardiovascular Diseases

Environmental toxins pose significant risks to human health and are considered major contributors to chronic diseases, particularly cardiovascular diseases (CVDs). Numerous studies have highlighted the detrimental impact of environmental toxicity on cardiovascular health. The primary sources of environmental toxins include pollutants containing particulate matter and organic substances, such as sulfate, nitrates, ammonium, elemental carbon, crystal elements, arsenic (As), mercury (Hg), cadmium (Cd), and Bisphenol A (BPA). Epidemiological research has closely monitored the link between environmental toxins and CVDs. Notably, aerosols and particulate matter, including PM10 and PM2.5, prevalent in ambient air pollution, have been implicated in various CVDs like ischemic heart disease, myocardial infarction, and dysrhythmia. Additionally, heavy metals such as lead and pesticides from environmental toxins are known to contribute to CVDs, even at low levels of exposure over extended periods. Mercury exposure, even at low concentrations, can adversely affect multiple organs, including the heart, kidneys, nervous system, and immune system. With Pb2+ ions exhibiting Ca2+-like properties, lead disrupts various pathways and can lead to cardiac and vascular lesions and functional impairments when blood lead concentrations exceed 100 µg% in adults and 60 µg% in children. Furthermore, cadmium exposure is higher in smokers, primarily due to tobacco use, and is associated with peripheral artery disease. Arsenic toxicity is well-documented, particularly its cardiotoxic effects, which can result in fatal and irreversible myocardial damage. Bisphenol A (BPA) has also been found in urine samples, underscoring its presence as an environmental toxin impacting human health.

Exposome and unhealthy aging: environmental drivers from air pollution to occupational exposures

The aging population worldwide is facing a significant increase in age-related non-communicable diseases, including cardiovascular and brain pathologies. This comprehensive review paper delves into the impact of the exposome, which encompasses the totality of environmental exposures, on unhealthy aging. It explores how environmental factors contribute to the acceleration of aging processes, increase biological age, and facilitate the development and progression of a wide range of age-associated diseases. The impact of environmental factors on cognitive health and the development of chronic age-related diseases affecting the cardiovascular system and central nervous system is discussed, with a specific focus on Alzheimer's disease, Parkinson's disease, stroke, small vessel disease, and vascular cognitive impairment (VCI). Aging is a major risk factor for these diseases. Their pathogenesis involves cellular and molecular mechanisms of aging such as increased oxidative stress, impaired mitochondrial function, DNA damage, and inflammation and is influenced by environmental factors. Environmental toxicants, including ambient particulate matter, pesticides, heavy metals, and organic solvents, have been identified as significant contributors to cardiovascular and brain aging disorders. These toxicants can inflict both macro- and microvascular damage and many of them can also cross the blood-brain barrier, inducing neurotoxic effects, neuroinflammation, and neuronal dysfunction. In conclusion, environmental factors play a critical role in modulating cardiovascular and brain aging. A deeper understanding of how environmental toxicants exacerbate aging processes and contribute to the pathogenesis of neurodegenerative diseases, VCI, and dementia is crucial for the development of preventive strategies and interventions to promote cardiovascular, cerebrovascular, and brain health. By mitigating exposure to harmful environmental factors and promoting healthy aging, we can strive to reduce the burden of age-related cardiovascular and brain pathologies in the aging population.

Association of Combined Metals and PFAS with Cardiovascular Disease Risk

This study sought to investigate the impact of exposure to metals and per- and polyfluoroalkyl substances (PFASs) on cardiovascular disease (CVD)-related risk. PFASs, including PFOA, PFOS, PFNA, and PFHxS, as well as metals such as lead (Pb), cadmium (Cd), and mercury (Hg), were analyzed to elucidate their combined effects on CVD risk.

METHODS

Utilizing data from the National Health and Nutrition Examination Survey (NHANES) spanning from 2007 to 2014, this investigation explored the effects of PFASs and metals on CVD risk. A spectrum of individual CVD markers, encompassing systolic blood pressure (SBP), diastolic blood pressure (DBP), high-density lipoprotein (HDL), low-density lipoprotein (LDL), total cholesterol, and triglycerides, was examined. Additionally, comprehensive CVD risk indices were evaluated, namely the Overall Cardiovascular Biomarkers Index (OCBI), including the Framingham Risk Score and an Overall Cardiovascular Index. Linear regression analysis was employed to probe the relationships between these variables. Furthermore, to assess dose-response relationships between exposure mixtures and CVD while mitigating the influence of multicollinearity and potential interaction effects, Bayesian Kernel Machine Regression (BKMR) was employed.

RESULTS

Our findings indicated that exposure to PFAS and metals in combination increased CVD risk, with combinations occurring with lead bringing forth the largest impact among many CVD-related markers.

CONCLUSIONS

This study finds that combined exposure to metals and PFASs significantly elevates the likelihood of CVD risk. These results highlight the importance of understanding the complex interplay between multipollutant exposures and their potential implications for cardiovascular health.

