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Indiana State Department of Health

Environmental Public Health Home > Water Fluoridation Program > Fluoride and Water Fluoridation Information Fluoride and Water Fluoridation Information

Fluoride in Nature

Fluorine is one of 102 naturally occurring elements in nature, like oxygen, carbon, iron, or nitrogen.  It is the 13th most abundant element, and can be found in the ocean, soil, plants, rocks and most food.  Being one of the earth’s most common elements, fluorine does not harm the environment.  It occurs naturally in all water, at varying concentrations.  In Indiana, most surface water and groundwater has a natural fluoride concentration of 0.1-0.2 milligrams per liter (mg/l).  Elements are the basic chemical building blocks for all materials, be they solid, liquid or gas.  Few elements are found free in nature; usually, they are combined with other elements into compounds.  In the case of fluorine, it is always found combined with other elements.  Dissolved in water, any compound will dissociate into its component elements, called ions.  Thus fluorine in water is present as the fluoride ion.  One fluoride ion is the same as the next, no matter what other elements it was originally combined with.  There is no difference between water that naturally contains fluoride ions, and water that has been purposely fortified with fluoride ions at the optimum concentration for reduction of tooth decay.  Adding fluoride to water is no different than fortifying salt with the iodine, milk with vitamins A and D, orange juice with vitamin C, or flour with iron and B vitamins.

How Fluoride Prevents Tooth Decay

Water fluoridation reduces tooth decay in children by 40-70%, and in adults by 40-60%.  Fluoride prevents tooth decay in three ways.  It reduces the ability of plaque bacteria to produce acid.  It is absorbed into the crystalline structure of tooth enamel, thereby reducing the ability of acid to attack it.  Finally, fluoride remineralizes tooth enamel that has lost minerals due to the attack of acid producing bacteria.  In effect, fluoride stops, and can even reverse, the decay process in teeth. Fluoride is just as important to elderly Americans, as it prevents or impedes decay of exposed tooth roots.  Most people are aware of the benefits of fluoridation for children.  But it is also very beneficial late in life.  Tooth root decay is a significant problem for the elderly, and it is difficult for a dentist to treat.  Many older adults do not produce saliva in sufficient amounts, which makes tooth cleaning more difficult.  Additionally, their gums recede, exposing the roots of teeth, thereby increasing the risk of tooth root decay.  A 1988 survey showed that more than 90% of people aged 45 or older had some tooth root surfaces exposed.  Fluoride remineralizes exposed tooth roots the same as it does tooth enamel.

Facts in Support of Water Fluoridation

Tooth decay remains the most prevalent chronic disease of childhood.  In the U.S., tooth decay affects 50% of children aged 5-9 years, 67% of adolescents aged 12-17 years, and 94% of adults aged 18 or older.  But during the second half of the 20th century a major decline in the prevalence and severity of tooth decay has occurred.  Medical, dental, and public health professionals attribute that decline to fluoridation of public water supplies.  Decades of research and hundreds of studies throughout the world show that optimally fluoridated drinking water is safe and effective in reducing tooth decay.  Water fluoridation is cost-effective, and the most efficient method of reaching the whole population.  Everyone benefits equally from fluoridation without the need for expensive daily interventions such as fluoride rinses, which some cannot afford.  Fluoridation reduces pain and suffering from tooth decay; it reduces time lost from school and work; and it reduces the cost of dental care.  The average per capita cost of fluoridating a public water supply is 54 cents per year, or $40.50 for a lifetime.  The cost of just one dental filling is more than $50.  Data from the federal Centers for Disease Control and Prevention (CDC) show that for every dollar spent on water fluoridation, $38 are saved in reduced costs for dental care.  Studies show that when fluoridation ceases, tooth decay climbs.  Given enough time, decay rates go back to pre-fluoridation levels.  Although other sources of fluoride are now available, customers of water supplies without fluoridation continue to have higher rates of dental decay than those served by fluoridated water supplies. 

