Hair Manganese Research Articles

Blood and Hair Manganese Concentrations in Pregnant Women from the Infants’ Environmental Health Study (ISA) in Costa Rica

Manganese (Mn), an essential nutrient, is a neurotoxicant at high concentrations. We measured Mn concentrations in repeated blood and hair samples collected from 449 pregnant women living near banana plantations with extensive aerial spraying of Mn-containing fungicide mancozeb in Costa Rica, and examined environmental and lifestyle factors associated with these biomarkers. Mean blood Mn and geometric mean hair Mn concentrations were 24.4 μg/L (8.9–56.3) and 1.8 μg/g (0.05–53.3), respectively. Blood Mn concentrations were positively associated with gestational age at sampling (β = 0.2; 95% CI: 0.1 to 0.2), number of household members (β = 0.4; 95% CI: 0.1 to 0.6), and living in a house made of permeable and difficult-to-clean materials (β = 2.6; 95% CI: 1.3 to 4.0); and inversely related to smoking (β = −3.1; 95% CI: −5.8 to −0.3). Hair Mn concentrations were inversely associated with gestational age at sampling (% change = 0.8; 95% CI: −1.6 to 0.0); and positively associated with living within 50 m of a plantation (% change = 42.1; 95% CI: 14.2 to 76.9) and Mn concentrations in drinking water (% change = 17.5; 95% CI: 12.2 to 22.8). Our findings suggest that pregnant women living near banana plantations aerially sprayed with mancozeb may be environmentally exposed to Mn.

Biomonitorization of chromium, copper, iron, manganese and nickel in scalp hair from orthodontic patients by atomic absorption spectrometry

The study was aimed to assess Cu, Cr, Fe, Mn and Ni levels in human scalp hair from a broad population group treated with orthodontic appliances (n=70) to determine, whether the concentration of a given metal was significantly influenced by the orthodontic treatment in comparison to control group (n=56). Levels of metal compounds were determined by atomic absorption spectrometry. The mean, ranges, median and 5th and 95th percentiles of metals analyzed in hair that were hypothesized to be systemically absorbed from stainless steel, are provided. The influence of individual factors on metal concentrations was considered (gender, age), and inter-element interactions were studied by evaluation of correlation coefficients between elements, as well as by multiple regression analysis. Differences in the content of metals in hair were only significantly increased for Mn when compared to the control group, but their levels were of the same magnitude to other control populations, and consequently, no risks linked to the treatment have been found. The orthodontic treatment increased significantly Mn levels in young patients (<20 years old) when compared with control group. Scalp hair analysis is a good method to investigate the release of the elements from fixed orthodontic appliances.

Evaluation of chromium and manganese in biological samples (scalp hair, blood and urine) of tuberculosis and diarrhea male human immunodeficiency virus patients.

The consequence of trace elements deficiency has been associated with an increased risk of human immunodeficiency virus type 1 (HIV-1) disease progression and mortality. This study examined the association between high concentrations of chromium (Cr) and manganese (Mn) in scalp hair, blood, and urine and opportunistic infections in hospitalized patients with the acquired immune deficiency syndrome (AIDS). The study was performed on 62 male HIV+ patients (HIV-1) from different cities of Pakistan. The patients were divided in two groups according to secondary infections (tuberculosis, diarrhea, or high fever). The biological samples (scalp hair, blood and urine) were collected from AIDS patients, and for comparative study 120 healthy subjects (males) of same age group (31 - 45 years), socio-economic status, localities, and dietary habits were also included. The elements in the biological samples were analyzed by electrothermal atomic absorption spectrophotometry after microwave-assisted acid digestion. The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and with the values obtained by conventional wet acid digestion method on the same CRMs. The results indicated significantly lower concentrations of Cr and Mn in the biological samples (scalp hair, blood, and urine) of male HIV-1 patients, compared with control subjects. It was observed that the lower levels of these trace elements may be predictors for secondary infections in HIV-1 patients. There was a significant decrease in mean values of Cr and Mn in whole blood and scalp hair, whilst higher concentrations were observed in urine samples of the three groups of AIDS patients as compared to a controlled healthy male group (p < 0.001). Low Cr and Mn levels may be due to increased Cr and Mn losses. These data present guidance to clinicians and other professional investigating deficiencies of Cr and Mn in biological samples of AIDS patients.