Mercury and cadmium-induced inflammatory cytokines activation and its effect on the risk of preeclampsia: a review

During the last decade, there has been an increase in exposure to heavy metals that can affect human health and the environment, especially mercury (Hg) and cadmium (Cd). These exposures can pollute the rivers or oceans, then contaminating marine organisms. Humans as the last consumer of this food chain cycle can be a place for the bioaccumulation of Hg and Cd, especially for people living in coastal areas, including pregnant women. Exposure to heavy metals Hg and Cd can have a high risk of triggering blood vessel disorders, penetrating the blood-brain barrier (BBB) and the placental barrier, one of which can increase the risk of preeclampsia. Several immunological biomarkers such as some cytokines associated with Hg and Cd exposure are also involved in the pathophysiology of preeclampsia, which are the placental implantation process and endothelial dysfunction in pregnant women. Therefore, countries that have a high incidence of preeclampsia should be aware of the environmental factors, especially heavy metal pollution such as Hg and Cd.

Characterization of atmospheric mercury from mercury-added product manufacturing using passive air samplers

Although alternatives to mercury (Hg) are available in most products and industrial activities, Hg continues to be an ingredient in some products, including fluorescent lamps and electrical and electronic equipment (EEE). In this work, low-cost passive air samplers (PASs) were used to investigate the atmospheric Hg pollution in Zhongshan, a large industrial city and major hub of mercury-added product manufacturing in South China. The GEM concentrations in the atmosphere were measured for two weeks during the summer of 2019 at a total of 144 sites across Zhongshan. Comparison with the results of active sampling confirmed that the PASs yielded accurate and reliable gaseous elemental mercury (GEM) concentrations and were thus well-suited for multi-site field monitoring. The mean GEM concentrations in the areas with mercury-added product manufacturing activities (5.1 ± 0.4 ng m-3) were significantly higher than those in other parts of Zhongshan (1.5 ± 0.4 ng m-3), indicating that local releases, rather than regional transport, were responsible for the atmospheric Hg pollution. Elevated GEM concentrations (up to 11.4 ng m-3) were found in the vicinity of fluorescent lamp and EEE factories and workshops, indicating significant Hg vapor emissions, presumably from the outdated production technologies and non-standard operation by under-trained workers. The Hg emissions from mercury-added product manufacturing were estimated to be 0.06 and 7.8 t yr-1 for Zhongshan and China, respectively, based on the scales of fluorescent lamp and EEE production. The non-carcinogenic health risk of Zhongshan residents from inhalation and ingestion was judged acceptable, whereby the inhalation exposure in Hg-polluted areas exceeded that of dietary ingestion. These findings demonstrate that mercury-added product manufacturing still contributes notably to anthropogenic gaseous Hg releases in the industrial areas with intense mercury-added product manufacturing activities.

Contaminant Metals and Cardiovascular Health

A growing body of research has begun to link exposure to environmental contaminants, such as heavy metals, with a variety of negative health outcomes. In this paper, we sought to review the current research describing the impact of certain common contaminant metals on cardiovascular (CV) health. We reviewed ten metals: lead, barium, nickel, chromium, cadmium, arsenic, mercury, selenium, zinc, and copper. After a literature review, we briefly summarized the routes of environmental exposure, pathophysiological mechanisms, CV health impacts, and exposure prevention and/or mitigation strategies for each metal. The resulting article discloses a broad spectrum of pathological significance, from relatively benign substances with little to no described effects on CV health, such as chromium and selenium, to substances with a wide-ranging and relatively severe spectrum of CV pathologies, such as arsenic, cadmium, and lead. It is our hope that this article will provide clinicians with a practical overview of the impact of these common environmental contaminants on CV health as well as highlight areas that require further investigation to better understand how these metals impact the incidence and progression of CV diseases.

Chronic exposure to mercury increases arrhythmia and mortality post-acute myocardial infarction in rats

Introduction: Mercury (Hg) is a heavy metal that causes a variety of toxic effects in eukaryotic cells. Previous studies have reported detrimental effects of mercury toxicity in the cardiovascular system. Given the importance of understanding the relationship between Hg and cardiovascular disease, we sought to investigate if the Hg could worsen the myocardial repercussions following ischemic injury. We demonstrated that once mercury toxicity is established, it can influence the outcome of myocardial infarction (MI). Methods: Male Wistar rats received intramuscular injections of either saline (NaCl 0.9%) or mercuric chloride (HgCl2, first dose of 4.6 μg/kg, and subsequent doses of 0.07 μg/kg/day) for 4 weeks. Three weeks post-exposure, we induced transmural infarction in the left ventricle free wall through coronary artery occlusion surgery. Results: ECG recordings obtained from MI groups demonstrated alterations in the rhythm of the heartbeat/heart electrical activity, as expected, including ventricular extrasystoles and ventricular tachycardia. However, the MI group exposed to Hg (MI-Hg) exhibited augmented ventricular extrasystoles and ventricular tachycardia compared to the MI group. Also, Basckó coefficient revealed that the arrhythmic events-after MI-were aggravated by Hg exposure. Discussion: Our results indicate that the significantly increased mortality in MI-Hg groups when compared to MI (21%, MI vs 32%, MI-Hg) is correlated with greater occurrence of arrhythmias. In conclusion, this study further supports the idea that exposure to mercury (Hg) should be recognized as a significant risk factor that exacerbates the impact of cardiac ischemic injury, potentially leading to an increased mortality rate among patients experiencing acute MI.

