RESUMEN
BACKGROUND: The fluoride ion toxicity has been associated with both dental fluorosis and neurotoxicity; dental fluorosis has tended to be considered with respect to tooth appearance and function rather than as a marker for neurotoxicity. AIMS AND OBJECTIVES: This study assessed the intelligence quotient (IQ) of school-going children aged 10-12 years in villages of Nalgonda district with different fluoride levels. MATERIALS AND METHODS: A cross-sectional study was conducted among the permanent residents of Nalgonda district of Telangana state, India. A total of 480 government schoolchildren aged 10-12 years were selected by stratified random sampling from three different areas with different levels of naturally occurring fluoride in drinking water. Intelligence levels were assessed by conducting the Ravens standard progressive matrices test (1991 edition). STATISTICAL ANALYSIS: The data were subjected to analysis of variance (ANOVA), Student's t-test, and Krustal-Wallis ANOVA. A logistic regression model was performed (SPSS version; 21(IBM corporation, Chicago,IL, USA)). RESULTS: The mean IQ levels were more in the villages with low fluoride concentration in drinking water (15.26) compared to villages with medium fluoride content (12.91) and high fluoride content (9.1). A significant statistical association was found (P < 0.001). CONCLUSION: The overall IQ levels in children exposed to high fluoride level significantly lower than the low fluoride areas. Thus, children intelligence can be affected by high water fluoride levels.