Spatial Distribution of Risk Factors and Fluoride Levels in Public Water Supplies on a Municipal Scale

Abstract

Fluoridation of public water supplies is an important measure to prevent dental caries and is linked to Sustainable Development Objective 6. This study aimed to evaluate the fluoride content of Ceará's municipalities. The research used secondary data from SISAGUA (municipality; year, date, source and point of collection; form of supply; supply system; chlorine and fluoride concentrations) and the IBGE (HDI, population, FIRJAN Municipal Development Index, and estimated population) for spatial distribution and the analysis of fluoride risk factors. Of the 26,390 samples collected, only 17.8% had ideal fluoride content, with a higher prevalence in samples collected in 2016, in isolated urban areas, in water supply systems, and in chlorine levels above the ideal. Of the 182 municipalities evaluated, 16.7% had most of the samples with ideal fluoride content. In a multivariate analysis, municipalities with a population below 30 thousand inhabitants had a prevalence of inadequate fluoride content (below or above the ideal) 2.12 (95% CI = 1.92-4.88) times higher than municipalities with large populations. It is concluded that less than a fifth of Ceará's population is exposed to adequate public water fluoride levels, and cities with fewer than 30,000 inhabitants are the most affected. Keywords: Fluoride. Water Fluoridation. Environmental Health Surveillance. Health Geography.