Mercury Exposure, Blood Pressure, and Hypertension: A Systematic Review and Dose-response Meta-analysis

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.

Toxic potential evaluation of liquid effluents discharged into nature by the university hospital centers (UHC) and mixed wastewater treatment station (WWTS) at Ouagadougou-Burkina Faso

In Burkina Faso, several investigations have raised suspicions that hospital liquid effluents are the source of contaminants in porbeagle-culture products and surface water in urban and peri-urban areas. This study aimed to evaluate the hygienic quality of hospital liquid effluents discharged into nature by the UHC Bogodogo (UHC-BOG), Yalgado Ouédraogo (UHC-YO), and the WWTS of Kossodo (WWTS-KOS). Thus, 15 samples of liquid effluents (five per site) discharged into nature were collected. Within the physicochemical parameters, the pH, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), suspended solids (TSS), conductivity, copper, iron, hafnium, silver, mercury, lead, and cadmium of these samples were determined using standard methods. The mean values of pH were 8.84 ± 0.42,8.06 ± 0.54, and 8.55 ± 0.53 for WWTS-KOS, UHC-BOG, and UHC-YO, respectively. Conductivity values were 1956.80 ± 81.30, 812.80 ± 45.22, and 956.00 ± 39.96 µS/cm, respectively. TSS were 338.20 ± 38.80, 45.00 ± 5.79, and 187.80 ± 27.58 mg/L, respectively. COD were 274.80 ± 20.46, 35.00 ± 5.52, and 139.80 ± 25.53 mg/L, respectively. BOD5 were 186.40 ± 68.68, 26.20 ± 4.82, and 81.80 ± 15.63 mg/L, respectively. Mercury values were 1.93 ± 0.38, 4.04 ± 0.38, and 14.37 ± 1.65 µg/L, respectively. Lead values were 434.70 ± 202.42, 310.50 ± 4.09, and 367.43 ± 94.01 µg/L, respectively. Cadmium values were 79.59 ± 19.48, 109.94 ± 8.43, and 80.26 ± 7.85 µg/L, respectively. Copper values were 27.66 ± 3.33, 30.84 ± 1.65, and 28.32 ± 2.36 mg/L, respectively. Iron was detected only on the STEP-KOS with an average of 71.01 ± 37.83 mg/L. Hafnium values were 50.27 ± 4.49 and 51.58 ± 4.61 mg/L for WWTS-KOS and UHC-BOG, respectively. Silver values were 34.26 ± 3.06 for WWTS-KOS. On the three sites, the differences found were significant (p < 0.05). Liquid hospital effluents from Ouagadougou discharged into nature on the whole do not compile with the Burkinabè normative values for the discharge of wastewater into the environment.

Are lead, cadmium and mercury risk factors for resistant hypertension?

BACKGROUND

Lead (Pb), cadmium (Cd) and mercury (Hg) are toxic trace elements that represent a public health problem as risk factors for cardiovascular disease and hypertension (HT) and could also contribute to the development of resistant hypertension (rHT) AIMS: To compare the blood concentrations of Pb, Cd and Hg in subjects with resistant and non-resistant HT and to define whether there is a relationship between its levels and rHT.

METHODS

Cross-sectional study. Subjects aged ≥ 21 to ≤ 80 years with a body mass index < 40 kg/m2 were recruited on a discretionary basis from October 2001 to October 2004 in a hypertension unit of a tertiary hospital amongst those sent to the hypertension unit by their family physician. Resistant hypertension was defined according to the American Heart Association (AHA) criteria. Whole blood concentrations of Cd, Pb and Hg were measured by electrothermal atomic absorption spectrometry.

RESULTS

46 out of 73 included subjects (63%) suffered from rHT. Blood Pb median: HT 3.9 (IQR 2.7-5.2) vs. rHT 3.6 (IQR 2.8-6.0) µg/dL (p=0.941). Blood Cd median: HT 0.07 (IQR 0.07-0.80) vs. rHT 0.30 (IQR 0.07-0.65) µg/L (p=0.681). Blood Hg median: HT 7.9 (IQR 5.8-12.9) vs. rHT 7.3 (IQR 4.6-13.3) µg/L (p=0.611). Considering the 75th percentile of each element (Pb: 5.55 µg/dL, Cd: 0.75 µg/L, Hg: 13.15 µg/L), a multiple logistic regression analysis (adjusted for age, BMI, diabetes mellitus, clearance of creatinine and only for Cd the smoking habit) showed an OR = 3.44 (0.84-14.10, p=0.086) for Pb, OR = 1.80 (0.39-8.24, p=0.451), for Cd and OR = 2.31 (0.59-9.14, p=0.232) for Hg. Moreover, the stratified analyses showed that men with Pb ≥5.55 µg/dL have a 14 times higher risk of suffering from rHT (p=0.026). Interestingly, a 9-fold increased risk was found for non-obese subjects with elevated Pb levels, above 5.55 µg/dL (p=0.029). Also in men, the probability of suffering from rHT was more than 7 times higher if Cd levels were ≥ 0.75 µg/L (p=0.076). Most smokers had higher Cd levels, with a high risk of suffering from rHT (ORa 12.6 (0.8-200.2), p=0.072).

CONCLUSION

A higher blood Pb levels, defined by the 75th percentile (Pb ≥ 5.55 µg/dL), is associated with a greater risk of suffering from rHT and to a lesser extent in the case of Cd and Hg.

Metals on the Menu-Analyzing the Presence, Importance, and Consequences

Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium, potassium, magnesium, calcium, iron, zinc, and copper are crucial for various physiological functions and must be consumed through the diet, others, like lead, mercury, and cadmium, are toxic even at low concentrations and pose serious health risks. This study comprehensively analyzes the presence, importance, and consequences of metals in the food chain. We explore the pathways through which metals enter the food supply, their distribution across different food types, and the associated health implications. By examining current regulatory standards for maximum allowable levels of various metals, we highlight the importance of ensuring food safety and protecting public health. Furthermore, this research underscores the need for continuous monitoring and management of metal content in food, especially as global agricultural and food production practices evolve. Our findings aim to inform dietary recommendations, food fortification strategies, and regulatory policies, ultimately contributing to safer and more nutritionally balanced diets.

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.

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.

Environmental and genetic predictors of whole blood mercury and selenium concentrations in pregnant women in a UK birth cohort

There is evidence that tissue concentrations of mercury (Hg) and selenium (Se) are predicted by numerous dietary, sociodemographic, environmental, and genetic factors. This study aimed to estimate the relative importance of predictors of Hg and Se concentrations in blood samples taken from pregnant women. The Avon Longitudinal Study of Parents and Children (ALSPAC) in the UK measured whole blood Hg and Se concentrations in 3,972 pregnant women. We identified 30 potential predictors of Hg and 24 of Se, which were evaluated using cross-validated random forests to identify the optimal models for predictive power. The relative importance of individual variables was estimated by averaging the added-R2 per predictor. Linkage disequilibrium score regression was used to estimate the variance explained by genotype. A multivariable model of 14 predictors explained 22.4% of Hg variance (95% CI: 13.0 to 37.1), including 6.9% from blood Se and 3.2% from white fish consumption. There were 11 predictors which explained 15.3% of Se variance (CI: 8.9 to 25.9), including 6.4% from blood Hg, 1.3% from blood lead, and 1.3% from oily fish. Measured genetic variation explained 30% of Hg variance (CI: 8.4 to 51.5) and 37.5% of Se (CI: 10.4 to 64.5). A high proportion of Hg and Se variance could be explained from dietary, sociodemographic, metabolic, and genetic factors. Seafood consumption was less predictive of Hg than may be expected and other factors should be considered when determining risk of exposure. There was tentative evidence that genotype is a major contributor to Hg and Se variation, possibly by modifying the efficacy of internal metabolism.

