[External control of fluoride levels in the public water supply in Lages, Santa Catarina State, Brazil].

The purpose of this study is a monthly assessment of fluoride levels in the public water supply in Lages, Santa Catarina State, Brazil. This town was divided into ten regions, where water samples were collected from October 2004 to September 2005. Two samples were drawn from each region and sent to the Fluoride Health Surveillance Laboratory at Vale do Itajaí University for analysis through an electrometric method (Orion 920A/Orion Electrode 9609).