Fluorosis of Teeth
Fluorosis of teeth develops during formation of teeth when children are young. Drinking water having more than 1.5 ppm of fluoride can give rise to enamel defects and discoloration of teeth, leading to endemic fluorosis in the population. These effects may vary from mild to severe. For example, in the Great Rift Valley area of East Africa, the ground water has high levels of fluoride, leading to high rates of dental fluorosis—nearly 90 percent in some parts of Kenya (Chibole 1987). Some individuals in developed countries can acquire fluorosis of teeth as a result of the widespread use of different forms of fluorides in the prevention of caries, though the degree of fluorosis often is mild compared with endemic fluorosis.
Defluoridation of the central water supplies is possible when naturally occurring fluoride is excessive in the drinking water. However, most developing countries do not have central water distribution systems, and the cost of defluoridation equipment and its maintenance can be high. WHO encourages effective and inexpensive methods that are useful for individual households or community defluoridation of drinking water (WHO 1994). Such methods exist, but a number of operational problems have been identified, requiring further initiatives in this field (Kloos and Haimanot 1999).
