Water Fluoridation: When, Where and Why
Fluoride’s effect on teeth was first observed in the 1930s. Dentists started to notice that rates of tooth decay were low in areas where the drinking water naturally contained fluoride.
Communities have added fluoride to water supplies since 1945. Fluoridation involves adjusting the natural level of fluoride in the water. The new goal is a level of 0.7 parts per million (ppm).
In 1945, Grand Rapids, Mich., became the first city in the world to add fluoride to its water. A 15-year study there showed that this reduced tooth decay in children by more than 60%. Around the country, adding fluoride to water has led to reduction in decay rates of:
- 30% to 60% in children younger than 8
- 20% to 40% in children ages 8 to 12
- 15% to 35% in older children and adults
With less tooth decay, fewer teeth have to be filled or extracted. Dental treatment costs go down.
Today, about 74% of people served by public water supplies have adequate levels of fluoride in their water. Of the 50 largest U.S. cities, 44 have water fluoridation systems. About 60 other countries also add fluoride to water. Water fluoridation is also inexpensive. In the United States, it costs about 62 cents per person per year for a city or $3.90 per person for a small community (2004 dollars).
A 1998 survey found broad support for the practice. It found that 70% of Americans favor putting fluoride in water supplies. However, some people oppose the practice. Some say it limits their freedom of choice. Others misinterpret scientific information on the safety of fluoride. In fact, the U.S. Public Health Service ranked community water fluoridation as 1 of 10 great public health achievements in the 20th century.
To date, more than 70 studies have shown that fluoride helps to reduce tooth decay. The most recent studies have shown less of a benefit than older studies did. That’s because more people are now getting fluoride from sources besides drinking water. Other common sources include toothpaste and mouth rinses. Also, more foods and drinks — for example, soft drinks and spaghetti sauce — now contain fluoride because they are made with fluoridated water.
Is My Water Fluoridated?
In 2018, nearly 2 out of 3 Americans who used a public water supply were receiving fluoridated water.
The easiest way to find out if your water is fluoridated is to contact your local water district or water company. They also can tell you the concentration of fluoride in your water. Information on how to contact your water supplier should be on your water bill. If your water supply is public-owned, try the “Local Government” section of your phone book. You also may be able to find information on this website of the U.S. Centers for Disease Control and Prevention.
Some types of home water filters can remove significant amounts of fluoride from water. Reverse-osmosis systems and distillation units have been shown to remove fluoride. Research on other systems has not shown conclusive results. Pitcher filters and filters that attach to your water faucet generally do not remove fluoride. To be certain, check with the manufacturer or read the information that came with the filter.
If you use a home water-treatment system, have the fluoride level of your water tested at least once a year. You may be able to get tests through your local or state health department. A private laboratory is another option.