Mn In Children Research Articles

Source apportionment and health risk assessment of PM10 bound carbonaceous and elemental species in the central Himalayas

In this extensive investigation, the sources and health risk assessment of carbonaceous aerosols, as well as the elemental compositions (Ca, Al, Fe, S, K, Mg, Pd, B, Mo, Zn, Ag, Nb, Ga, Cl, Ti, Zr, Na, Cr, Cu, Mn, Cs, P, Y, Sb, Ni, Sn, F, Sr, Br, Pm, U, Pb, Th, Br, Rb, and V) of PM10, were conducted throughout January-December 2021 in Nainital, a central Himalayan region of India. The average annual mass concentration of PM10 was determined to be 64±6 µg m-3. Carbonaceous aerosols (CAs), comprising OC, EC, WSOC, and SOC, exhibited annual averages of 9.3±0.8 µg m-3, 4.9±0.5 µg m-3, 1.5±0.2 µg m-3, 2.7±0.2 µg m-3, and 2.97±0.45 µg m-3, respectively. The elemental composition featured major contributors such as Ca, Al, Fe, S, and K, alongside trace levels of various elements (Mg, Pd, B, Mo, Zn, Ag, Nb, Ga, Cl, Ti, Zr, Na, and Cr). Positive Matrix Factorization (PMF) identified six primary contributors to PM10, each with varying percentage contributions: crustal/soil/road dust, soil re-suspension, combustion, vehicular emissions, industrial emissions, and biomass burning. The health risk assessment revealed elevated Hazard Quotient (HQ) values for Cr and Mn in children, indicating a non-carcinogenic health risk. Adults exposed to high Cr levels may face potential carcinogenic risks, while elements like Al, Pb, Cu, Zn, and Ni pose no health hazards, aligning with USEPA guidelines.

Exposição a metais em uma população infantil após rompimento de barragem de rejeitos da mineração. Projeto Bruminha

Objective: This study aimed to analyze the urinary concentrations of As, Cd, Pb, Hg, and Mn in children living in areas directly affected by the tailings of the Brumadinho disaster. Methods: We performed a cross-sectional descriptive study on a population of 217 children aged 0 to 6 years, living in Córrego do Feijão (CF), Parque da Cachoeira (PC), Aranha (AR), and Tejuco (TJ), enrolled in the Longitudinal Study of Child Health in Brumadinho (Minas Gerais) — Projeto Bruminha. Socioeconomic data and urine samples were collected to determine the concentration of selected metals. Results: Children living in locations not directly affected by the disaster (AR and TJ) had higher concentrations of As and Mn than those in directly affected areas (CF and PC). Additionally, children living in locations not potentially exposed to dust from tailings mud or mining activity (AR) showed higher urinary As concentrations than those potentially exposed (CF, PC, and TJ). Conclusion: Our results suggest the need to investigate possible sources of As exposure in children living in areas not directly affected by the disaster and not potentially exposed to dust.

Metal exposure in a child population after a mine tailings dam failure. Projeto Bruminha

This study aimed to analyze the urinary concentrations of As, Cd, Pb, Hg, and Mn in children living in areas directly affected by the tailings of the Brumadinho disaster. We performed a cross-sectional descriptive study on a population of 217 children aged 0 to 6 years, living in Córrego do Feijão (CF), Parque da Cachoeira (PC), Aranha (AR), and Tejuco (TJ), enrolled in the Longitudinal Study of Child Health in Brumadinho (Minas Gerais) - Projeto Bruminha. Socioeconomic data and urine samples were collected to determine the concentration of selected metals. Children living in locations not directly affected by the disaster (AR and TJ) had higher concentrations of As and Mn than those in directly affected areas (CF and PC). Additionally, children living in locations not potentially exposed to dust from tailings mud or mining activity (AR) showed higher urinary As concentrations than those potentially exposed (CF, PC, and TJ). Our results suggest the need to investigate possible sources of As exposure in children living in areas not directly affected by the disaster and not potentially exposed to dust.

