Fluctuations in public water fluoride level in Bauru, Brazil.
OBJECTIVE
The aim of this study was to monitor the quality of public water supply fluoridation in Bauru, in the state of São Paulo, Brazil.


METHODS
Water samples collected three times a week during four weeks in 20 areas of distribution of water were supplied by the City Water Department of Bauru, São Paulo, Brazil. Fluoride was analyzed using the ion-specific electrode (Orion model 9409) after sample buffering with an equal volume of TISAB II. Data were compared to fluoride concentration reported by City Water Department.


RESULTS
Fluoride content ranged between 0.01 ppm and 9.35 ppm (n = 240). There was great variation among the different areas of distribution of water, as showed by the Levene test (P < .001). Kruskal-Wallis test showed a statistically significant difference in mean fluoride concentration among different areas (P < .001). Mean fluoride concentration was less than the optimum concentration (0.8 ppm) in 89 percent of samples. The values reported by the City water Department were always higher than the analyzed fluoride concentrations.


CONCLUSIONS
Based on the results from this study, more rigorous surveillance and monitoring of water fluoridation in Bauru is recommended.
Department of Biological Sciences, Bauru Dental School, University of São Paulo, Brazil. mbuzalaf@fob.usp.br
Marília A R
MA
Buzalaf
José M
JM
Granjeiro
Carla A
CA
Damante
Flávia
F
Ornelas
D000704:Analysis of Variance; D001938:Brazil; D005457:Fluoridation / Q000706:statistics & numerical data*; D005459:Fluorides / Q000032:analysis; D017736:Ion-Selective Electrodes; D018709:Statistics, Nonparametric
D005459:Fluorides