Occupational Risk Factors for Stroke: A Comprehensive Review

For primary prevention, it is important for public health and clinical medicine to identify and characterize modifiable risk factors of stroke. In existing literature, the impact of occupational variables on ischemic and hemorrhagic stroke has been extensively studied. This review summarizes the available data on the significance of occupational variables in stroke. The results of this review suggest that there is sufficient evidence for the relationship between increased risk of stroke and job stress, working in extreme temperatures, long working hours, and/or shift work. The association between long working hours and occupational exposure to noise and chemicals remains inconclusive although several studies have reported this finding. This review will act as a step toward future research and provide information that may serve as a baseline for developing targeted interventions to prevent stroke in the working population.

Fish muscle mercury concentration and bioaccumulation fluctuate year-round - Insights from cyprinid and percid fishes in a humic boreal lake

Boreal lakes demonstrate pronounced seasonality, where the warm open-water season and subsequent cold and ice-covered season dominate natural cycles. While fish muscle total mercury concentration (mg/kg) [THg] is well documented in open-water summer months, there is limited knowledge on the ice-covered winter and spring mercury dynamics in fish from various foraging and thermal guilds. This year-round study tested how seasonality influences [THg] and its bioaccumulation in three percids, perch (Perca fluviatilis), pikeperch (Sander lucioperca), ruffe (Gymnocephalus cernua), and three cyprinids, roach (Rutilus rutilus), bleak (Alburnus alburnus), and bream (Abramis brama) in deep boreal mesotrophic Lake Pääjärvi, southern Finland. Fish were sampled and [THg] was quantified in the dorsal muscle during four seasons in this humic lake. Bioaccumulation regression slopes (mean ± STD, 0.039 ± 0.030, range 0.013-0.114) between [THg] and fish length were steepest during and after spawning and shallowest during autumn and winter for all species. Fish [THg] was significantly higher in the winter-spring than summer-autumn in all percids, however, not in cyprinids. The lowest [THg] was observed in summer and autumn, likely due to recovery from spring spawning, somatic growth and lipid accumulation. Fish [THg] was best described by multiple regression models (R2adj: 52-76%) which included total length and varying combinations of seasonally changing environmental (water temperature, total carbon, total nitrogen, and oxygen saturation) and biotic factors (gonadosomatic index, and sex) in all species. The seasonal variation in [THg] and bioaccumulation slopes across multiple species suggests a need for standardized sampling seasons in long-term monitoring to avoid any seasonality bias. From the fisheries and fish consumption perspective in seasonally ice-covered lakes, monitoring of both winter-spring and summer-autumn would improve knowledge of [THg] variation in fish muscle.

Shared Lifestyle-Related Risk Factors of Cardiovascular Disease and Cancer: Evidence for Joint Prevention

Cardiovascular disease (CVD) and cancer are leading causes of mortality and morbidity worldwide and are the major focus of the World Health Organization's joint prevention programs. While, diverse diseases, CVD and cancer, have many similarities. These include common lifestyle-related risk factors and shared environmental, metabolic, cellular, inflammatory, and genetic pathways. In this review, we will discuss the shared lifestyle-related and environmental risk factors central to both diseases and how the strategies commonly used to prevent atherosclerotic vascular disease can be applied to cancer prevention.

Interaction of mercury species with proteins: towards possible mechanism of mercurial toxicology

The nature of the binding of mercurials (organic and inorganic) and their subsequent transformations in biological systems is a matter of great debate as several different hypotheses have been proposed and none of them has been conclusively proven to explain the characteristics of Hg binding with the proteins. Thus, the chemical nature of Hg-protein binding through the possible transportation mechanism in living tissues is critically reviewed herein. Emphasis is given to the process of transportation, and binding of Hg species with selenol-containing biomolecules that are appealing for toxicological studies as well as the advancement of environmental and biological research.

