In Stanley Kubrick’s classic 1964 movie, Dr. Strangelove, the deranged General Jack D. Ripper thinks he knows a secret communist plot to destroy Americans from within. “A foreign substance is introduced into our precious bodily fluids without the knowledge of the individual. Certainly without any choice,” he says ominously. He’s referring to water fluoridation, “the most monstrously conceived and dangerous communist plot we have ever had to face.” Kubrick seems to be mocking the anti-fluoridation activists of his day.

Forty years later, some Americans still view fluoride as a threat — though not a Soviet one, and probably not dangerous to our precious bodily fluids so much as to our solid parts. Fluoridation’s opponents are fighting against momentum; three in five Americans now drink fluoridated water, and that number is growing as more cities fluoridate their water supplies. But the movement against fluoridation, buoyed by new studies and the Internet, is amassing credible ammunition in its favor

THE SCIENCE

Fluoride is a natural substance that exists in all water at some level. The gaseous element fluorine combines with other elements to form fluoride compounds in rocks and soil, which dissolve into flowing water. Most groundwater contains trace levels of fluoride, and ocean water contains about 1.3 parts per million (ppm) flouride.

Public water fluoridation actually means “adjusting to the optimum” — adding or removing fluoride to achieve a level of about 1 ppm, which the Center for Disease Control (CDC) has determined as the optimum concentration for strengthening teeth without causing serious dental fluorosis (or tooth mottling, a funky cosmetic effect). In places with high levels of naturally occurring fluoride, adjusting to the optimum means removing fluoride from the water supply. In most places, though, it means adding fluoride.

Governments fluoridate water as a means to prevent tooth decay. When we eat sugar or other refined carbohydrates, oral bacteria produce acid that erodes minerals on the surface of teeth. Our saliva attempts to reverse this process by re-building the tooth’s mineral shield with a bath of calcium and phosphate. But a high-sugar diet produces acidic bacteria faster than mineral-rich saliva can repair the damage, causing cavities over time.

When we ingest fluoride in water, it changes the calcium phosphate structure on the tooth’s surface, resulting in enamel that is about 10 times more acid-resistant than teeth that have not been exposed to fluoride. That helps to prevent cavities, but it also makes teeth more brittle. Teeth that have been exposed to fluoride tend to break more easily than those that have not.

What happens to teeth often happens to bone. According to fluoride critic Dr. Hardy Limeback, head of preventative dentistry at the University of Toronto, 95 percent of ingested fluoride ends up in bones, not teeth. And what happens there worries some scientists and doctors.

BONES ABOUT FLUORIDE

In the past five years, scientists have produced an influx of peer-reviewed research linking fluoride consumption with bone damage. In a recent study, 96 percent of Tibetan children with dental fluorosis (caused by high fluoride intake from brick tea) exhibited developmental skeletal abnormalities in wrist x-rays. A May 2003 study in the journal Fluoride links increased fluoride consumption with lower IQs in Chinese children. A study in Rheumatology Journal reports that moderate levels of fluoride intake (1.9-3.6 ppm) correlates to knee osteoarthritis. And a 2001 Harvard doctoral thesis links fluoridated water to an increase in young boys’ risk of developing osteosarcoma, a rare form of childhood bone cancer.

Proponents are quick to point out that high doses of fluoride may be toxic, but water supplies are fluoridated to a relatively low dose. The Environmental Protection Agency (EPA), however, reports that even at 1 ppm, fluoride can cause moderate dental fluorosis in a small percentage of people. The EPA sets a “maximum contaminant level” of fluoride at 4 ppm, warning that children exposed to this amount are at increased risk of bone disease and severe dental fluorosis. Canada has set its optimum fluoride level for water at 0.6 ppm, and most Western European countries — including those with government-subsidized dentistry — have rejected fluoridation outright. (See sidebar for more dosage info.)

The FDA regulates fluoride as a drug when it is administered topically to prevent tooth decay (as in fluoridated toothpaste). But fluoride in the water supply is officially classified as a contaminant rather than a drug, and the EPA regulates it. Agency managers have remained largely mum on the subject, but unionized EPA scientists voted against fluoridation in 1997. “We hold that fluoridation is an unreasonable risk,” union senior Vice President Dr. J. William Hirzy testified. “The toxicity of fluoride is so great and the purported benefits associated with it are so small — if there are any at all — that requiring every man, woman and child in America to ingest it borders on criminal behavior on the part of the local governments.”

FLUORIDE’S FRIENDS

Despite the concerns about fluoride, the CDC calls fluoridation one of the 10 greatest public health achievements of the 21st century, and the American Dental Hygienists’ Association credits it with a 50-60 percent reduction in tooth decay since World War II. The American Dental Association, the American Medical Association, the U.S. Public Health Service and the American Water Works Association all endorse it.

