Fluoride in Bottled Waters Consumed in Northeastern Brazil

ABSTRACT Objective: To assess the fluoride concentration of bottled waters from municipalities in northeastern Brazil. Material and Methods: Bottled mineral waters were purchased in two periods at different commercial places of four large municipalities (João Pessoa, Campina Grande, Patos, and Cajazeiras) in the Paraíba state. The municipalities selected to present the following annual average temperature: João Pessoa 26.5 °C, Campina Grande 23.3 °C, Patos and Cajazeiras 27.5 °C. Fluoride concentration was determined using a combined ion-specific electrode. Readings (in mV) were conducted in triplicates for each standard solution and converted into fluoride concentration (mg F/L) using the Excel® software. Results: A total of 72 samples from six brands of bottled water were analyzed. The fluoride concentrations of all samples were low (0.11-0.21mg/L) but higher than those reported on the label and varied among different batches of the same brand. Conclusion: The fluoride levels in bottled water vary among brands, and these actual values are not stated in the labels.

Level of natural fluoride in public water supply: geographical and meteorological factors in Brazil's Northeast

Abstract This study analyzed the relationships between the concentration of natural fluoride in public water supply and meteorological and hydrographic factors in a northeastern region of Brazil. This was a descriptive, analytical, ecological, longitudinal, and field study conducted by collecting water in 23 municipalities (2019 to 2020) of four macroregions of Paraíba (Brazil): coast (1), borborema (2), agreste (3), and outback (4). Four collection sites were selected per municipality: two near and two distant from the water treatment plant. Fluoride concentration was determined using a combined ion-specific electrode and classified according to the Collaborating Center of the Ministry of Health in Oral Health Surveillance. Meteorological, hydrographic, and population characteristics were also collected. All analyzed samples showed natural fluoride; macroregions 2 and 4 showed the highest mean fluoride concentration, macroregion 4 presented the highest mean temperature, and all macroregions showed a similar pattern of precipitation. The mean fluoride concentration of the four macroregions was below the appropriate value to prevent caries. An increase in precipitation would decrease the fluoride concentration in water. In conclusion, the concentration of natural fluoride varied according to meteorological and hydrographic factors. The concentration in surface waters increased during periods of low precipitation. Therefore, this study provided important information to support implementation of community water fluoridation in this region.