Hair Mn Research Articles

Manganese exposure and cognitive deficits: A growing concern for manganese neurotoxicity

This symposium comprised five oral presentations dealing with recent findings on Mn-related cognitive and motor changes from epidemiological studies across the life span. The first contribution highlighted the usefulness of functional neuroimaging of the central nervous system (CNS) to evaluate cognitive as well as motor deficits in Mn-exposed welders. The second dealt with results of two prospective studies in Mn-exposed workers or welders showing that after decrease of Mn exposure the outcome of reversibility in adverse CNS effects may differ for motor and cognitive function and, in addition the issue of plasma Mn as a reliable biomarker for Mn exposure in welders has been addressed. The third presentation showed a brief overview of the results of an ongoing study assessing the relationship between environmental airborne Mn exposure and neurological or neuropsychological effects in adult Ohio residents living near a Mn point source. The fourth paper focused on the association between blood Mn and neurodevelopment in early childhood which seems to be sensitive to both low and high Mn concentrations. The fifth contribution gave an overview of six studies indicating a negative impact of excess environmental Mn exposure from air and drinking water on children's cognitive performance, with special attention to hair Mn as a potential biomarker of exposure. These studies highlight a series of questions about Mn neurotoxicity with respect to cognitive processes, forms and routes of exposure, adequate biomarkers of exposure, gender differences, susceptibility and exposure limits with regard to age.

Analysis of Heavy Metals in Human Scalp Hair Using Energy Dispersive X-Ray Fluorescence Technique

Analysis of six heavy metals (Cr, Mn, Ni, Cu, Zn and Mo) in human scalp hair was carried out among various occupational distributions to ascertain their heavy metal burden, using energy dispersive x-ray fluorescence technique (ED-XRF). The result of the analysis shows that mean concentrations (mg/kg) of heavy metals obtained were as follows: Cr = 17.1 ± 12.7; Mn = 3.11 ± 0.50; Ni = 11.3 ± 9.3; Zn = 451 ± 128; Cu = 83.3 ± 35.8 and Mo is 9.16 ± 9.1.While the mean concentrations of Cr, Cu, and Mo were higher in the females, that of Mn, Ni and Zn were more in the males. Statistical analysis of the results for both genders at 0.05 probably shows significant difference for Ni, Zn and Mo while Cr, Mn and Cu showed no significant difference. The relationships between age, body mass, height, and heavy metal concentrations were also investigated. Statistical analysis of the results indicates that there was no correlation between the body mass (R2 ≤ 0.048), height (R2 ≤ 0.002) and heavy metal concentration in hair. Zn showed the highest deviation among other elements in the individual samples for both genders which reflect the individual variation in the concentration of Zn.

Comparative evaluation of trace elements in the scalp hair of arthritis patients and healthy donors

This study was aimed to evaluate the comparative distribution, correlation and apportionment of selected elements (Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Pb and Zn) in the scalp hair of arthritis patients and healthy subjects. The hair samples collected from the patients (rheumatoid and osteoarthritis) and healthy donors were digested in nitric acid and perchloric acid mixture, followed by the quantification of trace elements using atomic absorption spectrometry. In the case of healthy donors, highest mean concentration was shown by Ca (3240 µg g−1), followed by Mg (340 µg g−1), Zn (192 µg g−1), Fe (184 µg g−1) and Pb (27 µg g−1), whereas, the estimated average metal levels in rheumatoid arthritis and osteoarthritis patients were 3160, 290, 197, 61 and 23 µg g−1, and 3090, 300, 182, 50 and 21 µg g−1, respectively. Most of the elements revealed diverse and random distribution in the scalp hair of the donor groups. The correlation study pointed out significant disparities in the mutual relationships among the trace elements in the patients and controls. Principal component analysis and cluster analysis of the element data manifested diverse apportionment of the selected elements in the scalp hair of the patients compared with the healthy counterparts.