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.

Revisiting Genetic Influence on Mercury Exposure and Intoxication in Humans: A Scoping Review

Human intoxication to mercury is a worldwide health problem. In addition to the type and length of exposure, the genetic background plays an important role in mercury poisoning. However, reviews on the genetic influence in mercury toxicity are scarce and not systematic. Therefore, this review aimed to systematically overview the most recent evidence on the genetic influence (using single nucleotide polymorphisms, SNPs) on human mercury poisoning. Three different databases (PubMed/Medline, Web of Science and Scopus) were searched, and 380 studies were found that were published from 2015 to 2022. After applying inclusion/exclusion criteria, 29 studies were selected and data on characteristics (year, country, profile of participants) and results (mercury biomarkers and quantitation, SNPs, main findings) were extracted and analyzed. The largest number of studies was performed in Brazil, mainly involving traditional populations of the Tapajós River basin. Most studies evaluated the influence of the SNPs related to genes of the glutathione system (GST, GPx, etc.), the ATP-binding cassette transporters and the metallothionein proteins. The recent findings regarding other SNPs, such as those of apolipoprotein E and brain-derived neurotrophic factor genes, are also highlighted. The importance of the exposure level is discussed considering the possible biphasic behavior of the genetic modulation phenomena that could explain some SNP associations. Overall, recommendations are provided for future studies based on the analysis obtained in this scoping review.

Genome-Wide Association Study of Blood Mercury in European Pregnant Women and Children

Mercury has high industrial utility and is present in many products, and environmental contamination and occupational exposure are widespread. There are numerous biological systems involved in the absorption, metabolism, and excretion of Hg, and it is possible that some systems may be impacted by genetic variation. If so, genotype may affect tissue concentrations of Hg and subsequent toxic effects. Genome-wide association testing was performed on blood Hg samples from pregnant women of the Avon Longitudinal Study of Parents and Children (n = 2893) and children of the Human Early Life Exposome (n = 1042). Directly-genotyped single-nucleotide polymorphisms (SNPs) were imputed to the Haplotype Reference Consortium r1.1 panel of whole genotypes and modelled againstlog-transformed Hg. Heritability was estimated using linkage disequilibrium score regression. The heritability of Hg was estimated as 24.0% (95% CI: 16.9% to 46.4%) in pregnant women, but could not be determined in children. There were 16 SNPs associated with Hg in pregnant women above a suggestive p-value threshold (p < 1 × 10-5), and 21 for children. However, no SNP passed this threshold in both studies, and none were genome-wide significant (p < 5 × 10-8). SNP-Hg associations were highly discordant between women and children, and this may reflect differences in metabolism, a gene-age interaction, or dose-response effects. Several suggestive variants had plausible links to Hg metabolism, such as rs146099921 in metal transporter SLC39A14, and two variants (rs28618224, rs7154700) in potassium voltage-gated channel genes. The findings would benefit from external validation, as suggestive results may contain both true associations and false positives.

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.

Exposure to mercury among Spanish adolescents: Eleven years of follow-up

The toxic effects of mercury exposure on human health are a public health concern. The most important source of this exposure is the consumption of fish and marine mammals. This study aims to describe hair mercury concentrations and their evolution from birth until eleven years of age in adolescents from the INMA (Environment and Childhood) birth cohort study, and to assess the association of hair mercury concentrations at eleven years of age with sociodemographic and dietary factors. The sample comprised 338 adolescents from the sub-cohort of Valencia (in eastern Spain). Total mercury (THg) was measured in hair samples collected at 4, 9 and 11 years old and in cord blood at birth. The equivalent of hair for cord-blood THg concentrations was calculated. Fish consumption and other characteristics at 11 years old were collected through questionnaires. Multivariate linear regression models were conducted to explore the association between THg concentrations, fish consumption and covariates. The geometric mean of hair THg concentrations at 11 years of age was 0.86 μg/g (95%CI: 0.78-0.94) and 45.2% of the participants presented concentrations above the equivalent RfD proposed by the US EPA (1 μg/g). Consumption of fish such as swordfish, canned tuna and other large oily fish was associated with higher levels of hair mercury at 11 years of age. Swordfish had the highest effect with an increase of 125% in hair mercury (95%CI: 61.2-214.9%) given a 100 g/week increase in its consumption, and, taking into account the frequency of consumption, canned tuna was the main contributor to Hg exposure among our population. The hair THg concentrations at 11 years of age represented a reduction of around 69% with respect to that estimated at childbirth. Even though THg exposure shows a sustained decreasing trend, it can still be considered elevated. INMA birth cohort studies provide a longitudinal assessment of mercury exposure in a vulnerable population, its associated factors and temporal trends, and this information could be used to adjust recommendations about this issue.

Association between environmental chemical exposure and albumin-to-creatinine ratio is modified by hypertension status in women of reproductive age

Chemicals have been identified as a potential risk factor of renal dysfunction. However, studies that consider both multiple chemicals and non-chemical risk factors, such as hypertension, are rare. In this study, we assessed the associations between exposure to several chemicals, including major metals, phthalates, and phenolic compounds, and the albumin-to-creatinine ratio (ACR). A group of Korean adult women in reproductive age (n = 438, aged between 20 and 49 years), who had previously been studied for association of several organic chemicals, was chosen for this purpose. We constructed multivariable linear regression models for individual chemicals and weighted-quantile sum (WQS) mixtures, by hypertension status. Among the study population, approximately 8.5% of the participants exhibited micro/macro-albuminuria (ACR ≥30 mg/g), and 18.5% and 3.9% exhibited prehypertension and hypertension, respectively. Blood cadmium and lead levels showed a stronger association with ACR only among women with prehypertension or hypertension. Among organic chemicals, depending on the statistial model, benzophenone-1 (BP-1) and mono(2-ethyl-5-hydroxyhexyl) phthalate (MEHHP) showed a significant association regardless of hypertension status, but most associations disappeared in the (pre)hypertensive group. These findings clearly indicate that hypertension status can modify and may potentiate the association of environmental chemicals with ACR. Our observations suggest that low-level environmental pollutant exposure may have potential adverse effects on kidney function among general adult women. Considering the prevalence of prehypertension in the general population, efforts to reduce exposure to cadmium and lead are necessary among adult women to minimize the risk of adverse kidney function.

Environment-wide association study of elevated liver enzymes: results from the Korean National Environmental Health Survey 2018-2022

Background

Environmental exposure is characterized by low concentration, chronic, and complex exposure. Traditional epidemiological studies show limitations in reflecting these characteristics since they usually focus on a single or very limited number of exposure factors at a time. In this study, we adopted the methodology of environment-wide association study (EWAS) to figure out the association of human liver function with various environmentally hazardous substances.

Methods

We analyzed 2,961 participants from the Korean National Environmental Health Survey Cycle 4 (2018-2020). Using generalized linear model (GLM) analysis, we analyzed the association of 72 variables with 3 liver function indices (aspartate aminotransferase [AST], alanine aminotransferase [ALT], and gamma glutamyl transferase [GGT]). Finally, we visualized our results with Manhattan plot.

