Manganese exposure from drinking water and children’s academic achievement
Drinking water manganese (WMn) is a potential threat to children’s health due to its associations with a wide range of outcomes including cognitive, behavioural and neuropsychololgical effects. Although adverse effects of Mn on cognitive function of the children indicate possible impact on their academic achievement little evidence on this issue is available. Furthermore, little is known regarding potential interactions between exposure to Mn and other metals, especially water arsenic (WAs). In Araihazar, a rural area of Bangladesh, the authors conducted a cross-sectional study of 840 children to investigate associations between WMn and WAs and academic achievement in mathematics and languages among elementary school-children, aged 8-11 years. Data on As and Mn exposure were collected from the participants at the baseline of an ongoing longitudinal study of school-based educational intervention. Annual scores of the study children in languages (Bangla and English) and mathematics were obtained from the academic achievement records of the elementary schools. WMn above the WHO standard of 400 íg/L was associated with 6.4% score loss (95% CI)-12.3 to -0.5) in mathematics achievement test scores, adjusted for WAs and other sociodemographic variables. The authors did not find any statistically significant associations between WMn and academic achievement in either language. Neither WAs nor urinary As was significantly related to any of the three academic achievement scores. The authors concluded that based on the findings from this study, a large number of children in rural Bangladesh may experience deficits in mathematics due to high concentrations of Mn exposure in drinking water.