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Environmental Health Perspectives Nov 2022The Minamata Convention on Mercury (Article 4) prohibits the manufacture, import, or export of skin-lightening products containing mercury concentrations above .... (Review)
Review
BACKGROUND
The Minamata Convention on Mercury (Article 4) prohibits the manufacture, import, or export of skin-lightening products containing mercury concentrations above . 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 . 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 ) "Mercury in products," ) "Usage of products," ) "Human biomarkers of exposure," and ) "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 ; 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.
Topics: Humans; Mercury; Biomarkers
PubMed: 36367779
DOI: 10.1289/EHP10808 -
International Journal of Environmental... Sep 2022Electronic waste (e-waste) recycling releases mercury (Hg) into the environment, though to our knowledge Hg levels at such sites have yet to be examined on a worldwide... (Meta-Analysis)
Meta-Analysis Review
Electronic waste (e-waste) recycling releases mercury (Hg) into the environment, though to our knowledge Hg levels at such sites have yet to be examined on a worldwide basis. A systematic review of scientific studies was conducted to extract, analyze, and synthesize data on Hg levels in e-waste products, environments near recycling sites, and in people. Data were extracted from 78 studies from 20 countries, and these included Hg levels in 1103 electrical and electronic products, 2072 environmental samples (soil, air, plant, food, water, dust), and 2330 human biomarkers (blood, hair, urine). The average Hg level in products was 0.65 μg/g, with the highest levels found in lamps (578 μg/g). Average soil and sediment Hg levels (1.86 μg/g) at e-waste sites were at least eight times higher than at control sites. Average urinary Hg levels (0.93 μg/g creatinine) were approximately two-fold higher among e-waste workers versus control groups. Collectively, these findings demonstrate that e-waste recycling may lead to Hg contamination in environments and human populations in close proximity to processing sites. These findings contribute to a growing knowledge base of mercury exposure through diverse source-exposure pathways, and the work has potential policy implications in the context of the Minamata Convention.
Topics: Biomarkers; Creatinine; Dust; Electronic Waste; Environmental Monitoring; Humans; Mercury; Soil; Waste Products; Water Pollutants, Chemical
PubMed: 36231146
DOI: 10.3390/ijerph191911843 -
Sleep Medicine Reviews Aug 2023Environmental exposures may influence sleep; however, the contributions of environmental chemical pollutants to sleep health have not been systematically investigated.... (Review)
Review
Environmental exposures may influence sleep; however, the contributions of environmental chemical pollutants to sleep health have not been systematically investigated. We conducted a systematic review to identify, evaluate, summarize, and synthesize the existing evidence between chemical pollutants (air pollution, exposures related to the Gulf War and other conflicts, endocrine disruptors, metals, pesticides, solvents) and dimensions of sleep health (architecture, duration, quality, timing) and disorders (sleeping pill use, insomnia, sleep-disordered breathing)). Of the 204 included studies, results were mixed; however, the synthesized evidence suggested associations between particulate matter, exposures related to the Gulf War, dioxin and dioxin-like compounds, and pesticide exposure with worse sleep quality; exposures related to the Gulf War, aluminum, and mercury with insomnia and impaired sleep maintenance; and associations between tobacco smoke exposure with insomnia and sleep-disordered breathing, particularly in pediatric populations. Possible mechanisms relate to cholinergic signaling, neurotransmission, and inflammation. Chemical pollutants are likely key determinants of sleep health and disorders. Future studies should aim to evaluate environmental exposures on sleep across the lifespan, with a particular focus on developmental windows and biological mechanisms, as well as in historically marginalized or excluded populations.
Topics: Child; Humans; Environmental Pollutants; Sleep Initiation and Maintenance Disorders; Dioxins; Sleep; Sleep Apnea Syndromes
PubMed: 37392613
DOI: 10.1016/j.smrv.2023.101805 -
Revista Brasileira de Ginecologia E... Dec 2022The present review aimed to synthesize the evidence regarding mercury (Hg) exposure and hypertensive disorders of pregnancy (HDP).
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.
Topics: Humans; Pregnancy; Female; Animals; Mercury; Hypertension, Pregnancy-Induced; Maternal Exposure; Biomarkers
PubMed: 36580940
DOI: 10.1055/s-0042-1760215 -
International Journal of Clinical... 2022Scopus and PubMed databases were systematically searched from their inception to November 2021 to obtain pertinent studies. Standardized mean differences (SMDs) with... (Meta-Analysis)
Meta-Analysis Review
METHODS
Scopus and PubMed databases were systematically searched from their inception to November 2021 to obtain pertinent studies. Standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) were calculated to evaluate the difference in Hg levels between people with and without T2DM. The association of the Hg exposure with T2DM was assessed using a random-effects model by pooling the odds ratios (ORs) and 95% CIs.
