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July 23, 2012
WICHITA By the time it reaches the tap, most drinking water in Kansas has been treated with all kinds of chemicals.
Chlorine, ammonia, alum, phosphates and polymers are among the most commonly used.
But of the hundreds of chemicals certified for use at water treatment plants, only one seems to excite public attention and controversy: fluoride.
And the clamor this year over the additive probably is as loud in Wichita as it is anywhere else in the U.S.
Kansas’ largest city for many years has been among the minority of American cities that do not fluoridate the drinking water. As is, Wichita’s water, drawn from Cheney Lake and aquifers, has a naturally occurring or “background” fluoride level of about 0.3 parts per million. One ppm is equivalent to 1 milligram per liter of water.
A group of residents — Wichitans for Healthy Teeth — has been circulating a petition asking city officials to boost the level of fluoride in the city’s water to 0.7 ppm as a way to combat tooth decay, especially among low-income persons who might not have regular access to dentists. About 8,300 signatures have been collected so far.
"Fluoridated water can reduce decay by about 25 percent," said Dr. Sara Meng, chair of Wichitans for Health Teeth. "A very conservative estimate of how much can be saved is $4.5 million annually, in preventing fillings and basic services. That does not count all the crowns, root canals and other major services."
If the group were successful, the city’s residents would experience no tactile differences in their water. It takes about 600 milligrams to equal a quarter teaspoon of salt, so 0.7 ppm of fluoride in the water would be nothing a normal person could taste or feel.
But that’s not what bothers the opponents of fluoridation in Wichita who have organized under the banners of Wichitans for Pure Water, a new group, and Fluoride Free Kansas, which launched its website in the late 1990s to fight an earlier effort to fluoridate the water.
Spokespersons for the opponents say the potential health hazards of fluoride, added at treatment plants in industrial quantities, aren’t fully understood. Some argue that government has no right to put what they consider medication in the drinking water.
"Fluoride is not the end-all, be-all to preventing cavities that we once thought it was, and there are potential side effects. We need to be investigating these," said Michael Hicks, volunteer executive director of Wichitans for Pure Water.
Health experts, however, say long-experience and research have shown the benefits of fluoridation far outweigh potential risks, which are inconsequential if the fluoride is used appropriately.
"The fact is, scientists involved in this have a very detailed and deliberate knowledge of (fluoridation),” said Kip Duchon, a fluoridation engineer at the federal Centers for Disease Control and Prevention. “We struggle because it's difficult for us to explain very complex things in lay terms."
Peer-reviewed research on the subject has convinced public health experts that fluoridation is safe and effective. But there are a few scientists who say their research suggests otherwise, and that their findings have been marginalized.
One of those is Albert Burgstahler, University of Kansas emeritus professor of chemistry and editor of the journal "Fluoride."
The journal focuses on the potential problems of fluoride, providing a venue for the “marginalized” researchers. For example, a report by a New Zealand scientist published in the journal in July 2011 concluded that the additive could cause cognitive impairment and that "the only assuredly safe level is zero" fluoride in drinking water.
Burgstahler declined requests to be interviewed, citing unfair treatment by the media in the past, but offered some information to KHI News Service via email.
"The public needs to have access to the best available evidence to make wise decisions. Asking the public to have faith in endorsements and opinions is not the same as seeing actual evidence," Burgstahler wrote via email, attaching several articles included here.
Among the concerns fluoride opponents commonly cite is the way most large water treatment plants add it in the treatment process, by pumping in hydrofluosilicic acid.
The acid is a byproduct of phosphate production. The opponents generally describe it as a "toxic waste," added to drinking water despite the fact that no studies have been done on its possible health effects.
• hydrofluosilicic acid: 63% in U.S., 37% in Kansas
• sodium silicofluoride: 28%, 60%
• sodium fluoride: 9%, 3%
Source: CDC, 1992 census (PDF)
Most of the studies have been done on a different fluoride compound, sodium fluoride, the white powder used when fluoridation started in the 1940s, but which today is only used in the smallest treatment plants.
Duchon, the CDC's fluoridation engineer, said his office fields calls from the media across the country about once per month, asking about the health risks of hydrofluosilicic acid.
"What are the health risks of fluorosilicates? The answer is there have never been health studies on fluorosilicates. When they hear that, they say that's horrible ... we should be concerned," Duchon said.
But he said that’s a bogus argument because fluorosilicates can only exist in a highly concentrated acid form.
Photo courtesy of Kip Duchon.
"When you neutralize the water to the pH that people drink and you dilute it to the level that's in water, fluorosilicates cease to exist," Duchon said. "But have we done studies on fluoride? Absolutely — there have been decades of study."
Duchon said the acid is no different than the other additives used to treat water. At high concentrations it would be toxic, but not at 0.7 parts per million (ppm), the optimal fluoride level recommended by the CDC.
"Poison is the concentration, not the substance," said Duchon.
In Ottawa, water treatment plant superintendent David Buehler said hydrofluosilicic acid, or HFS, is cheaper and much easier to apply than powdered sodium fluoride, allowing treatment engineers to keep a constant, precise fluoride level in the water.
"At one time we did feed the sacked, powdered chemical into a fluoridation tank. But getting a consistent level of treatment out of it was kind of an art form. With the HFS, you just hook it up to a pump and adjust your flow, so it's much easier and more consistent to apply," Buehler said.
Another concern cited by fluoridation opponents has to do with a once-common cosmetic side effect of fluoride.
Fluorosis, a condition that permanently stains teeth, can be caused by relatively low levels of fluoride — as low as 2 ppm, according to the Environmental Protection Agency. Water treatment plants must notify customers any time the fluoride level rises above 2 ppm.
In January 2011, the CDC lowered the recommended level of fluoride from 1 ppm to 0.7 ppm, said Linda Orgain, spokeswoman for the CDC's Division of Oral Health.
"Why the change now? Because, unlike when water fluoridation was first implemented back in the 1940s, we only had that as our main source of fluoride. People didn't have toothpaste. But now there's many different sources of fluoride," she said.
Orgain said that — despite the current prevalence of toothpaste and other sources of fluoride — the CDC still recommends the lower amount be added to drinking water because, among other things, children in families with lower incomes are less likely to be taught good oral hygiene habits. Oral health experts say complications from tooth decay can lead to problems beyond bad teeth and emergency room visits, such as poor nutrition and difficulty concentrating in school.
According to Wichitans for Healthy Teeth, the cost to fluoridate the water would be about $2 million initially and then about $150,000 annually.
The KHI News Service is an editorially independent initiative of the Kansas Health Institute and is committed to timely, objective and in-depth coverage of health issues and the policy making environment. Find more about the News Service at khi.org/newsservice or contact us at (785) 783-2529.