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Environmental Health Perspectives Aug 2023Neural tube defects (NTDs) affect pregnancies worldwide annually. Few nongenetic factors, other than folate deficiency, have been identified that may provide... (Review)
Review
BACKGROUND
Neural tube defects (NTDs) affect pregnancies worldwide annually. Few nongenetic factors, other than folate deficiency, have been identified that may provide intervenable solutions to reduce the burden of NTDs. Prenatal exposure to toxic metals [arsenic (As), cadmium (Cd), mercury (Hg), manganese (Mn) and lead (Pb)] may increase the risk of NTDs. Although a growing epidemiologic literature has examined associations, to our knowledge no systematic review has been conducted to date.
OBJECTIVE
Through adaptation of the Navigation Guide systematic review methodology, we aimed to answer the question "does exposure to As, Cd, Hg, Mn, or Pb during gestation increase the risk of NTDs?" and to assess challenges to evaluating this question given the current evidence.
METHODS
We selected available evidence on prenatal As, Cd, Hg, Mn, or Pb exposure and risk of specific NTDs (e.g., spina bifida, anencephaly) or all NTDs via a comprehensive search across MEDLINE, Embase, Web of Science, and TOXLINE databases and applied inclusion/exclusion criteria. We rated the quality and strength of the evidence for each metal. We applied a customized risk of bias protocol and evaluated the sufficiency of evidence of an effect of each metal on NTDs.
RESULTS
We identified 30 studies that met our criteria. Risk of bias for confounding and selection was high in most studies, but low for missing data. We determined that, although the evidence was limited, the literature supported an association between prenatal exposure to Hg or Mn and increased risk of NTDs. For the remaining metals, the evidence was inadequate to establish or rule out an effect.
CONCLUSION
The role of gestational As, Cd, or Pb exposure in the etiology of NTDs remains unclear and warrants further investigation in high-quality studies, with a particular focus on controlling confounding, mitigating selection bias, and improving exposure assessment. https://doi.org/10.1289/EHP11872.
Topics: Female; Pregnancy; Humans; Cadmium; Lead; Prenatal Exposure Delayed Effects; Neural Tube Defects; Mercury; Manganese; Arsenic
PubMed: 37647124
DOI: 10.1289/EHP11872 -
European Journal of Pediatrics Jan 2022With the progressive elimination of mercury column devices for blood pressure (BP) measurement in children and adolescents, valid alternatives are needed. Oscillometric... (Meta-Analysis)
Meta-Analysis Review
Blood pressure measurement in pediatric population: comparison between automated oscillometric devices and mercury sphygmomanometers-a systematic review and meta-analysis.
With the progressive elimination of mercury column devices for blood pressure (BP) measurement in children and adolescents, valid alternatives are needed. Oscillometric devices provide a replacement without mercury, are fully automated, and have excellent reliability among evaluators. Here, the goal was to test the accuracy of automatic blood pressure monitor devices compared to the mercury sphygmomanometer for BP measurement in children and adolescents. Electronic databases are EMBASE, MEDLINE (PubMed), SCOPUS, and Web of Science. We selected 8974 potentially eligible articles and two authors independently. We separately reviewed 370 full papers. Potentially eligible articles were selected according to the following criteria: (a) articles published in Portuguese, English, and Spanish; (b) screening of titles; (c) screening of abstracts; and (d) retrieval and screening of the full article to determine whether it met the inclusion criteria. We included 45 articles for analysis, 28 of which were selected for meta-analysis. The systolic BP measured by automatic blood pressure monitors presents 1.17 mmHg on average (95% CI 0.85; 1.48); for diastolic BP, it produced -0.08 mmHg (95% CI -0.69; 0.54) compared with a mercury sphygmomanometer. There is high heterogeneity between studies (> 90%) in the meta-analysis, partly explained by the device model, study environment, and observer training. Only articles that reported BP measurement by both methods were included.Conclusion: Automatic blood pressure monitors have strong measurement validity when compared with the mercury column. Thus, these can be safely used in blood pressure measurements of children and adolescents in clinical and epidemiological studies. What is Known: •The "gold standard" for indirect BP measurement is the mercury sphygmomanometer. •The accuracy of the automatic device is critical to any blood pressure measurement method. What is New: •Oscillometric or automatic devices can be a suitable alternative to auscultation for initial screening, consistent with current pediatric guidelines. •The automatic devices compared to the mercury column have a good validity of measurements, which can be used in blood pressure measurements of children and adolescents in clinical and epidemiological settings, provided that international protocols are followed.
