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Journal of Diabetes and Metabolic... Jun 2024Obesity and metabolic syndrome are global health concerns associated with development of different types of diseases and serious health threats in the long term. Their... (Review)
Review
BACKGROUND
Obesity and metabolic syndrome are global health concerns associated with development of different types of diseases and serious health threats in the long term. Their metabolic imbalance can be attributable to inherited and environmental factors. As a considerable environmental agent, heavy metals exposure can predispose individuals to diseases like obesity. This systematic review and meta-analysis aimed to evaluate the association between heavy metals exposure and the risk of obesity.
METHODS
PubMed/MEDLINE, EMBASE and Web of Science were systematically searched until December 17, 2022. Only observational studies that evaluated heavy metals exposure and obesity were included. Studies were excluded if they assessed maternal or prenatal exposure, the mixture of heavy metals and other chemicals, reported the association with overweight or other diseases, and undesirable study designs. The Joanna Briggs Institute checklist was used for quality assessment. The pooled adjusted odds ratio (aOR) and the pooled standardized mean difference (SMD) with their 95% confidence intervals (CIs) were calculated, respectively. The publication bias was evaluated using Egger's and Begg's tests.
RESULTS
Twenty studies (n = 127755), four case-control and sixteen analytical cross-sectional studies, were included. Lead exposure was significantly associated with a lower risk of obesity (aOR: 0.705, 95% CI: 0.498-0.997), while mercury (aOR: 1.458, 95% CI: 1.048-2.031) and barium (aOR: 1.439, 95% CI: 1.142-1.813) exposure increased the risk of obesity. No significant publication bias was found and the studies had a low risk of bias.
CONCLUSION
Overall, lead exposure reduced obesity risk, while mercury and barium exposure raised it. Further large-scale observational studies are recommended to determine the roles of heavy metals in obesity.Study registration ID: CRD42023394865.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s40200-023-01307-0.
PubMed: 38932800
DOI: 10.1007/s40200-023-01307-0 -
Exposure to Mercury in the Air and Its Effect on Cardiovascular Diseases (CVD): A Systematic Review.Iranian Journal of Public Health May 2024We aimed to verify the exposure to mercury in the air and its effect on cardiovascular disorders. (Review)
Review
BACKGROUND
We aimed to verify the exposure to mercury in the air and its effect on cardiovascular disorders.
METHODS
The review was conducted using PubMed, Scopus, Web of Science, Embase, and national databases (such as SID) from 1995-2022.
RESULTS
Mercury exposure can cause many disorders in humans, including neurodevelopmental disorders in fetuses and children, adverse cardiovascular outcomes, hypertension, and diabetes. Mercury is a human neurotoxin, and in recent years its potentially harmful effects on cardiovascular disease (CVD) have raised concerns, mainly due to mercury's role in reducing oxidative stress.
CONCLUSION
Possible mechanisms of mercury toxicity in CVD include mercury-selenium interaction, increased lipid peroxidation, and oxidative stress. In this article, we review studies that have investigated the relationship between mercury and CVD.
PubMed: 38912156
DOI: 10.18502/ijph.v53i5.15583 -
ACS Omega Jun 2024Heavy metal ions (HMIs) are very harmful to the ecosystem when they are present in excess of the recommended limits. They are carcinogenic in nature and can cause... (Review)
Review
Heavy metal ions (HMIs) are very harmful to the ecosystem when they are present in excess of the recommended limits. They are carcinogenic in nature and can cause serious health issues. So, it is important to detect the metal ions quickly and accurately. The metal ions arsenic (As), cadmium (Cd), chromium (Cr), lead (Pb), and mercury (Hg) are considered to be very toxic among other metal ions. Standard analytical methods like atomic absorption spectroscopy, atomic fluorescence spectroscopy, and X-ray fluorescence spectroscopy are used to detect HMIs. But these methods necessitate highly technical equipment and lengthy procedures with skilled personnel. So, electrochemical sensing methods are considered to be more advantageous because of their quick analysis with precision and simplicity to operate. They can detect a wide range of heavy metals providing real-time monitoring and are cost-effective and enable multiparametric detection. Various sensing applications necessitate severe regulation regarding the modification of electrode surfaces. Numerous nanomaterials such as graphene, carbon nanotubes, and metal nanoparticles have been extensively explored as interface materials in electrode modifiers. These nanoparticles offer excellent electrical conductivity, distinctive catalytic properties, and high surface area resulting in enhanced electrochemical performance. This review examines different HMI detection methods in an aqueous medium by an electrochemical sensing approach and studies the recent developments in interface materials for altering the electrodes.