Results

In GLM analysis, perfluorooctanesulfonate were positively associated with ALT (odds ratio [OR]: 2.2; 95% confidence interval [CI]: 1.39-3.46; p adjusted = 0.0147) and perfluorodecanoic acid showed positive association with GGT (OR: 2.73; 95% CI: 1.36-5.5; p adjusted = 0.0256). Plasma mercury showed positive association with GGT (OR: 1.45; 95% CI: 1.14-1.84; p adjusted = 0.0315). Using a plastic container while keeping food in the refrigerator was associated with elevated GGT compared to using a glass container (OR: 1.51; 95% CI: 1.16-1.95; p adjusted = 0.0153). 2-ethyl-5-oxohexyl phthalate, showed a negative trend with all 3 indices, with AST (OR: 0.54; 95% CI: 0.39-0.73; p adjusted = 0.00357), ALT (OR: 0.5; 95% CI: 0.34-0.75; p adjusted = 0.036), GGT (OR: 0.55; 95% CI: 0.4-0.76; p adjusted = 0.00697). Bisphenol S and frequent use of sunblock cream showed negative association with ALT (OR: 0.77; 95% CI: 0.66-0.89), and GGT (OR: 0.25; 95% CI: 0.11-0.55), respectively.

Conclusions

We conducted an exploratory study on environmental exposure and human liver function. By using EWAS methodology, we identified 7 factors that could have potential association with liver function.

Hair mercury is associated with dyslipidemia and cardiovascular risk: An anthropometric, biochemical and genetic cross-sectional study of Amazonian vulnerable populations

This cross-sectional study evaluated the association between human exposure to mercury and cardiovascular risk using lipid profile (including apolipoproteins) and genetic analysis of Amazonian riverine population. Anthropometric data (gender, age, height, weight, blood pressure, and neck and waist circumferences) of the participants were recorded. Total mercury and methylmercury (MeHg) content were quantified in hair by ICP-MS and GC-pyro-AFS system. Polymorphisms rs662799, rs693, rs429358 and rs7412 (of genes of apolipoproteins A-V, B, and E at positions 112 and 158, respectively) were genotyped by real-time PCR. The population presented a dyslipidemia profile significantly correlated with high mercury levels. The apolipoprotein B/apolipoprotein A-I (ApoB/ApoA-I) index was also positively correlated with mercury, supporting a possible causal relationship. Allelic distributions were similar to those described in other populations, suggesting that genetic susceptibility may not have a significant role in the lipid alterations found in this work. This study demonstrated for the first time: i) the relationship between mercury exposure and cardiovascular risk-related apolipoproteins in humans, ii) the ApoB levels and the ApoB/ApoA-I index as the risk factors more strongly associated to the mercury-related dyslipidemia in humans, and iii) the prevalence of high/moderate risk of acute myocardial infarction in the vulnerable and chronically exposed-populations of the Amazon, in addition to the genotypic profile of the three most frequent polymorphisms in apolipoproteins of relevance for cardiovascular risk. This early detection of lipid alterations is essential to prevent the development of cardiovascular diseases (CVD), especially in chronically exposed populations such as those found in the Amazon. Therefore, in addition to provide data for the Minamata Convention implementation, our work is in line with the efforts joined by all members of the World Health Organization committed to reducing premature deaths originating from non-communicable diseases by 25% in 2025, including CVD.

Sociobehavioral, Biological, and Health Characteristics of Riverside People in the Xingu Region, Pará, Brazil

This study aimed to evaluate the sociodemographic, behavioral, and biological profile and its relationship with the emergence of chronic non-communicable diseases in riverside populations in the Xingu region, Pará, Brazil. Characteristics related to health indicators and which risk factors are considered most important were analyzed. This is a cross-sectional, exploratory, and descriptive study. The sample consisted of riverside people of over 18 years of both sexes. The sample size (n = 86) was calculated with a confidence level of 95% and a sample error of 5%. The K-means clustering algorithm was adopted through an unsupervised method to divide the groups, and the values were expressed as a median. For continuous and categorical data, the Mann-Whitney and chi-square tests were used, respectively, and the significance level was set at p < 5%. The multi-layer perceptron algorithm was applied to classify the degree of importance of each variable. Based on this information, the sample was divided into two groups: the group with low or no education, with bad habits and worse health conditions, and the group with opposite characteristics. The risk factors considered for cardiovascular diseases and diabetes in the groups were low education (p < 0.001), sedentary lifestyle (p < 0.01), smoking, alcoholism, body mass index (p < 0.05), and waist-hip ratio, with values above the expected being observed in both groups. The factors considered important so as to be considered to have good health condition or not were the educational and social conditions of these communities, and one part of the riverside population was considered healthier than the other.

Interaction between blood cadmium and lead concentration and physical activity on hypertension from the Korean national health and nutrition examination survey in 2008-2013

BACKGROUND

Previous studies have suggested that blood Cd, Pb exposure, and physical activity levels may influence the development of hypertension. This study aimed to investigate the relationship between blood Cd, Pb levels, and hypertension by the level of physical activity in Korean adults using The Korea National Health and Nutrition Examination Survey (KNHANES).

METHODS

We used data from the KNHANES (2008-2013), a nationally representative, cross-sectional, population-based study. We included 8,510 participants who had records of blood Cd, Pb and, blood pressure measurements. Multiple logistic regression was used to examine the association between blood Cd and Pb exposure and the development of hypertension, as well as the modifying effects of physical activity levels. Additive interaction was estimated using relative excess risk due to interaction (RERI), attributable proportion due to interaction (AP) and synergy index (S).

RESULTS

Following covariates adjustments, we found significant associations of blood Cd and Pb with higher hypertension prevalence. This association was more apparent in low physical activity while blood Cd and Pb concentrations were not significantly associated with hypertension in participants with more activity. Additionally, there was a significant interaction between blood Cd and physical activity on hypertension risk (RERI = 0.17, 95% CI: -0.36-0.7; AP = 0.12, 95% CI: -0.28-0.52; S = 1.75, 95% CI:1.36-2.14).

CONCLUSIONS

Our results suggest that low physical activity may substantially amplify the adverse effects of blood Pb and Cd exposure on hypertension risk. However, interactions were only found for Cd. Further studies are needed to confirm these findings.

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.

Association of mercury exposure with the serum high-sensitivity C-reactive protein level in Korean adults

Although there is evidence that mercury (Hg) exposure may be a potential risk factor for cardiovascular disease (CVD), few nationwide epidemiological researches have analyzed the association between blood Hg concentration and serum high-sensitivity C-reactive protein (hs-CRP) level as a biomarker of CVD. The present population-based national study was performed with data from the 2016–2017 National Health and Nutrition Examination Survey. In the total sample of 3,773 adults aged ≥20 years, the serum hs-CRP concentrations were 1.03 mg/L among participants in the lowest quartile of blood Hg level and 1.18 mg/L among those in highest quartile. The trend for the prevalence of a risky (&gt;1.0 mg/L) hs-CRP level (moderate risk and high risk) was significantly related to an increased quartile blood Hg concentration. After adjustment for confounders, participants with the highest quartiles of blood Hg had increased odds of a risky (&gt;1.0 mg/L) hs-CRP level (adjusted odds ratio = 1.34; 95% confidence interval, 1.02–1.77) compared with those with the lowest quartile of blood Hg. These findings demonstrate that a high blood Hg level increases the concentration of serum hs-CRP, a sensitive marker of chronic low-grade inflammation, and imply that the increased body burden associated with high blood Hg is a potential risk factor in the development of many inflammatory diseases, including CVD.

