Hair Manganese Concentrations Research Articles

Maternal blood and hair manganese concentrations, fetal growth, and length of gestation in the ISA cohort in Costa Rica

BackgroundAnimal studies have shown that both deficiency and excess manganese (Mn) may result in decreased fetal size and weight, but human studies have reported inconsistent results. MethodsWe examined the association of blood and hair Mn concentrations measured at different times during pregnancy with fetal growth among term births and length of gestation in a cohort of 380 mother–infant pairs living near banana plantations aerially sprayed with Mn-containing fungicides in Costa Rica. We used linear regression and generalized additive models to test for linear and nonlinear associations ResultsMean (± SD) blood Mn concentration was 24.4±6.6μg/L and geometric mean (geometric SD) hair Mn concentration was 1.8 (3.2) μg/g. Hair Mn concentrations during the second and third trimesters of gestation were positively related to infant chest circumference (β for 10-fold increase=0.62cm; 95% CI: 0.16, 1.08; and β=0.55cm; 95% CI: −0.16, 1.26, respectively). Similarly, average maternal hair Mn concentrations during pregnancy were associated with increased chest circumference (β for 10-fold increase=1.19cm; 95% CI: 0.43, 1.95) in infants whose mothers did not have gestational anemia, but not in infants of mothers who had gestational anemia (β=0.39cm; 95% CI: −0.32, 1.10; pINT=0.14). All these associations were linear. Blood Mn concentrations did not show consistent linear nor nonlinear relationships with any of the birth outcomes ConclusionsMn plays an important role in fetal development, but the extent to which environmental exposures may cause adverse health effects to the developing fetus is not well understood. Among women living near banana plantations in Costa Rica, we did not observe linear or nonlinear associations of Mn concentrations with lowered birth weight or head circumference, as reported in previous studies. However, we did find positive linear associations between maternal hair Mn concentrations during pregnancy and infant chest circumference.

Maternal Blood and Hair Manganese Concentrations, Fetal Growth, and Length of Gestation in the ISA Cohort in Costa Rica

Background Animal studies have shown that both deficiency and excess manganese (Mn) may result in decreased fetal size and weight, but human studies have reported inconsistent results.

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.

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.

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.

Changes in Trace Element Concentrations in Hair of Growing Children

Head hair concentrations of zinc, copper, manganese, alid iron from a total of 418 subjects (154 male and 264 female) aged between 6 mo and 20 yr were measured mainly with flameless atomic absorption spectrophotometry. Only zinc analysis of a part of the female samples (n = 140) were analyzed with inductively coupled plasmaatomic emission spectrometry. The two analytical methods showed close agreement. The mean concentration of copper and manganese were significantly higher in male subjects than in female subjects. The trace element concentrations in hair varied with the subject's age. Zinc concentration in hair decreased from 6 mo to 14 yr in the male subjects and decreased from 6 mo to 12 yr in the female subjects. Then, the concentrations increased gradually to 20 yr in the both sexes. Age-dependent variations of copper and manganese concentrations in hair showed similar trends to those of zinc. The results of this study suggest that a higher concentration in the diet of these trace elements may be required for growing children, especially in the period of adolescence.

Hair manganese concentrations in newborns and their mothers

The study was designed to investigate the manganese (Mn) status of mothers and their offspring at delivery. Hair Mn concentrations in 31 full-term, 18 preterm and 12 newborn infants with congenital malformations and their mothers were determined by the flameless atomic absorption technique. Both in infants with congenital malformations and their mothers, hair Mn levels were significantly lower than the full-term and preterm infant-mother pairs. With the exception of mothers of infants with congenital malformations, hair Mn concentrations in mothers were significantly higher as compared with their infants. Low hair Mn concentrations of infants with congenital malformations and their mothers may possibly reflect a state of Mn deficiency in these women. These results imply that 1) Mn deficiency may play a role as one potential factor in intrauterine malformations, 2) Mn is supplied to the fetus by a homeostatic mechanism which is mainly dependent on the Mn status of the mother, 3) prenatal Mn analysis in maternal hair may prove to be a reliable indicator for the risk of intrauterine malformations.