Ecotoxicological and health risk assessment of toxic metals and metalloids burdened soil due to anthropogenic influence

Landfill area is one of developing countries' most common anthropogenically contaminated sites. The pressure of urbanization has led to increased waste generation in major cities, commonly deposited in landfills; hence, heavy metals contaminations are closer to the human environment than ever. The study assessed the environmental risk of Arsenic (As), Cadmium (Cd), Zinc (Zn), Manganese (Mn), Copper (Cu), Colbat (Co), Cranium (Cr), Nickel (Ni), and Lead (Pb) in an abandoned landfill system and health-related risk using United State Environmental Protection Agency model. The Concentration of the elements descended as follows; Mn > Zn > Cr > Pb > Cu > Ni > Co > As > Cd and exceeded the WHO permissible limit. The Enrichment factor (EF) and potential ecological risk (ER) indicated no enrichment and low risk for all the elements except Cd (3.67, 426), with moderate enrichment and very high ecological risk. The hazard index (HI) value of the elements indicated no significant risk of non-carcinogenic effect for both Adults and Children except for Mn in Children with a value of 1.69 × 100; however, the HI value of the elements descended as; Co > Mn > Zn > As > Cd > Cu > Pb > Ni > Cr for adult and Mn > Cd > Co > Cr > As > Zn > Pb > Cu > Ni for children. The total carcinogenic risk (TCR) value of the toxic metals descended as Ni > Cd > Cr > As > Pb for both adults and Children, while the metals showed no carcinogenic to acceptable risk to humans. The Principal Component Analysis (PCA) indicated that the metals have similar sources and distribution which could be both lithogenic and anthropogenic influenced. Engaging the environment through sustainable practices will ensure efficient waste disposal and management.

Assessment of Potential Human Health Risks from Exposure to Select Heavy Metals in Road Dust Around Mining Sites in Carrascal, Surigao Del Sur, Philippines

Road dust samples around human settlements nearby mining areas in Carrascal, Surigao del Sur, Philippines were investigated to quantify the levels of chromium (Cr), nickel (Ni), manganese (Mn) and zinc (Zn) and assess the potential health risks from selected heavy metals. Metal concentrations of chromium (Cr), nickel (Ni), manganese (Mn) and zinc (Zn) in road dust were analyzed using Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer. Analytical results showed that the average concentrations of Cr, Ni, Mn, and Zn were very high at 15,668, 14,814, 7,054, and 684 mg/kg, respectively. Measured concentrations exceeded standards stipulated in international regulations and guidelines by several orders of magnitude. Mortality and morbidity cases with causes probably related to dust inhalation (e.g., upper respiratory tract infection and pneumonia) noticeably increased during the peak years of mining operations. Non-carcinogenic health risk assessment revealed that children are more prone to develop non-carcinogenic health effects than adults (HI values >1 for Cr, Ni and Mn for children and only Cr for adults), owing to their smaller body weight and activities exposing them to these metals via the ingestion route. Assessment of carcinogenic risk value or the lifetime probability of an individual to develop cancer due to exposure to Ni revealed that such risk is negligible. This study suggests that mining companies and government units should proactively take measures to reduce dust exposure (e.g., dust inhalation) of mine workers and residents in nearby communities. In developing management measures, children should be provided with attention given their greater risk of developing dust-related illnesses and diseases.

Contamination by hazardous elements in low-priced children's plastic toys bought on the local markets of Karachi, Pakistan.

Children's plastic toys may contain toxic metals to which infants and young children can be orally exposed and may pose acute or chronic adverse health effects. This research aims to evaluate the total metal concentrations (TMCs) of Pb, Cd, Cr, Ni, Zn, Cu, and Mn in children's plastic toys bought in the local markets of Karachi, Pakistan, and compare TMCs to different toy safety regulatory limits. A total of 44 children's plastic toys sourced in the Karachi local markets were analyzed by an atomic absorption spectrophotometer for contamination of hazardous elements. Toy samples were divided into two groups: plastic toys (DCT) and plastic toys with paints or coatings (DPCT). For plastic toys, 83% (19) of samples had TMCs that exceeded European Union (EU) toy safety regulation limits for Pb, and 65% (15) of samples that exceeded for Cd. For plastic toys with paints or coating, 43% (9) of samples had TMCs that exceeded EU migration limits for Pb and 24% (5) for Cd. More than 20 samples exceeded the United States Consumer Product Safety Commission (US CPSC), Canadian, and Bureau of Indian Standards (BIS) toy safety regulation limits. In toy samples (n = 44), very high TMCs of Pb (64%), Cd (45%), Cr (5%), and Ni (2%) were observed. Zn, Cu, and Mn TMCs existed but were below the regulation limits. The contamination levels of Pb, Cd, Cr, and Ni and smaller extent of Zn, Cu, and Mn still pose health issues in children and may cause serious problems in their health.