PubMed: 38911761
DOI: 10.1021/acsomega.4c00933 -
Environmental Pollution (Barking, Essex... Jun 2024Bats constitute about 22% of known mammal species; they have various ecological roles and provide many ecosystem services. Bats suffer from several threats caused by... (Review)
Review
Bats constitute about 22% of known mammal species; they have various ecological roles and provide many ecosystem services. Bats suffer from several threats caused by anthropization, including exposure to toxic metals and metalloids. We analyzed 75 papers in a systematic literature review to investigate how species, diet, and tissue type impact bioaccumulation. Most studies documented element accumulation in fur, liver, and kidney; at least 36 metals and metalloids have been measured in bat tissues, among the most studied were mercury and zinc. Comparisons with known toxicological thresholds for other mammals showed concerning values for mercury and zinc in bat hair, lead and some essential metals in liver, and iron and calcium in kidneys. Moreover, accumulation patterns in tissues differed depending on bat diet: insectivorous bats showed higher metal concentrations in fur than in liver and kidney while frugivorous species showed higher values in liver and kidney than in fur. Finally, among the bat species that have been studied in more than two papers, the big brown bat (Eptesicus fuscus) show values of mercury in hair and copper in liver that exceed the known thresholds; as does copper in the liver of the little brown bat (Myotis lucifugus). Most studies have been conducted in temperate North America and Eurasia, areas with the lowest bat species diversity; there is a paucity of data on tropical bat species. This review points out several information gaps in the understanding of metal contamination in bats, including a lack of measured toxicity thresholds specific for bat tissues. Data on trace element bioaccumulation and its associated health effects on bats is important for conservation of bat species, many of which are threatened.
PubMed: 38866315
DOI: 10.1016/j.envpol.2024.124349 -
Pharmacological Research Jul 2024Nonalcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease worldwide. Epidemiological studies have reported that exposure of the... (Meta-Analysis)
Meta-Analysis Review
Nonalcoholic fatty liver disease (NAFLD) is one of the leading causes of chronic liver disease worldwide. Epidemiological studies have reported that exposure of the population to environmental endocrine-disrupting chemicals (EDCs) is associated with NAFLD. However, EDCs are of different types, and there are inconsistencies in the relevant evidence and descriptions, which have not been systematically summarized so far. Therefore, this study aimed to determine the association between population exposure to EDCs and NAFLD. Three databases, including PubMed, Web of science, and Embase were searched, and 27 articles were included in this study. Methodological quality, heterogeneity, and publication bias of the included studies were assessed using the Newcastle-Ottawa scale, I statistics, Begg's test, and Egger's test. The estimated effect sizes of the included studies were pooled and evaluated using the random-effects model (I > 50 %) and the fixed-effects model ( I < 50 %). The pooled-estimate effect sizes showed that population exposure to Phthalates (PAEs) (OR = 1.18, 95 % CI:1.03-1.34), cadmium (Cd) (OR = 1.37, 95 % CI:1.09-1.72), and bisphenol A (OR = 1.43, 95 % CI:1.24-1.65) were positively correlated with the risk of NAFLD. Exposure to mercury (OR =1.46, 95 % CI:1.17-1.84) and Cd increased the risk of "elevated alanine aminotransferase". On the contrary, no significant association was identified between perfluoroalkyl substances (OR =0.99, 95 % CI:0.93-1.06) and NAFLD. However, female exposure to perfluorooctanoic acid (OR =1.82, 95 % CI:1.01-3.26) led to a higher risk of NAFLD than male exposure. In conclusion, this study revealed that EDCs were risk factors for NAFLD. Nonetheless, the sensitivity analysis results of some of the meta-analyses were not stable and demonstrated high heterogeneity. The evidence for these associations is limited, and more large-scale population-based studies are required to confirm these findings.
