Fluoridated Water

Virtually all water contains fluoride. In the 1940s, scientists discovered that the higher the level of natural fluoride in the community water supply, the fewer the dental caries (cavities) among the residents. Currently, more than half of all Americans live in areas where fluoride is added to the water supply to bring it up to the level considered best for dental health.

The possible relationship between fluoridated water and cancer has been debated at length. However, a February 1991 Public Health Service (PHS) report on the results of a year-long survey showed no evidence of an association between fluoride and cancer in humans. The survey, which involved a review of more than 50 human epidemiological studies produced over the past 40 years, led the investigators to conclude that optimal fluoridation of drinking water "does not pose a detectable cancer risk to humans as evidenced by extensive human epidemiological data reported to date."

In one of the studies reviewed for the PHS report, scientists at the National Cancer Institute evaluated the relationship between the fluoridation of drinking water and the number of deaths due to cancer in the United States during a 36-year period, and the relationship between water fluoridation and number of new cases of cancer during a 15-year period. After examining more than 2.2 million cancer death records and 125,000 cancer case records in counties using fluoridated water, the researchers concluded that there was no indication of increased cancer risk associated with fluoridated drinking water.