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SAGE Open Medicine 2022There are an estimated 5 million children working in artisanal and small-scale gold mines worldwide; however, the hazards are poorly characterized and often... (Review)
Review
There are an estimated 5 million children working in artisanal and small-scale gold mines worldwide; however, the hazards are poorly characterized and often underreported. We systematically reviewed the literature on reports of hazards among children as a consequence of such activities through PubMed database using pre-defined search terms. We identified 113 articles published between 1984 and 2021 from 31 countries. Toxicological hazards were reported in 91 articles, including mercury, lead, and arsenic. Infectious hazards, noted in 18 articles, included malaria, cholera, and hepatitis. Six articles reported occupational hazards, including malnutrition, heat stroke, and reactive airway disease. Three articles reported traumatic hazards, including cave-ins, burns, animal attacks, falls, and weapon-inflected wounds. Those findings likely indicate a profound underreporting of the prevalence and consequences of such hazards among children. More work is needed both to characterize the burdens of those hazards and to address the underlying drivers of child labor in those settings.
PubMed: 35173966
DOI: 10.1177/20503121221076934 -
Environmental Pollution (Barking, Essex... Feb 2023Anthropogenic activities contribute to nearly half of current Hg emissions to the atmosphere. In the marine habitat, oceanic predator fishes bioaccumulate Hg throughout... (Review)
Review
Anthropogenic activities contribute to nearly half of current Hg emissions to the atmosphere. In the marine habitat, oceanic predator fishes bioaccumulate Hg throughout their lives, making their consumption the main route of Hg exposure in humans. In this context, several publications, between 1973 and 2022, were selected, analyzed, and duly compiled, with the objective to investigate Hg contamination in nine species of bony fish: Thunnus thynnus (8 publications), Thunnus albacares (19), Thunnus obesus (7), Thunnus atlanticus (5), Thunnus alalunga (4), Katsuwonus pelamis (8), Xiphias gladius (18), Coryphaena hippurus (7) and Euthynnus alletteratus (4), as well as two species of cartilaginous fishes Prionace glauca (13 publications) and Isurus oxyrinchus (8). These studies totaled 5973 individuals. We classified species according to taxonomic groups and region of capture and found a significant difference between sharks and bony fishes, with higher Hg concentrations in sharks. The regions of occurrence were divided into 4 large areas (North Atlantic - NAO, South Atlantic - SAO, Equatorial Atlantic Ocean - EAO, and Mediterranean - MED), but no significant differences were observed when comparing the overall Hg concentrations in fish among regions (including all species). Additionally, a thorough discussion of the risks associated with human consumption of these species was conducted, as nine of the selected species presented individuals with Hg concentration values that exceeded the safety limits (1 ppm) set by health agencies worldwide.
Topics: Animals; Humans; Mercury; Sharks; Tuna; Oceans and Seas; Fishes
PubMed: 36509349
DOI: 10.1016/j.envpol.2022.120821 -
Chemical Research in Toxicology Nov 2020Autism spectrum disorder (ASD) is a complex neurobehavioral disorder that is believed to be multifactorial in origin. As the incidence of ASD is rising along with... (Meta-Analysis)
Meta-Analysis
Autism spectrum disorder (ASD) is a complex neurobehavioral disorder that is believed to be multifactorial in origin. As the incidence of ASD is rising along with industrialization, and because certain metals have been linked to neurological problems, it is important to consider whether such metals may play a role in the development of ASD. Previously, we performed a meta-analysis of existing literature to examine the potential link between inorganic arsenic and lead exposure and ASD. This is a continuation of that study investigating the association of the exposure to aluminum (Al), cadmium (Cd), and mercury (Hg) and ASD. These metals were chosen because they are abundant in our environment, are known to cause neurological problems in humans, and have multiple published studies examining their potential links with ASD. Following the same approach as our previous paper, we conducted a systematic review of the existing literature and performed a meta-analysis to evaluate the current evidence regarding these metals and their potential relationship with autism. We reviewed 18 studies on Al, 18 on Cd, and 23 on Hg, and the individual studies showed inconsistent results. When the measurements were integrated into the meta-analysis, we found significant associations between all the metals and ASD, but the associations were not always in the same direction. Levels of Hg in hair, urine, and blood were all positively associated with ASD. Levels of Al in hair and urine were positively associated with ASD, while levels of Al in blood were negatively associated. In comparison, levels of Cd in hair and urine were negatively associated with ASD. These results imply that, while these metals are all neurotoxic, their impact on the development of ASD and their modes of action could be different. Further research is warranted to examine the longitudinal effects of these toxic metals on the risk of ASD, to assess the critical period when exposure may affect development, and to investigate potential factors that may enhance or ameliorate the effect of metals. Overall, these findings support policies that advocate limiting exposure to neurotoxic metals, particularly for pregnant women and young children, in order to help reduce the rising incidence of ASD.
