Water fluoridation
Health and dental organizations worldwide have endorsed its safety and effectiveness. Its use began in 1945, following studies of children in a region where higher levels of fluoride occur naturally in the water. Further research showed that moderate fluoridation prevents tooth decay.
Water fluoridation in the United States
Fluoridation became an official policy of the U.S. Public Health Service by 1951, and by 1960 water fluoridation had become widely used in the U.S., reaching about 50 million people. By 2006, 69.2% of the U.S. population on public water systems were receiving fluoridated water, amounting to 61.5% of the total U.S. population. Near the end of 2012, 67.1% of the U.S. population were getting water from community water systems (CWS) supplying water that had fluoride at or above recommended levels. Those included the 3.5% of the population that were on CWS with naturally occurring fluoride at or above recommended levels. 74.6% of those on CWS were receiving water with fluoride at or above recommended levels.