Evaluation of cadmium and mercury on cardiovascular and neurological systems: Effects on humans and fish

Chemicals are at the top of public health concerns and metals have received much attention in terms of toxicological studies. Cadmium (Cd) and mercury (Hg) are among the most toxic heavy metals and are widely distributed in the environment. They are considered important factors involved in several organ disturbances. Heart and brain tissues are not among the first exposure sites to Cd and Hg but they are directly affected and may manifest intoxication reactions leading to death. Many cases of human intoxication with Cd and Hg showed that these metals have potential cardiotoxic and neurotoxic effects. Human exposure to heavy metals is through fish consumption which is considered as an excellent source of human nutrients. In the current review, we will summarize the most known cases of human intoxication with Cd and Hg, highlight their toxic effects on fish, and investigate the common signal pathways of both Cd and Hg to affect heart and brain tissues. Also, we will present the most common biomarkers used in the assessment of cardiotoxicity and neurotoxicity using Zebrafish model.

Individual, Independent, and Joint Associations of Toxic Metals and Manganese on Hypertensive Disorders of Pregnancy: Results from the MIREC Canadian Pregnancy Cohort

BACKGROUND

Toxic metals, such as lead (Pb), cadmium (Cd), arsenic (As), and mercury (Hg), may be associated with a higher risk of gestational hypertension and preeclampsia, whereas manganese (Mn) is an essential metal that may be protective.

OBJECTIVES

We estimated the individual, independent, and joint associations of Pb, Cd, As, Hg, and Mn on the risk of developing gestational hypertension and preeclampsia in a cohort of Canadian women.

METHODS

Metal concentrations were analyzed in first and third trimester maternal blood (n=1,560). We measured blood pressure after 20 wk gestation to diagnose gestational hypertension, whereas proteinuria and other complications defined preeclampsia. We estimated individual and independent (adjusted for coexposure) relative risks (RRs) for each doubling of metal concentrations and examined interactions between toxic metals and Mn. We used quantile g-computation to estimate the joint effect of trimester-specific exposures.

RESULTS

Each doubling of third trimester Pb (RR=1.54; 95% CI: 1.06, 2.22) and first trimester blood As (RR=1.25; 95% CI: 1.01, 1.58) was independently associated with a higher risk of developing preeclampsia. First trimester blood As (RR=3.40; 95% CI: 1.40, 8.28) and Mn (RR=0.63; 95% CI: 0.42, 0.94) concentrations were associated with a higher and lower risk, respectively, of developing gestational hypertension. Mn modified the association with As such that the deleterious association with As was stronger at lower concentrations of Mn. First trimester urinary dimethylarsinic acid concentrations were not associated with gestational hypertension (RR=1.31; 95% CI: 0.60, 2.85) or preeclampsia (RR=0.92; 95% CI: 0.68, 1.24). We did not observe overall joint effects for blood metals.

DISCUSSION

Our results confirm that even low blood Pb concentrations are a risk factor for preeclampsia. Women with higher blood As concentrations combined with lower Mn in early pregnancy were more likely to develop gestational hypertension. These pregnancy complications impact maternal and neonatal health. Understanding the contribution of toxic metals and Mn is of public health importance. https://doi.org/10.1289/EHP10825.

[Spatial analysis of hypertension in Peruvian adults, 2022]

Objectives

To perform a spatial analysis of arterial hypertension in the Peruvian adult population to identify geographic patterns with a higher concentration of cases.

Materials and methods

A spatial analysis was conducted using data from the Demographic and Family Health Survey (ENDES) 2022. A sample of 29,422 adults was included, and the global Moran's index and Getis-Ord Gi* analysis were used to evaluate spatial autocorrelation and cluster concentration.

Results

The age-standardized prevalence of arterial hypertension was 19.2%. Clusters with a high concentration of arterial hypertension were observed in departments along the Peruvian coast such as Tumbes, Piura, Lambayeque, La Libertad, Ancash, and Lima, as well as in the northern regions of the Highlands. Clusters were also found in the regions of Loreto and Madre de Dios in the Peruvian jungle.

Conclusions

This study revealed geographic patterns of arterial hypertension in Peru, with a higher concentration of cases along the Peruvian coast and in certain regions of the Highlands and Jungle. These findings highlight the need to develop strategies for the prevention and control of the disease, especially in the areas identified as high-prevalence clusters.

The effects of mercury exposure on Amazonian fishes: An investigation of potential biomarkers