Topics: Adolescent; Blood Pressure; Blood Pressure Determination; Blood Pressure Monitors; Child; Humans; Hypertension; Mercury; Reproducibility of Results; Sphygmomanometers
PubMed: 34272985
DOI: 10.1007/s00431-021-04171-3 -
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 -
Chemosphere Feb 2023The various ingredients and impurities that can be detected within tattoo inks have been associated with a myriad of dermatologic complications. Legislation regarding... (Meta-Analysis)
Meta-Analysis Review
The various ingredients and impurities that can be detected within tattoo inks have been associated with a myriad of dermatologic complications. Legislation regarding these antigenic substances varies widely around the world, with Europe serving as both the research and regulatory center on these intradermal formulations. Although industry is said to be moving away from metallic and metalloid pigments in exchange for organic or organometallic dyes, surveys of commercially available inks continue to detect these elements at concentrations considered unsafe for application into the dermis. In order to better assess the formulation and safety of tattoo ink, we present a systematic review and meta-analysis of studies quantifying restricted metals and metalloids in commercially available tattoo ink products. Among the papers selected, inconsistencies were noted in the degree of specificity by which ink products were identified and the elements sampled for. In addition, the analytical targets' valency and/or solubility were not always considered in accordance with regulation criteria. Of note, chromium, by total content and that of its regulated +6 valency, exceeded its maximum allowed concentration in nearly every sample tested. Total copper content exceeded the limit for soluble copper in half of inks sampled. In descending order, concentrations of cadmium, barium, mercury, soluble copper, arsenic, zinc, antimony, and lead violated regulations in one-sixth or fewer of samples tested. Cobalt and tin levels never violated regulation. Overall, our findings indicate that unsafe levels of restricted elements continue to be detected across studies, warranting further investigation under a regulatory lens.
Topics: Tattooing; Ink; Copper; Metalloids; Metals; Coloring Agents
PubMed: 36436582
DOI: 10.1016/j.chemosphere.2022.137291 -
Journal of Clinical and Diagnostic... Oct 2015Utility of various dental materials ranging from diagnosis to rehabilitation for the management of oral diseases are not devoid of posing a potential risk of inducing... (Review)
Review
INTRODUCTION
Utility of various dental materials ranging from diagnosis to rehabilitation for the management of oral diseases are not devoid of posing a potential risk of inducing allergic reactions to the patient, technician and dentist. This review aims to develop a systematic approach for the selection and monitoring of dental materials available in the market thereby giving an insight to predict their risk of inducing allergic reactions.
MATERIALS AND METHODS
Our data included 71 relevant articles which included 60 case reports, 8 prospective studies and 3 retrospective studies. The source of these articles was Pub Med search done with the following terms: allergies to impression materials, sodium hypochlorite, Ledermix paste, zinc oxide eugenol, formaldehyde, Latex gloves, Methyl methacrylate, fissure sealant, composites, mercury, Nickel-chromium, Titanium, polishing paste and local anaesthesia. All the relevant articles and their references were analysed. The clinical manifestations of allergy to different dental materials based on different case reports were reviewed.
RESULTS
After reviewing the literature, we found that the dental material reported to cause most adverse reactions in patients is amalgam and the incidence of oral lichenoid reactions adjacent to amalgam restorations occur more often than other dental materials.
CONCLUSION
The most common allergic reactions in dental staff are allergies to latex, acrylates and formaldehyde. While polymethylmethacrylates and latex trigger delayed hypersensitivity reactions, sodium metabisulphite and nickel cause immediate reactions. Over the last few years, due to the rise in number of patients with allergies from different materials, the practicing dentists should have knowledge about documented allergies to known materials and thus avoid such allergic manifestations in the dental clinic.
