Neurobehavioral function in school-age children exposed to manganese in drinking water

• Published in: Environmental health perspectives 2014-12, Vol.122 (12), p.1343-1350
• Main Authors: Oulhote, Youssef, Mergler, Donna, Barbeau, Benoit, Bellinger, David C, Bouffard, Thérèse, Brodeur, Marie-Ève, Saint-Amour, Dave, Legrand, Melissa, Sauvé, Sébastien, Bouchard, Maryse F
• Format: Article
• Language: English
• Subjects: Airborne particulates; Attention Deficit and Disruptive Behavior Disorders - chemically induced; Attention Deficit and Disruptive Behavior Disorders - epidemiology; Behavior; Biomarkers; Bottled water; Child; Children; Children & youth; Children's Health; Contamination; Cross-sectional studies; Drinking water; Environmental Exposure - statistics & numerical data; Exposure; Female; Groundwater; Hair; Hair - chemistry; Health; Health aspects; Humans; Hyperactivity; Ingestion; Intakes; Intelligence; Intelligence tests; Laboratories; Male; Manganese; Manganese - adverse effects; Manganese - analysis; Mathematical models; Motors; Neurotoxicity; Occupational exposure; Organic mental disorder; Quebec - epidemiology; Risk factors; Studies; Water Pollutants, Chemical - adverse effects; Water Pollutants, Chemical - analysis; Water Supply
• ISSN: 0091-6765; 1552-9924
• DOI: 10.1289/ehp.1307918

Manganese neurotoxicity is well documented in individuals occupationally exposed to airborne particulates, but few data are available on risks from drinking-water exposure. We examined associations of exposure from concentrations of manganese in water and hair with memory, attention, motor function, and parent- and teacher-reported hyperactive behaviors. We recruited 375 children and measured manganese in home tap water (MnW) and hair (MnH). We estimated manganese intake from water ingestion. Using structural equation modeling, we estimated associations between neurobehavioral functions and MnH, MnW, and manganese intake from water. We evaluated exposure-response relationships using generalized additive models. After adjusting for potential confounders, a 1-SD increase in log10 MnH was associated with a significant difference of -24% (95% CI: -36, -12%) SD in memory and -25% (95% CI: -41, -9%) SD in attention. The relations between log10 MnH and poorer memory and attention were linear. A 1-SD increase in log10 MnW was associated with a significant difference of -14% (95% CI: -24, -4%) SD in memory, and this relation was nonlinear, with a steeper decline in performance at MnW > 100 μg/L. A 1-SD increase in log10 manganese intake from water was associated with a significant difference of -11% (95% CI: -21, -0.4%) SD in motor function. The relation between log10 manganese intake and poorer motor function was linear. There was no significant association between manganese exposure and hyperactivity. Exposure to manganese in water was associated with poorer neurobehavioral performances in children, even at low levels commonly encountered in North America.