Associations between mercury exposure with blood pressure and lipid levels: A cross-sectional study of dental professionals

Mercury (Hg) exposure is a public health problem worldwide that is now being addressed through the Minamata Convention on Mercury. Fish containing methylmercury and dental amalgam containing elemental Hg are the major sources of exposure for most populations. There is some evidence that methylmercury impacts cardiovascular and metabolic health, primarily in populations with high exposure levels. Studies of elemental Hg and these outcomes are relatively rare. We aimed to examine associations between Hg exposure (both elemental and methylmercury) and blood pressure, as well as cholesterol and triglyceride levels. In 2012, we recruited dental professionals attending the Health Screening Program at the American Dental Association (ADA) Annual Session in California. Total Hg levels in hair and blood samples were analyzed as indicators of methylmercury exposure and in urine as an indicator of primarily elemental Hg exposure (n = 386; mean ± sd age 55 ± 11 years). We measured blood pressure (systolic and diastolic) and lipid profiles (total cholesterol, high-density lipoprotein cholesterol [HDL], low-density lipoprotein cholesterol [LDL] and triglycerides). The geometric means (geometric standard deviations) for blood, hair, and urine Hg were 3.64 (2.39) μg/L, 0.60 (2.91) μg/g, and 1.30 (2.44) μg/L, respectively. For every one μg/L increase in specific gravity-adjusted urine Hg, LDL increased by 2.31 mg/dL (95% CI = 0.09, 4.54), in linear regression adjusting for BMI, race, sex, polyunsaturated fatty acid intake from fish consumption, smoking status, and use of cholesterol-lowering medication. No significant associations between Hg biomarkers and blood pressure or hair or blood Hg with lipid levels were observed. Results suggest that elemental Hg exposure may influence LDL concentrations in adults with low-level exposure, and this relationship merits further study in other populations.

The association between carbon and nitrogen stable isotope ratios of human hair and hypertension

BACKGROUND

The relationship between stable isotope ratios and dietary protein sources has been reported. However, few studies have examined the effect of stable isotope ratios on metabolic risk in humans. We investigated whether the stable isotope ratios of carbon and nitrogen in human hair are associated with blood pressure and hypertension.

METHODS

We conducted a cross-sectional study of 392 subjects (228 men and 164 women). Hair samples of the subjects were used for the measurement of stable isotope ratios of carbon (δ¹³C) and nitrogen (δ¹⁵N).

RESULTS

The δ¹³C and δ¹⁵N values showed positive correlations with diastolic blood pressure in the subjects without antihypertensive medication. In the subjects without antihypertensive medication, the multivariable-adjusted odds ratio (95% confidence interval) for hypertension was 1.55 (1.04-2.30) per 1‰ increase in δ¹⁵N and 1.22 (0.86-1.73) per 1‰ increase in δ¹³C, respectively. However, in the subjects with antihypertensive medication, neither δ¹³C nor δ¹⁵N values showed a significant association with hypertension.

CONCLUSIONS

The stable isotopic ratio of nitrogen in scalp hair is independently associated with hypertension in subjects without antihypertensive medication. The hair δ¹⁵N value might be used as a surrogate marker to screen a high-risk population for hypertension.

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.

Mercury Contamination in Fish and Its Effects on the Health of Pregnant Women and Their Fetuses, and Guidance for Fish Consumption-A Narrative Review

As a principal source of long-chain omega-3 fatty acids (3FAs), which provide vital health benefits, fish consumption also comes with the additional benefit of being rich in diverse nutrients (e.g., vitamins and selenium, high in proteins and low in saturated fats, etc.). The consumption of fish and other seafood products has been significantly promoted universally, given that fish is an important part of a healthy diet. However, many documents indicate that fish may also be a potential source of exposure to chemical pollutants, especially mercury (Hg) (one of the top ten chemicals or groups of chemicals of concern worldwide), and this is a grave concern for many consumers, especially pregnant women, as this could affect their fetuses. In this review, the definition of Hg and its forms and mode of entrance into fish are introduced in detail and, moreover, the bio-accumulation of Hg in fish and its toxicity and action mechanisms on fish and humans, especially considering the health of pregnant women and their fetuses after the daily intake of fish, are also reviewed. Finally, some feasible and constructive suggestions and guidelines are recommended for the specific group of pregnant women for the consumption of balanced and appropriate fish diets in a rational manner.

A Systematic Review of Mercury Exposures from Skin-Lightening Products

BACKGROUND

The Minamata Convention on Mercury (Article 4) prohibits the manufacture, import, or export of skin-lightening products containing mercury concentrations above 1 ppm. However, there is a lack of knowledge surrounding the global prevalence of mercury-added skin-lightening products.

OBJECTIVE

The objective of this study was to increase our understanding of worldwide human mercury exposure from skin-lightening products.

METHODS

A systematic search of peer-reviewed scientific literature was performed for relevant articles in four databases (PubMed, Web of Science Core Collection, Scopus, and TOXLINE). The search strategy, eligibility criteria, and data-extraction methods were established a priori. The search identified 2,303 unique scientific articles, of which 41 were ultimately deemed eligible for inclusion after iterative screens at the title, abstract, and whole-text levels. To facilitate data extraction and synthesis, all papers were organized according to four data groups a) "Mercury in products," b) "Usage of products," c) "Human biomarkers of exposure," and d) "Health impacts."

RESULTS

This review was based on data contained in 41 peer-reviewed scientific papers from 22 countries worldwide published between 2000 and 2022. In total, we captured mercury concentration values from 787 skin-lightening product samples [overall pooled central median mercury level was 0.49μg/g; interquartile range (IQR): 0.02-5.9] and 1,042 human biomarker measurements from 863 individuals. We also synthesized usage information from 3,898 individuals and self-reported health impacts associated with using mercury-added products from 832 individuals.

DISCUSSION

This review suggests that mercury widely exists as an active ingredient in many skin-lightening products worldwide and that users are at risk of variable and often high exposures. These synthesized findings identify data gaps and help increase our understanding of the health risks associated with the use of these products. https://doi.org/10.1289/EHP10808.

Occupational risk factors for hypertension

The identification and characterization of the modifiable risk factors of hypertension is of great value for public health and clinical medicine to achieve primary prevention. A large amount of literature on the effects of occupational factors on blood pressure and hypertension has been published. In this review, I summarize current evidence regarding the role of occupational factors in hypertension. The results of this review suggest that there is sufficient evidence to support the association between increased risk of hypertension and job stress, shift work, occupational lead exposure, and noise exposure. The association of hypertension with physical inactivity, sedentary behavior, and occupational exposure to mercury, arsenic, cadmium, or carbon disulfide remains inconclusive, although several studies have reported this finding. This review will serve as a step toward future research and provide baseline information for developing strategic interventions to prevent hypertension in the working population.

Systematic Review and Meta-analysis of Environmental Toxic Metal Contaminants and the Risk of Ischemic Stroke

Background

Stroke is the second largest cause of mortality (WHO 2014) and long-lasting disability worldwide. Many risk factors are associated with stroke, such as age, gender, chronic illnesses, cardiovascular disease, lifestyle, and smoking. With global industrialization, the roles of environmental contaminants and their association with stroke are still unclear and have attracted much more attention.

Materials and Methods

We conducted a systematic review on the environmental toxic metal contaminants and the risk of ischemic stroke. A comprehensive literature search was carried out till June 30, 2021 from databases such as PubMed, Science Direct, Embase, and Scopus. The quality of all the articles which met our inclusion criteria was assessed using Newcastle-Ottawa scaling, and four eligible studies were included for our systematic review.

Results

The serum and urine cadmium concentrations were positively associated with the risk of ischemic stroke. There was an inverse association of serum and urine concentrations of mercury (Hg), serum concentration of gold and cerium with ischemic stroke, and the serum and urine concentrations of lead (Pb) had no association with ischemic stroke risk.

Conclusion

The study showed strong associations between heavy metals and ischemic stroke, but more studies are required to prove the associations.

Selenium and mercury concentrations in biological samples from patients with COVID-19

BACKGROUND

Coronavirus disease 2019 (COVID-19) is a systemic disease affecting multiple organs. Furthermore, viral infection depletes several trace elements and promotes complex biochemical reactions in the body. Smoking has been linked to the incidence of COVID-19 and associated mortality, and it may impact clinical effects, viral and bacterial conversion, and treatment outcomes.

