Questions about the safety of this cavity-fighting chemical aren’t just for right-wing conspiracists anymore

Have you read the fine print on your toothpaste tube recently? Check it out. If your toothpaste contains fluoride — which nearly every brand in the United States does — there’s a consumer advisory message that might surprise and alarm you, especially if you’re the parent of young children.

The advisory, which began appearing on fluoridated toothpaste in April 1997, by order of the Food and Drug Administration, begins with the familiar command to brush thoroughly at least twice a day. But then it includes special instructions for children ages two to six: “Use only a pea sized amount and supervise child’s brushing and rinsing (to minimize swallowing).” Then comes an additional warning to keep the toothpaste “out of the reach of children under 6 years of age,” and finally the ominous advice, “In case of accidental ingestion … contact a Poison Control Center immediately.”

What’s going on here? Isn’t toothpaste supposed to be good for us? Haven’t we been told for decades — by the government, by the American Dental Association, by countless Crest and Colgate television commercials — that fluoride is essential to fighting cavities? Isn’t that why nearly two-thirds of the public water supplies in the United States are fluoridated?

A recent issue of the new environmental newsletter News on Earth challenges this and other fluoride orthodoxies. Fluoride is, after all, an extremely toxic compound that originally was sold as a bug and rat poison. A growing body of scientific research suggests that long-term fluoride consumption may cause numerous health problems, ranging from cancer and impaired brain function to brittle bones and fluorosis (the white splotches on teeth that indicate weak enamel). An estimated 22 percent of American children have some form of fluorosis.

Research is also beginning to show that the cavity-fighting power of fluoride may have been overstated. Recent studies in the Journal of Dental Research conclude that tooth decay rates in Western Europe, which is 98 percent unfluoridated, have declined as much as they have in the United States in recent decades. Indeed, it’s only in the United States that fluoride is championed by the government; most European nations — including Germany, France, Sweden and Holland — prohibit fluoride on public health grounds.

Opposition to fluoride was once confined to far-right conspiracy buffs, as parodied in the movie Dr. Strangelove. But the new evidence against fluoride comes from credentialed scientists in such mainstream institutions as the Environmental Protection Agency and Harvard’s Forsyth Research Institute. And where water fluoridation was once a liberal cause, opposition to fluoride now comes from the left, specifically some environmental groups and at least one labor union. Local 2050 of the National Federation of Federal Employees, which represents all the scientists, engineers and other professionals at EPA headquarters in Washington, D.C., has voted unanimously to co-sponsor a citizens’ petition to prevent fluoridation of California’s waters. (Local 2050 has also filed a grievance asking for bottled water at EPA headquarters, due to fears about fluoride.) The union’s letter endorsing the petition, sent in 1997, read in part:

“Our members’ review of the body of evidence over the past eleven years, including animal and human epidemiology studies, indicates a causal link between fluoride/fluoridation and cancer, genetic damage, neurological impairment, and bone pathology. Of particular concern are recent epidemiology studies linking fluoride exposure to lower IQ in children … there is substantial evidence of adverse health effects, and contrary to public perception, virtually no evidence of significant benefits.”

“Would you brush your teeth with arsenic?” asks Dr. Robert Carton, a former scientist at the Environmental Protection Agency whose union is Local 2050. “Fluoride is somewhat less toxic than arsenic and more toxic than lead, and you wouldn’t want either of them in your mouth.”

Nevertheless, the official momentum behind fluoride is considerable. The Clinton administration’s stated goal is to increase the number of Americans with fluoridated tap water from 62 percent today to 75 percent by 2000. The National Institute of Health supports this target. “We are for water fluoridation, of course, 100 percent,” says Sally Wilberding of NIH’s National Dental Research Institute. The same goes for the American Dental Association.

“I’m a very big supporter of appropriate use of fluorides,” says Dr. John Stamm, dean of the School of Dentistry at the University of North Carolina at Chapel Hill and an official fluoride spokesman for the ADA. Stamm argues that fluoridation has significantly decreased tooth decay in the United States over the past 50 years. He attributes Western Europeans’ shunning of fluoridation to “cultural differences” in the approach to dental care.

