[Fluorosis due to fluoride in drinking water. A health risk even in Norway?]

Abstract

About 99% of the Norwegian population are supplied with surface water with very low fluoride levels. Accordingly, they need to use fluoride preparations to prevent dental caries. Groundwater with excess fluoride is a problem mainly in a few areas of South-Eastern Norway, where in some samples of borehole water the fluoride concentration has even exceeded 10 ppm. A warning is given against the use of high-fluoride water when preparing drinks and foods for children. Infants given dried milk formulas diluted with water are at particular risk of developing fluorosis. The recommended daily meals for a three month-old child contain 900 ml water. At a level of 2 ppm, the fluoride content of this volume will exceed the upper limit of the safe and adequate intake for a child this age by 3-4 times. Water used for this purpose should preferably not contain more than 0.5 ppm fluoride. While only few Norwegians are at risk of being exposed to high-fluoride water this problem affects many persons in other parts of the world. With reference to a joint Kenyan-Norwegian research project, the paper is illustrated by cases of dental fluorosis from a Kenyan village supplied with 9 ppm fluoride water. Dental fluorosis of such severity has never been encountered in Norway.