Fluoride statistics span public-water coverage, natural concentrations, dental disease, fluorosis and neurodevelopment research. The figures below distinguish U.S. community-water service from total population, and recommendations from regulatory limits or research estimates.
Key Fluoride Statistics
The most broadly useful fluoride statistics include:
- In 2022, 209.4 million people in the United States received community water adjusted to the recommended fluoride concentration.
- In 2022, 72.3% of people served by U.S. community water systems received fluoridated water.
- In 2018, 211.4 million Americans received fluoridated community water.
- In 2018, 73.0% of the U.S. community-water-system population received fluoridated water.
- The CDC-recommended U.S. community-water concentration is 0.7 milligrams per liter under current guidance.
- EPA’s enforceable U.S. fluoride maximum contaminant level is 4.0 milligrams per liter.
- EPA’s secondary fluoride standard is 2.0 milligrams per liter.
- The WHO drinking-water guideline value for fluoride is 1.5 milligrams per liter.
- WHO reports that most surface waters contain less than 0.3 milligrams per liter of fluoride.
- WHO reports that fluoride concentrations in some groundwater areas can exceed 10 milligrams per liter.
- In NHANES 2011–2016, 51.2% of U.S. adolescents aged 12–19 had permanent-tooth caries.
- In NHANES 2011–2016, 90.2% of U.S. adults aged 20–64 had dental caries.
- In NHANES 2011–2016, 96.8% of U.S. adults aged 65 and older had dental caries.
- The Cochrane review estimated about 35% less dmft/DMFT in children in contemporary fluoridation studies.
- The Cochrane review estimated a 12-percentage-point absolute increase in fluorosis of aesthetic concern in fluoridated areas.
- NTP classified fluoride exposure above 1.5 milligrams per liter in drinking water as associated with lower IQ with moderate confidence.
- NTP’s meta-analysis reported an average IQ difference of about 4.4 points between higher- and lower-fluoride exposure groups.
- WHO states that endemic fluorosis has been reported in at least 25 countries.
Contents
- U.S. community-water fluoridation statistics
- Fluoride concentration standards and exposure levels
- Dental caries statistics and prevention outcomes
- Dental fluorosis and neurodevelopment evidence
- Global fluoride exposure and drinking-water data
- Fluoride monitoring and public-water trends
U.S. Community-Water Fluoridation Statistics
CDC coverage statistics describe people served by community water systems, not every U.S. resident and not private-well users. That denominator matters when comparing coverage percentages with total-population estimates.
| Period | Fluoridated population | Share of community-water population |
|---|---|---|
| 2018 | 211.4 million | 73.0% |
| 2022 | 209.4 million | 72.3% |
Source: CDC Community Water Fluoridation Data & Statistics. The figures are CDC service-population estimates rather than household-level survey results.
CDC’s public overview describes community water fluoridation as serving more than 200 million people in the United States and says about 75% of Americans who use public water systems receive fluoridated water. Those are rounded overview figures, while the data table supplies the more precise annual estimates.
CDC identifies community water fluoridation as one of the 10 great public-health achievements of the 20th century. The U.S. Public Health Service’s 2015 recommendation changed the target from a range of 0.7–1.2 mg/L to a single 0.7 mg/L concentration.
Source: CDC About Community Water Fluoridation.
Fluoride Concentration Standards and Exposure Levels
Fluoride numbers often appear contradictory because they describe different purposes: an operating recommendation, a health-protective regulatory ceiling, a secondary aesthetic standard and a global guideline.
| Value | Meaning | Geography or scope |
|---|---|---|
| 0.7 mg/L | CDC recommended community-water concentration | United States |
| 1.5 mg/L | WHO drinking-water guideline value | Global guidance |
| 2.0 mg/L | EPA secondary maximum contaminant level | United States |
| 4.0 mg/L | EPA enforceable maximum contaminant level | U.S. public water systems |
Sources: CDC guidance, EPA primary regulations, EPA secondary standards, and WHO Fluoride in Drinking-water.
The U.S. 0.7 mg/L recommendation is 46.7% of the WHO 1.5 mg/L guideline value. EPA’s 4.0 mg/L MCL is 2.67 times the WHO guideline, but these comparisons do not represent comparative risk estimates because the values have different purposes.
WHO reports that most surface waters contain less than 0.3 mg/L fluoride, while seawater generally contains about 1.3 mg/L. In some fluoride-rich groundwater areas, concentrations can exceed 10 mg/L, and WHO identifies 1.5 mg/L as the point at which dental-fluorosis risk becomes an important water-quality consideration.
