WASHINGTON — Amid growing debates over the safety of water fluoridation, fueled by the nomination of fluoride skeptic Robert F. Kennedy, Jr. to head the nation’s Department of Health and Human Services, water authorities in Maryland, Virginia, and Washington, D.C. remain unchanged in their support for fluoridated water as a critical public health measure.
But the national conversation is heating up, with a federal judge in September raising concerns about the risk of neurological harm to children and several U.S. cities recently eliminating fluoride from their water supplies.
Senior Judge Edward M. Chen with the U.S. District Court for the Northern District of California on Sept. 24 ordered the EPA to develop new fluoride regulations.
Chen’s ruling relied, in part, on an analysis from the U.S. National Toxicology Program finding “with moderate confidence” that lower IQ scores in children outside the U.S. are linked to fluoride levels up to twice as high as the recommended level for fluoridation in U.S. public water systems.
Fluoride supporters insist that the lower level of fluoridation common in the U.S. is completely safe. They cite a 2023 meta-analysis of studies which found no association between low-level fluoridation and IQ scores.
“It’s comparing apples to oranges,” said Dr. Aaron Yancoskie, the Associate Dean for Academic Affairs at the Touro College of Dental Medicine. “The unfortunate fact is that the studies that were used by the National Toxicology Program in the preparation of that report were actually from places outside of the United States where fluoride occurs naturally at very high levels, much higher than what we use for community water fluoridation programs."
The Centers for Disease Control and Prevention’s recommended level in public water supplies is .07 milligrams of fluoride per liter.
Where regional public health authorities stand
Public health authorities in Maryland and Virginia have consistently emphasized the benefits of fluoride in reducing dental decay by as much as 30% and the overall public health benefit of reducing dental disease.
According to the Virginia Department of Health, over 96% of residents served by public water systems receive fluoridated water.
Similarly, Maryland municipalities widely adhere to fluoridation practices, where more than 94% of state residents are on fluoridated water systems, according to a 2018 Maryland Health Department report.
In Washington, D.C., fluoridation remains a cornerstone of public health efforts to prevent cavities, particularly in underserved communities, according to a Department of Health and Human Services report. The Washington Aqueduct adds fluoride to the drinking water supplied to the District of Columbia and large sections of Northern Virginia, including Arlington County, Falls Church, and parts of Fairfax County, to meet the optimal level of 0.7 milligrams per liter (mg/L) recommended by the CDC.
In Maryland, the Department of Health told WUSA9 it favors fluoride in public water supplies but pointed out fluoridation is a local issue.
“The Maryland Department of Health continues to support fluoride as a tool in reducing tooth decay,” the department said in a written statement. “The Maryland Department of Health does not authorize or deauthorize the use of fluoride."
Officials representing the health departments in D.C. and Virginia did not respond to WUSA9’s requests to comment on the documents supporting fluoridation in public water supplies published by their agencies.
WSSC Water, which supplies water to more than 4 million people in Maryland’s suburbs issued a statement to WUSA9:
“WSSC Water has followed the recommendations of leading public health authorities since beginning the practice of water fluoridation over 60 years ago. Our approach to water fluoridation is based on years of research, science, and recommendations of leading public health authorities.” the utility said.
The American Dental Association
The positions taken by regional health authorities mirror the recommendation of the American Dental Association (ADA), which says fluoridation of public water supplies has been responsible for dramatically improving the public’s oral health and has been lauded as one of the “ten great public health achievements of the 20th century,” on par with the elimination of polio, according to the ADA’s Fluoridation Facts report.
“For more than 70 years, detailed reports have been published on multiple aspects of fluoridation,” the ADA states in its report.
“The accumulated dental, medical, and public health evidence concerning fluoridation has been reviewed and evaluated numerous times by academicians, committees of experts, special councils of governments, and most of the world’s major national and international health organizations. The consensus of the scientific community is that water fluoridation, at the level recommended to prevent tooth decay, safely provides oral health benefits which in turn supports improved general health,” the ADA’s report says.
The report notes that “community water fluoridation benefits everyone, especially those without access to regular dental care.”
In its reports, the ADA points out that studies included in the National Toxicology Program’s analysis linking fluoride to neurocognitive effects in children did not occur in the U.S. and that the levels investigated were higher than the recommended levels in the US.
The ADA did not respond to WUSA9’s request for further comments.
Reports Supporting Fluoride’s Safety:
- A 2023 meta-analysis of eight fluoride research studies “found no statistically significant difference” between the CDC recommended levels of public water system fluoridation and fluctuation in IQ scores and “no relationship” between low level fluoridation an IQ effects.
- According to the National Institutes of Health, a 2018 cross-sectional study on the associations between fluoridated community water and tooth decay in the U.S. concluded that fluoride in public water was associated with a 30% reduction in the rate of tooth decay in primary teeth and a 12% reduction in the rate of decay in permanent teeth.
Studies Raising Concerns:
- U.S. National Toxicology Program finding “with moderate confidence” that lower IQ scores in children outside the U.S. are linked to fluoride levels up to twice as high as the recommended level for fluoridation in U.S. public water systems. The study was based primarily on epidemiology studies in non-U.S. countries such as Canada, China, India, Iran, Pakistan, and Mexico.
