Somebody put a dead rat in Curtis Smith's mailbox. Someone else has made anonymous phone calls accusing him of trying to poison his neighbors. And all around the usually placid university town of Bellingham, Wash., activists from a group called Citizens Against Forced Fluoride have planted lawn signs adorned with skull and crossbones. "I had no idea it would get this intense," says Smith, 70, a retired dentist who is leading a Nov. 8 ballot initiative to add fluoride to the local drinking water. "These are very angry people."
Angry indeed: fluoridation to fight tooth decay, a hot-button issue from the 1950s--when it was attacked as a communist plot--is back on the front burner and not just in Washington State. Fueled by health concerns, cancer fears and a grass-roots campaign that has flooded the Internet with antifluoridation Web pages, citizens across the U.S. are increasingly suspicious of what the Centers for Disease Control (CDC) considers "one of the 10 great public-health achievements of the 20th century." In the past three years, legislation to encourage fluoridation has been defeated or tabled in Oregon, Arkansas, Nebraska and Hawaii. New battles are brewing in New Jersey, Massachusetts and across the Canadian border in Montreal.
No one disputes the fact that fluoride, a natural element found in rocks and groundwater, protects tooth enamel. Since 1945, municipal systems serving 170 million Americans have added fluoride (mostly in the form of hydrofluorosilicic acid) to their water, and the prevalence of cavities in the U.S. has fallen dramatically. "A community can save about $38 in dental-treatment costs for every $1 invested in fluoridation," says William Maas, the CDC's director of oral health. "How many other investments yield that kind of return?"
But much has changed since 1945, starting with our toothpastes. Today fluoride is an ingredient in most brands of dentifrice on the market. Because toothpaste is designed to be spit out, it's a more efficient way to get the decay-fighting ingredient where it is needed and nowhere else. Even some dentists, who see firsthand the benefits of fluoridation, wonder whether people who get fluoride from toothpaste should get it in their drinking water as well.
What has also changed is how much toxicologists know about the harmful effects of fluoride compounds. Ingested in high doses, fluoride is indisputably toxic; it was once commonly used in rat poison. Hydrogen fluoride is regulated as a hazardous pollutant in emissions from chemical plants and has been linked to respiratory illness. Even in toothpaste, sodium fluoride is a health concern. In 1997 the Food and Drug Administration toughened the warning on every tube to read, "If more than used for brushing is accidentally swallowed, get medical help or contact a poison-control center right away."
The most recent--and controversial--charge links fluoridation with bone cancer. In June the Environmental Working Group (EWG), a watchdog organization, petitioned the National Institutes of Health (NIH) to list fluoride in tap water as a carcinogen. The group cited "decades of peer-review studies" on fluoride's "ability to mutate DNA and its known deposition on the ends of growing bones, the site of osteosarcoma"--a rare, often fatal cancer that affects mainly boys.