OBJECTIVES

To study the relationship between severe acute respiratory syndrome coronavirus type 2 and the elemental concentrations of selenium (Se) and mercury (Hg) in biological samples from smokers and nonsmokers infected with the virus and in healthy individuals.

METHOD

We evaluated changes in the concentrations of essential (Se) and toxic (Hg) elements in biological samples (blood, nasal fluid, saliva, sputum, serum, and scalp hair) collected from male smokers and nonsmokers (aged 29-59 years) infected with COVID-19 and from healthy men in the same age group. The patients lived in different cities in Sindh Province, Pakistan. The Se and Hg concentrations were determined using atomic absorption spectrophotometry.

RESULTS

Se concentrations in all types of biological samples from smokers and nonsmokers with COVID-19 were lower than those of healthy smokers and nonsmokers. Hg concentrations were elevated in both smokers and nonsmokers with COVID-19.

CONCLUSIONS

In the current study, persons infected with COVID-19 had higher concentrations of toxic Hg, which could cause physiological disorders, and low concentrations of essential Se, which can also cause weakness. COVID-19 infection showed positive correlations with levels of mercury and selenium. Thus, additional clinical and experimental investigations are essential.

Exposure to metal mixtures and hypertensive disorders of pregnancy: A nested case-control study in China

Exposure to metals has been linked with the risk of hypertensive disorders of pregnancy (HDP), but little is known about the potential effects of exposure to metal mixtures. Thus, our study aimed to investigated the impact of a complex mixture of metals on HDP, especially the interactions among metal mixtures. We did a population-based nested case-control study from October 2013 to October 2016 in Wuhan, China, including 146 HDP cases and 292 controls. Plasma concentrations of Aluminum (Al), Barium (Ba), Cobalt (Co), Copper (Cu), Lead (Pb), Mercury (Hg), Molybdenum (Mo), Nickel (Ni), Selenium (Se), Strontium (Sr), Thallium (Tl), and Vanadium (V) were measured and collected between 10 and 16 gestational weeks. We employed quantile g-computation, conditional logistic regression models, and Bayesian Kernel Machine Regression (BKMR) to assess the association of individual metals and metal mixtures with HDP risk. In the quantile g-computation, the OR for a joint tertile increase in plasma concentrations was 3.67 (95% CI: 1.70, 7.91). Hg contributed the largest positive weights and followed by Al, Ni, and V. In conditional logistic regression models, concentrations of Hg, Al, Ni, and V were significantly associated with the risk of HDP (p-FDR < 0.05). Compared to the lowest tertiles, the ORs (95% CI) for the highest tertiles of these four metals were 2.67 (1.44, 4.95), 3.09 (1.70, 5.64), 5.31 (2.68, 10.53), and 4.52 (2.26, 9.01), respectively. In the BKMR analysis, we observed a linear positive association between Hg, Al, V, and HDP, and a nonlinear relationship between Ni and HDP. A potential interaction between Al and V was also identified. We found that exposure to metal mixtures in early pregnancy, both individually and as a mixture, was associated with the risk of HDP. Potential interaction effects of Al and V on the risk of HDP may exist.

Total arsenic, dimethylarsinic acid, lead, cadmium, total mercury, methylmercury and hypertension among Asian populations in the United States: NHANES 2011-2018

BACKGROUND

Non-Hispanic Asians (NHA) in USA have been reported with higher arsenic (As), lead (Pb), cadmium (Cd), mercury (Hg) and their specific species levels, comparing with non-NHA. This study aimed to investigate the associations of these metal/metalloid levels with blood pressure levels and prevalence of hypertension among general NHA using the 2011-2018 National Health and Nutrition and Examination Survey (NHANES) data.

METHODS

The study included participants aged 20 years and older with determinations of As, Dimethylarsinic acid (DMA), Pb, Cd, Hg and methyl-Hg (MeHg) in blood (n = 10, 177) and urine (n = 5, 175). These metals/metalloid levels were measured by inductively coupled plasma mass spectrometry. Systolic (SBP) and diastolic blood pressure (DBP) levels were examined through a standardized protocol. Censored normal regression model and logistic regression model were employed to explore the associations of As, DMA, Pb, Cd, Hg and MeHg levels with blood pressure levels and prevalence of hypertension respectively, and potential confounders were adjusted in these regression models. Quantile-based g-computation approach was used to analysis joint effect of metals mixture on blood pressure level and hypertension.

RESULTS

For NHA, urinary As and Hg levels were associated with increased DBP level; Higher blood Hg and MeHg levels were related to increased blood pressure levels and hypertension; However, negative association was observed between urinary Cd and SBP level; Blood metals mixture (including blood Pb, Cd and Hg) was associated with increased DBP level, but not for hypertension. For non-NHA, urinary As and DMA levels were associated with increased SBP level, but not DBP level and prevalence of hypertension; Urinary Pb level was associated with decreased DBP level; Nevertheless, positive associations were observed between blood Pb levels and SBP and prevalence of hypertension; Blood Hg level was associated with decreased DBP level and prevalence of hypertension; Furthermore, blood MeHg level was associated with decreased DBP level; Positive association was observed between blood metals mixture and increased SBP level among non-NHA.

CONCLUSIONS

Highly exposed to Hg level among NHA was associated with increased blood pressure levels and prevalence of hypertension. Urinary As level was associated with increased DBP level among NHA. Furthermore, blood metals mixture was related to increased DBP level among NHA. Further prospective studies with larger sample size should be performed to warrant the results.

The impact of mercury contamination on human health in the Arctic: A state of the science review

The 2021 Arctic Monitoring and Assessment Programme (AMAP) Mercury (Hg) Assessment is motivated by Arctic populations, and most notably Indigenous Peoples in the region, who are particularly vulnerable to Hg pollution. The objective of this review paper is to answer the following AMAP policy-relevant question: what is the human health impact of Hg pollution in the Arctic? In doing so, this state of the science review paper builds on information published 10 years ago in the last AMAP Hg assessment. The synthesized results demonstrate that: a) global influences (e.g., sources and transport pathways, biogeochemical processes, climate change, globalization) drive Hg exposures into human communities; b) Hg exposures are realized through dietary intake of certain country food items, and that new exposure science approaches are helping to deepen understandings; c) the nutritional and cultural benefits of country foods are immense, though a dietary transition is underway raising concerns over metabolic syndrome and broader issues of food security as well as cultural and social well-being; d) blood Hg measures are among the highest worldwide based on the results of human biomonitoring studies; e) Hg exposures are associated with adverse health outcomes across life stages (e.g., neurodevelopmental outcomes in young children to cardiovascular disease in adults); and f) risk communication needs to be balanced, targeted and clear, culturally appropriate, and be done collaboratively. These synthesized findings are particularly timely and policy-relevant given that the Minamata Convention entered into legal force worldwide in 2017 as a regulatory scheme to reduce the use and environmental release of Hg in order to protect human health and the environment. The Convention was influenced by health concerns raised by northern populations as indicated in the preamble text which makes reference to "the particular vulnerabilities of Arctic ecosystems and Indigenous communities".