- Similar Research published in the European Journal of Public Health investigated the relationship between prenatal fluoride exposure and child IQ. The study found that higher maternal urinary fluoride concentrations during pregnancy are associated with lower IQ scores in children, indicating a dose-dependent effect.
Federal Lawsuit Against the EPA
Despite a long history of U.S. government support for public water fluoridation, confidence in fluoride was badly shaken in September when a federal judge found that adding fluoride to drinking water may risk lowering children’s IQs and that the Environmental Protection Agency (EPA) must respond by developing regulation.
“The court finds there is an unreasonable risk of such injury, a risk sufficient to require the EPA to engage with a regulatory response,” ruled Senior Judge Edward M. Chen with the U.S. District Court for the Northern District of California on Sept. 24.
“It should be noted that this finding does not conclude with certainty that fluoridated water is injurious to public health,” Chen said. But Chen ordered the EPA to examine the mineral’s harmful potential and formulate a response.
The ruling came after a coalition of advocacy groups, including the Fluoride Action Network, filed a federal lawsuit against the EPA demanding stricter regulations to reduce the potential neurotoxic risks of fluoride. The lawsuit included studies reviewed by the National Toxicology Program suggesting that prenatal fluoride exposure may lower IQ in children, urging the EPA to reexamine current guidelines.
The National Toxicology Program review was based primarily on epidemiology studies in non-U.S. countries such as Canada, China, India, Iran, Pakistan, and Mexico where some pregnant women, infants, and children received total fluoride exposure amounts higher than 1.5 mg fluoride/L of drinking water.
“The NTP review was designed to evaluate total fluoride exposure from all sources and was not designed to evaluate the health effects of fluoridated drinking water alone. It is important to note, however, that there were insufficient data to determine if the low fluoride level of 0.7 mg/L currently recommended for U.S. community water supplies has a negative effect on children’s IQ,” the National Toxicology Program report stated.
The NTP found no evidence that fluoride exposure had adverse effects on adult cognition.
Stuart Cooper, who speaks for The Fluoride Action Network which brought the lawsuit against the EPA called the ruling a landmark.
“This judge was able to look at that information, all of the research over eight years, and hear expert testimony under oath, under penalty of perjury, and was able to determine that fluoride posed an unreasonable risk based on the hazard assessment guidelines that EPA was supposed to follow. But politics got intervened in the EPA process; the politics did not intervene in the judge’s ruling,” Cooper said.
Robert F. Kennedy Jr.’s Role
Robert F. Kennedy Jr., a vocal critic of water fluoridation, has amplified the conversation, claiming fluoride poses significant health risks. Recently nominated as Secretary of Health and Human Services, Kennedy has called for a nationwide reevaluation of fluoridation policies.
“On January 20, the Trump White House will advise all U.S. water systems to remove fluoride from public water. Fluoride is an industrial waste associated with arthritis, bone fractures, bone cancer, IQ loss, neurodevelopmental disorders, and thyroid disease,” Kennedy posted on X on Nov. 2.
Cities Eliminating Fluoride
With conflicting studies, some cities in the U.S. have decided to eliminate fluoride from their water supplies, while voters have refused to authorize fluoridation.
November ballot measures in two Oregon cities rejected fluoridation. Similar referendums have been rejected four separate times in the city of Portland, which remains the nation’s largest city without fluoridated drinking water.
Recent examples of cities deciding to eliminate fluoridation include Winter Haven, Florida and Yorktown, New York, both citing health concerns and public opinion. Brushy Creek, Texas, also stopped fluoridation in late 2023, prompting calls from the Texas Dental Association to highlight the benefits of fluoridated water. Legislators in Arkansas are now considering repealing a state mandate to fluoridate public water supplies.
Despite increasing pressures to eliminate fluoride in public water supplies, no water systems in the D.C. region are currently being challenged in court or by legislators to stop the practice.
About Fluoride
According to the CDC, fluoride is a naturally present mineral in water and soil as well as being in many foods and available as a dietary supplement.
Fluoride is documented to stop or reverse the initiation and progression of tooth decay. It also stimulates new bone formation.
The CDC reports that soil, water, plants, and foods contain trace amounts of fluoride. Most of the fluoride that people consume comes from fluoridated water, foods and beverages prepared with fluoridated water, and toothpaste and other dental products containing fluoride.
The CDC recommends public water systems treat water to maintain a level of 0.7 milligrams of fluoride per liter (mg/L).
What should you do if you are concerned?
In the recently decided federal case, most evidence focused on studies linking fluoride to risks of neurological effects in children from prenatal and early exposure to the mineral. The Fluoride Action Network recommends that pregnant women avoid drinking fluoridated water and that families not use fluoridated water to mix infant formula.
Signs that an individual may be receiving too much fluoride include white spots or white streaks on the teeth of children and teens, according to the CDC. The condition is called dental fluorosis, which occurs when too much fluoride is consumed during tooth development, usually in childhood.