A bill that would pressure Portland and most of Oregon to put fluoride in drinking-water supplies-and also potentially add harmful substances such as lead and arsenic-heads to the Oregon Senate after passing the state House last week.

In the United States, the fluoridation flap was a source of humor in the 1964 Stanley Kubrick movie Dr. Strangelove, in which a wacked-out general calls fluoridation a Communist plot to sully his purity of essence. And many of fluoridation's nonfictional critics, including the ultra-right John Birch Society, have been downright loopy. But in recent years, exhaustive British and Canadian government studies have raised safety concerns-echoing most of Europe, which does not fluoridate (see "The F Word," WW, Feb. 21, 2001).

Proponents of fluoridation focus on the benefits for poor children whose parents don't make sure their kids brush. Backers also cite potential savings for the state of not having to pay for those youngsters' additional health care.

Dental care is not cheap, says Kurt Ferré, a Portland dentist who supports fluoridation. "What we're talking about is improving the health of all Oregonians."

The fact that Oregon ranks about average among states in dental health despite being largely unfluoridated is, according to Ferré, the result of "a lot of dentists working very hard."

But opponents, including a new, more mainstream cast ranging from the Oregon Sierra Club to the Oregon Center for Environmental Health, say fluoridation addresses one risk-cavities-while adding others. Fluoride is typically added to water using a fertilizer-industry waste product, one that a recent report for Congress found often contains cancer-causing arsenic and lead, which harms child development.

If people knew they might be getting toxic metals along with fluoride, "they wouldn't want to do it," says lawyer Brent Foster of the Oregon Sierra Club.

"It violates common sense."

Dr. Richard Bayer, who in the 1990s led a crusade to provide free lead testing to Northeast Portlanders, agrees. "There is no such thing as a safe blood-lead level,'' Bayer says. "I think letting something like [fluoridation] pass without a lot of public discussion would be a tremendous mistake."

Scientists have long disagreed over whether fluoride causes cancer or has other harmful effects. The National Academy of Sciences is expected to release a report later this year, and, considering several recent studies questioning fluoride's safety, it is likely to be the most skeptical U.S. government report on fluoridation ever.

Dental scientists now concede that fluoride's main benefit comes from applying it to the surface of teeth, as in brushing or mouthwash-not ingesting it. That means the fluoride pills many parents still give their children are little more than placebos.

Portland has repeatedly rejected fluoridation, most recently in 1994. But the bill now in the state Senate "takes the decision out of the hands of cities and quite frankly it takes it out of the hands of the state," says Willie Tiffany, lobbyist for the League of Oregon Cities. Water suppliers would be required to fluoridate as soon as money becomes available-usually through nonprofit dental foundations.

Mort Anoushiravani, head of Portland's water bureau, says his agency will do whatever it's told-despite being on the hook for at least $550,000 of yearly operating expenses even if startup costs are covered by private grants. He has tracked the dispute over fluoridation and is on the fence. "On a strictly personal level," he says, "the biggest issue for me is: Is this the best and brightest use of water rates if there are potentially other ways of providing fluoride to the community?"

A history of fluoridation

1930s: Dentist observes fewer cavities in towns with fluoride naturally occurring in water. 1945: First fluoridation of water in Newburgh, N.Y., and Grand Rapids, Mich.

1950: U.S. government endorses fluoridation despite ultra-conservatives' concerns of a Communist plot.

1965: Harvard study finds dental health in Newburgh and Grand Rapids hardly differs from national average.

1980: Portlanders vote down fluoridation for the third time since 1956.

1983: A U.S. government expert committee expresses health concerns about fluoridation but is overruled by Surgeon General C. Everett Koop, who supports fluoridation.

1985: U.S. Environmental Protection Agency scientists internally oppose fluoridation but are overruled.

1986: Government biologists find fluoride in Pacific Northwest waterways is toxic to salmon.

1990: EPA study suggesting fluoride causes cancer is rewritten over staff objections.

1994: Portland City Hall advisory committee opposes fluoridation.

2000: Dartmouth professor's study links fluoridation chemical to high blood-lead levels in kids.

2001: National Sierra Club opposes fluoridation.

2003: National Academy of Sciences tries to settle disputes over fluoridation safety with a study that's still pending.

2004: Scotland joins most of Europe in rejecting fluoridation.

January 2005: Consultant's report to Congress finds lead and arsenic in most common fluoridation chemical.

March 2005: Oregon House approves bill requiring water suppliers serving more than 10,000 people to fluoridate.