Jane Myers, director of the Oregon Dental Association’s public affairs department, believes that the mainstream majority supports fluoridation. She says that if local jurisdictions won’t fluoridate their water supplies, the state should mandate it. “The world abounds in junk science,” she says. “We require seat belts and motorcycle helmets and inoculations and a number of things, and they’re frequently met with resistance by vocal minorities.”

In addition to improving the state’s teeth, Myers says, water fluoridation is good for the economy. She claims that every $1 spent on fluoridation yields about $38 in saved dental costs, which could make a big dent in the state’s annual $70 million Medicaid dental bill.

Myers, admitting that she’s not an MD, has nothing to say about fluoride’s potential threats to the body — but she suspects that they’re overblown. “They’ve been doing this for 60 years in the United States,” she says. “It comes down to who you’re gonna believe. Are you gonna believe the Department of Health, which has our well being at stake, or the opponents? Who are they, and what are their credentials?”

FLUORIDE’S FOES

Lynne Campbell, director of the anti-fluoridation group Oregon Citizens for Safe Drinking Water, suspects that something fishy is going on with fluoridation, though she doesn’t know the details. She notes that the Public Health Service, the agency in charge of fluoridation research, is also fluoridation’s primary endorser. In her view, that conflict of interest has created skewed policies based on biased science. “We have found that the conclusions drawn by promoters are not supported by the hard data,” she says.

Most of the fluoride used for water fluoridation is industrial waste: sodium fluoride, sodium fluorosilicate and fluorosilicic acid from phosphate fertilizer, glass, steel and aluminum production. Unlike organic fluorine, these compounds come with pollutant hitchhikers that get a free ride into public water supplies. Rather than paying to dispose of these compounds as hazardous waste, industries sell them to public water utilities.

Injecting hazardous industrial waste into the public water supply without FDA regulation is, in Campbell’s view, a recipe for disaster. “Forcing populations to ingest a medication laced with lead and arsenic, a known carcinogen, is antithetical to health,” she says. “Especially for children.”

Beyond the question of fluoride’s effects on the human body is its impacts on the environment. As with other issues related to fluoride, credible scientists have different opinions.

A report published in the September 2004 issue of International Journal of Occupational and Environmental Health concludes that fluoridation of the public water supply is safe for the environment as well as for people. But Environment Canada found that fluoride levels higher than 0.12 ppm can be toxic to invertebrates, and UO chemistry professor Paul Engelking maintains that even low concentrations of fluoride in rivers are harmful to salmonids. “I and my students have been measuring the levels of fluoride in Oregon waters since [1997],” Engelking wrote in a letter to former Gov. John Kitzhaber, an avid fly fisherman who supports fluoridation. “We now know with certainty that in some locations, the levels we have measured are high enough to affect fish and other aquatic organisms.”

OREGON’S LOW DOSE

In the 1920s, a dentist named Dr. Frederick McKay noticed that many of his patients in Colorado Springs, Colo., had brown stains mottling their teeth — but they had fewer cavities than most. Research in the 1930s revealed that naturally occurring fluoride in the water likely caused both effects. Studies in other communities followed in the ’40s, and by early ’50s, with the blessing of the Public Health Service, dozens of cities were rushing to fluoridate. Today, 60 percent of Americans drink fluoridated water.

But Oregon, with only one in five residents drinking fluoridated water, is proving to be among the states most resistant to fluoridation. Only Utah and Hawaii have lower fluoridation rates.

Currently in Oregon, the decision to fluoridate is a local one. Salem, Beaverton, Tigard, Florence and Forest Grove fluoridate their public water supplies, while Eugene, Oakridge, Hood River, Medford, Ashland, Portland and Bend do not. The split reflects a larger ambivalence. While 70 percent of Americans say they support fluoridation, voters have rejected it in 60 percent of all fluoridation referenda since 1950.

Eugene is no exception. In 1964, Eugene voters approved the addition of fluoride to the water supply. Eight months later, they changed course and banned fluoridation. The same thing happened in 1977: Eugene voters first approved, then rejected, fluoridation.

“This is a polarized issue,” says Eugene Water and Electric Board spokesman John Mitchell. “Either you swear by fluoridation because you grew up in a place that had it and your teeth are the best around; or, if you are on the other side of the fence, it’s the worst thing possible.”

Oregon continues to hold out against the national trend toward fluoridation, but pro-fluoride activists are putting mounting pressure on legislators to mandate fluoridation on a statewide level. Three bills to fluoridate Oregon’s public water supplies have come before the Legislature since 1999. None of them have passed, and the most recent, this session, never made it to the Senate floor for a vote. But the issue promises to return to Salem in the future (see sidebar).

FLUORIDE FOG

What’s striking about the fluoridation debate is the near-religious conviction on both sides of the issue, a myopic adherence to the idea of Fluoride As Boon or Fluoride As Doom. Opinions are so disparate that few leading fluoridation activists seem willing to acknowledge the validity of the science on the other side of the argument.

