Water Fluoridation: When, Where and Why

Fluoride's benefits to teeth were discovered in the 1930s. Dentists started to notice that people who drank water that naturally contained fluoride had less tooth decay.

Communities have added fluoride to water supplies since 1945. Fluoridation involves adjusting the natural level of fluoride in the water. The goal is a level of 0.7 to 1.2 parts per million (ppm). This is one part of fluoride in one million parts of water. It's roughly comparable to one minute in two years, or one cent in $10,000.

In 1945, Grand Rapids, Mich., became the first city in the world to have its water fluoridated. A 15-year study there showed that water fluoridation 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 62% of people served by public water supplies have adequate levels of fluoride in their water. Of the 50 largest U.S. cities, 43 have water fluoridation systems. In the United States, water fluoridation costs an average of 50 cents per person per year. About 60 other countries also practice water fluoridation.

A 1998 survey found that 70% of Americans support community water fluoridation. However, some people oppose the practice. Some say it limits their freedom of choice. Others misinterpret scientific information on the safety of fluoride.

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 to water fluoridation than older studies did. That's because more people are now getting fluoride from sources besides water. Other common sources include toothpaste and mouth rinses. Also, more foods and beverages — for example, soft drinks and spaghetti sauce — now contain fluoride because they are made with fluoridated water.

Is My Water Fluoridated?

he 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. You also could look in the "Local Government" section of your phone book.

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.