PubMed: 26557634
DOI: 10.7860/JCDR/2015/15640.6589 -
Occupational Medicine (Oxford, England) Dec 2017The waste and recycling sector is a growing part of industry. Whether health surveillance is indicated and how it should be undertaken is unclear. (Review)
Review
BACKGROUND
The waste and recycling sector is a growing part of industry. Whether health surveillance is indicated and how it should be undertaken is unclear.
AIMS
To undertake a review of the literature to identify hazards to health, biological effects and occupational illnesses for workers in the sector.
METHODS
A systematic review of the published literature and two UK databases.
RESULTS
Rates of fatal, non-fatal injuries and self-reported work-related illness were found to be higher in the waste and recycling sector than in UK industry as a whole. There was an increased prevalence of respiratory, gastro-intestinal and skin complaints in workers exposed to compost relative to controls. They may also be at increased risk of extrinsic allergic alveolitis, allergic bronchopulmonary aspergillosis, occupational asthma and abnormalities of lung function. Workers involved with the recycling of batteries and cables may be at risk of lead poisoning and exposure to other heavy metals. There were case reports of mercury poisoning from the recycling of fluorescent lights. Cases of occupational asthma have been reported in association with wood and paper recycling. The recycling of e-waste may cause exposure to heavy metals and organic pollutants, such as polybrominated diphenyl ethers, dioxins and polyaromatic hydrocarbons, which have been associated with damage to DNA and adverse neonatal outcomes.
CONCLUSIONS
Ill-health and adverse biological effects have been described in waste and recycling workers, but their true prevalence has probably not been captured. Targeted health surveillance may be required to assess exposure and to identify occupational illness.
Topics: Humans; Manufacturing Industry; Occupational Diseases; Prevalence; Recycling; Waste Disposal Facilities; Workforce
PubMed: 29165683
DOI: 10.1093/occmed/kqx153 -
Progress in Neuro-psychopharmacology &... Oct 2017Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder that affects cognitive and higher cognitive functions. Increasing prevalence of ASD and... (Meta-Analysis)
Meta-Analysis Review
Systematic review and meta-analysis links autism and toxic metals and highlights the impact of country development status: Higher blood and erythrocyte levels for mercury and lead, and higher hair antimony, cadmium, lead, and mercury.
BACKGROUND
Autism spectrum disorder (ASD) is a heterogeneous neurodevelopmental disorder that affects cognitive and higher cognitive functions. Increasing prevalence of ASD and high rates of related comorbidities has caused serious health loss and placed an onerous burden on the supporting families, caregivers, and health care services. Heavy metals are among environmental factors that may contribute to ASD. However, due to inconsistencies across studies, it is still hard to explain the association between ASD and toxic metals. Therefore the objective of this study was to investigate the difference in heavy metal measures between patients with ASD and control subjects.
METHODS
We included observational studies that measured levels of toxic metals (antimony, arsenic, cadmium, lead, manganese, mercury, nickel, silver, and thallium) in different specimens (whole blood, plasma, serum, red cells, hair and urine) for patients with ASD and for controls. The main electronic medical database (PubMed and Scopus) were searched from inception through October 2016.
RESULTS
52 studies were eligible to be included in the present systematic review, of which 48 studies were included in the meta-analyses. The hair concentrations of antimony (standardized mean difference (SMD)=0.24; 95% confidence interval (CI): 0.03 to 0.45) and lead (SMD=0.60; 95% confidence interval (CI): 0.17 to 1.03) in ASD patients were significantly higher than those of control subjects. ASD patients had higher erythrocyte levels of lead (SMD=1.55, CI: 0.2 to 2.89) and mercury (SMD=1.56, CI: 0.42 to 2.70). There were significantly higher blood lead levels in ASD patients (SMD=0.43, CI: 0.02 to 0.85). Sensitivity analyses showed that ASD patients in developed but not in developing countries have lower hair concentrations of cadmium (SMD=-0.29, CI: -0.46 to -0.12). Also, such analyses indicated that ASD patients in developing but not in developed lands have higher hair concentrations of lead (SMD=1.58, CI: 0.80 to 2.36) and mercury (SMD=0.77, CI: 0.31 to 1.23). These findings were confirmed by meta-regression analyses indicating that development status of countries significantly influences the overall effect size of mean difference for hair arsenic, cadmium, lead, and mercury between patients with ASD and controls.
