Can fluoridated water cause cancer?
The possible relationship between fluoridated water and cancer has been debated at length. The debate resurfaced in 1990 when a study by the National Toxicology Program, part of the National Institute of Environmental Health Sciences, showed an increased number of osteosarcomas (bone tumors) in male rats given water high in fluoride for 2 years (3). However, other studies in humans and in animals have not shown an association between fluoridated water and cancer (4). In a February 1991 Public Health Service (PHS) report, the agency said it found no evidence of an association between fluoride and cancer in humans. The report, based on a review of more than 50 human epidemiological (population) studies produced over the past 40 years, concluded 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 (4). In one of the studies reviewed for the PHS report, scientists at the National
