A Answers (2)
American Dental Association answeredCommunity water fluoridation began in the United States 66 years ago and continues to be safe and effective in preventing tooth decay for all ages. More than 125 national and international organizations recognize the public benefits of fluoridation. In the United States, 73.9 percent of the population on public water systems receive fluoridated public water, or a total of 204 million people.
Riverside Cancer Care Center answered
In 1945, Grand Rapids, Michigan, adjusted the fluoride content of its water supply to 1.0 ppm and thus became the first city to implement community water fluoridation. By 1992, more than 60 percent of the U.S. population served by public water systems had access to water fluoridated at approximately 1.0 ppm, the optimal level to prevent tooth decay.
The Centers for Disease Control and Prevention (CDC) considers fluoridation of water one of the greatest achievements in public health in the 20th century.
This answer is based on source information from the National Cancer Institute.