Elevated manganese exposure and school-aged children's behavior: A gender-stratified analysis

High levels of waterborne manganese have been associated with problematic behavior in school-aged children, however to date this has not been reported for children exposed to airborne manganese. The objective of the present study was to examine behavioral traits among children with exposure to airborne manganese from a ferro-manganese alloy plant, located in the metropolitan region of Salvador, Brazil. The study included 34 boys and 36 girls, aged 7–12 years, living in two communities within a 3-km radius from the plant. For each child, hair manganese levels (MnH) and blood lead (PbB) levels were analyzed by graphite furnace atomic absorption spectrometry. The Children's Behavior Check List (CBCL) (Portuguese version validated in Brazil) was administered to parents or caregivers, providing scale scores of internalizing (withdrawn, somatic complaints, and anxious/depressed scales), externalizing (disruptive and aggressive) behaviors and a separate scale for attention problems. Median and range for MnH and PbB were 11.48μg/g (range: 0.52–55.74); 1.1μg/dL (range: 0.5–6.1), respectively. Spearman correlation analyses showed that several behavioral indices were significantly correlated with MnH levels for girls, but not for boys: total externalizing behavior (rho=0.484 vs rho=0.041) and attention problem scores (rho=0.542 vs rho=0.003) coefficients were significantly at p<0.001 level, respectively for girls and boys. No significant correlation was observed with any of the internalizing sub-scales. A linear regression model was fitted with the total externalizing behavior, inattention and total CBCL scores as dependent variables, with log transformed MnH stratified by sex, adjusting for age and maternal IQ. Total externalizing behaviors and attention problem scores were significantly associated with girls’ MnH levels but not with boys’. Adjusting for maternal IQ, the β-coefficients for LogMnH associations with total externalizing and attention problems are 8.85 (95%CI 2.44–15.24) and 4.03 (95%CI 1.50–6.56) for girls. For boys, after adjusting for age, the β-coefficients are 0.08 (95%CI 11.51–11.66) and −0.05 (95%CI 4.34–4.25), respectively. The findings of this study suggest a positive association between elevated Mn exposure and externalizing behavioral problems and inattention, with girls presenting more pronounced effects. Future studies on Mn exposure in children should attempt to further elucidate sex and/or gender differences in Mn exposed populations.

Nonoccupational Environmental Exposure to Manganese is Linked to Deficits in Peripheral and Central Olfactory Function

Manganese is of growing concern as a toxic air pollutant. It is readily transported from the olfactory epithelium to the olfactory bulb, and unlike other metals, it is transported transynaptically to structures deep within the brain. However, little is known regarding the possible effect of nonoccupational exposure to manganese on olfactory function. Using the Sniffin' Sticks test battery, we compared the olfactory performance of subjects from a manganese mining district living <1 km from a manganese processing plant, with nonexposed subjects living 50 km from the closest source of exposure (N = 30/group). Groups were matched for age, sex, and schooling, and none had ever worked in mining-related activities. Concentrations of manganese in hair were measured as a biomarker of exposure; exposed subjects had significantly higher concentrations than nonexposed subjects. They were also significantly outperformed by the nonexposed subjects on all olfactory measures (threshold, discrimination, and identification), indicating adverse effects of manganese exposure on a range of olfactory functions, including those involving higher order cognitive processes. This contrasts with previous findings showing adverse peripheral but not central effects on olfactory function of big city air pollution, which mostly consists of toxicants known to affect the olfactory epithelium but with lower transynaptic transport capacity compared with manganese. We conclude that nonoccupational exposure to airborne manganese is associated with decrements in both peripheral and central olfactory function.