RESULTS
A total of 17 studies, with 42,917 participants, aged ≥18 years, were analyzed. Overall, Hg levels were significantly higher in T2DM patients compared with non-T2DM controls (SMD = 1.07; 95%CI = 0.59 to 1.55, ≤ 0.001), with significant heterogeneity across studies (I = 96.1%; =≤0.001). No significant association was found between Hg exposure and risk of T2DM in the overall analysis and subgroup analysis based on the source of sample and study design. However, higher exposure to Hg was related to reduced risk of T2DM in men (OR = 0.71; 95%CI = 0.57 to 0.88), but not in women. No significant evidence for publication bias was detected.
CONCLUSIONS
Although the Hg level in T2DM is significantly higher than that of nondiabetics, there was no association between Hg exposure and the overall risk of T2DM. Nevertheless, our study shows that higher exposure to Hg might reduce the risk of T2DM in men.
Topics: Adolescent; Adult; Diabetes Mellitus, Type 2; Female; Humans; Male; Mercury; Odds Ratio
PubMed: 36101810
DOI: 10.1155/2022/7640227 -
Journal of Trace Elements in Medicine... Dec 2017The relationship between mercury and autism spectrum disorders (ASD) has always been a topic of controversy among researchers. This study aimed to assess the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND & AIMS
The relationship between mercury and autism spectrum disorders (ASD) has always been a topic of controversy among researchers. This study aimed to assess the relationship between ASD and mercury levels in hair, urine, blood, red blood cells (RBC), and brain through a meta-analysis.
METHODS
A systematic search was performed in several databases including PubMed, ISI Web of Science, Cochrane register of controlled trials, Google Scholar, Scopus, and MagIran until June 2017. Case-control studies evaluating concentration of total mercury in different tissues of ASD patients and comparing them to the healthy subjects (control group) were identified. Necessary data were extracted and random effects model was used to calculate overall effect and its 95% corresponding confidence interval (CI) from the effect sizes.
RESULTS
A total of 44 studies were identified that met the necessary criteria for meta-analysis. The mercury level in whole blood (Hedges=0.43, 95% CI: 0.12, 0.74, P=0.007), RBC (Hedges=1.61, 95% CI: 0.83, 2.38, P<0.001), and brain (0.61ng/g, 95% CI, 0.02, 1.19, P=0.043) was significantly higher in ASD patients than healthy subjects, whereas mercury level in hair (-0.14mg/g, 95% CI: -0.28, -0.01, P=0.039) was significantly lower in ASD patients than healthy subjects. The mercury level in urine was not significantly different between ASD patients and healthy subjects (0.51mg/g creatinine, 95% CI: -0.14, 1.16, P=0.121).
CONCLUSIONS
Results of the current meta-analysis revealed that mercury is an important causal factor in the etiology of ASD. It seems that the detoxification and excretory mechanisms are impaired in ASD patients which lead to accumulation of mercury in the body. Future additional studies on mercury levels in different tissues of ASD patients should be undertaken.
Topics: Autism Spectrum Disorder; Brain; Child; Child, Preschool; Erythrocytes; Hair; Humans; Mercury
PubMed: 28965590
DOI: 10.1016/j.jtemb.2017.09.002 -
The Science of the Total Environment Jan 2024Prenatal exposure to metal mixtures is associated with adverse pregnancy and birth outcomes like low birth weight, preterm birth, and small for gestational age. However,... (Review)
Review
BACKGROUND
Prenatal exposure to metal mixtures is associated with adverse pregnancy and birth outcomes like low birth weight, preterm birth, and small for gestational age. However, prior studies have used individual metal analysis, lacking real-life exposure scenarios.
OBJECTIVES
This systematic review aims to evaluate the strength and consistency of the association between metal mixtures and pregnancy and birth outcomes, identify research gaps, and inform future studies and policies in this area.
METHODS
The review adhered to the updated Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) checklist, along with the guidelines for conducting systematic reviews and meta-analyses of observational studies of etiology (COSMOS-E). Our data collection involved searching the PubMed, MEDLINE, and SCOPUS databases. We utilized inclusion criteria to identify relevant studies. These chosen studies underwent thorough screening and data extraction procedures. Methodological quality evaluations were conducted using the NOS framework for cohort and case-control studies, and the AXIS tool for cross-sectional studies.
RESULTS
The review included 34 epidemiological studies, half of which focused on birth weight, and the others investigated neonate size, preterm birth, small for gestational age, miscarriage, and placental characteristics. The findings revealed significant associations between metal mixtures (including mercury (Hg), nickel (Ni), arsenic (As), cadmium (Cd), manganese (Mn), cobalt (Co), lead (Pb), zinc (Zn), barium (Ba), cesium (Cs), copper (Cu), selenium (Se), and chromium (Cr)) and adverse pregnancy and birth outcomes, demonstrating diverse effects and potential interactions.
