Fluoridation of public water supplies and public health: an old controversy revisited

Abstract

The controversy surrounding the fluoridation of public water supplies has been reignited in recent months following a decision to stop adding fluoride to the local water, by the Legislative Assembly of The Australian Capital Territory in September 1989. The decision was reversed a week later and the issue is now the subject of a parliamentary committee enquiry. The prevalence of dental caries has been declining in many parts of the western world in recent years, both in areas which have fluoridated water supplies and in those which do not. Fluoride is now widely available in topical applications and this medium has probably contributed significantly to the decline, though American studies indicate that there is a residual benefit to children who have always drunk fluoridated water. Concerns have been raised that the total intake of fluoride in some communities has now risen to a level which might create a health hazard to some individuals, and the matter has been brought to a head by a preliminary report of animal carcinogenicity in circumstances of high oral fluoride intake. Although clinical and epidemiological studies in humans have repeatedly failed to detect convincing toxicity in humans from the the upward adjustment of the fluoride content of water supplies to about 1 ppm, these new circumstances demand a continuing review of the costs and benefits of various methods of fluoride supplementation.