Study of blood and pubic hair mineralograms of alcoholic people

The quantification of minerals present in the blood and pubic hair of alcoholic people is of paramount importance, since the excessive consumption of liquor over several years can cause an imbalance of minerals. In this sense, the present study sought to compare the mineralograms of pubic hair and blood of alcoholic and non-alcoholic persons. After making the opening of the samples, the concentrations of minerals were obtained by Atomic Emission Spectroscopy with Inductively Coupled Plasma (ICP-MS). Statistical analysis was performed in 5.0 BioEstat. Statistical differences were considered at p ≤ 0.05. The results show that there was a significant increase in concentrations of iron, manganese and copper in the pubic hair of alcoholics compared to the control group. The average concentration in mg L-1 Fe, Mn and Cu found in the pubic hair of group A were respectively: 83.8 (p = 0.029); 2.894 (p = 0.021) and 9.6 (p = 0.0144). These data show that ingestion of liquor contaminated with copper and the metabolism of alcohol itself are compromising the balance of minerals in the body of those patients and may lead to premature aging.Keywords: Rum, alcohol, hair analysis, biological materials.

Associations Between Hair Manganese Levels and Cognitive, Language, and Motor Development in Preschool Children from Montevideo, Uruguay

ABSTRACT Environmental manganese (Mn) exposure in childhood has been associated with developmental deficits. This study investigated associations between low-level Mn exposure and developmental scores in children aged 14–45 months. Children's hair samples (n = 60) were analyzed for Mn and lead (Pb) using inductively coupled plasma mass spectrometry (ICP-MS). Children were assessed with the Bayley Scales of Infant Development III (BSID). Mean hair Mn and Pb concentrations were 0.98 ± 0.74 and 10.1 ± 10.5 μg/g, respectively. Unadjusted inverse associations were seen between Mn and BSID subscales, with girls having lower scores related to Mn than boys. No significant associations remained in covariate-adjusted models, although when stratified by sex boys had a positive association between hair Mn levels and language scores. This study does not show clear evidence of an association between hair Mn concentrations and children's developmental scores in a region of low-level Mn exposure.

Manganese‐induced parkinsonism in methcathinone abusers: bio‐markers of exposure and follow‐up

Methcathinone abuse is a new cause of manganism. The psychostimulant is prepared from pseudoephedrine using potassium permanganate as an oxidant. We describe the clinical, biological, neuroimaging characteristics and follow-up results in a large Estonian cohort of intravenous methcathinone users. During 2006-2012 we studied 38 methcathinone abusers with a mean age of 33 years. Subjects were rated by the Unified Parkinson's Disease Rating Scale (UPDRS), Hoehn and Yahr (HY), and Schwab and England (SE) rating scales. Twenty-four cases were reassessed 9-70 (20 ± 15) months after the initial evaluation. Manganese (Mn) in plasma and hair was analysed by inductively coupled plasma-atom emission spectrometry. Magnetic resonance imaging (MRI) was performed in 11, and single-photon emission computed tomography (SPECT) with iodobenzamide (IBZM) in eight subjects. The average total UPDRS score was 43 ± 21. The most severely affected domains in UPDRS Part III were speech and postural stability, the least affected domain was resting tremor. At follow-up there was worsening of HY and SE rating scales. Subjects had a higher mean level of Mn in hair (2.9 ± 3.8 ppm) than controls (0.82 ± 1.02 ppm), P = 0.02. Plasma Mn concentrations were higher (11.5 ± 6.2 ppb) in active than in former users (5.6 ± 1.8 ppb), P = 0.006. Active methcathinone users had increased MRI T1-signal intensity in the globus pallidus, substantia nigra and periaquaductal gray matter. IBZM-SPECT showed normal symmetric tracer uptake in striatum. Methcathinone abusers develop a distinctive hypokinetic syndrome. Though the biomarkers of Mn exposure are characteristic only of recent abuse, the syndrome is not reversible.

