naturally occurring in soil and ground water
areas of high concentration in Quebec, Canada, not sure where else
workplace: miners and steelworkers
soy infant formula: soybean plants absorb and concentrate manganese from the soil-->200x more than breast milk
fluoride (fluoridated water) can increase manganese absorption
fluorides also-->zinc deficiency-->incr manganese levels
fluorides act as a TSH (thyroid-stimulating-hormone) analogue
EFFECTS OF TOO MUCH MANGANESE
lower intellectual functioning
lower IQ even when exposures are well within allowable range
brain damage in infants and altered behaviors in adolescents
lead researcher: Maryse Bouchard, adjunct professor and a researcher at Sainte-Justine University Hospital
Center for Interdisciplinary Research in Biology, Health, Environment and Society (CINBIOSE)
Université du Québec à Montréal
Donna Mergler, professor emerita in the Department of Biological Sciences and a member of CINBIOSE
study shows that children exposed to high concentrations of manganese in drinking water
performed worse on tests of intellectual functioning than children with lower exposures
published in the journal Environmental Health Perspectives
article entitled "Intellectual Impairment in School-Age Children Exposed to Manganese from Drinking Water."
n = 362 Quebec children, ages 6-13, living in homes supplied by with groundwater (individual or public wells)
concentration of manganese, Fe, Cu, Pb, Zn, Ar, Mg, Ca in tap water from their home
amount of manganese from both tap water and food was estimated from a questionnaire
battery of tests assessing cognition, motor skills, and behavior
average IQ of kids drinking h2o in top 20% of Mn concentration:
6 points lower than kids with little/no exposure
considered confounders: family income, maternal intelligence, maternal education, other metals
"very marked effect"
WHAT TO DO
drink filtered water: filtering pitchers reduce Mn by 60-100% and eliminate fluoride
revise national and international guidelines for safe manganese in water
avoid soy formula for infants, and avoid soy foods for adults
Environ Health Perspect. 2010 Sep 7. [Epub ahead of print]
Intellectual Impairment in School-Age Children Exposed to Manganese from Drinking Water.
Bouchard MF, Sauvé S, Barbeau B, Legrand M, Brodeur ME, Bouffard T, Limoges E, Bellinger DC, Mergler D.
Université de Montréal.
Background: Manganese is an essential nutrient, but in excess, can be a potent neurotoxicant. Despite the common occurrence of manganese in groundwater, the risks associated with this source of exposure are largely unknown. Objectives: Our first aim was to assess the relations between exposure to manganese from drinking water and children's intellectual quotient (IQ). Secondly, we examined the relations between manganese exposures from water consumption and from the diet with children's hair manganese concentration. Methods: This cross-sectional study included 362 children ages 6 to 13 years 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. Results: The median MnW in children's home tap water was 34 µg/L (range: 1-2700 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 intervals: -3.9, -0.9; P < 0.01), adjusting for maternal intelligence, family income, and other potential confounders. There was a 6.2-IQ point difference between children in the lowest and highest MnW quintiles. MnW was more strongly associated with Performance IQ than Verbal IQ. Conclusions: The findings of this cross-sectional study suggest that exposure to manganese at levels common in groundwater is associated with intellectual impairment in children.
PMID: 20855239 [PubMed - as supplied by publisher]