CONCLUSION
The findings help highlighting the role of toxic metals as environmental factors in the etiology of ASD, especially in developing lands. While there are environmental factors other than toxic metals that greatly contribute to the etiology of ASD in developed lands. It would be, thus, expected that classification of ASD includes etiological entities of ASD on the basis of implication of industrial pollutants (developed vs. developing ASD).
Topics: Autism Spectrum Disorder; Developed Countries; Developing Countries; Humans; Metals, Heavy
PubMed: 28716727
DOI: 10.1016/j.pnpbp.2017.07.011 -
Autoimmunity Reviews Jan 2017Autoimmune diseases result from an interplay of genetic predisposition and factors which stimulate the onset of disease. Mercury (Hg), a well-established toxicant, is an... (Review)
Review
Autoimmune diseases result from an interplay of genetic predisposition and factors which stimulate the onset of disease. Mercury (Hg), a well-established toxicant, is an environmental factor reported to be linked with autoimmunity. Hg exists in several chemical forms and is encountered by humans in dental amalgams, certain vaccines, occupational exposure, atmospheric pollution and seafood. Several studies have investigated the effect of the various forms of Hg, including elemental (Hg), inorganic (iHg) and organic mercury (oHg) and their association with autoimmunity. In vitro studies using peripheral blood mononuclear cells (PBMC) from healthy participants have shown that methylmercury (MeHg) causes cell death at lower concentrations than iHg albeit exposure to iHg results in a more enhanced pro-inflammatory profile in comparison to MeHg. In vivo research utilising murine models susceptible to the development of metal-induced autoimmunity report that exposure to iHg results in a lupus-like syndrome, whilst mice exposed to MeHg develop autoimmunity without the formation of immune complexes. Furthermore, lower concentrations of IgE are detected in MeHg-treated animals in comparison with those treated with iHg. It appears that, oHg has a negative impact on animal models with existing autoimmunity. The research conducted on humans in this area is diverse in study design and the results are conflicting. There is currently no evidence to implicate a role for Hg exposure from dental amalgams in the development or perpetuation of autoimmune disease, apart from some suggestion of individual sensitivity. Several studies have consistently shown a positive correlation between iHg exposure and serum autoantibody concentrations in gold miners, although the clinical impact of iHg remains unknown. Furthermore, a limited number of studies have reported individuals with autoimmune disease have higher concentrations of blood Hg compared to healthy controls. In summary, it appears that iHg perpetuates markers of autoimmunity to a greater extent than oHg, albeit the impact on clinical outcomes in humans is yet to be elucidated.
