Using data from the Ontario Longitudinal Study of Aging (LSA) and data for aluminum and fluoride water concentration in areas where the LSA subjects resided, a preliminary analysis suggests that persons who show no indications of impaired mental functioning are more likely to have resided in areas where the aluminum concentrations (in drinking water) are relatively low and where fluoride concentrations (in drinking water) are relatively high. The difficulties in analyses of this type include the likelihood that many persons who are affected by impaired mental functioning do not respond to surveys, the identification of impaired mental functioning, and obtaining good exposure estimates of fluoride and aluminum drinking water concentrations.