Fish consumption habits of pregnant women in Itaituba, Tapajós River basin, Brazil: risks of mercury contamination as assessed by measuring total mercury in highly consumed piscivore fish species and in hair of pregnant women

The Tapajós River basin in the Amazon region, Brazil is one of the most active gold mining areas in the world. In this study, we evaluated fish consumption habits and mercury exposure in 110 pregnant women in the city of Itaituba by measuring their total hair mercury concentrations. In addition, we investigated seasonal differences in mercury concentrations in two highly consumed piscivorous fish species, tucunaré (Cichla spp.) and pescada (Plagioscion squamosissimus). Total fish mercury concentrations (THg) during the dry season were 0.62±0.07 mg/kg for Cichla spp. and 0.73±0.08 mg/kg for P. squamosissimus. During the rainy season they were 0.39±0.04 and 0.84±0.08 mg/ kg, respectively. Of our participants 44 % declared that they ate Cichla spp. and 67 % P. squamosissimus. Mean mercury concentration in their hair was 1.6±0.2 mg/kg and was above the US Environmental Protection Agency (US EPA) reference dose of 1 mg/kg in 48 % of them. Mean fish THg concentrations were also above the joint Food and Drug Administration and US EPA safety limit of 0.5 mg/kg for P. squamosissimus during both seasons and for Cichla spp. during the dry season only. These results show that pregnant women should avoid consumption of these piscivorous fish species during pregnancy and call for a regular programme to monitor Hg levels in that area.

The impact of essential and toxic elements on cardiometabolic risk factors in adults and older people

BACKGROUND AND AIM

Evidence suggests an association between essential and toxic elements and the worsening of cardiometabolic risk factors. This study aimed to investigate the concentrations of zinc, copper, selenium, arsenic, cadmium, and mercury and their relationship with cardiometabolic risk factors in adults and older people.

METHODS

This cross-sectional study was carried out with 112 adults with a mean age of 59 (sd 14) years old and a BMI of 29.30 (sd 5.11) Kg/m². The subject's weight and height were measured for body mass index (BMI) calculation, classified according to the cut-off points recommended by the World Health Organization (WHO). We evaluated sociodemographic, clinical, lifestyle, waist circumference - WC, visceral adiposity index - VAI, glycemic lipid profile, blood pressure, and high-sensitive C-reactive protein (hs-CRP). Cardiovascular risk was defined by The Global Risk Score (GRS) score. Plasma zinc, selenium, copper levels, urinary arsenic, cadmium, and mercury levels were measured using the inductively coupled plasma mass spectrometry technique (ICP-MS).

RESULTS

There was a negative association between urinary arsenic and VAI (β - 0.03, p < 0.01), triglycerides (β - 1.10, p < 0.01), and VLDL cholesterol (β - 0.14, p = 0.02). Plasma copper and copper/zinc ratio were positively associated with fasting glucose and hs-CRP (β 0.38, p < 0.01; β 36.02, p = 0.01, β 0.004, p < 0.01, β 0.68, p < 0.001, respectively). Urinary arsenic (β - 0.14, p = 0.04) and cadmium (β - 36.42, p = 0.04) were negatively associated with systolic blood pressure. Also, urinary cadmium was negatively associated with diastolic blood pressure (β - 21.55, p = 0.03), and urinary mercury showed an opposite behavior (β 1.45, p = 0.03).

CONCLUSION

Essential and toxic elements in urine and plasma could be potential biomarkers for cardiovascular risk factors. A healthy lifestyle should be adopted; in addition, government policies should be developed to guarantee sustainable production and a safe environment.

Blood pressure mediated the effects of cognitive function impairment related to aluminum exposure in Chinese aluminum smelting workers

OBJECTIVES

The aim of this study is to investigate the effects that the Al on blood pressure and the effect of hypertension in aluminum-induced cognitive impairment in electrolytic aluminum worker.

METHODS

The study was conducted 392 male aluminum electrolytic workers in an aluminum plant of China. The concentration of alumina dust in the air of the electrolytic aluminum workshop is 1.07mg/m3-2.13mg/m3. According to the Permissible concentration-Time Weighted Average of alumina dust is 4mg/ m3, which does not exceed the standard. The blood pressure of the workers was measured. The plasma aluminum concentration of workers was determined by ICP-MS (Inductively Coupled Plasma Mass Spectrometry). Cognitive functions were measured using MMSE (Mini-Mental State Examination), VFT (Verbal Fluency Test), ATIME (Average Reaction Time), FOM (Fuld Object Memory Evaluation), DST (Digit Span Test), CDT (Clock Drawing Test) scales. Modified Poisson regression was used to analyze the risk of hypertension and cognitive impairment with different plasma aluminum concentrations. Generalized linear regression model was used to analyze the relationship between aluminum and cognitive function, blood pressure and cognitive function. Causal Mediation Analysis was used to analyze the mediation effect of blood press in aluminum-induced cognitive impairment.

RESULTS

Plasma aluminum appeared to be a risk factor for hypertension (PR (prevalence ratio) = 1.630, 95%-CI (confidence interval): 1.103 to 2.407), systolic blood pressure (PR = 1.578, 95%-CI: 1.038 to 2.399) and diastolic blood pressure (PR = 1.842, 95%-CI: 1.153 to 2.944). And plasma aluminum increased by e-fold, the scores of MMSE and VFT decreased by 0.630 and 2.231 units respectively and the time of ATIME increased by 0.029 units. In addition, generalized linear regression model showed that blood press was negatively correlated with the scores of MMSE and VFT. Finally, causal Mediation Analysis showed that hypertension was a part of the mediating factors of aluminum-induced decline in MMSE score, and the mediating effects was 16.300% (7.100%, 33.200%). In addition, hypertension was a part of the mediating factors of aluminum-induced decline in VFT score, and the mediating effects was 9.400% (2.600%, 29.000%) CONCLUSION: Occupational aluminum exposure increases the risk of hypertension and cognitive impairment. And hypertension may be a mediating factor of cognitive impairment caused by aluminum exposure.

Associations between toxic elements and blood pressure parameters in adolescents

BACKGROUND

Both exposure to toxic elements and hypertension (HT) are a global health problem. We planned to examine the associations between some toxic elements in urine, and blood pressure (BP) and its diurnal changes in adolescents.

METHODS

In this cross-sectional study, 48 adolescents who were newly diagnosed with HT and 38 adolescents with age-appropriate BP and normal physical examination were included. Anthropometric measurements, urinary toxic elements, carotid intima media thickness (cIMT), and office and 24-hour ambulatory BP measurements (ABPM) of participants were taken. Urinary elements levels were studied with ICP-MS. Elements were grouped in tertiles according to urinary levels. Logistic regression analyses were performed to show the interactions.

RESULTS

Urinary cadmium, mercury, lead, and arsenic were found to be at detectable level in 90.7%, 69.8%, 91.9% and 100% of the participants, respectively. Univariate analyses showed that elevated daytime systolic and/or diastolic BP was associated with urinary cadmium and mercury. No association between urinary toxic elements and nighttime BP was found. When height and body mass index z-scores adjusted for, age, gender, and all four urinary creatinine-corrected toxic elements analyzed, multiple logistic regression revealed that there was an association between mercury (high vs. low; AOR:3.85) and office HT, and mercury (high vs. low; AOR:6.18) and cadmium (middle vs. low; AOR: 13.38) were associated with "elevated 24-hour systolic BP and/or diastolic BP", and "elevated 24-hour mean arterial BP" in ABPM.

CONCLUSION

There are complex relationships between toxic elements and BP parameters in adolescents, and more studies are needed to define the evolution of these relations.

The association between environmental cadmium exposure, blood pressure, and hypertension: a systematic review and meta-analysis

We performed a systematic and meta-analysis study to find the association between cadmium (Cd) exposure and blood pressure (BP)/hypertension (HTN) in exposed general populations. We searched main databases for literature published between year 2000 and April 15, 2021. Quality assessment was performed with the Joanna Briggs Institute (JBI) critical appraisal tools. Heterogeneity between studies was determined by I-squared (I²) statistic. The random effects model was used to determine the association between blood and urine Cd levels with hypertension. The overall standard differences in mean for Cd level in hypertensive and control groups were 3.34, 1.79, and 8.09 based on samples from blood, urine, and hair, respectively. The overall standard differences in mean for Cd level in the low and high exposure groups were - 0.795 and - 1.036 based on blood and urinary samples, respectively. Our findings indicate a positive relationship between blood and hair Cd levels and hypertension. We also found that hair is the optimal biological sample to find the relationship between Cd exposure and hypertension for both genders. However, more studies are needed to confirm these findings.