Relationship between lead, cadmium, zinc, manganese and iron in hair of environmentally exposed subjects

Trace level analysis of two toxic metals lead and cadmium and three essential metals zinc, manganese and iron was examined in hair of 25 workers of metals finishing units and metal recycling units of State of Rajasthan, India, as Exposed Group (EG). Twenty-five subjects as controls were selected from the office staff of the same units Control Group A (CGA) and 25 subjects selected from the population of State of Rajasthan, India, who were not exposed to metal pollution at their work place were selected as another control group Control Group B (CGB). Head hair samples were collected, decontaminated and digested followed by analysis for trace levels of Pb, Cd, Zn, Mn and Fe by Atomic Absorption Spectrophotometer (AAS), ECIL Model-AAS4141 using air acetylene flame. The significant levels of metals in between EG, CGA and CGB have been computed by Student’s ‘t’ test. The Pearson rank correlation of the data of five metals revealed significant positive correlation between Mn/Cd, Mn/Pb, Mn/Fe, Cd/Pb, Cd/Fe and Pb/Fe in hair of Exposed Group (EG), Mn/Zn, Mn/Cd, Mn/Pb, Zn/Cd, Zn/Pb, Cd/Pb and Cd/Fe in hair of Control Group A (CGA) and Mn/Cd in hair of Control Group B (CGB). Significant negative correlation was observed between Pb/Fe in hair of CGB.

Tremor, olfactory and motor changes in Italian adolescents exposed to historical ferro-manganese emission

Background and objectiveIncreased prevalence of Parkinsonism was observed in Valcamonica, Italy, a region impacted by ferroalloy plants emissions containing manganese and other metals for a century until 2001. The aim of this study was to assess neurobehavioral functions in adolescents from the impacted region and the reference area of Garda Lake. MethodsAdolescents age 11–14 years were recruited through the school system for neuro-behavioral testing. Metals including manganese, lead, iron, zinc, copper were measured in airborne particulate matter collected with 24-h personal samplers, and in soil, tap water, blood, urine and hair. Independent variables included parental education and socio-economic status, children's body mass index, number of siblings, parity order, smoking and drinking habits. ResultsA total of 311 subjects (49.2% females), residing in either the exposed (n=154) or the reference (n=157) area participated. Average airborne and soil manganese were respectively 49.5ng/m3 (median 31.4, range 1.24–517) and 958ppm (median 897, range 465–1729) in the impacted area, and 27.4ng/m3 (median 24.7, range 5.3–85.9) ng/m3 and 427ppm (median 409 range 160–734) in the reference area. Regression models showed significant impairment of motor coordination (Luria-Nebraska test, p=0.0005), hand dexterity (Aiming Pursuit test, p=0.0115) and odor identification (Sniffin’ task, p=0.003) associated with soil manganese. Tremor intensity was positively associated with blood (p=0.005) and hair (p=0.01) manganese. ConclusionHistorical environmental exposure to manganese from ferroalloy emission reflected by the concentration in soil and the biomarkers was associated with sub-clinical deficits in olfactory and motor function among adolescents.

Heavy Metals in Hair of Wild Canids from the Brazilian Cerrado

In this study, we aimed to assess whether free-ranging wild canids are exposed to heavy metals in one of the most developed and populated regions of Brazil. Hair of 26 wild canids (maned wolves Chrysocyon brachyurus, crab-eating foxes Cerdocyon thous, and hoary foxes Lycalopex vetulus) from the Cerrado biome in Southeast Brazil were analyzed by spectrophotometry to detect cadmium, chromium, and lead, and also the essential copper, iron, manganese, and zinc traces. All samples showed traces of copper, iron, manganese, and zinc. Non-essential lead was detected in 57% (2.35 ± 0.99 mg/kg), and chromium in 88% (2.98 ± 1.56 mg/kg) of samples. Cadmium traces (detection limit 0.8 mg/kg) were not found. Crab-eating foxes had more copper, iron, and manganese in hair than maned wolves. Correlations among element levels differed between maned wolves and crab-eating foxes. Concentrations of chromium and lead were outstandingly higher than in wild canids from other areas. Addressing the causes of such levels and the impacts of the heavy metal pollution in Neotropical ecosystems is urgent for animal health and conservation purposes. We argue that heavy metal pollution should be considered as dangerous threats to wildlife health in Brazil and recommend hair sampling as a biomonitoring tool for heavy metals in Neotropical terrestrial mammals.