The first pollution investigation of road sediment in Gary, Indiana: Anthropogenic metals and possible health implications for a socioeconomically disadvantaged area

An investigation of road sediment in Gary, Indiana revealed high levels of various trace metals such as Zn, Mn, and Cr, often exceeding those of background reference concentrations as shown through geoaccumulation indices and contamination factors. The hazard index (HI) value for Mn in children was >1 (1.7), suggesting possible long-term non-carcinogenic health risk. Mn HI for children is even higher for the five samples closest to a US Steel facility, with an HI of 2.8. Through SEM-EDS analysis, the prevalence of small particulates (PM2.5 and PM2.5–10) containing potentially harmful elements such as Mn and Pb illustrate a health risk through direct inhalation or ingestion. The small nature of particulates in general may also pose an increased health risk for respiratory diseases such as asthma. Mn concentrations in the road sediment were particularly high, with 30 out of 32 samples exceeding 1800 ppm. Mn and V concentrations show a strong spatial trend of decreasing concentration away from a US Steel facility. These spatial trends along with correlation plots of the bulk chemistry suggest that industrial steel manufacturing, particularly US Steel in Gary, is a major contributing source of Mn and V. Fe and Cr show a moderate decrease in concentrations away from the US Steel facility, which suggests some sourcing from the steel facility when coupled with bulk chemistry plots. Zn and Cu do not show much evidence of sourcing from the US Steel facility, likely due to increased mixing from other sources. Further work constraining anthropogenic sources, the bioaccessible fraction of metals, and analysis of direct atmospheric particulates can help with remedial activity and risk assessment.

Manganese exposure and association with hormone imbalance in children living near a ferro-manganese alloy plant

It has been suggested that manganese (Mn) plays a fundamental role in the reproductive system through interference with the regulation of the secretion of hormones related to puberty. The objective of this study was to evaluate the environmental exposure to Mn and its effects on the endocrine regulation of hormones related to puberty in school-aged children living near a ferro-manganese alloy plant. Toenails, occipital hair, and blood samples were collected from 225 children, between 7 and 12 years of age, in four elementary schools in Simões Filho, Bahia, Brazil, who were exposed to different Mn levels owing to different Mn dust deposition rates. The Mn content was determined in the toenails (MnTn), hair (MnH), and blood (MnB), in addition to blood lead levels (PbB), by using graphite furnace atomic absorption spectrometry. Luteinizing hormone (LH), prolactin (PRL), estradiol (E2), testosterone (T), and thyroid stimulating hormone (TSH) levels were determined by using a chemiluminescence method. Of the total participants, 50.2% were boys, with an average age of 9 years. PRL values were higher in children attending the school with a higher Mn deposition rate (p < 0.004). We observed that MnTn was positively correlated with PRL levels and exhibited a non-linear association with LH levels. None of the tested Mn biomarkers were associated with E2, T, or TSH levels. To date, despite several animal studies that have focused on the correlation between Mn exposure and the endocrine regulation of hormones and pubertal development, very few studies have reported a similar relationship between environmental Mn effects and the human endocrine system. Our findings support the hypothesis that elevated exposure to Mn in children may be associated with hormonal imbalances that might trigger the early onset of puberty.

Pathways of inhalation exposure to manganese in children living near a ferromanganese refinery: A structural equation modeling approach

Manganese (Mn) is both essential element and neurotoxicant. Exposure to Mn can occur from various sources and routes. Structural equation modeling was used to examine routes of exposure to Mn among children residing near a ferromanganese refinery in Marietta, Ohio. An inhalation pathway model to ambient air Mn was hypothesized. Data for model evaluation were obtained from participants in the Communities Actively Researching Exposure Study (CARES). These data were collected in 2009 and included levels of Mn in residential soil and dust, levels of Mn in children's hair, information on the amount of time the child spent outside, heat and air conditioning in the home and level of parent education. Hair Mn concentration was the primary endogenous variable used to assess the theoretical inhalation exposure pathways. The model indicated that household dust Mn was a significant contributor to child hair Mn (0.37). Annual ambient air Mn concentration (0.26), time children spent outside (0.24) and soil Mn (0.24) significantly contributed to the amount of Mn in household dust. These results provide a potential framework for understanding the inhalation exposure pathway for children exposed to ambient air Mn who live in proximity to an industrial emission source.

