Waukon was the first city in Iowa to fluoridate its water in 1951. Since then, cities across the state have been adjusting fluoride levels in their water supplies to bolster oral health.
But some Iowa cities — typically communities with smaller populations — have either opted out of adjusting the fluoride levels in water or never did it at all.
Why do some communities fluoridate their water while others do not?
That’s what one person asked Curious Iowa, a series from The Gazette that answers readers’ questions about our state, its people and the culture.
Why do some cities add fluoride to their water?
According to the Centers for Disease Control and Prevention, 10 water systems in Linn County adjust fluoride levels in the water supply to reach “optimal levels.” The other 29 water systems listed by the CDC don’t add or adjust fluoride in the water. Some cities said they’ve never adjusted them, while others have stopped in recent years.
Coggon is one example of a city that does not adjust the fluoride levels in its water.
“We do not treat our water and never have. No special reason other than our water seems to be fine without it,” said Brenda Quandt, city clerk and finance officer for the city of Coggon.
Similarly, Walker — home to fewer than 700 people — also doesn’t add fluoride to its water, City Clerk Connie Helms said, adding that Walker’s water “has a sufficient amount of natural fluoride.”
Fairfax used to adjust fluoride in its water, but it stopped that practice in 2016.
”The city’s Department of Natural Resources water permit does not require it to be added, and there were challenges of controlling and monitoring the water to stay within the quantity limits,“ said Fairfax Mayor Jo Ann Beer. ”Fairfax’s water supply has some naturally occurring fluoride, but the risk of oversupplying was a key factor in the decision to discontinue fluoride addition.“
Cedar Rapids has been adjusting its fluoride levels since 1952 — one of the earlier cities to adopt the practice.
Roy Hesemann, utilities director for the City of Cedar Rapids, said the process for adjusting fluoride levels in the city’s water hasn’t changed much over the years, with the exception of new equipment being used.
Hesemann said a city can fluoridate its water with either liquid or powdered fluoride. Cedar Rapids uses the powder — called sodium fluorosilicate — due to its availability.
Cedar Rapids’ water plant has a machine that signals a mixing pump for how much dry fluoridepowder to add to the water. The mixing pump “immediately” combines the powder and the water.
The optimal range level for fluoride is 0.7 milligrams per liter. Hesemann said there can be a little bit of variation — slightly over or below 0.7 — and that doesn’t pose a risk for communities.
Cedar Rapids’ water also is treated with phosphate to help decrease the possibility of lead leaching out into the tap water, and it is exposed to ultraviolet light for disinfection. From there, the water is pumped out of the facility into Cedar Rapids homes and businesses.
Hesemann says it costs about $1 per person, per year to fluoridate Cedar Rapids’ water supply. In 2023, that totaled about $135,958.
Hesemann, who has been in the water utilities business for almost 40 years, said some water supplies actually have too much naturally occurring fluoride in their water, which requires a more expensive process to remove.
About 13 years ago, Cedar Rapids’ fluoride levels were at 1 part per million when the U.S. Department of Health and Human Services adjusted its recommendations for fluoride, bringing the optimal dosage down to 0.7. The city responded by reducing the fluoride it added to the water.
What is fluoride? What does it do?
Fluoride is a naturally occurring mineral found in water and in the Earth. It comes from the element fluorine, which is found naturally in water, soil and foods like brewed teas, some seafood and raisins. It can be taken in supplement form, too.
Steve Levy, a professor of preventive and community dentistry at the University of Iowa, said most people consume some level of fluoride because even cities that do not adjust their fluoride may have it naturally occurring in their water supply.
He said Coralville is one city that does not have to adjust its fluoride levels because it naturally reaches the 0.7 milligrams per liter threshold.
Cities around the country began adjusting fluoride in their water following studies in the 1930s. That was before fluoride-treated toothpastes and mouthwashes were available on the market.
Levy said when some communities started adding fluoride to water in the 1940s, they found that residents in places that had fluoride-treated water had about 50 percent less tooth decay than residents in cities with untreated water.
Now, with many people using fluoride-treated toothpastes and mouth washes, the CDC has found that drinking fluoridated water can decrease the risk of tooth decay by up to 25 percent.
In Iowa, the number of fluoridated water systems is about the same as the number of unfluoridated water systems. However, Levy said, the water systems with fluoridation serve much larger cities, resulting in the majority of people statewide receiving treated water.
Levy said about 90 percent of people in Iowa receive fluoride-treated water.
In 2023, 96 community water systems in Iowa were awarded a Water Fluoridation Quality Award from the CDC.
The Iowa Department of Health and Human Services said fluoridation is “one of the best investments a community can make in maintaining the oral health of its citizens,” estimating that for every dollar put into fluoridation efforts in a city, it saves more than $20 in dental costs.
Why do some water supplies not add fluoride?
While fluoride-treated water is beneficial, Levy said treating water isn’t always practical.
“It’s just not feasible with very small communities,” he said, referring to some communities with only 15 or 20 homes on one water system.
However, some people believe that adjusted fluoridation shouldn’t occur at all.
Stuart Cooper is executive director for the Fluoride Action Network, an organization that works to educate the public about “the toxicity of fluoride compounds.”
“Most at risk right now is the fetus who has no teeth and there’s no claim benefit, and bottle fed infants who have no teeth … there’s no claim benefit, there’s only risk,” Cooper said. He said the organization also researches the link between added fluoride exposure to a lower IQ and neurobehavioral disorders like ADHD.
Levy said there isn’t evidence of this in people who drink fluoridated water at appropriate levels. If someone takes in too much fluoride, Levy said they can develop dental fluorosis, which can change the mineralization in the teeth.
“Dental fluorosis is when someone can get white spots on their teeth if they have a little bit higher than recommended levels,” Levy said. “But at much higher levels, they can actually get brown staining of the teeth.”
Cooper said he believes that policymakers are well meaning, but they follow the CDC’s guidance because they “don’t have the opportunity to spend months on an issue there.”
City councils and legislators “have a hundred issues a day to deal with, and so they trust health authorities more than they ought to in this scenario,” Cooper said.
Levy said investing in fluoridation efforts can help the underserved.
“Those who have the least access to [dental] prevention will benefit, because it’s a passive thing. They don’t have to have enough money to buy a toothbrush and toothpaste, or go to the dentist,”
Original article online at: https://www.thegazette.com/curious-iowa/curious-iowa-why-do-some-cities-fluoridate-their-water-while-others-do-not/