Exposure to mercury can interfere with the expression of proteins and enzymes, compromise important pathways, such as apoptosis and glucose metabolism, and even induce the expression of metallothioneins. In this study, analytical techniques were used to determine the concentration of total mercury (THg) in muscle and liver tissue, protein pellets, and spots [using graphite furnace atomic absorption spectrometry (GFAAS)], and molecular techniques were used to identify metalloproteins present in mercury-associated protein spots. Thirty individuals from three different fish species, Cichla sp. (n = 10), Brachyplatystoma filamentosum (n = 10), and Semaprochilodus sp. (n = 10) from the Brazilian Amazon were used. Oxidative stress indicators [such as glutathione peroxidase (GSH-Px), catalase (CAT), superoxide dismutase (SOD), a marker of lipid peroxidation (LPO)] and the possible expression of metallothioneins in muscle and liver tissues were investigated. The two piscivorous species, Cichla sp. and B. filamentosum, presented the highest concentrations of mercury in their hepatic tissue, 1219 ± 15.00 and 1044 ± 13.6 μg kg^-1, respectively, and in their muscle tissue, 101 ± 1.30 μg kg^-1 and 87.4 ± 0.900 μg kg^-1, respectively. The non-carnivorous species Semaprochilodus sp. had comparatively low concentrations of mercury in both its hepatic (852 ± 11.1 μg kg^-1) and muscle (71.4 ± 0.930 μg kg^-1) tissues. The presence of mercury was identified in 24 protein spots using GFAAS; concentrations ranged from 11.5 to 787 μg kg^-1, and mass spectrometry identified 21 metal-binding proteins. The activities of GSH-Px, CAT, and SOD, related to oxidative stress, decreased proportionally as tissue Hg concentrations increased, while the levels of LPO markers increased, indicating the presence of stress. Our study results demonstrate possible mercury interference in oxidative stress markers (GSH-Px, CAT, SOD, and LPO), in addition to the identification of 21 metal-binding proteins as possible biomarkers of mercury exposure in fish.

Assessment of the consumptive safety of mercury in fish from the surface waters of the Vologda region in northwestern Russia

It is known that the consumption of fish is the main source of mercury intake in human beings. In this study, the concentration of mercury in the muscle tissue of fish from different reservoirs of northwestern Russia was found to be 0.01-1.68 μg/g wet weight. The features of mercury accumulation in the muscle tissue of fish, depending on their type, trophic specialization, body weight, length, and the type of water body, were also revealed. Of the fish studied, 7% had mercury concentrations above the regulatory levels of the Russian Federation. The proportion of examined fish, the consumption of which will lead to an excess of the permissible weekly intake of mercury in the individual, is 44% for preschool children (2-5 years old), 34% for children of primary school age (6-10 years old), and 17% for adults. Special attention is drawn to the fact that the mercury content in fish that does not exceed the sanitary and hygienic standards (normative levels) of the Russian Federation may still be unsafe for the health of the population, especially children.

Association between prenatal metals exposure and blood pressure in 5-6 years children: A birth cohort study

BACKGROUND

The trajectory of blood pressure (BP) from childhood to early middle age suggested that individuals with elevated BP in early childhood were more likely to be affected by cardiovascular disease in adulthood. Exposure to metals may affect BP in children, and pregnancy is a sensitive time for metal exposure. This study assessed the relationship between different stages of prenatal exposure to metals or metal mixtures and BP in children aged 5-6 years.

METHODS

The study included 2535, 2680, 2534 mother-child pairs in three trimesters, from the Ma'anshan birth cohort study (MABC). We collected maternal blood samples during pregnancy and measured the serum levels of four metals (arsenic, selenium, cadmium, and mercury). BP was measured in children aged 5-6 years. A linear regression model and Bayesian kernel machine regression (BKMR) were used to explore associations between prenatal exposure to metals at different stages and multiple metal exposure with BP in children aged 5-6 years.

RESULTS

Associations were observed between the arsenic in the third trimester and children's diastolic blood pressure (DBP) (β = 0.88, 95% CI: 0.44, 1.33), systolic blood pressure (SBP) (β = 0.72, 95% CI: 0.19, 1.24) and mean arterial pressure (MAP) (β = 0.83, 95% CI: 0.42, 1.23), as well as between the mercury and children's DBP (β = 0.65, 95% CI: 0.13, 1.16) and MAP (β = 0.60, 95% CI: 0.14, 1.07). The BKMR analysis showed that multiple metals had a significant positive joint effect on children's DBP, SBP and MAP. A potential interaction between arsenic and mercury was observed (β = -0.85, 95% CI: -1.62, -0.08).

CONCLUSIONS

Exposure to arsenic and mercury during pregnancy was associated with altered BP in children. The third trimester may represent an important window of opportunity to reduce the effects of metal exposure on children's blood pressure and long-term health.

Omega-3 Fatty Acids in Cardiovascular Disease and Diabetes: a Review of Recent Evidence

PURPOSE OF REVIEW

Omega-3 fatty acids (n-3 FA) lower triglycerides, have anti-inflammatory properties, and improve metabolism. Clinical evidence of cardiovascular benefit with omega-3 fatty acids is mixed. We discuss mechanisms providing biological plausibility of benefit of omega-3 fatty acids in cardiovascular risk reduction and review clinical trials investigating the benefits of prescription omega-3 fatty acids in dyslipidemia, atherosclerotic cardiovascular disease (ASCVD), and diabetes.