Serum prolactin rises in Mexican school children exposed to airborne manganese

Early studies on manganese (Mn) exposure have shown that this transition metal affects dopamine neurotransmission. Dopamine serves as a tonic inhibitor of prolactin release in the anterior hypophysis, thus the serum prolactin levels in occupationally Mn exposed workers has been found increased. However, little is known about environmental Mn exposure effect on this hormone. In the present study we assessed serum prolactin in environmentally (mainly through air) exposed children living in the proximity of a rich Mn zone in Mexico and a control group with similar socioeconomic and ethnic characteristics. We also determined Mn levels in blood and hair, hemoglobin and anthropometric variables. Children between 7 and 11 years old were included (77 from Mn exposed and 93 from control communities). Blood Mn was higher in exposed children (median 9.5μg/L, rank [5.5, 18]) as compared to the control group (median 8μg/L, rank [5, 14]) (p<0.05, Mann–Whitney). Hair Mn was also increased in the exposed group (median 13.2μg/g, rank [4.2, 48]) in comparison to the control group (median 0.6μg/g rank [0.06, 3.6]). Prolactin was found increased in the exposed children (median 12.35ng/ml, rank [2.90, 33.70]) versus controls (median 7.77ng/ml, rank [2.7, 23.6]). Positive correlations were found between prolactin and both blood Mn and hair Mn (Rho=0.217 and 0.250, respectively, p<0.05). A linear regression, with prolactin as the dependent variable, showed hair Mn as the determinant variable after adjusting by age, hemoglobin and sex. After a stratification of hair and blood Mn into low, medium and high content, significant associations were also found, confirming the relationship between prolactin and hair Mn. Results suggest that children from these Mn environmentally exposed communities could be at risk of endocrine alterations.

Heavy metal status of Polish Konik horses from stable-pasture and outdoor maintenance systems in the masurian environment

Among domestic animals, cattle and horses kept on pasture and fed with hay and straw are exposed most prominently to environmental pollution. Determination of the status of heavy metals in bodies of horses is important for two reasons. Firstly, it helps to assess the level of environmental contamination. Secondly, heavy metals can have considerable influence on animals living outdoors. The aim of the study has been to verify whether the level of Cr, Mn, Cu, Cd, Pb and Ni in the coat hair and cornified structures of hooves may differ between horses maintained alternately in a stable and on pasture and living outdoors all year long, with Polish Koniks from Mazury (the Masurian Lake District) taken as an example. Possible effects of the feeding season and age of horses were considered. In total, 35 Polish Konik horses were examined, either kept in a stable-pasture system in Popielno or outdoors in Wojnowo. Sixty-two samples of summer and winter coat hair, 28 samples of hoof horn, as well as 10 samples of pasture plants and water were analyzed. The data were elaborated with the use multi-factor analysis of variance, T-Tukey-Kramer test and Pearson’s correlation. The results show that Polish Konik horses bred in Mazury have a low heavy metal concentration in the coat hair and hoof horn. The stable-pasture and outdoor maintenance systems hardly differentiate the element content, whereas the winter feeding results in

Background Values for Essential and Toxic Elements in Children’s Nails and Correlation with Hair Levels

Human nails are an attractive matrix for assessing environmental exposures to toxic elements as well as the deficiency of essential elements since it is noninvasively collected and can be stored at room temperature. However, reference or baseline levels in nonexposed and healthy populations are not yet established. Then, the aims of this study were (a) to estimate background values for essential and toxic elements in nails from a healthy young population in southern Brazil and (b) to evaluate possible correlations between essential and toxic elements in nails. Furthermore, this report took part of a recent study of background values in the hair of a young population. Thus, correlations between chemical elements in nails and hair were also evaluated. Nails were collected from healthy children (n = 126), and element concentrations were determined by inductively coupled plasma mass spectrometry. This study provides new and reliable reference concentrations for toxic and essential elements in children's nails. The results can be used as reference values for epidemiological or clinical investigations based on trace elements in nails. Additionally, we also showed weak to strong correlations between Cu, Mg, Mn, Se, and Zn levels in nails and hair.

Heavy metal content in scalp hair of the inhabitants near Dexing Copper Mine, Jiangxi Province, China

Levels of seven metals (Mn, Cu, Zn, Pb, Cr, Cd, and Se) in the scalp hair of Daicun and Xiangtian inhabitants were determined by ICP-MS/AFS. Daicun, as an experimental site, is near Dexing Copper Mine, Jiangxi Province, China, and exposed to mining pollution; Xiangtian, as a control site, is free from any mining and other industrial pollution. The heavy metal distribution in the scalp hair of the two diverse population segments exposed to different environments was discussed against the background of the heavy metal content of local plants, waters, and soils. The results show: 1) Levels of Cu, Zn, Pb, Cr, and Cd in the scalp hair of Daicun inhabitants were higher compared with Xiangtian counterparts which showed higher comparative levels of Se and Mn. But there were no significant differences of the levels of Cu and Zn in the hair samples between the two villages. In the hair of the inhabitants in the two villages, the levels for Se, Zn, and Cu were lower, while the level for Mn was higher, than the corresponding levels from other regions of the world. Compared with the standard issued by the Trace Element Research Council of China for Chinese inhabitants there were serious Se, Zn, Cu and Cr-deficiency phenomena in the hair samples from Daicun and Xiangtian. 2) Against the geological background of high levels of Zn, Cu, Se and Cr, there were deficiencies of Zn, Cu, Se and Cr in the hair samples of the Daicun population. This may have been caused by the distribution forms of the heavy metals in the soils, and antagonism among the elements. 3) Principal Component Analysis (PCA) and Cluster Analysis (CA) indicated that the origins of the heavy metals in the hair samples from the two villages had some differences as well as some similarities, this should be contributed mainly to the influence of the mining activities.