Assessment of health risk of trace metal pollution in surface soil and road dust from e-waste recycling area in China

Informal recycling of e-waste and the resulting heavy metal pollution has become a serious burden on the ecosystem in Guiyu, China. In this investigation, we evaluated the trace metal concentration of community soil and road dust samples from 11 locations in Guiyu and 5 locations (consisting of residential areas, kindergarten/school, and farm field) in a reference area using graphite furnace atomic absorption spectrophotometer. The study spanned four seasons, 2012-2013, with a view to assess the risk associated with e-waste recycling in the study area. The concentrations of Pb, Cd, Cr, and Mn were 448.73, 0.71, 63.90, and 806.54mg/kg in Guiyu soil and 589.74, 1.94, 69.71, and 693.74mg/kg, in the dust, respectively. Pb and Cd values were significantly higher (P ≤ 0.05) than the reference area, and the mixed model analysis with repeated seasonal measurements revealed soil Pb and Cd levels that were 2.32 and 4.34 times, while the ratios for dust sample were 4.10 and 3.18 times higher than the reference area. Contamination factor, degree of contamination, and pollution load index indicated that all sampling points had a high level of metal contamination except farm land and kindergarten compound. The cumulative hazard index of Pb, Cd, Cr, and Mn for children in exposed area was 0.99 and 1.62 for soil and dust, respectively, suggesting non-cancer health risk potential. The significant accumulation of trace metals in the e-waste recycling area predisposes human life, especially children, to a potentially serious health risk.

Spatial distribution of dust–bound trace elements in Pakistan and their implications for human exposure

This study aims to assess the spatial patterns of selected dust-borne trace elements alongside the river Indus Pakistan, their relation with anthropogenic and natural sources, and the potential risk posed to human health. The studied elements were found in descending concentrations: Mn, Zn, Pb, Cu, Ni, Cr, Co, and Cd. The Index of Geo-accumulation indicated that pollution of trace metals were higher in lower Indus plains than on mountain areas. In general, the toxic elements Cr, Mn, Co and Ni exhibited altitudinal trends (P < 0.05). The few exceptions to this trend were the higher values for all studied elements from the northern wet mountainous zone (low lying Himalaya). Spatial PCA/FA highlighted that the sources of different trace elements were zone specific, thus pointing to both geological influences and anthropogenic activities. The Hazard Index for Co and for Mn in children exceeded the value of 1 only in the riverine delta zone and in the southern low lying zone, whereas the Hazard Index for Pb was above the bench mark for both children and adults (with few exceptions) in all regions, thus indicating potential non-carcinogenic health risks. These results will contribute towards the environmental management of trace metal(s) with potential risk for human health throughout Pakistan.

Childhood exposure to manganese and postural instability in children living near a ferromanganese refinery in Southeastern Ohio

Airborne manganese (Mn) exposure can result in neurotoxicity and postural instability in occupationally exposed workers, yet few studies have explored the association ambient exposure to Mn in children and postural stability. The goal of this study was to determine the association between Mn and lead (Pb) exposure, as measured by blood Pb, blood and hair Mn and time weighted distance (TWD) from a ferromanganese refinery, and postural stability in children. A subset of children ages 7–9years enrolled in the Marietta Community Actively Researching Exposure Study (CARES) were invited to participate. Postural balance was conducted on 55 children residing in Marietta, Ohio and the surrounding area. Samples of blood were collected and analyzed for Mn and Pb, and samples of hair were analyzed for Mn. Neuromotor performance was assessed using postural balance testing with a computer force platform system. Pearson correlations were calculated to identify key covariates. Associations between postural balance testing conditions and Mn and Pb exposure were estimated with linear regression analyses adjusting for gender, age, parent IQ, and parent age. Mean blood Mn was 10μg/L (SEM=0.36), mean blood Pb was 0.85μg/dL (SEM=0.05), and mean hair Mn was 0.76μg/g (SEM=0.16). Mean residential distance from the refinery was 11.5km (SEM=0.46). All three measures of Mn exposure were significantly associated with poor postural balance. In addition, low-level blood Pb was also negatively associated with balance outcomes. We conclude that Mn exposure and low-level blood Pb are significantly associated with poor postural balance.

Neurocognition of children living near a ferromanganese refinery in southeastern Ohio

Background: Airborne manganese (Mn) exposure can result in neurotoxicity and neuromotor deficits in occupationally exposed workers, yet few studies have explored chronic environmental exposure to Mn in children from industrial ambient emissions. Marietta, Ohio has the longest operating ferromanganese refinery in the United States. Aims: The goal of this study was to determine the association between Mn exposure and neuromotor performance in children. Methods: A subset of children ages 7-9 years enrolled in the Marietta Community Actively Researching Exposure Study (CARES) were invited to participate. Samples of blood and hair were collected and analyzed for Mn. Neuromotor function was assessed using the Reitan Electric Finger Tapping Task, grooved pegboard and the Bruiniks-Osteretsky Test of Motor Proficiency-2. Child intellectual function was assessed using the Weschler Intelligence Scale for Children-IV. Pearson correlations were calculated to identify key covariates. Multiple regression analyses were used to examine the relationship between internal dose markers of Mn, covariates, and confounders on neuromotor performance. Results: Neuromotor performance was evaluated on 324 children. Mean blood Mn was 10.1 µg/L (95% confidence interval (CI): 9.8, 10.5 µg/L) and mean hair Mn was 0.67 µg/g (95% CI: 0.54-0.80 µg/g). Mean residential distance from the refinery was 12.0 km (95% CI: 11.3, 12.6 km). Hair Mn was significantly correlated with child IQ (p?0.03). We found a significant inverse relationship between ln hair Mn and finger tapping with the right hand (p&lt;0.006) and ln blood Mn and line drawing (p=0.04) and copying a square (p=0.03). Child age, gender, height/weight ratio, and IQ were also significant for many motor function tests. Conclusions: Exposure to airborne Mn may affect fine motor coordination in children.