Fluoride’s positive image in the United States may rest in part on the whitewashing of unwelcome research findings and the firing of scientists who dared question fluoride’s benefits. Dr. William Marcus, formerly the chief toxicologist for the EPA’s Office of Drinking Water, lost his job in 1991 after he insisted on an unbiased evaluation of fluoride’s potential to cause cancer. Marcus fought his dismissal in court, proved that it was politically motivated and eventually won reinstatement. Marcus now declines comment on the episode beyond saying, “I was right about fluoride’s carcinogenicity, and now we know that.” An investigation by the Senate Environment and Public Works Committee in 1991 supported Marcus’ charges, documenting that government scientists had been coerced to change their findings and portray fluoride more favorably.

Dr. William Hirzy, a senior EPA scientist and the senior vice president of Local 2050, explains that, in 1977, Congress had instructed NIH’s National Toxicology Program to investigate fluoride’s effects on lab animals, a task that got assigned to the government’s Battelle Laboratories. In the tests, rats and mice were given fluoride in their drinking water. Thirteen years later, the results came back, but not until they had been “adjusted” by a senior official of the United States Public Health Service to suggest that fluoride had no carcinogenic effects.

In response, Marcus urged in a May 1, 1990, memo that the fluoride study be “reviewed by an outside panel not related to the Public Health Service, because the PHS has been in the business of promoting fluoridation for more than fifty years.” The memo from Marcus said, “In almost all cases, the Battelle-board certified pathologists’ findings were downgraded [by the PHS], with the effect of downgrading the study’s conclusion from definitive evidence of carcinogenicity to equivocal evidence.”

“One of the most telling parts of that study,” says Hirzy, who stresses that he speaks as a union official rather than an EPA spokesman, “is that the rats who got bone cancer had lower levels of fluoride in their bones than people who drink tap water with 4 parts per million (ppm) of fluoride would have. But EPA says that 4 ppm is absolutely no danger to your health; in fact, that’s the official standard in this country. That conclusion is such a fraud there are no words to describe it.” Hirzy adds that Local 2050 has “filed a grievance asking to be given bottled water here in the EPA headquarters, because the tap water has 1 ppm of fluoride, and all the data we look at says 1 ppm is hazardous.”

“There are three or four very strong anti-fluoridation experts in the EPA union, but we feel there’s no scientific basis for their charges,” responds Tom Reeves, a national fluoridation engineer at the federal Center for Disease Control in Atlanta. Reeves says that two major studies — one commissioned by the National Academy of Science, one by the Public Health Service — “examined those charges and found no truth to them.” Reeves denies Marcus’ accusation that the data gathered by Battelle scientists were tampered with, though he concedes that the congressional investigation concluded otherwise.

At Harvard, Dr. Phyllis Mullenix says she lost her job at the Forsyth Research Institute, which specializes in dental issues, in 1994, after she insisted on publishing research results in the scholarly journal Neurotoxicology and Teratology showing that fluoride adversely affected brain function. By then, Mullenix had spent 12 years at Forsyth’s toxicology department, 11 of them as department chairwoman; she was highly regarded for her previous research demonstrating how exposure to lead and radiation lowered children’s IQ levels.

“To be honest, I thought studying fluoride would be a waste of time,” says Mullenix. “I mean, it’s in the water supply, so it’s got to be safe, right?” But Mullenix’s research found that rats who experienced prenatal exposure to fluoride exhibited higher levels of hyperactivity, while rats with postnatal exposure suffered the reverse: “hypoactivity — that is, a slowing down of their spontaneous movements — sitting, standing, smelling, turning the head, etc. … The reactions of these animals reminded me of the reactions you’d find from high exposures to radiation.”

Mullenix says that her superiors ordered her not to publish her results. “Don Hay, the associate director of Forsyth, came and told me, ‘If you publish this information, we won’t get any more grants from NIDR [the National Institute of Dental Research],’ and Forsyth gets about 90 percent of its money from NIDR. I was really upset. I’d never been told not to publish a paper.” Within hours of learning that she was indeed publishing her paper, Forsyth fired her, says Mullenix.