Do breastfed and formula‐fed infants differ on hair manganese levels?

Manganese (Mn) toxicity is observed in children exposed to high Mn levels in water and in total parenteral nutrition. Infant formula contains 5–28 times as much Mn as breast milk, but is not widely studied as a source of Mn toxicity. The objective of this study is to determine the difference in hair Mn levels between infants who are predominantly formula‐fed (FF) or breast‐fed (BF), and explore other salient predictors of hair Mn levels. Infants 3–6 mo who were FF (n=5) or BF (n=30) were recruited. Water and hair Mn levels for mother and infant were determined by ICP‐MS analysis. Mean±SD (median) hair Mn for BF and FF infants was 2.21±2.77 (1.45) μg/mL and 2.76±1.80 (3.16) μg/mL, respectively. Group medians differed significantly (p=0.002). 50.0% of FF displayed elevated hair Mn levels (&gt;3 μg/g), compared to 13.8% of BF infants. Mean water Mn concentration was 0.92±2.10 ng/mL for BF and 0.21±0.16 ng/mL for FF infants. Infant hair Mn was not correlated with water Mn concentration (p=0.32), sex (p=0.21) or age (p=0.25). Additional samples are being collected to provide more definitive results.

Biomonitorization of cadmium, chromium, manganese, nickel and lead in whole blood, urine, axillary hair and saliva in an occupationally exposed population

Heavy metal contamination from occupational origin is a cause for concern because of its potential accumulation in the environment and in living organisms leading to long term toxic effects. This study was aimed to assess Cd, Cr, Mn, Ni and Pb levels in whole blood, urine, axillary hair and saliva from 178 individuals with occupational exposure to heavy metals. Levels of metal compounds were determined by atomic absorption spectrometry. We collected information on occupation, lifestyle habits and food intake by questionnaire. Multiple linear regression analyses for metal ion concentration in whole blood, urine, axillary hair and saliva were adjusted for age, gender, smoking and alcohol consumption, lifetime workplace exposure, residence area and food habits. Overall, blood and urine median concentrations found for the five metals analyzed do not exceed biological exposure indexes, so that they are very similar to a non-occupationally exposed population. Toxicokinetic differences may account for the lack of correlations found for metal levels in hair and saliva with those in blood or urine. For those heavy metals showing higher median levels in blood with respect to hair (Cd, Mn and Pb) indicating lesser hair incorporation from blood, the lifetime working experience was inversely correlated with their hair levels. The longer the lifetime working experience in industrial environments, the higher the Mn and Ni concentration in saliva. Axillary hair and saliva may be used as additional and/or alternative samples to blood or urine for biomonitoring hair Mn, and saliva Ni in subjects with occupational exposure.

Chromium and Manganese Levels in Biological Samples of Normal and Night Blindness Children of Age Groups (3–7) and (8–12) Years

This study was designed to compare the levels of chromium (Cr) and manganese (Mn) in scalp hair, blood, and urine of night blindness in children age ranged (3-7) and (8-12) years of both genders, comparing them to sex- and age-matched controls. A microwave-assisted wet acid digestion procedure, was developed as a sample pretreatment, for the determination of Cr and Mn in biological samples of night blindness children. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, blood and urine. The digests of all biological samples were analyzed for Cr and Mn by electrothermal atomic absorption spectrometry. The results indicated significantly higher levels of Cr, whilst low level of Mn in the biological samples (blood and scalp hair) of male and female night blindness children, compared with control subjects of both genders. These data present guidance to clinicians and other professional investigating deficiency of Mn and excessive level of Cr in biological samples (scalp hair and blood) of night blindness children.

