Many people take for granted the addition of fluoride into public drinking water systems that aims to prevent tooth decay.
The U.S. Centers for Disease Control and Prevention considers it to be one of the 10 top public health achievements of the 20th century and it is backed by the American Dental Association and the World Health Organization.
But fluoridation is not nearly as universally accepted and practiced as one might think – often because of public perceptions that it is harmful, not cost-effective or no longer necessary.
At least seven cities or towns across the country debated the issue just this summer.
In Healdsburg, Calif., voters will revisit a ballot question in November regarding whether to stop adding the mineral to the water supply. In fact, Healdsburg is the only city in Sonoma County that currently adds fluoride to its water. The city of about 11,000 people has done so since the 1950s, according to city clerk Maria Curial.
The Healdsburg ballot measure would require that a toxicological report confirm the safety of fluoridating chemicals used in the city’s water. But examining every batch of these chemicals is not realistic, Curiel said, and the measure ultimately would force the city to stop fluoridation.
California law requires water systems with 10,000 or more service connections to fluoridate water. But suppliers must find their own funding to fluoridate, so it doesn’t always happen right away.
San Jose, with a population of more than 1 million, is the largest metropolitan city in the country that does not fluoridate its water. The Santa Clara Valley Water District, which provides the city’s water, will only begin delivering fluoridated water in some areas this coming December, after many years of debate and four years after district officials first voted to go ahead. The district has since been raising money and retrofitting water plants to prepare for the change.
Dr. Sara Cody, the Santa Clara County public health director, explained that cities in the county receive their water from different sources, and while neighboring cities have fluoridated water, San Jose has been the exception.
Communities such as East San Jose, a traditionally low-income neighborhood, tend to have worse health outcomes, Cody said. Those are the communities that would benefit most from community fluoridation, she said. “If everyone had access to regular dental care, that would be great, but that’s not the world we live in,” Cody said.
“There has always been periodic discussion,” said Steven Levy, a dentistry professor at the University of Iowa. Levy is involved in an Iowa-based longitudinal study that tracks fluoride intake and its effects on children’s bones. “We are seeing more challenges now because of the communication explosion with the internet.”
The debate over fluoridation started well before 1945 when Grand Rapids, Mich., became the first U.S. city to add fluoride to its water supply. In the decades since, opposition usually has stemmed from concerns that fluoride intake by children lowers IQs, creates higher rates of attention deficit/hyperactivity disorder and can lead to toxicity.
Although fluoridation has become a fairly common practice, with about 74 percent of the population receiving fluoridated water from community water systems, the intervention continues to raise grassroots concerns. These arguments range from casting fluoride as unnecessary and ineffective to portraying the mineral as “mass medication” and a “damaging environmental pollutant.”
“Fluoridation is not safe or cost-effective,” said Bill Osmunson, director of the Fluoride Action Network, a national organization against fluoridation of water supplies, adding that people should be given the freedom to decide so they can avoid ingesting excess fluoride.
In Wellington, Fla., officials only decided to add fluoride back into the water in July after the city council voted two years ago to remove it. Mayor Anne Gerwig often fields angry emails on this issue.
“I watch the videos that they email me, I read the information they send me,” Gerwig said.
Gerwig has no background in science, but she read studies and fact-checked the claims being made by the town’s residents. Gerwig said she decided to support fluoridation after she found scientific consensus about the benefits of fluoridation in preventing tooth decay.
The CDC considers water fluoridation to be the most cost-effective method of delivering fluoride to all, reducing tooth decay by 25 percent in children and adults. Tooth decay is still one of the most common chronic conditions among children.
“A big thing about community water fluoridation is that it’s a passive intervention, you don’t really have to do anything other than drink tap water,” said Katherine Weno, oral health director at the CDC. “You don’t have to buy a product or access to a dental professional. It benefits people who don’t have money to go to a dentist or don’t have any insurance.”
But some question the need for continued fluoridation, especially because products such as toothpaste and rinses containing fluoride are available, and because the chemical’s levels vary and indications of harm are not always clear.
“Our dental health is clearly much less dependent on fluoride in drinking water than way back when this important public health intervention was initiated,” Grandjean said.
In a 2016 Harvard Public Health article, Grandjean wrote about the need for more research about populations that may be vulnerable to the mineral and the proper dose of it in drinking water. The article drew multiple critical letters.
“The article misrepresents the current state of the science of community water fluoridation, and does not provide a fair and balanced perspective,” wrote Francis Kim and Scott L. Tomar from the American Association of Public Health Dentistry and Bruce Donoff, dean of the Harvard School of Dental Medicine in one of the letters.
New studies are published almost every year that bring up concerns about fluoridation in drinking water, linking the intake with various developmental issues and even thyroid problems, issues that Osmunson also brought up.
Weno and Levy said those studies were performed in places where natural fluoride levels are higher and where residents may get fluoride through milk or salt rather than water. Excessive fluoride intake does have health implications — a problem commonly found in places with high concentrations of natural fluoride such as China, India and Africa. Most Americans receive water with low natural levels of fluoride.
Health officials also monitor and review what is appropriate. The Department of Health and Human Services in April 2015 released new recommendations for fluoride levels in drinking water, updating and replacing the level in place since 1962 to reflect the fact that Americans now have more sources of fluoride in toothpaste, mouthwashes and other products.
But other local jursidictions continue to wrestle with the issue. In July, the commissioners of Soddy-Daisy, Tenn., voted to stop adding fluoride and Houston’s city council chose to leave it in. In August, Port Angeles, Wash., stopped fluoridation until voters decide in November 2017.
For some of the local officials involved in these debates, their take is part of even greater political questions.
“The individuals who benefit the most are poor children,” said Dick White, mayor pro tem of Durango, Colo. The town decided in June to continue adding fluoride to its water. “If we get national health care for every single person, we could probably eliminate fluoridation in the water because we can ensure that every child is getting dental care.”