Interplay of Obesity, Ethanol, and Contaminant Mixture on Clinical Profiles of Cardiovascular and Metabolic Diseases: Evidence from an Animal Study

Obesity, ethanol, and contaminants are known risk factors of cardiovascular and metabolic diseases (CMD). However, their interplay on clinical profiles of these diseases remains unclear, and thus were investigated in this study. Male lean or obese JCR rats were given water or 10% ethanol and orally treated with or without a contaminant mixture (CM) dissolved in corn oil and loaded on two cookies at 0, 1.6, or 16 mg/kg BW/day dose levels for 4 weeks. The CM consisted 22 environmental contaminants found in human blood or serum of Northern populations. Over 60 parameters related to CMD were examined. The results revealed that obesity in JCR rats resembles the clinical profiles of non-alcoholic fatty liver disease in humans. Obesity was also associated with increased serum and organ retention of mercury, one of the chemical components of CM. Exposure to ethanol lightened hyperlipidemia, increased liver retention of mercury, and increased risk for hypertension in the obese rats. CM lessened hyperlipidemia and hyperenzymemia, worsened systemic inflammation and increased the risk for hypertension in the obese rats. CM markedly increased serum ethanol levels with or without ethanol exposure. Tissue total mercury contents significantly correlated with clinical parameters with altered profiles by both ethanol and obesity. These results suggest that obese individuals may be more prone to contaminant accumulation. Ethanol and CM exposure can alter clinical profiles associated with obesity, which may lead to misdiagnosis of CMD associated with obesity. CM can alter endogenous production and/or metabolism of ethanol, further complicating disease progression, diagnosis, and treatment.

Family History of Hypertension and Cobalt Exposure Synergistically Promote the Prevalence of Hypertension

It has been previously reported that family history of hypertension (FHH) and exposure to metals are each independent risk factor for hypertension, but the interaction between the two in relation to hypertension risk has been poorly studied. The object of this study is Dong ethnic group in Guizhou, China. The impacts of exposure to metals and FHH on hypertension incidence were examined by using the restrictive cubic spline (RCS) model as well as the multivariate logistic regression model. As a result, FHH, together with cobalt and lead exposure, was identified to show independent significant correlation with hypertension incidence (P < 0.05). The risk of hypertension increased with the increase in lead and cobalt exposure quartiles. Typically, the RCS model revealed such dose-response relation. To further confirm the association of cobalt, lead, and FHH with the risk of hypertension, multiplication and addition models were used to analyze the influence of the interactions between these variables on the risk of hypertension. The results showed that there was a multiplying interaction between the influence of the FHH and cobalt on the risk of hypertension. As for the additive interaction between cobalt and FHH, the relative excess risk due to interaction (RERI) was determined to be 0.596 (95% Cl: 0.001-1.191), the attributable proportion due to interaction (AP) was calculated as 0.256 (95% Cl: 0.075-0.437), whereas the synergy index (S) was identified to be 1.814 (95% Cl: 1.080-3.047). Our study provides some limited evidence that a FHH and cobalt exposure synergistically promote the prevalence of hypertension.

Exposure to Metal Mixtures in Association with Cardiovascular Risk Factors and Outcomes: A Scoping Review

Since the National Institute of Environmental Health Sciences (NIEHS) declared conducting combined exposure research as a priority area, literature on chemical mixtures has grown dramatically. However, a systematic evaluation of the current literature investigating the impacts of metal mixtures on cardiovascular disease (CVD) risk factors and outcomes has thus far not been performed. This scoping review aims to summarize published epidemiology literature on the cardiotoxicity of exposure to multiple metals. We performed systematic searches of MEDLINE (PubMed), Scopus, and Web of Science to identify peer-reviewed studies employing statistical mixture analysis methods to evaluate the impact of metal mixtures on CVD risk factors and outcomes among nonoccupationally exposed populations. The search was limited to papers published on or after 1998, when the first dedicated funding for mixtures research was granted by NIEHS, through 1 October 2021. Twenty-nine original research studies were identified for review. A notable increase in relevant mixtures publications was observed starting in 2019. The majority of eligible studies were conducted in the United States (n = 10) and China (n = 9). Sample sizes ranged from 127 to 10,818. Many of the included studies were cross-sectional in design. Four primary focus areas included: (i) blood pressure and/or diagnosis of hypertension (n = 15), (ii) risk of preeclampsia (n = 3), (iii) dyslipidemia and/or serum lipid markers (n = 5), and (iv) CVD outcomes, including stroke incidence or coronary heart disease (n = 8). The most frequently investigated metals included cadmium, lead, arsenic, and cobalt, which were typically measured in blood (n = 15). The most commonly utilized multipollutant analysis approaches were Bayesian kernel machine regression (BKMR), weighted quantile sum regression (WQSR), and principal component analysis (PCA). To our knowledge, this is the first scoping review to assess exposure to metal mixtures in relation to CVD risk factors and outcomes. Recommendations for future studies evaluating the associations of exposure to metal mixtures with risk of CVDs and related risk factors include extending environmental mixtures epidemiologic studies to populations with wider metals exposure ranges, including other CVD risk factors or outcomes outside hypertension or dyslipidemia, using repeated measurement of metals to detect windows of susceptibility, and further examining the impacts of potential effect modifiers and confounding factors, such as fish and seafood intake.

Mercury Contamination: A Growing Threat to Riverine and Urban Communities in the Brazilian Amazon

In recent decades, widespread and uncontrolled use of mercury (Hg) in artisanal small-scale gold mining has released thousands of tons of mercury-contaminated waste in the Amazon biome, endangering the largest tropical rainforest worldwide. In this study, we assessed and compared blood Hg levels in individuals living in urban and riverine areas in the lower Tapajós basin and examined the association between Hg exposure and specific biochemical parameters. In total, 462 adults from eight riverine communities and one urban area were assessed. Overall, 75.6% of the participants exhibited Hg concentrations exceeding the safe limit (10 µg/L). Hg exposure was higher in the riverine population (90%) than in urban areas (57.1%). Mean Hg levels were 21.8 ± 30.9 µg/L and 50.6 µg/L in urban and riverine residents, respectively. The mean Hg level was higher in those aged 41–60 years in both urban and riparian areas, with riparian residents exhibiting a mean double that of urban residents. The highest glucose and hepatic biomarker levels were detected in the urban area, whereas the highest levels of renal biomarker occurred in the riverine population. Our results indicate that Hg contamination remains a persistent challenge for the urban population of Santarém, a major city in the Brazilian Amazon.

Uma revisão de escopo de revisões sistemáticas sobre exposição humana ao mercúrio

Resumo: Introdução: a promulgação da Convenção de Minamata no Brasil em 2018 incentivou o cumprimento dos seus objetivos em reduzir o uso e a poluição por mercúrio. Objetivo: caracterizar a produção científica sobre exposição humana ao mercúrio e identificar lacunas de conhecimento a fim de subsidiar a tomada de decisão em saúde. Métodos: revisão de escopo de revisões sistemáticas e metanálises, sem restrição de idioma ou data de publicação, utilizando as bases PubMed, BVS e Cochrane Library. Resultados: 71 estudos atenderam aos critérios de elegibilidade, com 40 revisões sistemáticas, 30 metanálises e 1 overview. Amálgama dentário e contaminação alimentar e ambiental por atividades que utilizam mercúrio foram as fontes de exposição mais mencionadas. Os temas mais estudados contaram com transtornos mentais e comportamentais, assim como uso de biomarcadores e testes neurocomportamentais relacionados à exposição ao mercúrio. Discussão: lacunas como a exposição ocupacional ao mercúrio, uso em práticas tradicionais e em cosméticos apontam para a necessidade de mais estudos. As revisões identificadas podem oferecer subsídios para sínteses de evidências e protocolos de atenção à saúde de populações expostas, assim como para a elaboração de políticas públicas que visem o controle do uso e da exposição ao mercúrio.