Topics: Non-alcoholic Fatty Liver Disease; Humans; Endocrine Disruptors; Phthalic Acids; Environmental Pollutants; Phenols; Benzhydryl Compounds; Cadmium; Fluorocarbons
PubMed: 38862070
DOI: 10.1016/j.phrs.2024.107251 -
Environmental exposure to metal(loid)s and hypertensive disorders of pregnancy: A systematic review.Environmental Research Jun 2024Environmental 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... (Review)
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.
PubMed: 38857855
DOI: 10.1016/j.envres.2024.119391 -
Journal of Applied Microbiology Jun 2024Antimicrobial-resistance genes (ARGs) are spread among bacteria by horizontal gene transfer, however, the effect of environmental factors on the dynamics of the ARG in...
Antimicrobial-resistance genes (ARGs) are spread among bacteria by horizontal gene transfer, however, the effect of environmental factors on the dynamics of the ARG in water environments has not been very well understood. In this systematic review, we employed the regression tree algorithm to identify the environmental factors that facilitate/inhibit the transfer of ARGs via conjugation in planktonic/biofilm-formed bacterial cells based on the results of past relevant research. Escherichia coli strains were the most studied genus for conjugation experiments as donor/recipient in the intra-genera category. Conversely, Pseudomonas spp., Acinetobacter spp., and Salmonella spp. were studied primarily as recipients across inter-genera bacteria. The conjugation efficiency (ce) was found to be highly dependent on the incubation period. Some antibiotics, such as nitrofurantoin (at ≥0.2 µg ml-1) and kanamycin (at ≥9.5 mg l-1) as well as metallic compounds like mercury (II) chloride (HgCl2, ≥3 µmol l-1), and vanadium (III) chloride (VCl3, ≥50 µmol l-1) had enhancing effect on conjugation. The highest ce value (-0.90 log10) was achieved at 15°C-19°C, with linoleic acid concentrations <8 mg l-1, a recognized conjugation inhibitor. Identifying critical environmental factors affecting ARG dissemination in aquatic environments will accelerate strategies to control their proliferation and combat antibiotic resistance.
Topics: Gene Transfer, Horizontal; Anti-Bacterial Agents; Conjugation, Genetic; Bacteria; Drug Resistance, Bacterial; Water Microbiology; Escherichia coli; Genes, Bacterial; Acinetobacter; Biofilms
PubMed: 38830804
DOI: 10.1093/jambio/lxae129 -
Reproductive Toxicology (Elmsford, N.Y.) Jun 2024The primary route of mercury exposure for the general population is through consumption of contaminated seafood. There is a biological basis for an adverse effect of... (Review)
Review
The primary route of mercury exposure for the general population is through consumption of contaminated seafood. There is a biological basis for an adverse effect of mercury exposure on human fertility. The goal of this review was to evaluate the existing literature on the association between mercury and pregnancy, among men and women attempting to conceive with and without assisted reproductive technology (ART). Systematic searches were performed in PubMed, EMBASE, Scopus and Web of Science for papers published up to March 2023 with no early date restriction, only including studies with a biomarker measurement of mercury exposure. We identified 11 studies examining mercury and natural fertility and 12 studies examining mercury and outcomes of assisted reproduction (implantation or clinical pregnancy). The accumulated evidence provides some support for a null association between bodily mercury concentrations and natural fertility among women, however, a large proportion of studies did not report adjusted estimates or were extremely imprecise. The majority of studies of natural fertility were also cross-sectional in nature. There was no evidence for an inverse or null association between mercury and natural fertility among men, or mercury and ART outcomes among men or women. In spite of biological plausibility, the existing evidence includes studies that are imprecise and often conflicting and does not allow us to make definitive conclusions on the associations of mercury exposure with successful pregnancy. Additional, larger studies are warranted, especially among individuals with high concentrations of mercury exposure as these individuals may be underrepresented in the current literature.
