Community water fluoridation prevails in San Diego County following successful advocacy by SDCDS, CDA and partners
Community water fluoridation (CWF) remains one of the most studied and effective public health interventions in dentistry, yet it continues to face scrutiny driven by persistent misinformation. As federal agencies revisit the science, and local water districts consider operational changes, CDA is promoting responsive clinical resources and coordinated advocacy to ensure decisions reflect high-quality evidence.
EPA to review science on fluoride in drinking water, CDA weighs in
The Environmental Protection Agency on Jan. 22 announced a “fast-track effort” to explore any potential health effects of fluoride exposure on childhood development, emphasizing neurodevelopment and cognitive function.
CDA responded by submitting formal comments recommending that the EPA consider the latest high-quality population studies and include the benefits of optimal fluoride concentrations in its assessment. Alongside 140 organizations, CDA also signed onto the American Academy of Pediatric Dentistry’s letter which warns that the EPA’s current trajectory relies on discredited reports and inapplicable information that threatens safe community water fluoridation, triggering a public health crisis for American children.
CDA urged the EPA to consider the fluoride concentrations cited in publications about fluoride in drinking water. For example, research such as the NTP Monograph on fluoride and neurocognition clearly states the systematic review does not apply to water fluoridation at 0.7 mg/L as practiced in the U.S., Canada and Australia. The report found only an association, not causation, with fluoride levels greater than 1.5 mg/L, which naturally occurs in countries such as China and India.
The review of science on fluoride in drinking water should prioritize high-quality, longitudinal, population-based studies from countries with similar fluoride levels as the U.S. Furthermore, the important, positive impact of water fluoridation in reducing dental caries should not be excluded.
Read CDA’s full comments to the EPA.
Community water fluoridation prevails in San Diego County following successful advocacy
San Diego County’s Olivenhain Municipal Water District recently considered a staff-led recommendation to discontinue community water fluoridation due to cost and fluoride packaging concerns. CDA and the San Diego County Dental Society had earlier coordinated and mobilized leaders and member dentists to fight disinformation about fluoride. Eighteen individuals testified at the district’s January board meeting, including ten dentists, all speaking in favor of continuing water fluoridation. The motion to discontinue fluoridation failed by a four-to-one vote.
In a follow-up meeting on March 18, the board discusssed making engineering changes to the system or a potential rollback of water fluoridation. With CDA, SDCDS and partners once again present at the meeting to advocate, the board decided to invest in community water fluoridation rather than discontinue it.
‘We must rely on high-quality evidence’ – Dr. Purnima Kumar
Despite the evidence, misinformation about water fluoridation affecting neurodevelopment and the gut biome persists.
All high-quality fluoridation studies that consider the concentration of fluoride found no negative side-effects with CWF. Community water fluoridation is effective in reducing dental caries and safe for total well-being and development across the lifespan. Like salt, iron, vitamin D and oxygen, the effect of fluoride depends on the dose or concentration. The single dose of fluoride that could cause acute fluoride toxicity is 5 mg/kg of body weight. That means an individual would need to drink more than seven liters of fluoridated water for every kilogram of body weight.
Oral and gut microbiome expert Purnima Kumar, DDS, PhD, states: “To inform responsible policy and clinical practice, we must rely on high-quality evidence before drawing conclusions about fluoride’s effects beyond the oral cavity. The best evidence shows the concentrations used in community water fluoridation does not negatively impact the gut microbiome or neurodevelopment.”
Last November, the largest population study of fluoride and cognition found that childhood exposure to fluoride at typical levels of CWF is associated with modestly better cognitive performance with no harm to cognitive functioning in adulthood. A 2025 study also found gut microbiome changes only in chronically high doses of fluoride, over 2 mg/L.
CDA shares evidence-based practices for community water fluoridation
Consult CDA’s new one-pager “Water Fluoridation: The Science of Concentration” to better understand the science behind CWF and to confidently address patient concerns about safety and common misconceptions. Explore all of CDA’s fluoride fact sheets and resources.