[Evaluation of fluoride levels in drinking water of towns in the Ribeirão Preto area]. / Avaliação teor de fluoreto na água de abastecimento de cidades na região de Ribeirão Preto.

ABSTRACT

A fluoride selective electrode was employed to determinate the fluoride levels in samples of city water from Ribeirão Preto region. Values between 0.1-0.5 ppm, 0.5-0.7 ppm and 0.7-1.0 ppm were detected in the water from respectively 17 (25%), 13 (19.1%) and 7 (10.3%) cities. Samples from the others 31 (45.6%) cities studied did not show significant levels of fluoride when analyzed by this method.