PubMed: 38830454
DOI: 10.1016/j.reprotox.2024.108613 -
Toxicology Research Apr 2024Selenium is an important and essential trace element in organisms, but its effects on organisms are also a "double-edged sword". Selenium deficiency or excess can... (Review)
Review
Selenium is an important and essential trace element in organisms, but its effects on organisms are also a "double-edged sword". Selenium deficiency or excess can endanger the health of humans and animals. In order to thoroughly understand the nutritional value and toxicity hazards of selenium, researchers have conducted many studies on the model animal zebrafish. However, there is a lack of induction and summary of relevant research on which selenium acts on zebrafish. This paper provides a review of the reported studies. Firstly, this article summarizes the benefits of selenium on zebrafish from three aspects: Promoting growth, Enhancing immune function and anti-tumor ability, Antagonizing some pollutants, such as mercury. Then, three aspects of selenium toxicity to zebrafish are introduced: nervous system and behavior, reproductive system and growth, and damage to some organs. This article also describes how different forms of selenium compounds have different effects on zebrafish health. Finally, prospects for future research directions are presented.
PubMed: 38645626
DOI: 10.1093/toxres/tfae062 -
The Science of the Total Environment Jun 2024Children are at high risk for exposure to toxic metals and are vulnerable to their effects. Significant research has been conducted evaluating the role of these metals... (Review)
Review
BACKGROUND
Children are at high risk for exposure to toxic metals and are vulnerable to their effects. Significant research has been conducted evaluating the role of these metals on immune dysfunction, characterized by biologic and clinical outcomes. However, there are inconsistencies in these studies. The objective of the present review is to critically evaluate the existing literature on the association between toxic metals (lead, mercury, arsenic, and cadmium) and pediatric immune dysfunction.
METHODS
Seven databases (PubMed (NLM), Embase (Elsevier), CINAHL (Ebsco), Web of Science (Clarivate Analytics), ProQuest Public Health Database, and ProQuest Environmental Science Collection) were searched following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines in February 2024. Rayaan software identified duplicates and screened by title and abstract in a blinded and independent review process. The remaining full texts were reviewed for content and summarized. Exclusions during the title, abstract, and full-text reviews included: 1) not original research, 2) not epidemiology, 3) did not include toxic metals, 4) did not examine an immune health outcome, or 5) not pediatric (>18 years). This systematic review protocol followed the PRISMA guidelines. Rayaan was used to screen records using title and abstract by two blinded and independent reviewers. This process was repeated for full-text article screening selection.
RESULTS
The search criteria produced 7906 search results; 2456 duplicate articles were removed across search engines. In the final review, 79 studies were included which evaluated the association between toxic metals and outcomes indicative of pediatric immune dysregulation.
CONCLUSIONS
The existing literature suggests an association between toxic metals and pediatric immune dysregulation. Given the imminent threat of infectious diseases demonstrated by the recent COVID-19 epidemic in addition to increases in allergic disease, understanding how ubiquitous exposure to these metals in early life can impact immune response, infection risk, and vaccine response is imperative.
Topics: Humans; Child; Environmental Exposure; Metals, Heavy; Immune System Diseases; Environmental Pollutants; Arsenic; Child, Preschool; Adolescent; Metals
PubMed: 38599398
DOI: 10.1016/j.scitotenv.2024.172303