Metabolic Syndrome and Endocrine Disrupting Chemicals: An Overview of Exposure and Health Effects

Increasing prevalence of metabolic syndrome (MetS) is causing a significant health burden among the European population. Current knowledge supports the notion that endocrine-disrupting chemicals (EDCs) interfere with human metabolism and hormonal balance, contributing to the conventionally recognized lifestyle-related MetS risk factors. This review aims to identify epidemiological studies focusing on the association between MetS or its individual components (e.g., obesity, insulin resistance, diabetes, dyslipidemia and hypertension) and eight HBM4EU priority substances (bisphenol A (BPA), per- and polyfluoroalkyl substances (PFASs), phthalates, polycyclic aromatic hydrocarbons (PAHs), pesticides and heavy metals (cadmium, arsenic and mercury)). Thus far, human biomonitoring (HBM) studies have presented evidence supporting the role of EDC exposures on the development of individual MetS components. The strength of the association varies between the components and EDCs. Current evidence on metabolic disturbances and EDCs is still limited and heterogeneous, and mainly represent studies from North America and Asia, highlighting the need for well-conducted and harmonized HBM programmes among the European population. Rigorous and ongoing HBM in combination with health monitoring can help to identify the most concerning EDC exposures, to guide future risk assessment and policy actions.

Cadmium exposure induces cardiac glucometabolic dysregulation and lipid accumulation independent of pyruvate dehydrogenase activity

CONTEXT

Suppressed glucose metabolism, elevated fatty acid metabolism and lipid deposition within myocardial cells are the key pathological features of diabetic cardiomyopathy. Studies have associated cadmium exposure with metabolic disturbances.

OBJECTIVE

To examine the effects of cadmium exposure on cardiac glucose homeostasis and lipid accumulation in male Wistar rats.

METHODS

Male Wistar rats were treated for 21 days as (n = 5): Control, cadmium chloride Cd5 (5 mg/kg, p.o.), cadmium chloride Cd30 (30 mg/kg, p.o).

RESULTS

The fasting serum insulin level in this study decreased significantly. Pyruvate and hexokinase activity reduced significantly in the Cd5 group while no significant change in lactate and glycogen levels. The activity of pyruvate dehydrogenase enzyme significantly increased with an increasing dosage of cadmium. The free fatty acid, total cholesterol and triglyceride levels in the heart increased significantly with increasing dosage of cadmium when compared with the control. Lipoprotein lipase activity in the heart showed no difference in the Cd5 group but a reduction in the activity in the Cd30 group was observed.

CONCLUSION

This study indicates that cadmium exposure interferes with cardiac substrate handling resulting in impaired glucometabolic regulation and lipid accumulation which could reduce cardiac efficiency.

The association of arsenic exposure with hypertension and blood pressure: A systematic review and dose-response meta-analysis

Chronic arsenic exposure can induce cardiovascular diseases through oxidative stress injury, inflammation and endothelial dysfunction. However, evidence for hypertension related to chronic arsenic exposure remains limited and inconclusive. To investigate the association of arsenic exposure with hypertension, we reviewed cross-sectional, case-control and longitudinal studies among general population (only excluded pregnant woman and children). Compared with non-exposure (or low exposure) group, we assessed relationship between the exposure (or high exposure) of arsenic and hypertension or blood pressure. We also examined the dose-response relationship to provide a theoretical basis for precision interventions in the population by conducting a two-stage random-effects dose-response meta-analysis. The weighted mean difference (WMD) was calculated to compare the blood pressure of exposed and reference arsenic exposure groups. Twenty-seven studies comprising 117,769 participants were included. The pooled OR and RR for hypertension compared the highest with lowest arsenic exposure categories were 1.14 [95 % confidence interval (CI): 1.06-1.23] and 1.30 [95 % CI: 0.91-1.84], respectively. A dose-response assessment of six studies with the necessary data available demonstrated that the OR of hypertension increased with an increasement of arsenic exposure. The differences in systolic blood pressure levels between the exposed and reference groups were 4.03 mmHg (95 % CI: 1.24-6.82). The meta-analysis further revealed the significant association of chronic arsenic exposure with hypertension among cross-sectional studies and the marginal significance in cohort studies. Besides, arsenic was mainly associated with increasing systolic blood pressure but not significantly related to diastolic blood pressure. We also demonstrated statistical evidence of a nonlinear dose-response association. Details on mechanisms and cohort studies are required to elucidate population-wide health influence of chronic arsenic exposure.

Economic Impacts on Human Health Resulting from the Use of Mercury in the Illegal Gold Mining in the Brazilian Amazon: A Methodological Assessment

Artisanal small-scale gold mining (ASGM) in the Amazon results in the dumping of tons of mercury into the environment annually. Despite consensus on the impacts of mercury on human health, there are still unknowns regarding: (i) the extent to which mercury from ASGM can be dispersed in the environment until it becomes toxic to humans; and (ii) the economic value of losses caused by contamination becomes evident. The main objective of this study is to propose a methodology to evaluate the impacts of ASGM on human health in different contexts in the Brazilian Amazon. We connect several points in the literature based on hypotheses regarding mercury dispersion in water, its transformation into methylmercury, and absorption by fish and humans. This methodology can be used as a tool to estimate the extent of environmental damage caused by artisanal gold mining, the severity of damage to the health of individuals contaminated by mercury and, consequently, can contribute to the application of fines to environmental violators. The consequences of contamination are evaluated by dose-response functions relating to mercury concentrations in hair and the development of the following health outcomes: (i) mild mental retardation, (ii) acute myocardial infarction, and (iii) hypertension. From disability-adjusted life years and statistical life value, we found that the economic losses range from 100,000 to 400,000 USD per kilogram of gold extracted. A case study of the Yanomami indigenous land shows that the impacts of mercury from illegal gold mining in 2020 totaled 69 million USD, which could be used by local authorities to compensate the Yanomami people.

Cardiometabolic risk factors and mercury content in hair of women from a territory distant from mercury-rich geochemical zones (Cherepovets city, Northwest Russia)

For the first time in the Russian Federation, a study was conducted to determine the level of mercury in the hair of young and middle-aged women with or without metabolic syndrome (MS) and the Association of mercury content in hair with cardiometabolic risk factors. The studied cohort consisted of 387 women (204 with metabolic syndrome and 183 without metabolic syndrome as controls). The mercury content in the hair was determined by atomic absorption pyrolysis. The relationship between mercury in hair and cardiometabolic risk factors was evaluated using linear regression. Calculation of the odds ratio (OR) of the risk of metabolic syndrome among quartiles of mercury content in the hair was performed by multiple logistic regression. Hg concentrations in hair were higher in women with metabolic syndrome than without metabolic syndrome (Mean - 520; median - 360; versus Mean - 330; median - 260 µg/kg, P < 0.001). There is an increased risk of developing cardiometabolic syndrome in women, whose hair contain over 544 µg/kg of mercury. The results of this study indicate that the intake of Hg in the human body can be one of the factors that can increase the development of cardiometabolic risk.