Effect of long-term exposure to fluoride in drinking water on risks of bone fractures

Findings on the risk of bone fractures associated with long-term fluoride e xposure from drinking water have been contradictory. The purpose of this st udy was to determine the prevalence of bone fracture, including hip fractur e, in sh Chinese populations with water fluoride concentrations ranging fro m 0.25 to 7.97 parts per million (ppm), A total of 8266 male and female sub jects greater than or equal to 50 years of age were enrolled. Parameters ev aluated included fluoride exposure, prevalence of bone fractures, demograph ics, medical history, physical activity, cigarette smoking? and alcohol con sumption. The results confirmed that drinking water was the only major sour ce of fluoride exposure in the study populations, A U-shaped pattern was de tected for the relationship between the prevalence of bone fracture and wat er fluoride level, The prevalence of overall bone fracture was lowest in th e population of 1.00-1.06 ppm fluoride in drinking mater, which was signifi cantly lower (p < 0.05) than that of the groups exposed to water fluoride l evels <greater than or equal to>4.32 and less than or equal to0.34 ppm. The prevalence of hip fractures was highest in the group with the highest wate r fluoride (4.32-7.97 ppm). The value is significantly higher than the popu lation with 1.00-1.06 ppm water fluoride, which had the lon est prevalence rate. It is concluded that long-term fluoride exposure from drinking water containing greater than or equal to4.32 ppm increases the risk of overall f ractures as well as hip fractures. Water fluoride levels at 1.00-1.06 ppm d ecrease the risk of overall fractures relative to negligible fluoride in wa ter; however, there does not appear to be similar protective benefits for t he risk of lip fractures.