Intellectual Impairment in School-Age Children Exposed to Manganese from Drinking Water

BackgroundManganese is an essential nutrient, but in excess it can be a potent neurotoxicant. Despite the common occurrence of manganese in groundwater, the risks associated with this source of exposure are largely unknown.ObjectivesOur first aim was to assess the relations between exposure to manganese from drinking water and children’s intelligence quotient (IQ). Second, we examined the relations between manganese exposures from water consumption and from the diet with children’s hair manganese concentration.MethodsThis cross-sectional study included 362 children 6–13 years of age living in communities supplied by groundwater. Manganese concentration was measured in home tap water (MnW) and children’s hair (MnH). We estimated manganese intake from water ingestion and the diet using a food frequency questionnaire and assessed IQ with the Wechsler Abbreviated Scale of Intelligence.ResultsThe median MnW in children’s home tap water was 34 μg/L (range, 1–2,700 μg/L). MnH increased with manganese intake from water consumption, but not with dietary manganese intake. Higher MnW and MnH were significantly associated with lower IQ scores. A 10-fold increase in MnW was associated with a decrease of 2.4 IQ points (95% confidence interval: −3.9 to −0.9; p < 0.01), adjusting for maternal intelligence, family income, and other potential confounders. There was a 6.2-point difference in IQ between children in the lowest and highest MnW quintiles. MnW was more strongly associated with Performance IQ than Verbal IQ.ConclusionsThe findings of this cross-sectional study suggest that exposure to manganese at levels common in groundwater is associated with intellectual impairment in children.

Early biological markers of manganese exposure

To explore the biomarker of manganese exposure by analyzing the relationship between manganese exposure and concentration in some biomaterials. The air samples were collected through the individual air sample. According to the manganese levels in the air, workers were assigned to control group, low concentration group and high concentration group, and manganese in the hair, urine, serum, blood cell and saliva from different group were measured respectively. The correlations between concentration of external manganese exposure and manganese concentrations in biomaterials, and years of employment and concentrations in biomaterials were analyzed. In the high concentration group, saliva manganese was 32.17 µg/L, hair manganese was 37.39 mg/kg, urine manganese was 2.50 µg/L, plasma manganese was 29.61 µg/L, blood manganese was 14.49 µg/L, were higher than those in the control group (10.40 µg/L, 1.60 mg/kg, 0.77 µg/L, 10.30 µg/L, 4.56 µg/L respectively) (P < 0.01). The manganese concentration in the saliva was significantly correlated with airborne manganese concentration (r = 0.649, P < 0.01), with the years of employment (r = 0.404, P < 0.01), with the total exposure of manganese (r = 0.342, P < 0.01), with the manganese concentration of plasma (r = 0.303, P < 0.01) and with the manganese concentration in blood cells (r = 0.359, P < 0.01), respectively. The concentration of manganese in saliva could work as a biomarker of manganese internal exposure.

Manganese Concentrations In Hair and Fingernail of Some Kano Inhabitants

Manganese concentrations in hair and fingernails were determined by Flame Atomic Absorption Spectrometry (AAS).The mean manganese in hair and fingernail were 0.54 ± 0.35mg/g and 0.68 ± 0.30mg/g respectively. A progressive decrease in manganese concentrations in hair and fingernails with age indicated no significant difference in their means suggesting that manganese in hair and fingernails originate from a common source. Comparing the mean manganese concentrations in hair with the fingernails a significant difference is indicated in the two tissues (p≤0.05). Human hair and fingernails are therefore recording filaments that can reflect metabolic changes of many elements over long periods of time and hence furnish an imprint of post nutritional event as dietary levels of essential micro-elements.