History of Water Fluoridation

In the early 1900's, Colorado dentist Dr. Frederick S. McKay began searching for the cause of stained teeth that were prevalent among his patients.  He found that this staining (dental fluorosis) also occurred in other parts of the country, including Texas.  Dental fluorosis in its mildest form appears as small, white, opaque areas on teeth.  While mild dental fluorosis is almost invisible, severe fluorosis appears as brown staining.  By 1928, Dr. McKay noticed that that decay was much reduced in patients who had stained teeth, and concluded that both the staining and resistance to decay were caused by something in the water.   By 1931, others had identified it as fluoride.  Then the U.S. Public Health Service tried to determine if there was a concentration of fluoride in water that would prevent decay, but not stain teeth.  By checking the dental status of 7,000 children who drank naturally fluoridated water at different concentrations in four states, they determined that the ideal concentration would be 1.0 mg/l.  While this concentration did not cause staining, it did reduce cavities by two-thirds.  The next step was to test fluoridation of public water supplies.  Grand Rapids, Michigan, was the first U.S. city to fluoridate its water supply at the 1.0 mg/l level, starting on January 25, 1945.  Prior to that, in 1944, comparison studies were started in the neighboring cities of Newburgh and Kingston, New York; Muskegon and Grand Rapids, Michigan; Oak Park and Evanston, Illinois; and Sarnia and Brantford, Ontario.  First, the children in each city were examined by dentists and physicians; then fluoride was added to one of the two water supplies.  Children in Newburgh, New York, experienced 58% fewer cavities than those of unfluoridated Kingston.  The other paired cities experienced equally dramatic differences.  While these comparison studies were originally intended to last for ten years, the differences were so astounding that hundreds cities and towns started water fluoridation after only five years.  The first three Indiana public water supplies to fluoridate were Ft. Wayne, Indianapolis, and Huntingburg, all in 1951.  Close behind were Batesville, Bedford, Columbus, Kokomo, Logansport, Lyons, Marion, Michigan City, and Valparaiso, all of which started fluoridating in 1952.

Fluoridation Across the World

Contrary to the claims of some antifluoridationists, water fluoridation has not been banned anywhere in the world.  However, many countries use another form of fluoridation, salt fluoridation, similar to our iodination of salt.  While salt fluoridation is very effective, it’s not as efficient or accurate as water fluoridation, because the dietary intake of salt is more highly variable than it is for water.  Either way, a person’s intake of fluoride is being adjusted to prevent tooth decay.  Countries that adjust fluoride intake by one means or the other include Argentina, Austria, Australia, Barbados, Belgium, Bermuda, Bolivia, Brazil, Canada, Chile, Columbia, Costa Rica, Cuba, Cyprus, Czech Republic, Denmark, Ecuador, Egypt, Estonia, Fiji, France, Gabon, Guatemala, Germany, Great Britain, Grenada, Guyana, Haiti, Honduras, Hong Kong, Hungary, Iran, Ireland, Israel, Italy, Jamaica, Japan, Kiribati, Latvia, Libya, Lithuania, Malaysia, Mexico, Myanmar, Namibia, Nigeria, New Zealand, Norway, Panama, Papua, Paraguay, Peru, Philippines, Poland, Puerto Rico, Senegal, Serbia, Sierra Leone, Singapore, South Africa, South Korea, Spain, Sri Lanka, Sweden, Switzerland, Taiwan, Thailand, Trinidad & Tobago, Turkey, Tuvalu, Uganda, United States, Uruguay, Venezuela, Vietnam, Zaire, and Zambia.  More than 360,000,000 people world-wide benefit from fluoridation. 

Water Fluoridation in the United States, and Indiana

Of the 50 largest U.S. cities, 47 fluoridate.  According to CDC, nearly two-thirds of public water supply customers across the U.S. receive fluoridated water.  That’s almost 162 million people.  In Indiana, nearly 300 public water supplies and 33 rural schools fluoridate; 4.3 million Hoosiers receive optimally fluoridated water.   Many Hoosier water utilities serve water naturally fluoridated at the optimum level, including: Advance, Albany, Albion, Aqua Source-Aboite Township, Aqua Source-North End, Arlington Utilities, Auburn, Avilla, Berne, Bluffton, Brownsburg, Bunker Hill, Butler, Churubusco, Clarks Hill, Columbia City, Danville, Decatur, Dunkirk, Elwood, Fairmount, Farmland, Flowing Wells/Indiana Heights, Fountain City, Francisco, Frankfort, Garrett, Geneva, Glenwood, Goodland, Grabill, Greenfield, Greentown, Hamilton, Hartford City, Huntington, Jamestown, Kingman, Kirklin, L&M Regional Utility, LaFontaine, Lebanon, Lewisville, Lynn, Markle, Mecca, Medaryville, Milltown, Monroeville, Montpelier, Morristown, North Judson, North Manchester, North Salem, Orestes, Orleans, Ossian, Pennville, Pierceton, Pittsboro, Portland, Redkey, Roanoke, Royal Center, Russiaville, St. Joe, Schneider, Sharpsville, Shirley, Sheridan, Silver Lake, Staunton, Summitville, Swayzee, Tipton, Union City, Upland, Van Buren, Walton, Waterloo, West Lebanon, Windfall, and Woodburn.  It’s estimated that 100,000 Hoosiers receive optimally fluoridated water from private wells.  There’s a good chance that anyone living close to one of the communities listed above, also drinks optimally fluoridated water from their private wells.