RECENT FINDINGS

Although early trials showed no benefit of omega-3 fatty acids in ASCVD, the REDUCE-IT trial noted significant risk reduction in ASCVD events with highly purified EPA (icosapent ethyl) use which has changed the landscape for currently available therapeutic options. However, other large trials like STRENGTH and VITAL, which used different formulations of prescription omega-3 fatty acids, did not note significant cardiovascular risk reduction. Thus the effectiveness of omega-3 fatty acids for cardiovascular disease prevention is an ongoing topic of debate. A relative paucity of studies examining benefits for glycemic outcomes in persons with diabetes exists; however, few studies have suggested lack of benefit to date. Significant residual cardiovascular risk exists for individuals with hypertriglyceridemia. Prescription omega-3 fatty acids are more commonly used for CV risk reduction in these patients. Clinical guideline statements now recommend icosapent ethyl use for selected individuals with hypertriglyceridemia to reduce cardiovascular events given recent evidence from the REDUCE-IT trial. Nonetheless, data from other large scale trials has been mixed, and future research is needed to better understand how different preparations of omega-3 may differ in their cardiovascular and metabolic effects, and the mechanisms for their benefit.

Metalloproteomic approach to liver tissue of rats exposed to mercury

The aims of this study were to identify mercury-associated protein spots in the liver tissue of rats exposed to low concentrations of mercury and to elucidate the physiological and functional aspects of the proteins identified in the protein spots. Therefore, proteomic analysis of the liver tissue of Wistar rats exposed to mercury chloride (4.60 μg kg^-1 in Hg²⁺) was performed for thirty days (Hg-30 group) and sixty days (Hg-60 group). The proteomic profile of the liver tissue of the rats was obtained by two-dimensional electrophoresis (2D-PAGE), and the determinations of total mercury in the liver tissue, pellets and protein spots were performed by graphite furnace atomic absorption spectrometry (GFAAS). ImageMaster 2D Platinum 7.0 software was used to identify the differentially expressed mercury-associated protein spots, which were then characterized by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). The determinations by GFAAS indicated a total mercury bioaccumulation of 2812% in the Hg-30 group and 3298% in the Hg-60 group and 10 mercury-associated protein spots with a concentration range of 51 ± 1.0 to 412 ± 6.00 mg kg^-1 in the 2D PAGE gels from the liver tissue of the Hg-60 group. The LC-MS/MS analyses allowed the identification of 11 metal binding proteins in mercury-associated protein spots that presented fold change with upregulation >1.5, downregulation < -1.7 or that were expressed only in the Hg-60 group. Using the FASTA sequences of the proteins identified in the mercury-associated protein spots, bioinformatics analyses were performed to elucidate the physiological and functional aspects of the metal binding proteins, allowing us to infer that enzymes such as GSTM2 presented greater mercury concentrations and downregulation < -3; Acaa2 and Bhmt, which showed expression only in the Hg-60 group, among others, may act as potential mercury exposure biomarkers.

Maternal Mercury Exposure and Hypertensive Disorders of Pregnancy: A Systematic Review

OBJECTIVE

 The present review aimed to synthesize the evidence regarding mercury (Hg) exposure and hypertensive disorders of pregnancy (HDP).

DATA SOURCES

 The PubMed, BVS/LILACS, SciELO and UFRJ's Pantheon Digital Library databases were systematically searched through June 2021.

STUDY SELECTION

 Observational analytical articles, written in English, Spanish, or Portuguese, without time restriction.

DATA COLLECTION

 We followed the PICOS strategy, and the methodological quality was assessed using the Downs and Black checklist.

DATA SYNTHESIS

 We retrieved 77 articles, of which 6 met the review criteria. They comprised 4,848 participants, of which 809 (16.7%) had HDP and 4,724 (97.4%) were environmentally exposed to Hg (fish consumption and dental amalgam). Mercury biomarkers evaluated were blood (four studies) and urine (two studies). Two studies found a positive association between Hg and HDP in the group with more exposure, and the other four did not present it. The quality assessment revealed three satisfactory and three good-rated studies (mean: 19.3 ± 1.6 out 28 points). The absence or no proper adjustment for negative confounding factor, such as fish consumption, was observed in five studies.

CONCLUSION

 We retrieved only six studies, although Hg is a widespread toxic metal and pregnancy is a period of heightened susceptibility to environmental threats and cardiovascular risk. Overall, our review showed mixed results, with two studies reporting a positive association in the group with more exposure. However, due to the importance of the subject, additional studies are needed to elucidate the effects of Hg on HDP, with particular attention to adjusting negative confounding.

