Communities across the U.S. have put fluoride in their drinking water for decades due to its benefits for dental health. However, opposition to the practice has grown in recent years – even including criticism from national figures like U.S. Health and Human Services Secretary Robert F. Kennedy Jr., who has called the mineral an “industrial waste.”
That opposition has trickled down to Kentucky, where some lawmakers are trying to get rid of a more than 60-year-old state mandate that requires most water systems to fluoridate their water supplies, and instead let local groups decide whether they want to continue it.
The measure passed the state House in late February, but House Bill 16 is still awaiting approval in the Senate. It has been assigned to the Senate’s Health Services committee, where it was still waiting to be heard as of Thursday afternoon – a step that must be taken before it could be considered on the chamber’s floor.
According to the Centers for Disease Control and Prevention, nearly 94% of Kentuckians get fluoridated water in their taps. For Kentuckians that get their water from community systems, that number rises to 99.7% – one of the highest state fluoride access rates in the nation.
Speaking on the state House floor last month, Republican Rep. Mark Hart of Falmouth – the bill’s lead sponsor – said the measure simply removes the state mandate, and instead makes water fluoridation a “local option.” Despite his proposal, Hart said he thinks a decision like this is best left to medical professionals – not elected officials.
“I truly believe that the government shouldn't be making this decision. This decision should be made between the patient and their health care provider,” Hart said.
Dr. Steve Robertson, executive director of the Kentucky Dental Association, opposes the attempt to remove the state’s community fluoridation mandate.
“The dentists in the state of Kentucky are busy enough. We don't need more thrown on our plate through an arbitrary decision to discontinue the most successful public health campaign that we've ever had,” Robertson said.
Dentists won’t be the only ones gritting their teeth if Kentucky’s fluoridation mandate is removed. According to fiscal notes from Gov. Andy Beshear’s office, stopping fluoridation in some communities could cost the state and residents millions. For every 10% of the population with non-fluoridated water, the governor’s office estimates it would cost $19.7 million – including nearly $4 million in state funds – to treat additional dental health needs that could arise without access to fluoridated water.
A history of community fluoridation
The CDC ranked community fluoridation as one of the 10 great public health achievements of the 20th century, alongside other major developments like making motor vehicles safer and recognizing tobacco use as a health hazard.
Tooth decay – or dental caries – was once more commonplace than it is today. During World War II, more than 20% of people drafted to serve in the U.S. military were actually rejected due to dental issues – including cavities and tooth decay.
Dr. Scott Tomar, an associate dean at the University of Illinois Chicago’s College of Dentistry’s Prevention and Public Health Sciences division, said it was once inevitable for many children to lose their teeth and for some adults to be missing most. He said the practice of adding fluoride to water supplies has helped make that a thing of the past.
“[Water fluoridation] has literally changed the face of America,” Tomar said. “There’s still, unfortunately, plenty of tooth decay out there. But the magnitude and severity is nowhere near what it once was, and a big part of it is community water fluoridation.”
The practice of artificially increasing fluoride levels in local water supplies began 80 years ago in the United States, when Grand Rapids, Michigan became the first city to fluoridate its drinking water. This followed studies and observations by researchers in the early 20th century who found that people who drank water with naturally high levels of fluoride were less likely to experience tooth decay.
In 1951, Maysville became the first Kentucky city to launch community water fluoridation efforts, followed soon after by Louisville. By the 1960s, the Commonwealth had adopted a mandate requiring local utilities serving more than 3,000 people to fluoridate their water “to protect the dental health of the people served by the supply.”
Newer analysis suggests potential IQ impacts from fluoride – but some have issues with study’s methodology
The practice of community fluoridation has come under fire in recent years despite many dental professionals’ recommendations and some studies continuing to link the practice with lower levels of tooth decay.
Last year, the federally-run National Toxicology Program published a meta-analysis of more than 70 studies that suggest high levels of fluoride – starting at double the current recommended level in the United States – could negatively impact children’s IQ levels. However, the analysis specifically mentions that there’s not enough data to say that the U.S. standard fluoride level has an impact on children’s IQ.
Nonetheless, that publication has been used by the practice’s detractors as a basis to question whether the recommended level of fluoride in U.S. water supplies is safe.
In September 2024, a federal judge issued a ruling against the Environmental Protection Agency ordering the federal organization to evaluate the potential risk fluoride could pose to human health – including the suggestion that high levels of fluoride are associated with reductions in children’s IQ levels. Earlier this year, the EPA, under the Biden administration, filed a notice intending to appeal this ruling.
That study was also brought up at a Kentucky interim legislative committee hearing last year discussing legislation on fluoride mandates.
Some public health advocates, like Dr. Steven Levy, a professor of preventive and community dentistry at the University of Iowa, argue the NTP analysis is flawed.
“They included all of the very low quality studies, and even they, in their estimate, say that 70% of the studies they included were high risk of bias.”
Tomar also wrote an editorial that, in part, questioned how the NTP analysis was conducted and whether its results were applicable to U.S. fluoridation programs. He said, in some of the countries where the studies the analysis looked at were conducted, those regions have “much higher” naturally occurring levels of fluoride than what is typical for much of the United States. He also said some of the studies did not control for other potential variables like industrial pollution.
“When you're only looking for one agent, you only see that one agent. They don't look at a host of other things. And again, that's why so many of these studies were judged to be low quality,” Tomar said. “The studies that had fluoride exposure [levels] that [are] much more relevant to what we have in the United States and Kentucky in areas that practice community water fluoridation, there was no evidence at all of any effect on IQ or any other measure of children's brain development.”
Is fluoridated water still needed?
Some people have questioned whether fluoride is still necessary in water supplies given the increased presence of the mineral in toothpaste and other products, with the Kentucky legislature having weighed measures aimed at ending the mandate in the state seven times since 2018.
At a legislative committee hearing last month, Republican Rep. Emily Callaway recalled that when she was in school, she received cups with fluoride rinse in them to help prevent tooth decay. Robertson, the leader of the Kentucky Dental Association, said fluoride in topical treatments like that works differently from fluoride that is in more systemic treatments like water fluoridation.
“Fluoride is an interesting mineral in that it has to be allowed an extended period on the teeth, a minimum of 30 minutes to truly give you any effect to incorporate,” Robertson said.
“With the systemic fluoride, it’s not only taken up into the developing teeth – which increases the density and therefore the decay resistance – it's also incorporated into the saliva and gets excreted through this crevicular fluid, which kind of acts like a constant fluoride bath in the mouth.”
Community fluoridation advocates point out that some people cannot afford access to regular dental care – and that having access to fluoridated water may be the only fluoride access they can get. In this way, Robertson said, fluoridated water supplies can help improve the dental health of wide sections of the population across the state.
“Fluoridation literally helps every single individual that has access to that fluoridated water. It doesn't matter socioeconomic [status], geographic [region], none of those [factors] matter.”