Proponents suggest that critics of fluoridation, most of them crazy as Kubrick’s General Ripper, are trying to use quack science to sabotage the dental health of every man, woman and child in America. Opponents, for their part, imply that the entire fluoride scheme is a baseless mistake caused by corrupt, hasty science. In reality, valid science exists on both sides of the issue, and seldom in contradiction. Most new studies complement the old, providing more data sets for a 60-year experiment. The biggest gap between pro- and anti-fluoridation arguments is in the margin between a safe dose of fluoride and a toxic one — and that fine line becomes a wide rift over policy.

NEXT WEEK: Two Oregon dentistsspar over flouride.

FLUORIDE’S RUN THROUGH SALEM
A chronology of fluoride action this legislative session

Fall 2004: The Oregon Health Policy Commission recommends a state mandate on water fluoridation.

Feb. 24, 2005: Senate Bill 852 (the Water Quality Assurance Act), requiring the Food and Drug Administration’s approval for all substances being added to the public water supply, is referred to the Senate’s Environment and Land Use Committee, chaired by Sen. Charlie Ringo (D-Beaverton).

March 7, 2005: House Bill 2426, declaring a dental health emergency and allowing dental hygienists to prescribe fluoride, passes unanimously through the House and is referred to the Senate Health Policy committee.

March 29, 2005: House Bill 2025, requiring cities with more than 10,000 residents to add fluoride to the public water supply, passes in the House by a 36-22 vote. The bill is referred to the Senate’s Environment and Land Use Committee.

April 2005: The committee holds public hearings on HB 2025, HB 2426 and SB 852. Proponents and opponents of fluoridation offer vehement testimony.

April 21, 2005: HB 2426 passes unanimously in the Senate.

May 2005: Former Gov. John Kitzhaber, current Gov. Ted Kulongoski and the Healthy Smiles Coalition encourage a state mandate on fluoridation. Numerous environmental groups and Oregon city governments oppose it, urging the Senate to keep fluoridation under local control.

May 13, 2005: Kulongoski signs HB 2426 into law.

June 2005: The Environment and Land Use Committee closes for the session without reaching resolutions on pro-fluoridation bill HB 2025 or anti-fluoridation bill SB 852.

— Kera Abraham

FLUORIDE OVERDOSE?
A LOOK AT THE NUMBERS

The American Dental Association (ADA) recommends that people consume .05 milligrams of fluoride per kilogram (or about 0.023 milligrams per pound) of body weight per day.

Oregon Citizens for Safe Drinking Water Director Lynne Campbell warns that many people ingest more than the “optimum” dose by drinking fluoridated water, using fluoridated toothpaste and consuming food with fluoride content. “[Water fluoridation] seems like an irresponsible way of administering medicine, because there’s no control of dose,” she says.

A 1-year-old child drinking four 8-ounce glasses of water consumes 0.95 mg fluoride — above the ADA’s upper limit. Add in food and toothpaste sources, Campbell says, and it’s easy for a child to overdose on fluoride.

According to a chart prepared by the Parents of Fluoride Poisoned Children using data from lab tests and published studies, an 8-ounce serving of Gerber’s white grape juice contains 1.6 mg fluride; an 8-ounce Diet Coke, .53 mg fluoride; a cup of prepared black tea, 7.8 mg fluoride; a pound of shrimp, 61.7 mg fluoride. Soy-based infant formula contains about .5 mg fluoride per 8-ounce serving; just two servings could exceed the ADA’s “tolerable upper intake” of 0.9 mg fluoride per day for infants 7-12 months old.

Other ingestable sources of fluoride are numerous. The pesticide cryolite, which is used on a wide array of fruits and vegetables, is made of aluminum, sodium and fluoride. The anti-depression drugs Prozac and Paxil contain the fluoride compound fluorophenyl. Fluoridated toothpastes contain about 0.5 mg fluoride per recommended “pea-sized” dose, and their tubes carry FDA-mandated warnings to call a poison control center if accidentally swallowed.

The ADA cautions that fluoride consumption levels above the “tolerable upper limit” put a person at risk of developing moderate to severe dental fluorosis. The EPA warns that fluoride overdose can cause debilitating bone conditions. — Kera Abraham

AGE, ADEQUATE INTAKE PER DAY, TOLERABLE UPPER INTAKE PER DAY

• Infants 0-6 months .01 mg, 0.7 mg
• Infants 7-12 months 0.5 mg, 0.9 mg
• Children 1-3 years 0.7 mg, 1.3 mg
• Children 4-8 years 1.0 mg, 2.2 mg
• Children 9-13 years 2.0 mg, 10.0 mg
• Boys 14-18 years 3.0 mg, 10.0 mg
• Girls 14-18 years 3.0 mg, 10.0 mg
• Males 19+ years 4.0 mg, 10.0 mg
• Females 19+ years 3.0 mg, 10.0 mg

Source: “Fluoridation Facts,” American Dental Association