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.

Identification of Human Age Using Trace Element Concentrations in Hair and the Support Vector Machine Method

Trace element content in hair is affected by the age of the donor. Hair samples of subjects from four counties in China where people are known to have long lifespan ("longevity counties") were collected and the trace element content determined. Samples were subdivided into three age groups based on the age of the donors from whom these were taken: children (0-15years); elderly (80-99years); and centenarians (≥100years). We compared the trace element content in hair of different age groups of subjects. Support vector machine classification results showed that a non-linear polynomial kernel function could be used to classify the three age groups of people. Age did not have a significant effect on the content of Ca and Cd in human hair. The content of Li, Mg, Mn, Zn, Cr, Cu, and Ni in human hair changed significantly with age. The magnitude of the age effect on trace element content in hair was in the order Cu > Zn > Ni > Mg > Mn > Cr > Li. Cu content in hair decreased significantly with increasing age. The hair of centenarians had higher levels of Li and Mn, and lower levels of Cr, Cu, and Ni comparing with that of the children and elderly subjects. This could be a beneficial factor of their long lifespan.

A High Accumulation of Hair Minerals in Mongolian People: 2nd Report; Influence of Manganese, Iron, Lead, Cadmium and Aluminum to Oxidative Stress, Parkinsonism and Arthritis

It was previously reported that the hair of Mongolian people showed very high accumulation of manganese (Mn), which may increase oxidative stress. This study (2(nd) report), indicated that not only Mn but other minerals had also accumulated at high levels in hair. It describes the influence of these minerals on oxidative stress, Parkinson's disease-like symptom (Parkinsonism) and arthritis, these diseases being prevalent in Mongolia. 299 subjects were enrolled (including 21; Parkinsonism and 25; arthritis) from Ulaanbaatar and 5 other areas in Mongolia. Oxidative stress was evaluated by measuring the level of urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG). The minerals accumulated in scalp hair were measured by the inductively coupled plasma mass spectrometry method. As a control, 81 healthy Japanese subjects were enrolled. Mongolian subjects showed high accumulated levels of Mn, iron, lead, cadmium and aluminum accumulations in hair, as compared with Japanese subjects. These levels were correlated with urinary 8-OHdG levels. The subjects with Parkinsonism and arthritis demonstrated higher levels in these minerals than healthy subjects. High accumulations of these minerals may increase oxidative stress in Mongolian people, and induce Parkinsonism and arthritis through the high oxidative stress. The high accumulations of these minerals may be induced by eating large amounts of sheep meat. In addition, sandy wind pollution may also contribute to it.

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.

Impact of open manganese mines on the health of children dwelling in the surrounding area

Introduction:Chronic manganese (Mn) exposure is a health hazard associated with the mining and processing of Mn ores. Children living in an area with increased environmental exposure to Mn may have symptoms of chronic toxicity that are different from adults who experience occupational exposure. The aim of the study was to compare health outcomes in a pediatric population living near open Mn mines with a group of children from a reference area and then to develop and implement preventive/rehabilitation measures to protect the children in the mining region.Methods:After environmental assessment, a group of 683 children living in a Mn-rich region of Ukraine were screened by clinical evaluation, detection of sIgA (37 children), micronucleus analysis (56 children), and hair Mn content (166 children).Results:Impaired growth and rickets-like skeletal deformities were observed in 33% of the children. This was a significantly higher percentage than in children in the reference region (15%). The children from the Mn-mining region also had increased salivary levels of immunoglobulin A (104.4±14.2 mcg/ml vs. 49.7±6.1 mcg/ml among the controls (p<0.05), increased serum alpha 1 proteinase inhibitor levels (4.93±0.21 g/l compared with 2.91±0.22 g/l for controls; p<0.001) and greater numbers of micronuclei in the mucous cells of the oral cavity (0.070±0.008 vs. 0.012±0.009, p<0.001).Conclusions:These findings indicate the deleterious health consequences of living in a Mn-mining area. Medical rehabilitation programs were conducted and produced positive results, but further validation of their effectiveness is required. The study provided background information to formulate evidence-based decisions about public health in a region of high Mn exposure.