Analysis of Minerals and Toxic Elements in Commonly Consumed Herbal Medicines in Zahedan, Iran, and Associated Human Health Risk Assessment

ABSTRACT

Herbal medicines (HMDs) are widely used in some countries. However, a consumer's health may be threatened when pollutants are present in HMDs and a high quantity of these medications is consumed. This work was conducted to evaluate the accumulation of toxic elements and the potential human health risks associated with high consumption of HMDs in Zahedan, Iran. In this study, 15 brands of popular HMDs were selected from five pharmacies. In each pharmacy, three HMD samples were randomly chosen, for a total of 225 samples, and evaluated for 11 elements. Inductively coupled plasma-optical emission spectrometry was used to analyze cadmium (Cd), lead (Pb), nickel (Ni), chromium (Cr), copper (Cu), iron (Fe), zinc (Zn), manganese (Mn), and aluminum (Al) in each sample. Total arsenic (As) and mercury (Hg) were measured by atomic absorption spectrometry. The human health risk of each element from ingestion of each HMD was estimated. The mean concentrations of these elements in different types of HMDs were highly variable and significantly different within the same type of HMD (P < 0.001). All samples contained detectable concentrations of target elements. However, the mean concentrations of each element in all HMDs were significantly lower than the legal limit published by the World Health Organization. The outcomes of this work indicated that for both children and adults, the target hazard quotient (THQ) for each metal and the hazard index (HI) for all metals in all types of HMDs were significantly lower than the acceptable limit (THQ and HI = 1). The incremental lifetime cancer risk (ILCR) for each carcinogenic metal and the total carcinogenic risk (TCR) for all carcinogenic metals also were lower than the acceptable limit (ILCR and TCR = 10-4).

HIGHLIGHTS

CuAAC-Derived Selective Fluorescent Probe as a Recognition Agent for Pb(II) and Hg(II): DFT and Docking Studies

Copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) is a resourceful and stereospecific methodology that has considerably yielded promising 1,2,3-triazole-appended "click" scaffolds with the potential for selective metal ion recognition. Based on "click" methodology, this report presents a chemosensor probe (TCT) based on 4-tert-butylcatechol architecture, via the CuAAC pathway, as a selective and efficient sensor for Pb(II) and Hg(II) ions, categorized as the most toxic and alarming environmental contaminants among the heavy metal ions. The synthesized probe was successfully characterized by spectroscopy [IR and NMR (¹H and ¹³C)] and mass spectrometry. The chemosensing study performed in acetonitrile/water (4:1) solvent media, via UV-vis and fluorescence spectroscopy, established its selective sensitivity for Pb(II) and Hg(II) species among the list of explored metal ions with the limits of detection being 8.6 and 11 μM, respectively. Additionally, the ¹H NMR and IR spectra of the synthesized TCT-metal complex also confirmed the metal-ligand binding. Besides, the effect of time and temperature on the binding ability of TCT with Pb(II) and Hg(II) was also studied via UV-vis spectroscopy. Furthermore, density functional theory studies put forward the structural comprehension of the sensor by availing the hybrid density functional (B3LYP)/6311G++(d,p) basis set of theory which was subsequently utilized for investigating its anti-inflammatory potential by performing docking analysis with human leukotriene b4 protein.

Effects of heavy metals on cardiovascular diseases in pre and post-menopausal women: from big data to molecular mechanism involved

To assess the link between a mixed heavy metal (cadmium, lead, and mercury) and the 10-year risk of cardiovascular diseases (CVDs) in pre- and post-menopausal Korean women aged ≥20 years, as well as identify potential molecular mechanisms of mixed heavy metal-induced CVDs. Multivariate linear regression, weighted quantile sum (WQS) regression, quantile g-computation (gqcomp), and Bayesian kernel machine regression (BKMR) models were used to examine the effects of mixed heavy metals and the 10-year risk of CVDs. The Comparative Toxicogenomics Database, MicroRNA ENrichment TURned NETwork, and the microRNA sponge generator and tester were used as the key data-mining approaches. In our BKMR analysis, we found that the overall effect of mixed heavy metals was linked to the 10-year risk of CVDs in postmenopausal women in the upper 20^th percentiles and in premenopausal women in the upper 55^th percentiles. Mercury was identified as the key chemical for the 10-year risk of CVDs in pre- and postmenopausal women. In silico analysis revealed that a heavy metal mixture interacted with six genes associated with CVD development. Physical interactions (77.6%) were found to be the most common among CVD-related genes induced by the heavy metals studied. Several pathways have been identified as the main molecular mechanisms that could be affected by studied heavy metals and are implicated in the development of CVDs (e.g., lipid and lipoprotein metabolism, lipoprotein metabolism, cholesterol metabolism, and cardiovascular disease). ALB, APOE, ATF5, and CREB3L3 were the key genes and transcription factors related to CVDs induced by the mixture of the investigated heavy metals, respectively. The two miRNAs with the highest interaction and expression in the development of CVDs were hsa-miR-199a-5p and hsa-miR-199a-3p. We also designed and tested miRNA sponge sequences for these miRNAs. The cutoff thresholds for each heavy metal level linked with the 10-year risk of CVDs were described. A mixture of heavy metal exposures, especially mercury, was more strongly linked with the 10-year risk of CVDs in postmenopausal women than in premenopausal women. Early interventions in postmenopausal women should be considered to reduce CVD risks.

