水道水フッ化物添加
Water fluoridation is the controlled addition of fluoride to a public water supply to reduce tooth decay. Although many dental-health organizations support such fluoridation, the practice is opposed by conspiracy theorists. Allegations may include claims that it has been a way to dispose of industrial waste, or that it exists to obscure a failure to provide dental care to the poor. A further theory promoted by the John Birch Society in the 1960s described fluoridation as a communist plot to weaken the American population.