“Dr. Mullenix’s claim that I wanted to stop her publishing her results, showing a fluoride toxicity in rats, is false,” wrote Donald Hay, after consulting with his institute’s attorneys. “My concern was that Dr. Mullenix, who had no published record in fluoride research, was reaching conclusions that seemed to differ from a large body of research reported over the last fifty years. These extensive studies have been reviewed and approved by prestigious organizations (American Medical Association and American Dental Association), and indicated that fluoride at ordinary levels was safe. I brought these concerns to her attention.” Hay adds, “Dr. Mullenix’s claim that she was dismissed after her fluoride paper was accepted is false. We had no knowledge of the acceptance of her paper prior to the time she left [Forsyth].” Hay says Mullenix was dismissed because of problems with the quality of her work.

But if fluoride’s health advantages are at least open to question, why is it still being promoted in the United States? “The American Dental Association and the Public Health Service have been committed to fluoridation as a safe and effective way to reduce cavities for 50 years or so, so how could they now come out and admit maybe it isn’t safe and effective?” asks the EPA’s Hirzy, who adds that besides bureaucratic inertia, there is corporate incentive. Fluoride is a waste product of many heavy industries; it is emitted by aluminum, steel and fertilizer factories, coal-burning power plants and in the production of glass, cement and other items made from clay. These industries would have to pay dearly to dispose of their waste fluoride if they could not sell it to municipalities for adding to tap water. Hirzy cites a memo written on March 30, 1983, by Rebecca Hammer, the deputy assistant administrator in EPA’s Office of Drinking Water, which called water fluoridation “an ideal environmental solution to a long-standing problem.”

“In other words,” says Hirzy, “this [fluoride] that otherwise would be an air and water pollutant is no longer a pollutant as long as it’s poured into your reservoir and drinking water. The solution to pollution is dilution, and in this case the dilution is your drinking water. It’s a good deal for the fertilizer industry. Instead of paying a substantial amount to cart this stuff away, they get paid $180 a long ton by the water municipalities.”

Fluoridation may be an infamous right-wing cause, but the corporate history of fluoride could stir the blood of left-wing conspiracists as well. The fluoride disposal problem arose during World War II, when demand for war materials meant increased production of aluminum, steel and other fluoride-related products. At the end of the war, with massive amounts of fluoride waste needing disposal, the Public Health Service began pushing to add fluoride to the water in Grand Rapids, Mich., and dozens of other U.S. cities. At the time, the Public Health Service was being run by Treasury Secretary Andrew W. Mellon, a founder and major stockholder of the Aluminum Company of America (Alcoa), which had dominated fluoride research since the 1920s. By 1950, as the fluoridation campaign gained steam, the Public Health Service was headed by another top Alcoa official, Oscar R. Ewing, who in turn was aided by Edward L. Bernays, the father of modern public relations and author of the book “Propaganda,” who sought to portray fluoride’s opponents as wackos.

Whatever its origins, is it possible that America’s 50-year embrace of fluoridation has been a terrible mistake? The town of Natick, near Boston, recently reviewed the research and found that there was more than enough fluoride now packaged in our food, drinks and toothpastes; the town decided not to fluoridate its water. Los Angeles, Newark and Jersey City, N.J., and Bedford, Mass., have also removed fluoride from their water.

Critics like Mullenix, Hirzy, Marcus and Carton say we don’t yet know enough to say definitively that it’s all been a mistake. They want more research by the scientific community, more coverage of the dispute by the media and more awareness of the health risks by the American people. As more parents begin to notice the warnings on toothpaste labels — and those nasty, irreversible white spots on their kids’ teeth — the issue may once again get the attention and the debate it deserves.

Mark Hertsgaard is the author of four books, including “Earth Odyssey: Around the World in Search of Our Environmental Future,” published this month by Broadway Books. Phillip Frazer is the editor of News On Earth; subscriptions are available at