In addition, children can be at a higher risk than adults to compounds in drinking water because they consume more water per unit of body weight than adults (USEPA, 2011). To obtain a reliable estimate of Mn exposure in children, it is necessary to account for age-related differences in exposure factors such as water consumption rates, for Mn concentrations in various exposure media (e.g. drinking water) and for age-dependent differences in patterns of Mn-homeostasis.