Currently, 84 Hoosier public water supplies do not fluoridate.  Those that serve more than 900 customers include: Aberdeen-Pate Water Corporation, Akron, Arcadia, Bicknell, Cataract Lake Water Corporation, Cayuga, Crawford County Water Company, Dugger, Eaton, Everton Water Corporation, Farmersburg, Fayette Township Water Corporation, Jennings Water Inc., Jennings Northwest Regional Utility, Jonesboro, Linton, Lyford, Odon, Painted Hills, Paxton, Remington, Rossville, Shelburn, St. Paul, Switz City, Suburban Utilities-El Paco, Tri-Township Water Corporation, Troy, Van Bibber Lake, Waynetown, and West Terre Haute.
 

Endorsements of Fluoridation

During the 20th century, the life expectancy of U.S. citizens has lengthened by more than 30 years.  Twenty-five of those years are thought to be attributable to advances in public health.  Fluoridation has been identified by the CDC as one of the ten greatest public health achievements in the 20th Century.  According to CDC, water fluoridation "safely and inexpensively benefits both children and adults by effectively preventing tooth decay, regardless of socioeconomic status or access to care."  CDC has also stated that, "For every report which casts doubt on fluoridation, there are innumerable reports attesting to is safety and efficacy.  It is not surprising that some differences of opinion among scientists and professionals in research and medicine may occur.  What is surprising, however, is their almost universal agreement on the safety and effectiveness of fluoridation."  Virtually every reputable national health association endorses water fluoridation, including the American Medical Association, the American Dental Association, the American Academy of Pediatrics, the American Academy of Family Physicians, the American Public Health Association, the American Dental Hygienists Association, the American Nurses Association, the National Environmental Health Association and the American Water Works Association.

By a wide majority, the American people favor fluoridation.  In 1998, the Gallop Organization polled consumers about fluoridation and found that 70% favored it; 18% opposed it; while 12% had no opinion.  An earlier survey revealed that an even higher percentage of parents favor fluoridation.

According to Consumer Reports magazine, "Of all the numerous ills that have been attributed to fluoridation, from cancer to constipation in dogs, none has ever been shown to be valid.  The simple truth is that there's no 'scientific controversy' over the safety of fluoridation.  The practice is safe, economical, and beneficial.  The survival of this fake controversy represents, in CU's opinion, one of the major triumphs of quackery over science in our generation."  (A Two Part Report on Fluoridation, July & August, 1978).

Dr. C. Everett Koop, President Ronald Reagan’s Surgeon General, said "Fluoride is not a mysterious substance.  It's not an experiment.  You're not being asked to approve something that's been built on uncertain findings.  Does everyone agree with me?  Not by a long shot.  But I have to tell you, they're wrong.  I never lied to you as the surgeon general.  And the people who oppose the fluoridation of water don't know what they're talking about."

Dentists are continually called upon to defend fluoridation.  Had dentistry simply acceded to antifluoridationist demands, there would have been a lot more cavities to treat, and lot more money in the dentists’ pockets.   But dentists have steadfastly supported fluoridation, knowing how important it is to public health, and how sound the science is that supports it.  After all, their families benefit from fluoridation just as much as the rest of us.  No medical professional would subject their parents or children to fluoridated water if there was something wrong with it. 

Safety of Water Fluoridation

Three chemicals are used to fluoridate drinking water in the U.S: sodium fluoride (NaF); sodium fluorosilicate (Na2SiF6); and fluorosilicic acid (H2SiF6).  Fluorosilicic acid is a byproduct of the manufacture of phosphate fertilizer.  It is recovered as a vapor, which ensures a high degree of purity.  Both sodium fluoride and sodium fluorosilicate are made from fluorosilicic acid recovered in this manner.  Sodium fluorosilicate is created by neutralizing fluorosilicic acid with caustic soda, itself a water treatment chemical.  Sodium fluoride is created by neutralizing fluorosilicic acid with sodium chloride, common salt.  Antifluoridationists have pointed out that industrial grade fluoride chemicals are used by water utilities, implying that pharmaceutical grade chemicals should be used instead.  In fact, all of the 40+ water treatment chemicals used by U.S. water utilities are industrial grade.  But they all must meet National Sanitation Foundation (NSF) and American Water Works Association (AWWA) standards.  Pharmaceutical grade fluoride compounds are used to make prescription drugs, not for water treatment.