Topics: Animals; Autoimmune Diseases; Autoimmunity; Environmental Exposure; Environmental Pollutants; Humans; Leukocytes, Mononuclear; Mercury
PubMed: 27666813
DOI: 10.1016/j.autrev.2016.09.020 -
Food and Chemical Toxicology : An... Aug 2018Human consumption of fish protein, including canned tuna fish, is increasing steadily worldwide. However, there are some concerns about the potential exposure to... (Meta-Analysis)
Meta-Analysis Review
Human consumption of fish protein, including canned tuna fish, is increasing steadily worldwide. However, there are some concerns about the potential exposure to elevated concentrations of metals in canned tuna fish. Several studies have been conducted in Iran regarding the concentration of metals in seafood, including copper (Cu), selenium (Se), iron (Fe), zinc (Zn), mercury (Hg), lead (Pb), chromium (Cr), arsenic (As), nickel (Ni), tin (Sn), and cadmium (Cd) in canned tuna fish. The main aim of this study was to gather data from existing papers and to perform a meta-analysis of the pooled concentrations of metals to evaluate their non-carcinogenic and carcinogenic risks in children and adults consumers. Search was conducted retrieving data from the international biomedical databases with highly public access and consultation, e.g., Web of Science, PubMed, Science Direct, and Scopus, and national database (SID and Irandoc) between 1983 and November of 2017. Data from 23 articles and 1295 samples were assessed and extracted. The ranking order of metals based on mean concentrations (μg/g wet weight) were Fe (13.17) > Zn (9.31) > Se (2.23) > Al (1.8) > Cr (1.63) > Cu (1.52) > As (0.38) > Ni (0.33) > Pb (0.24) > Cd (0.14) > Hg (0.11) > Sn (0.1). Except for Cd and Se, concentrations of other metals in the canned tuna fish were lower than the limits recommended by the United States Environmental Protection Agency (USEPA), World Health Organization (WHO), Food and Agriculture Organization (FAO) and Iran National Standards Organization (INSO). The minimum and maximum target hazard quotient (THQ) for adults were 5.55E-5 for Al and 2.23E-08 for Cr. For children, they were 7.23E-05 for Al and 2.91E-08 for Cr. THQ, and total target hazard quotient (TTHQ) were ≤1.0 for adult and children consumers. The Incremental Lifetime Cancer Risk (ILCR) of As was 3.21E-5 in adults and 4.18E-5 in children. Adults and children that consume canned tuna fish in Iran are not at non-carcinogenic risk but have a carcinogenic risk due to As.
Topics: Animals; Carcinogens; Dietary Exposure; Food Handling; Humans; Iran; Metals; Risk Assessment; Seafood; Tuna
PubMed: 29913231
DOI: 10.1016/j.fct.2018.06.023 -
Circulation. Cardiovascular Quality and... Apr 2023Behavioral weight management programs (BWMPs) enhance weight loss in the short term, but longer term cardiometabolic effects are uncertain as weight is commonly... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Behavioral weight management programs (BWMPs) enhance weight loss in the short term, but longer term cardiometabolic effects are uncertain as weight is commonly regained. We assessed the impact of weight regain after BWMPs on cardiovascular risk factors, diabetes, and cardiovascular disease.
METHODS
Trial registries, 11 databases, and forward-citation searching (latest search, December 19) were used to identify articles published in English, from any geographical region. Randomized trials of BWMPs in adults with overweight/obesity reporting cardiometabolic outcomes at ≥12 months at and after program end were included. Differences between more intensive interventions and comparator groups were synthesized using mixed-effects, meta-regression, and time-to-event models to assess the impact of weight regain on cardiovascular disease incidence and risk.
RESULTS
One hundred twenty-four trials reporting on ≥1 cardiometabolic outcomes with a median follow-up of 28 (range, 11-360) months after program end were included. Median baseline participant body mass index was 33 kg/m; median age was 51 years. Eight and 15 study arms (7889 and 4202 participants, respectively) examined the incidence of cardiovascular disease and type 2 diabetes, respectively, with imprecise evidence of a lower incidence for at least 5 years. Weight regain in BWMPs relative to comparators reduced these differences. One and 5 years after program end, total cholesterol/HDL (high-density lipoprotein) ratio was 1.5 points lower at both times (82 studies; 19 003 participants), systolic blood pressure was 1.5 mm mercury and 0.4 mm lower (84 studies; 30 836 participants), and HbA1c (%) 0.38 lower at both times (94 studies; 28 083 participants). Of the included studies, 22% were judged at high risk of bias; removing these did not meaningfully change results.
CONCLUSIONS
Despite weight regain, BWMPs reduce cardiometabolic risk factors with effects lasting at least 5 years after program end and dwindling with weight regain. Evidence that they reduce the incidence of cardiovascular disease or diabetes is less certain. Few studies followed participants for ≥5 years.
REGISTRATION
URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42018105744.
Topics: Adult; Humans; Middle Aged; Diabetes Mellitus, Type 2; Cardiovascular Diseases; Incidence; Weight Reduction Programs; Weight Gain
PubMed: 36974678
DOI: 10.1161/CIRCOUTCOMES.122.009348