Elevated manganese and cognitive performance in school-aged children and their mothers

Background Growing evidence suggests that excess manganese (Mn) in children is associated with neurobehavioral impairments. In Brazil, elevated hair Mn concentrations were reported in children living near a ferro-manganese alloy plant. Objectives We investigated these children’s and caregivers’ cognitive function in relation to bioindicators of Mn exposure. Methods In this cross-sectional study, the WISC-III was administered to 83 children aged between 6 and 12 years; the Raven Progressive Matrix was administered to the primary caregivers (94% mothers), who likewise responded to a questionnaire on socio demographics and birth history. Mn in hair (MnH) and blood (MnB) and blood lead (PbB) were measured by graphite furnace atomic absorption spectrometry (GFAAS). Results Children’s mean MnB and MnH were 8.2 μg/L (2.7–23.4) and 5.83 μg/g (0.1–86.68), respectively. Mean maternal MnH was 3.50 μg/g (0.10–77.45) and correlated to children’s MnH (rho=0.294, p=0.010). Children’s MnH was negatively related to Full-Scale Intelligence Quotient (IQ) and Verbal IQ; β coefficients for MnH were −5.78 (95% CI −10.71 to −0.21) and −6.72 (−11.81 to −0.63), adjusted for maternal education and nutritional status. Maternal MnH was negatively associated with performance on the Raven’s ( β=−2.69, 95% CI −5.43 to 0.05), adjusted for education years, family income and age. Conclusions These findings confirm that high MnH in children is associated with poorer cognitive performance, especially in the verbal domain. Primary caregiver’s IQ is likewise associated to Mn exposure, suggesting that, in this situation, children’s cognition may be affected directly and indirectly by Mn 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 Function in Mexican Children Living in a Mining Area and Environmentally Exposed to Manganese

BackgroundExcessive exposure to manganese (Mn), an essential trace element, has been shown to be neurotoxic, especially when inhaled. Few studies have examined potential effects of Mn on cognitive functions of environmentally exposed children.ObjectiveThis study was intended to estimate environmental exposure to Mn resulting from mining and processing and to explore its association with intellectual function of school-age children.MethodsChildren between 7 and 11 years of age from the Molango mining district in central Mexico (n = 79) and communities with similar socioeconomic conditions that were outside the mining district (n = 93) participated in the cross-sectional evaluation. The revised version of the Wechsler Intelligence Scale for Children adapted for the Mexican population was applied. Concentrations of Mn in blood (MnB) and hair (MnH) were used as biomarkers of exposure.ResultsExposed children had significantly higher median values for MnH (12.6 μg/g) and MnB (9.5 μg/L) than did nonexposed children (0.6 μg/g and 8.0 μg/L, respectively). MnH was inversely associated with Verbal IQ [β = −0.29; 95% confidence interval (CI), −0.51 to −0.08], Performance IQ (β = −0.08; 95% CI, −0.32 to 0.16), and Total Scale IQ (β = −0.20; 95% CI, −0.42 to 0.02). MnB was inversely but nonsignificantly associated with Total and Verbal IQ score. Age and sex significantly modified associations of MnH, with the strongest inverse associations in young girls and little evidence of associations in boys at any age. Associations with MnB did not appear to be modified by sex but appeared to be limited to younger study participants.ConclusionsThe findings from this study suggest that airborne Mn environmental exposure is inversely associated with intellectual function in young school-age children.

