OUR EXPOSURE TO FLUORIDE
Stephen Levy, a researcher at the University of Iowa College of Dentistry, has been heading one of the nation's longest running studies on the public
health effects of fluoride. With 20 years of research behind him, Levy concludes that fluoride is still a benefit to society, although its impact is
"We consistently find a difference for those people in our study who are not having fluoridated water -- they are on average having more decay," Levy
says, but with a qualifier. "It's clear that, on average, the benefits of community water fluoridation would not be as great as they were many decades
ago when we had many fewer other fluoride exposure sources and when caries rates were so much higher. So, the absolute benefit is less; the percentage
benefit is less."
The other fluoride sources Levy refers to are soft drinks, packaged food, and anything made with fluoridated water. In 2008, Scientific American reported on the various sources
of fluoride in diets and found that some are higher than the CDC recommendations for tap water. For instance, the magazine found that brewed black tea
contains 3.73 ppm, raisins contain 2.34 ppm, and white wine has 2.02 ppm.
Levy does find some weight in the claim that fluoride can cause problems with bone structure, but only at exposures to concentrations of 8 or more ppm
for 20 years or more. "There have only been two or three documented cases ever in this country," he says, adding that there is a slight increased risk
of bone fractures for communities exposed to 4 ppm.
WHAT ABOUT COSTS?
Even if fluoride still has a noticeable, however waning, effect on dental health, is cutting it a legitimate cost-saving measure as some opponents
For cash-strapped municipalities, the $200,000 that Pinellas County will save annually could be put to good use. But this too might not be the case.
According to CDC data, the net cost of not fluoridating (accounting for the cost of extra cavities and missed work) Pinellas is $11,200,000 to
$13,300,000 per year. Fluoridated water, the CDC says, saves society $16 to $19 per person per year, yet it only costs $0.50 per person for communities
of 20,000 or larger.
But Connett has a rebuttal to this, too: In his book, he says the study discredits the costs of cosmetic treatments and overstates the amount of work
lost for taking the time to get a cavity filled.
WHAT WE KNOW
Any public health initiative is going to be doubted by some. We can't prove definitively that fluoride is 100 percent safe and will not negatively
affect public well-being. Dental research does not lend itself to causational studies -- researchers can't exactly separate people into random
fluoridated and non-fluoridated communities and observe them like mice.
"Fluoride has been scrutinized intensely," Levy says. "The EPA continues to look at it, the NIH, researchers, policy makers.... But for the individual
who is arguing against it, we can never reach the burden of proof that they put out there."