Topics: Aluminum; Autism Spectrum Disorder; Cadmium; Child; Humans; Mercury
PubMed: 32990432
DOI: 10.1021/acs.chemrestox.0c00167 -
Annals of Translational Medicine Jan 2023Recent studies have shown that the relationship between mercury exposure and diabetes is controversial. The aim of this study is to determine the relationship between...
BACKGROUND
Recent studies have shown that the relationship between mercury exposure and diabetes is controversial. The aim of this study is to determine the relationship between mercury exposure and diabetes using a systematic review and meta-analysis approach.
METHODS
We systematically searched PubMed, Web of Science, Cochrane, and Embase databases for cross-sectional, case-control, or cohort studies assessing the correlation between mercury exposure and diabetes in any population. Details of each included study were extracted using a pre-designed Excel spreadsheet. Quality assessment of cohort and case-control studies used the Newcastle-Ottawa Scale (NOS), whereas cross-sectional studies were assessed by the Agency for Healthcare Research and Quality (AHRQ) scale. Meta-analyses were performed using random-effects models to calculate the pooled odds ratio (OR), standardized mean difference (SMD), and their 95% confidence intervals (CIs). Subgroup and sensitivity analyses were employed to assess heterogeneity sources. Begg's and Egger's tests were used to evaluate publication bias.
RESULTS
Our meta-analysis included 8 eligible articles, comprising a total of 40,891 subjects, reporting mercury OR and/or concentrations. Among the included studies, one was a case control, one was a cohort study, and the rest were cross-sectional studies. Two studies were rated as high quality and six as medium quality. The results revealed no link between mercury exposure and diabetes (OR: 1.11, 95% CI: 0.80, 1.55, n=6, I=73.7%; and SMD: 0.41, 95% CI: -0.32, 1.14, n=3, I=88.7%). In the stratified male and female subgroups, the pooled OR was 0.71 (95% CI: 0.57, 0.90, n=3, I=0.0%), 1.11 (95% CI: 0.69, 1.79, n=3, I=67.7%). The Begg's test results revealed no significant publication bias (P=0.06), but the Egger's test results did (P=0.013). The sensitivity analysis confirmed the stability of our results.
CONCLUSIONS
No significant relationship was observed between mercury and diabetes mellitus. However, more well-designed studies on mercury exposure and diabetes risk are still needed, particularly on the type of mercury (i.e., elemental, inorganic, and organic), exposure time and dose, type of biological specimen, and the population's sex and age.
PubMed: 36819500
DOI: 10.21037/atm-22-6404 -
Biological Trace Element Research Feb 2022Metals, many of which are potentially toxic, are present in the aquatic environment originated from both natural and anthropogenic sources. In these ecosystems, these... (Review)
Review
Metals, many of which are potentially toxic, are present in the aquatic environment originated from both natural and anthropogenic sources. In these ecosystems, these elements are mostly deposited in the sediment, followed by water dissolution, potentially contaminating resident biota. Among several aquatic animals, crustaceans are considered excellent bioindicators, as they live in close contact with contaminated sediment. The accumulation of metal, whether they are classified as essential, when in excessive quantities or nonessential, not only cause damage to the health of these animals, but also to the man who consumes seafood. Among the main toxic elements to animal and human health are aluminum, arsenic, cadmium, chromium, copper, lead, mercury, nickel and silver. In this context, this systematic review aimed to investigate the dynamics of these metals in water, the main bioaccumulative tissues in crustaceans, the effects of these contaminants on animal and human health, and the regulatory limits for these metals worldwide. A total of 91 articles were selected for this review, and an additional 68 articles not found in the three assessed databases were considered essential and included, totaling 159 articles published between 2010 and 2020. Our results indicate that both chemical speciation and abiotic factors such as pH, oxygen and salinity in aquatic environments affect element bioavailability, dynamics, and toxicity. Among crustaceans, crabs are considered the main bioindicator biological system, with the hepatopancreas appearing as the main bioaccumulator organ. Studies indicate that exposure to these elements may result in nervous, respiratory, and reproductive system effects in both animals and humans. Finally, many studies indicate that the concentrations of these elements in crustaceans intended for human consumption exceed limits established by international organizations, both with regard to seafood metal contents and well as daily, weekly, or monthly intake limits set for humans, indicating consumer health risks.
Topics: Animals; Ecosystem; Environmental Biomarkers; Environmental Monitoring; Humans; Metals; Risk Assessment; Seafood; Water Pollutants, Chemical
PubMed: 33788164
DOI: 10.1007/s12011-021-02685-3 -
Journal of Biomedical Physics &... Jun 2022Approximately 50% of dental amalgam is elemental mercury by weight. Accumulating body of evidence now shows that not only static magnetic fields (SMF) but both ionizing...
