Water fluoridation, the practice of adding fluoride to water as a medical supplement, originated shortly after World War II. During and right after the war there were large amounts of industrial waste left over from processing copper. One of the chief components of the waste was fluoride. It is unclear how industrial waste translated into “prevents tooth decay” but none-the-less the United States makes a regular practice of fluoridating public water supplies. The idea that consuming fluoride prevents tooth decay and other common ailments of the poor or those unable to help themselves is endorsed by a number of dental and tooth related organizations. Whether or not studies exist to support the use of fluoride (weighing the costs against the benefits) is still in question. With any institutionalized viewpoint there will be studies and counter studies, each funded by a party that has interests in reaching certain predetermined outcomes.
It is worth noting two things at this point. The first is that the FDA has never approved the use of fluoride as a medical treatment (though it has approved the use of fluoride in bottled water). The second is that fluoride is considered a deadly poison by the CDC. If you swallow even a little more than used for brushing it is suggested you contact a Poison Control Center for help. As an addendum to the latter point it is medically recognized that the area under the tongue is one of the most absorbent areas in the human body (see the application of nitroglycerin for heart attack victims). Fluoride poisoning is especially dangerous in children, leading to decreased IQ, weak bones, poor gastrointestinal function, impaired kidney function, and much more. Read more on water fluoridation and what you can do about it here.
One of our readers from the UK has informed us that the water supply their is fluoridated. We have adjusted the title of the article accordingly.