Degree of fluorosis in areas of South Africa with differing levels of fluoride in drinking water.

The purpose of this study was to study the relationship between degree of fluorosis and varying fluoride concentrations in the drinking water in a relatively dry region in South Africa. A strong positive association was found between drinking water fluoride levels and fluorosis but only up to a level of approximately 2.0 ppm for areas with a high average daily temperature (approximately 79 degrees F). The results indicate that the optimum drinking water fluoride concentration for a region with a high average daily temperature should be less than 1.00 ppm.