Manganese and Cobalt Concentrations in Hair and Nail of Some Kano Inhabitants

Manganese and cobalt concentrations in hair and nail were determined by Flame Atomic Absorption Spectrophotometer (AAS).The mean manganese in hair and nail were 0.54 ± 0.35mg/g and 0.68 ± 0.30mg/g while the mean cobalt in hair and nail were 0.30 ± 0.24mg/g and 0.460.37mg/g respectively. A progressive increase in cobalt concentrations in hair and nails with age indicated no significant difference in their means suggesting that cobalt in hair and nails originate from a common source. Comparing the mean manganese concentrations in hair with the nails a significant difference is indicated in the two tissues (pdd0.05). Human hair and nails are hence recording filaments that can reflect metabolic changes of many elements over long periods of time and hence furnish a post nutritional event of some essential micro-elements.

Metal Exposure in the Children of Punjab, India

Our test results documented that hair and urine mineral analysis results support each other. This is of interest, because hair analysis evaluates past exposure while urine analysis detects immediate exposure. We evaluated barium, cadmium, manganese, lead and uranium in hair and urine. Our test results indicate that all of the children show evidence of past and immediate exposure to one or more metals. Hair mineral test results for the 114 children aged 12 and younger showed some type of toxic metal exposure for each one of the children; 88% exceeded the uranium reference range for hair. This indicates past and chronic exposure. After renal evaluation, 55 children aged 3–12 years who passed certain criteria were selected for urine baseline testing. Urine baseline concentrations are a direct reflection of immediate exposure. Of the 55 children, 47 showed elevated urine concentrations for one or more of the toxins listed above, demonstrating immediate exposure. DMSA is recommended as an oral antidote for lead and other metals. We selected 55 children aged 3–12 for a DMSA (Dimercapto succinic acid) urine challenge test. Our results showed that 98% of this group showed lead concentrations above the baseline level, demonstrating lead binding and excretion. The DMSA challenge did not affect barium, cadmium, manganese and uranium, suggesting that for these elements, DMSA may not be the chelating agent of choice. In summary, hair and urine mineral testing demonstrated that chronic and immediate toxic exposure had affected our test group of Punjabi children. The DMSA challenge test was effective in detoxifying lead, but did not affect barium, cadmium, manganese or uranium.

High levels of hair manganese in children living in the vicinity of a ferro-manganese alloy production plant

Manganese (Mn) is an essential element, but an effective toxic at high concentrations. While there is an extensive literature on occupational exposure, few studies have examined adults and children living near important sources of airborne Mn. The objective of this study was to analyze hair Mn of children living in the vicinity of a ferro-manganese alloy production plant in the Great Salvador region, State of Bahia, Brazil and examine factors that influence this bioindicator of exposure. We examined 109 children in the age range of 1–10 years, living near the plant. Four separate housing areas were identified a priori on the bases of proximity to the emission sources and downwind location. A non-exposed group ( n = 43) of similar socio-economic status was also evaluated. Mn hair (MnH) concentration was measured by graphite atomic absorption spectrometry (GFAAS). Possible confounding hematological parameters were also assessed. Mean MnH concentration was 15.20 μg/g (1.10–95.50 μg/g) for the exposed children and 1.37 μg/g (0.39–5.58 μg/g) for the non-exposed. For the former, MnH concentrations were 7.95 ± 1.40 μg/g (farthest from the plant), 11.81 ± 1.11 μg/g (mid-region), 34.43 ± 8.66 μg/g (closest to the plant) and 34.22 ± 9.15 μg/g (directly downwind). Multiple regression analysis on log transformed MnH concentrations for the exposed children derived a model that explained 36.8% of the variability. In order of importance, area of children's residence, gender (girls > boys) and time of mother's residence in the area at the birth of the child, were significantly associated with MnH. Post hoc analyses indicated two groupings for exposure areas, with those living closest to and downwind of the plant displaying higher MnH concentrations compared to the others. The contribution of the time the mother lived in the community prior to the child's birth to the children's current MnH suggests that in utero exposure may play a role. A study of neurobehavioral performance with respect to Mn exposure in these children is currently underway.