Relationship between blood manganese levels and children's attention, cognition, behavior, and academic performance—A nationwide cross-sectional study

Manganese (Mn) is neurotoxic at high concentrations. However, Mn is an essential element that can protect against oxidative damage; thus, extremely low levels of Mn might be harmful. Our aim was to examine whether either high or low environmental Mn exposure is related to academic and attention function development among school-aged children.This cross-sectional study included 1089 children 8–11 years of age living in five representative areas in South Korea. Blood Mn, blood lead, and urine cotinine were measured. We assessed IQ with the Wechsler Abbreviated Scale of Intelligence; attention with a computerized continuous performance test called the Attention-deficit/hyperactivity disorder (ADHD) Diagnostic System (ADS), the Korean version of the Stroop Color-Word Test, the Children's Color Trails Test (CCTT), and the ADHD Rating Scale; academic functions with the Learning Disability Evaluation Scale (LDES); and emotional and behavioral problems with the Korean version of the Child Behavior Checklist (CBCL). We further assessed the presence of ADHD using a highly structured diagnostic interview, the Diagnostic Interview Schedule for Children Version IV (DISC-IV).The median blood concentration of Mn was 14.14µg/L. We observed a nonlinear association between the CCTT2 completion time and the CPT commission error (F=3.14, p=0.03 and F=4.05, p=0.01, respectively). We divided the data into three groups: lower (<8.154µg/L), and upper 5th percentile (>21.453µg/L) and middle 90th percentile to determine whether a lack or overload of Mn could cause adverse effects. After adjusting for urine cotinine, blood lead, children's IQ, and other potential confounders, the high Mn group showed lower scores in thinking (B=−0.83, p=0.006), reading (B=−0.93, p=0.004), calculations (B=−0.72, p=0.005), and LQ (B=−4.06, p=0.006) in the LDES and a higher commission error in the CPT (B=8.02, p=0.048). The low Mn group showed lower color scores in the Stroop test (B=−3.24, p=0.040).We found that excess Mn in children is associated with lower scores of thinking, reading, calculation, and LQ in the LDES and higher scores of commission error in the ADS test. In contrast, lower Mn in children is associated with lower color scores in the Stroop test. The findings of this cross-sectional study suggest that excess exposure or deficiency of Mn can cause harmful effects in children.

Micronuclei frequency in children exposed to environmental mutagens: a review.

Cytogenetic monitoring has been traditionally used for the surveillance of populations exposed to genotoxic agents. In recent years sensitivity problems emerged in surveys of populations exposed to low levels of mutagens, and therefore alternative approaches have been explored. Biomonitoring studies in children are a promising field, since because of evident differences in the uptake, metabolism, distribution and excretion of mutagens this population seems to be more susceptible than adults. Further, the effect of major confounders such as cigarettes smoking, occupation, life-style, and dietary factors plays a minor role. Among cytogenetic assays, the micronucleus assay (MN) has several advantages and is increasingly used. A review was then carried out to synthesize the published data on the occurrence of MN in children and adolescents (age range 0-18 years), and to assess the impact of genotoxic exposure on MN frequency. Overall, 20 papers from international literature and 8 Russian papers were included. An effect of age was found within this age range, while the influence of gender on MN frequency was irrelevant. These results were confirmed by the re-analysis of data for 448 children selected from the HUMN database. An effect of chronic and infectious diseases on MN levels has been reported by various authors. Most studies describing the effect of exposure to genotoxic agents (ionizing radiation, chemicals, drugs, environmental tobacco smoke) found an increase of MN in exposed children. The limited number of published papers indicates that the conduct of properly designed studies on the effect of environmental pollutants in children may be difficult. This review confirmed the usefulness of MN assay in biomonitoring studies conducted in children, revealing that in many circumstances investigating children increases the sensitivity of the study, even with low dose exposures.