BACKGROUND
Approximately 50% of dental amalgam is elemental mercury by weight. Accumulating body of evidence now shows that not only static magnetic fields (SMF) but both ionizing and non-ionizing electromagnetic radiations can increase the rate of mercury release from dental amalgam fillings. Iranian scientists firstly addressed this issue in 2008 but more than 10 years later, it became viral worldwide.
OBJECTIVE
This review was aimed at evaluating available data on the magnitude of the effects of different physical stressors (excluding chewing and brushing) on the release of toxic mercury from dental amalgam fillings and microleakage.
MATERIAL AND METHODS
The papers reviewed in this study were searched from PubMed, Google Scholar, and Scopus (up to 1 December 2019). The keywords were identified from our initial research matching them with those existing on the database of Medical Subject Headings (MeSH). The non-English papers and other types of articles were not included in this review.
RESULTS
Our review shows that exposure to static magnetic fields (SMF) such as those generated by MRI, electromagnetic fields (EMF) such as those produced by mobile phones; ionizing electromagnetic radiations such as X-rays and non- Ionizing electromagnetic radiation such as lasers and light cure devices can significantly increase the release of mercury from dental amalgam restorations and/or cause microleakage.
CONCLUSION
The results of this review show that a wide variety of physical stressors ranging from non-ionizing electromagnetic fields to ionizing radiations can significantly accelerate the release of mercury from amalgam and cause microleakage.
PubMed: 35698539
DOI: 10.31661/jbpe.v0i0.2009-1175 -
Critical Reviews in Toxicology Feb 2021We performed a systematic review and meta-analysis to examine the relationship between heavy metals (HMs) exposure and the risk of chronic kidney disease (CKD).... (Meta-Analysis)
Meta-Analysis
We performed a systematic review and meta-analysis to examine the relationship between heavy metals (HMs) exposure and the risk of chronic kidney disease (CKD). Databases of Web of Science, Embase, MEDLINE, and Scopus were searched through June 2020 to identify studies assessing the relationships between exposure to HMs (i.e. cadmium, lead, arsenic, mercury) and the risk of CKD, evaluated by decreased estimated glomerular filtration rate (eGFR) and/or increased proteinuria risks in adults (≥18 years). Data were pooled by random-effects models and expressed as weighted mean differences and 95% confidence intervals. The risk of bias was assessed by the Newcastle-Ottawa scale (NOS). Twenty-eight eligible articles ( = 107,539 participants) were included. Unlike eGFR risk ( = 0.10), Cadmium exposure was associated with an increased proteinuria risk (OR = 1.35; 95% CI: 1.13, 1.61; < 0.001; = 79.7%). Lead exposure was associated with decreased eGFR (OR = 1.12; 95%CI: 1.03, 1.22; = 0.008; = 87.8%) and increased proteinuria (OR = 1.25; 95% CI: 1.04, 1.49; = 0.02; = 79.6) risks. Further, arsenic exposure was linked to a decreased eGFR risk (OR = 1.55; 95% CI: 1.05, 2.28; = 0.03; = 89.1%) in contrast to mercury exposure ( = 0.89). Only two studies reported the link between arsenic exposure and proteinuria risk, while no study reported the link between mercury exposure and proteinuria risk. Exposure to cadmium, lead, and arsenic may increase CKD risk in adults, albeit studies were heterogeneous, warranting further investigations. Our observations support the consideration of these associations for preventative, diagnostic, monitoring, and management practices of CKD.
Topics: Environmental Exposure; Environmental Pollutants; Humans; Metals, Heavy; Renal Insufficiency, Chronic
PubMed: 33960873
DOI: 10.1080/10408444.2021.1891196 -
Journal of Environmental Health Science... Jun 2020Exposure to mercury is one of the major global health concerns due to its stability, bioaccumulation and high toxicity. Therefore, the present study was conducted to... (Review)
Review
Exposure to mercury is one of the major global health concerns due to its stability, bioaccumulation and high toxicity. Therefore, the present study was conducted to assess the mean mercury level in hair and breast milk (BM) of Iranian lactating mothers (ILMs) through meta-analysis technique. We conducted a systematic literature search in online electronic databases included main domestic databases (SID, Magiran, Iran medex, Medlib and ISC) and international databases (Embase, Scopus and PubMed) for studies published between 2000 up 2018. Each process of research and evaluation of articles based on inclusion and exclusion criteria is done by two researchers, individually. From10 studies entered to meta-analysis process including 556 ILM, the mean hair mercury level (HML) and mean milk mercury level (MML) was estimated to be 0.15 μg/g (95 CI: 0.11-0.19, I2: 47.6%, P: 0.028) and 0.51 μg/l (95 CI: 0.28-0.74, I2: 1.9%, P: 0.421), respectively. In this meta-analysis, the mean HML and mean MML were estimated to be lower than the standard of World Health Organization (WHO). Although the mean mercury level in hair and BM of ILMs was lower than the WHO standard, but due to toxicity and serious concern of health, management and Periodic monitor are recommended in different cities of the country for evaluate the mercury levels in hair and BM of ILMs and to estimate the infant's exposure.