Validation of a method to quantify chromium, cadmium, manganese, nickel and lead in human whole blood, urine, saliva and hair samples by electrothermal atomic absorption spectrometry

For biological monitoring of heavy metal exposure in occupational toxicology, usually whole blood and urine samples are the most widely used and accepted matrix to assess internal xenobiotic exposure. Hair samples and saliva are also of interest in occupational and environmental health surveys but procedures for the determination of metals in saliva and hair are very scarce and to our knowledge there is no validation of a method to quantify Cr, Cd, Mn, Ni and Pb in four different human biological materials (whole blood, urine, saliva and axilary hair) by electrothermal atomization atomic absorption spectrometry (ETAAS). In the present study, quantification methods for the determination of Cr, Cd, Mn, Ni and Pb in whole blood, urine, saliva and axilary hair were validated according to the EU common standards. Pyrolisis and atomization temperatures have been determined. The main parameters evaluated were: detection and quantification limits, linearity range, repeatability, reproducibility, recovery and uncertainty. Accuracy of the methods was tested with the whole blood, urine and hair certified reference materials and recoveries of the spiked samples were acceptable ranged from 96.3 to 107.8%.

Manganese exposure and the neuropsychological effect on children and adolescents: a review

Manganese (Mn) is an essential element, but overexposure can have neurotoxic effects. In this article, we review and summarize studies on exposure to Mn and nervous system impairments in children. We identified 12 original articles published between 1977 and 2007. Overexposure to Mn was suspected to occur through diverse sources: infant milk formula, drinking water, industrial pollution, and mining wastes. The most common bioindicator of exposure to Mn was hair Mn content, but some studies measured Mn in blood, urine, or dentin; one study on prenatal exposure measured Mn content in cord blood. Most studies indicate that higher postnatal exposure to Mn is associated with poorer cognitive functions and hyperactive behavior. The limitations of the existing studies are numerous: most were cross-sectional, had a modest sample size, and lacked adjustment for important confounders. Future investigations should be performed on a larger sample size and include a more detailed exposure assessment, addressing multiple sources of exposure such as food, water, and airborne particulates.

Environmental manganese exposure in residents living near a ferromanganese refinery in Southeast Ohio: A pilot study

Manganese (Mn) is an essential element, yet is neurotoxic in excess. The majority of Mn research has been conducted on occupationally exposed adults with few studies focused on an environmentally exposed population. Marietta, OH is home to one of the largest airborne Mn emission sources in the United States, a ferromanganese refinery. In preparation for a community-based participatory research study, a preliminary pilot study was initiated to characterize the community's exposure to Mn in ambient air and to evaluate the relationship between biological indices of Mn exposure and genes associated with Mn metabolism in Marietta area residents. Participants in the pilot study were recruited through newspaper advertisement, fliers and direct mailing. Exposure to ambient Mn was estimated using an air pollution dispersion model, AERMOD. A total of 141 residents participated in the pilot study ranging in age from 2 to 81 years. Estimated annual average ambient air Mn concentrations in the study area obtained from AERMOD varied from 0.02 to 2.61 μg/m 3. Mean blood and hair Mn values were 9.12 μg/L (SD 3.90) and 5.80 μg/g (SD 6.40 μg/g), respectively and were significantly correlated ( r = 0.30, p < 0.01). Blood and hair Mn was significantly associated within families ( r = 0.27, p = <0.02 and r = 0.43, p < 0.01), respectively. The relationship between hair Mn and estimated ambient air Mn became significant when genes for iron metabolism were included in linear models. The preliminary ambient air and biological concentrations of Mn found in this population demonstrate the need for further research into potential health effects.

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.

Status of essential trace metals in biological samples of diabetic mother and their neonates

There is accumulating facts that the metabolism of essential trace elements is altered in diabetic patients. The aim of present study was to compare the status of essential trace elements, chromium (Cr), manganese (Mn), and zinc (Zn) in biological samples (whole blood, urine and scalp hair) of insulin dependent diabetic mothers (age ranged 30-40) and their newly born infants (n = 76). An age matched 68 non-diabetic mothers and their infants, residing in the same locality, were selected as referents. For a comparative study, the biological samples of non-diabetic and diabetic pregnant and non pregnant of same age group and socio-economics status were also analysed. The biological samples (scalp hair, blood and urine) were collected from study and referent groups. The Cr, Mn and Zn concentrations in all three biological samples were determined by a flame/electrothermal atomic absorption spectrometer, prior to microwave assisted acid digestion. The validity and accuracy of the methodology was checked by certified reference materials (CRMs) and using conventional wet acid digestion method on same CRMs. The mean values of Cr, Mn and Zn in scalp hair and blood samples of diabetic mothers and their infants were significantly lower as compared to the referent mothers-infants pairs (p < 0.01), while urinary excretion of all these elements were high in diabetic mother-infant pair samples. The deficiencies of essential trace elements, Cr, Mn and Zn in biological samples of diabetic women, may play role in the pathogenesis of diabetes mellitus and impacts on their neonates.