Over the last six years, Lynne Campbell has become accustomed to being called a liar and a kook.
That’s how long it’s been since she left her advertising job to fight fluoride full time, trying to keep the cavity-fighting chemical out of Portlanders’ drinking water.
But while fluoridation proponents have long maintained that Campbell and her allies are wrong to say the chemical’s safety is unproven, now the mild-mannered Lake Oswego woman for the first time has backup from Uncle Sam— a U.S. government study saying that, indeed, there are unanswered safety questions about fluoride.
The study has special significance for Portland, the largest city in the country that still does not fluoridate its water — and which remains a high-priority target for both sides in the fluoridation fight.
On Wednesday, a panel of the Washington, D.C.-based National Academy of Sciences released a report finding that fluoride is less safe than previously thought, and that the federal Environmental Protection Agency’s safety limit on fluoride in water should be lowered. Specifically, it said that levels of the cavity-fighting substance currently allowed under federal water-safety rules cause a harmful variety of dental fluorosis, a mottling of the tooth that in its more severe form actually can cause cavities.
Moreover, it found persuasive evidence that fluoride in water increases bone fractures as well as stiffness in the joints of the elderly, and that it also may be related to Alzheimer’s disease, marginally reduce IQ in children and alter the endocrine and hormonal levels that control most of the functions of the human body — with unknown effects. The chemical may even cause bone cancer, said the NAS — although the evidence is “tentative and mixed.”
“It’s progress,” said Campbell, who heads a group called Oregon Citizens for Safe Drinking Water. But she argued that the report, by failing to directly discuss whether water-fluoridation makes sense, does not go far enough. “We’ve got evidence of cancer, bone fractures and endocrine effects,” she said, adding, “How much longer do we have to wait?”
Kurt Ferre, a Portland dentist who heads local fluoridation efforts, echoed Campbell in noting that the report does not explicitly pass judgment on current water fluoridation levels. But after reading the report’s executive summary, he said he does not think the risks of fluoridation outweigh the benefits.
“I will continue, along with the Oregon Dental Association, to advocate for community water fluoridation as the most cost-effective way to help reduce dental decay across our population,” he said.
Brett Hamilton, director of the Oregon Dental Association, agreed, saying his group “continues to advocate for the process of adding fluoride to public water supplies to reach an optimal level in order to protect people against tooth decay.”
Last year, Ferre’s group, the Tri-County Fluoridation Forum, spearheaded efforts in Salem for a law that would force Portland, which has rejected fluoridation four times since 1956, to change its ways. Ferre has said he plans to try again next year.
Scientific credibility’s strong
If science were sports, the NAS would be the U.S. national team. Signed into law by Abraham Lincoln, the federally funded academy’s job is to survey the latest science, weed out questionable research and advise government agencies. Prepared by top scientists, the new report looked at hundreds of studies and was vetted by more than a dozen experts around the country.
Hamilton and Ferre correctly noted that much of the NAS report looks at levels of fluoride that are above the “optimal” level of water fluoridation to fight cavities: approximately 1 milligram per liter of water. The report concludes that the current U.S. maximum on naturally occurring fluoride in water, 4 milligrams per liter, is too high.
However, some of the research that is validated by the report suggests that water-fluoridation levels advocated by Hamilton and Ferre may be unhealthy, two members of the NAS panel said in interviews with the Portland Tribune.
NAS panel member Kathy Thiessen, a former senior scientist at Oak Ridge National Laboratory who has studied fluoride for the EPA, said the report showed “the potential is there” that water fluoridation is unhealthy. As for the studies finding that higher levels damage children’s IQ, she said it’s possible water fluoridation levels may have a similar, albeit reduced effect. She said in her personal opinion the research suggests “most people should minimize their fluoride intake” — which includes avoiding fluoridated water.
“I think you can look at most chapters of this report and say, ‘Whoa,’ ” she said. “We have made major strides from previous (looks) at this topic.”
NAS panel member Robert Isaacson, a distinguished professor of neurobehavioral science at the State University of New York in Binghamton, agreed, saying that the possible effects on endocrines and hormones from water-fluoridation are “something that I wouldn’t want to happen to me if I had any say in the matter.”
The report “should be a wake-up call,” he added.
Area dentists stand firm
This argument will be hard to swallow for Portland dentists, many of whom claim they can tell the difference between fluoridated and unfluoridated teeth. Most experts say the use of fluoride reduces cavities by between 10 percent and 25 percent.
Tom Maier, an assistant biosciences professor at the OHSU School of Dentistry, pointed out that the NAS panel — besides saying the current EPA maximum on fluoride in water is unsafe — mainly called for more definitive research. Although the report raises questions about fluoridation’s safety, “it doesn’t rise to the level that I’d think you would need to change (policy) at this point,” he said.
Water-fluoridation opponents argue that fluoride’s benefits are better derived from mouthwash or toothpaste — not by swallowing it. The NAS report showed “that you can protect your children’s teeth by brushing them, and you can protect their bones by getting rid of fluoride in tap water,” Tim Kropp, a toxicologist for the Washington, D.C.-based Environmental Working Group said in a prepared statement Wednesday.
Campbell, for her part, argues that the report “opens the door” to halting water fluoridation entirely: “It highlights (that) it’s really time to take these warnings seriously and get the research done.”