PubMed: 32399246
DOI: 10.1007/s40201-020-00460-5 -
Reviews on Environmental Health Mar 2021Mercury and methyl mercury are poisonous to human body. In the recent times, exposure to mercury has been anthropogenic in nature. Within the past several decades, many...
Mercury and methyl mercury are poisonous to human body. In the recent times, exposure to mercury has been anthropogenic in nature. Within the past several decades, many incidences of mercury poisoning have been documented in several countries including Pakistan. Mercury has been ingested where it has been used to preserve crops, through the point and non-point source discharge into the surface water, and consequently entering the food chain. We conducted this scoping review of mercury and its health effects in Pakistan in order to raise the flag to a silent ongoing Minamata disease in the country. We conducted a systematic search of the available literature in Google Scholar, PubMed, and grey literature of unpublished theses and reports of various universities across the country. We found that in the northern Pakistan, suspended sediments were the major pathway of the riverine mercury transport. Sediments of Hunza and Gilgit River were found high in mercury concentrations. Gold mining leads to an increase in mercury concentration in soil and river waters flowing in this region. High concentrations up to 108 ng/L were found in Shimsal River. It is suspected that that high level of mercury transport may be leading to accumulation of mercury in major water bodies and lakes downstream. Occupational exposure to mercury and other heavy metals is common in an unregulated private sector of the country. Goldsmiths burn the amalgamated gold without personal protective measures. Direct exposure to the fumes of mercury leads to respiratory, dermatological, systemic and neurological ailments specific to mercury poisoning. We found good evidence of bioaccumulation of mercury in fish and fish products in Pakistan. The untreated waste water discharge is responsible to not only afflicted the fish but also the birds which feed on this fish. Further, the same untreated waste water from factories and agriculture runoffs affect vegetables grown in it. Studies looking at the biomarkers for mercury in humans have shown increased and even toxic levels of mercury among the most vulnerable populations of the country. Other sources of mercury exposure included mercury in traditional medicines and cigarette products. Though no evidence was found for its presence in drinking water, its existence in the food chain and occupational exposure pose great threat to the humans as well as animals.
Topics: Environmental Exposure; Environmental Monitoring; Mercury; Mercury Poisoning, Nervous System; Pakistan; Vulnerable Populations
PubMed: 32822319
DOI: 10.1515/reveh-2019-0099 -
Ecotoxicology and Environmental Safety Jan 2023Risk assessment of heavy metals is critical in controlling and preventing risks of foodborne diseases. Fish can be used as bioindicators for exposure to potential toxic... (Review)
Review
Risk assessment of heavy metals is critical in controlling and preventing risks of foodborne diseases. Fish can be used as bioindicators for exposure to potential toxic elements (PTEs), which can represent potential risks for humans. The long Iranian coastline and three major fishery regions in the country, including the northern (Caspian Sea) and southern (Persian Gulf and Gulf of Oman) seas as well as inland waters and aquacultures (rivers, dams, wetlands and fish farms) have made Iran a large producer of fish. In the first step of the present study, data collection and report of PTEs in fish from the three fishery regions (2010-2022) were carried out. In the second step, health risks were assessed using Monte Carlo simulation in child and adult consumers. The average concentrations of Cd, Hg and Pb for the northern sea, southern sea, and inland waters and aquacultures were 0.273, 0.249, 1.077; 0.430, 0.423, 1.182; and 1.387, 0.232, 1.703 μg/g per dry weight, respectively. Based on the target hazard quotient results, Hg intake of Iranian children from all the three fishery regions was more than 1, which was alarming. In the adult age group, southern sea fish consumers were at risk of Hg adverse health effects. Moreover, Cd included the highest carcinogenic risk of toxic elements in fish from the three fishery regions of Iran. Estimation of THQ, HI, ILCR and EDI revealed that consumption of fish might induce health complexities for the consumers in Iran. Moreover, Iranians from northern and southern regions of the country consumed further seafood due to the availability of high seafood sources in these regions. Hence, various indices must be used for the risk assessment of general human health. Due to the high risks of carcinogenicity/non-carcinogenicity estimated in the risk assessment, consumption of fish by infants and pregnant women must critically be assessed.
Topics: Adult; Animals; Child; Female; Humans; Infant; Pregnancy; Cadmium; Environmental Monitoring; Fishes; Food Contamination; Indian Ocean; Iran; Mercury; Metals, Heavy; Risk Assessment
PubMed: 36508819
DOI: 10.1016/j.ecoenv.2022.114349