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.

Recent research (Vallerand et al., 2003) has supported the existence of two types of passion for activities: a harmonious and an obsessive passion. The purpose of this investigation was to study the processes likely to lead to the development of passion. Three studies using correlational and short-term longitudinal designs with varied populations ranging from beginners to experts reveal that identification with the activity, activity specialization, parents' activity valuation, and autonomy support predict the development of passion. Furthermore, results show that children and teenagers whose environment supports their autonomy are more likely to develop a harmonious passion than an obsessive one. Conversely, children and teenagers who highly value activity specialization, who rely heavily on their activity for self-definition, and whose parents highly value the activity are more likely to develop an obsessive passion.

The first objective of this study was to examine whether a relationship exists between types of goal orientation, self-regulatory processes and school performance and the second was toexamine how students' self-regulation and academic performancediffer according to their profiles resulting from combining learning and performance goals orientation. A total of 702 college students (463 females and 239 males) was administered a questionnaire assessing their orientation toward learning and performance goals, and reported their self-regulatory strategies for studying. Results showed that both for males and females there exist systematic relations between learning goal and self-regulation and academic achievement. Relations were also found for performance goal, but for boys only. Results also showed that, among the four profiles of goal orientation, more self-regulatory strategies were reported and higher academic performance was achieved by students having high concern with both learning and performance goals than by the others. More girls were classified in this profile, but in each profile girls were found to report more self-regulatory strategies and to achieve higher academic performance than did boys. Overall, these findings are consistent with those of previous studies conducted with younger students. Although adhesion to learning goal has a positive impact on self-regulation both for girls and boys, for the latter adhesion to performance goal can also be helpful. In view of the role of goal orientation on self-regulation in academic activities, research is needed to identify and understand the nature of the determinants of both the adhesion to these profiles and the gender differences.Metacognition refers both to the explicit knowledge individuals have about their cognitive resources and to the deliberate self-regulation they can exercise when applying this knowledge. Interest in metacognition has led to new research on learning processes in school settings. Studies based on the information processing approach in the development of models of metacognition have particularly focused on the self-regulatory processes, and have identified important components of self-regulation permitting effective learning management. The three major components of self-regulation identified are cognitive strategies, necessary to learn, memorise. understand, etc., metacognitive strategies, allowing adequate supervision during task execution, and motivation, determining the amount of effort needed

Background: Manganese neurotoxicity is well documented in individuals occupationally exposed to airborne particulates, but few data are available on risks from drinking-water exposure.Objective: 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.Methods: 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.Results: 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.Conclusion: Exposure to manganese in water was associated with poorer neurobehavioral performances in children, even at low levels commonly encountered in North America.Citation: Oulhote Y, Mergler D, Barbeau B, Bellinger DC, Bouffard T, Brodeur ME, Saint-Amour D, Legrand M, Sauvé S, Bouchard MF. 2014. Neurobehavioral function in school-age children exposed to manganese in drinking water. Environ Health Perspect 122:1343–1350; http://dx.doi.org/10.1289/ehp.1307918

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