CONCLUSION
In conclusion, this review consistently establishes connections between metal exposure during pregnancy and adverse consequences for birth weight, gestational age, and other vital birth-related metrics. This review further demonstrates the need to apply mixture methods with caution but also shows that they can be superior to traditional approaches. Further research is warranted to deeper understand the underlying mechanisms and to develop effective strategies for mitigating the potential risks associated with metal mixture exposure during pregnancy.
Topics: Female; Humans; Infant, Newborn; Pregnancy; Abortion, Spontaneous; Birth Weight; Cross-Sectional Studies; Fetal Growth Retardation; Mercury; Metals; Placenta; Premature Birth
PubMed: 37963536
DOI: 10.1016/j.scitotenv.2023.168380 -
Environmental Science and Pollution... May 2022The relationship between toxic metals in the environment and clinical stroke risk remains unclear, although their role as immunotoxicants and carcinogens has been well... (Meta-Analysis)
Meta-Analysis Review
The relationship between toxic metals in the environment and clinical stroke risk remains unclear, although their role as immunotoxicants and carcinogens has been well established. We conducted a systematic review of the relationship between five metals (arsenic, mercury, copper, cadmium, and lead) and stroke. First, we comprehensively searched 3 databases (Pubmed, EMBASE, and Cochrane) from inception until June 2021. Random-effects meta-analyses, pooled relative risks (RR) and 95% confidence intervals (CI) were applied to evaluate the effect value. We finally identified 38 studies involving 642,014 non-overlapping participants. Comparing the highest vs. lowest baseline levels, chronic exposure to lead (RR = 1.07; 95%CI,1.00-1.14), cadmium (RR = 1.30; 95%CI,1.13-1.48), and copper (RR = 1.19; 95%CI,1.04-1.36) were significantly associated with stroke risks. However, the other two metals (arsenic and mercury) had less effect on stroke risk. Further analysis indicated that the association was likely in a metal dose-dependent manner. The results may further support the possibility that environmental toxic metal contaminants in recent years are associated with the increased risk of stroke.
Topics: Arsenic; Cadmium; Copper; Heavy Metal Poisoning; Humans; Lead; Mercury; Stroke
PubMed: 35190994
DOI: 10.1007/s11356-022-18866-z -
Association Between Non-alcoholic Fatty Liver Disease and Heavy Metal Exposure: a Systematic Review.Biological Trace Element Research Dec 2023Non-alcoholic fatty liver disease (NAFLD) is a debilitating disease with adverse effects including cirrhosis and hepatocellular carcinoma. Heavy metals can cause severe... (Review)
Review
Non-alcoholic fatty liver disease (NAFLD) is a debilitating disease with adverse effects including cirrhosis and hepatocellular carcinoma. Heavy metals can cause severe dysfunction in different body organs including the liver. This review offers the study regarding the positive or negative association between heavy metals exposure and non-alcoholic fatty liver disease. The method used in this study is a systematic review based on searching in the PubMed, Scopus, and Science direct databases with the keywords of fatty liver, non-alcohol fatty liver, heavy metal, mercury, cadmium, arsenic, chromium, thallium, lead, iron, zinc, and nickel. There were 2200 articles searched in databases, and after assessment, 28 articles were selected. Positive association is established between arsenic, cadmium, iron, lead, mercury, and fatty liver disease. A negative relationship is found between zinc, copper, and progressive fatty liver disease. Furthermore, laboratory methods for NAFLD diagnosis were examined according to the obtained manuscripts. Among the different diagnostic methods, magnetic resonance imaging (MRI) is a sensitive method.
Topics: Humans; Non-alcoholic Fatty Liver Disease; Cadmium; Arsenic; Metals, Heavy; Mercury; Iron; Zinc
PubMed: 36929113
DOI: 10.1007/s12011-023-03629-9 -
Reproductive Toxicology (Elmsford, N.Y.) Apr 2019Evidences from human and animal studies suggest that reproductive function may be affected by mercury. The aim of this review was to explore the mercury influence on...
BACKGROUND
Evidences from human and animal studies suggest that reproductive function may be affected by mercury. The aim of this review was to explore the mercury influence on human fertility.
METHODS
A systematic search was made in PubMED for papers published between 1975-2017, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.
RESULTS
Increased mercury levels were associated with infertility or subfertility status. Further, infertile subjects with unexplained infertility showed higher levels of mercury in hair, blood and urine than fertile ones. Mercury exposure induced sperm DNA damage and abnormal sperm morphology and motility. Additionally, mercury levels were related with higher incidence of menstrual and hormonal disorders and increased rates of adverse reproductive outcomes.
CONCLUSIONS
Our review showed that mercury negatively impacts human reproduction, affecting the reproductive and endocrine systems in both male and female. However, the molecular mechanisms underlying the mercury-associated decline on fertility remains unknown.
Topics: Environmental Pollutants; Female; Fertility; Humans; Male; Mercury; Ovarian Follicle; Reproduction; Reproductive Health; Spermatozoa
PubMed: 30831212
DOI: 10.1016/j.reprotox.2019.02.012