Effects of chemical mixtures on liver function biomarkers in the Korean adult population: thresholds and molecular mechanisms for non-alcoholic fatty liver disease involved

There is a scarcity of research on the effects of a mixture of chemicals on liver function biomarkers and non-alcoholic fatty liver disease (NAFLD) indices, including FSI, HIS, and FBI-4. Thus, we aimed to explore whether there is an association between chemical mixtures, including 26 chemicals found in blood and urine, liver function biomarkers, and non-alcoholic fatty liver disease (NAFLD) indices in Korean adults. The effects of exposure to chemical mixtures on liver function biomarkers and NAFLD indices were investigated using linear regression models, weighted quantile sum (WQS) regression, quantile g-computation (qgcomp), and Bayesian kernel machine regression (BKMR) among 3669 adults. In silico toxicogenomic data-mining, we evaluated molecular mechanisms associated with NAFLD, including pathways, diseases, genes, miRNAs, and biological processes. The linear regression models showed blood or urine Hg levels were the most important factors associated with AST, ALT, GGT, FSI, and HSI levels, and significant trends were observed for these chemical quartiles (p < 0.01). The WQS index was significantly associated with ALT, GGT, FSI, and HSI. The qgcomp index also found an association between chemicals and AST, ALT, GGT, and FSI. In the BKMR model, the overall effect of the mixture was significantly related to ALT, GGT, FSI, and HSI. In silico analysis, we found mixed chemicals interacted with the CYP1A2 gene and were associated with NAFLD. Seventy-eight percent of interactions were identified as physical interactions in the CYP1A2 gene related to NAFLD. Transcription factor regulation in adipogenesis and lipid metabolic processes are fundamental molecular mechanisms that could be influenced by NAFLD-related mixed chemicals. Cutoff thresholds for chemical exposure levels associated with liver function indicators and NAFLD indices were also reported. The strongest interactions and expression of miRNAs involved in NAFLD development were also identified.

Mercury may reduce the protective effect of sea fish consumption on serum triglycerides levels in Chinese adults: Evidence from China National Human Biomonitoring

Sea fish contain omega-3 polyunsaturated fatty acids (omega-3 PUFAs) which have been found to reduce triglyceride (TG) levels. However, sea fish may contain pollutants such as mercury which cause oxidative stress and increase TG levels. Therefore, the relationship between sea fish and TG remains unclear. We aimed to explore whether blood mercury (BHg) can affect the effect of sea fish consumption frequency on TG level among Chinese adults. A total of 10,780 participants were included in this study. BHg levels were measured using inductively coupled plasma mass spectrometry (ICP-MS). The associations of sea fish consumption frequency with BHg and TG levels as well as the association of BHg with TG levels were evaluated using multiple linear regression. Causal mediation analysis was used to evaluate the mediation effect of BHg levels on the association of sea fish consumption frequency with TG levels. The frequency of sea fish consumption showed a negative association with TG level. Compared with the participants who never ate sea fish, the TG level decreased by 0.193 mmol/L in those who ate sea fish once a week or more [β (95%CI): -0.193 (-0.370, -0.015)]. Significant positive associations were observed of BHg with TG levels. With one unit increase of log2-transformed BHg, the change of TG level was 0.030 mmol/L [0.030 (0.009, 0.051)]. The association between sea fish consumption and TG was mediated by log2-transformed BHg [total effect = -0.037 (-0.074, -0.001); indirect effect = 0.009 (0.004, 0.015)], and the proportion mediated by log2-transformed BHg was 24.25%. BHg may reduce the beneficial effect of sea fish consumption frequency on TG levels among Chinese adults. Overall, sea fish consumption has more benefits than harms to TG.

An in-vivo microfluidic assay reveals cardiac toxicity of heavy metals and the protective effect of metal responsive transcription factor (MTF-1) in Drosophila model

Previous toxicity assessments of heavy metals on Drosophila are limited to investigating the survival, development rate, and climbing behaviour by oral administration while cardiac toxicity of these elements have not been investigated. We utilized a microfluidic device to inject known dosages of zinc (Zn) or cadmium (Cd) into the larvae's hemolymph to expose their heart directly and study their heart rate and arrhythmicity. The effect of heart-specific overexpression of metal responsive transcription factor (MTF-1) on different heartbeat parameters and survival of Drosophila larvae was investigated. The heart rate of wild-type larvae decreased by 24.8% or increased by 11.9%, 15 min after injection of 40 nL of 100 mM Zn or 10 mM Cd solution, respectively. The arrhythmicity index of wild-type larvae increased by 58.2% or 76.8%, after injection of Zn or Cd, respectively. MTF-1 heart overexpression ameliorated these effects completely. Moreover, it increased larvae's survival to pupal and adulthood stages and prolonged the longevity of flies injected with Zn and Cd. Our microfluidic-based cardiac toxicity assay illustrated that heart is an acute target of heavy metals toxicity, and MTF-1 overexpression in this tissue can ameliorate cardiac toxicity of Zn and Cd. The method can be used for cardiotoxicity assays with other pollutants in the future.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03336-7.