Dental Caries Statistics and Prevention Outcomes
NHANES 2011–2016 provides national U.S. oral-health estimates by age. These values describe disease status, not the effect of fluoride alone; diet, toothpaste, dental care and other factors also contribute.
| U.S. population, NHANES 2011–2016 | Dental caries | Untreated caries |
|---|---|---|
| Children aged 2–5 | 13.2% | 8.8% |
| Children aged 6–11 | 25.5% | 15.5% |
| Adolescents aged 12–19 | 51.2% | 13.4% |
| Adults aged 20–64 | 90.2% | 25.9% |
| Adults aged 65+ | 96.8% | 19.6% |
Source: NIDCR Dental Caries data. The childhood and adult measures use different dentition and survey definitions, and the estimates are not fluoridation-effect estimates.
The age pattern reflects accumulated disease experience as well as current untreated disease. Among adults aged 65 and older, 96.8% had dental caries but 19.6% had untreated caries; among adults aged 20–64, the corresponding figures were 90.2% and 25.9%.
The adolescent estimates were 51.2% for permanent-tooth caries and 13.4% for untreated permanent-tooth decay. For children aged 6–11, the estimates were 25.5% and 15.5%, respectively.
Dental Fluorosis and Neurodevelopment Evidence
The Cochrane review of water fluoridation included 20 studies assessing dental-fluorosis outcomes in its contemporary evidence base. Its estimates combine studies from multiple countries, and background fluoride from toothpaste and foods varied.
The review estimated about 35% less dmft/DMFT in children in contemporary studies and roughly 26% fewer children with caries-free permanent dentition in non-fluoridated communities than in fluoridated communities. It also found a 12-percentage-point absolute increase in children with fluorosis of aesthetic concern in fluoridated areas, with 12% of children in fluoridated areas judged to have fluorosis of aesthetic concern.
Source: Cochrane Water fluoridation for the prevention of dental caries. The review emphasizes observational evidence, heterogeneity and differences in fluorosis definitions and examination methods.
NTP’s 2024 systematic review classified fluoride exposure at concentrations higher than 1.5 mg/L in drinking water as associated with lower IQ with moderate confidence. This hazard conclusion does not quantify an effect at the U.S. 0.7 mg/L recommendation.
NTP identified 52 human studies relevant to fluoride exposure and neurodevelopmental effects. In its evidence review, 43 of 55 IQ studies found an association between higher fluoride exposure and lower IQ, while 12 of 55 did not find an association.
NTP’s meta-analysis reported an average IQ difference of about 4.4 points between higher- and lower-fluoride exposure groups. Its dose-response analysis estimated a 1.63-point lower IQ score for each 1 mg/L increase in urinary fluoride concentration; this is a model-based observational estimate, and urinary fluoride varies from day to day.
Source: NTP Monograph on Fluoride Exposure and Neurodevelopmental and Cognitive Health Effects.
Global Fluoride Exposure and Drinking-Water Data
Fluoride exposure varies sharply by geology and water source. WHO states that concentrations above 1.5 mg/L occur in groundwater in parts of Africa, Asia and the Americas, but the cited occurrence statements do not estimate the share of residents exposed.
WHO reports that volcanic rocks and geothermal activity can produce groundwater concentrations above 10 mg/L. These are extreme local concentrations rather than regional or global means.
WHO states that endemic fluorosis has been reported in at least 25 countries. The country count is not a prevalence estimate and can change with surveillance.
The WHO guideline value of 1.5 mg/L balances benefit and risk, but local climate, water intake and total fluoride exposure matter. Individual exposure can also include food, toothpaste swallowed and other beverages, so a water concentration alone is not a complete intake measure.
Source: WHO Fluoride in Drinking-water.
Fluoride Monitoring and Public-Water Trends
Between 2018 and 2022, CDC’s reported fluoridated population decreased from 211.4 million to 209.4 million, a difference of about 2.0 million people. The reported community-water coverage percentage decreased from 73.0% to 72.3%, or 0.7 percentage points; both changes are derived from rounded CDC values and do not identify causes.
Using separate Census total-population denominators produces a different perspective: the 2022 CDC fluoridated-population estimate was approximately 61.9% of about 338.3 million U.S. residents, while the 2018 estimate was approximately 64.4% of about 327.2 million. These are calculations, not CDC’s published coverage definition.
At 0.7 mg/L, one liter of water contains 0.7 mg of fluoride. Illustratively, two liters at that concentration contain 1.4 mg; two liters at the WHO guideline value contain 3.0 mg; and two liters at EPA’s 4.0 mg/L MCL contain 8.0 mg.
Those calculations describe concentration conversion, not population-average intake, and the MCL is not a recommended consumption level. EPA’s primary MCL is 4.0 mg/L, while its secondary standard is 2.0 mg/L and addresses aesthetic or cosmetic concerns.
Sources: CDC fluoridation data, CDC guidance, EPA primary regulations, EPA secondary standards, and WHO guidance.