Know Your Environment. Protect Your Health.

Fluoride

Town of Oakland

Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems to prevent cavities and support oral health in people.

In 2015, the Department of Health and Human Services updated its recommendation of an optimal level of 0.7 parts per million, or ppm, added to drinking water based on the health benefits of tooth decay prevention. Studies have shown that fluoride added to community water systems at this level reduces dental cavities, especially in children.

And studies have conclusively shown that fluoride in toothpaste and mouthwash can also provide these benefits. Read More.

Health Concerns

Although the HHS-recommended level of 0.7 ppm can help promote oral health in children and adults, this level is likely too high for bottle-fed babies. EWG recommends that caregivers mix baby formula with fluoride-free water.

And fluoride in water at higher levels can be detrimental for everyone, especially children.

Long-term ingestion of higher levels of fluoride in water increases dental fluorosis, which includes mottling, pitting and weakening of the teeth in children.

A 2024 authoritative assessment by the National Toxicology Program found that higher levels of fluoride exposure, such as drinking water containing more than 1.5 ppm of fluoride, are associated with lower IQ in children. The conclusion was based on studies in human populations outside of the U.S.

Affecting systems with naturally occurring fluoride, EPA’s maximum legal limit is set at 4 parts per million (ppm) to prevent skeletal fluorosis, a condition where bones become brittle and more susceptible to fracture. But these effects may occur at lower levels of exposure, raising concerns that the current limit may not adequately protect public health.

 

21

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.153 ppm42ND - 0.370 ppm
2019ND20ND
20200.200 ppm43ND - 0.360 ppm
20210.390 ppm440.270 ppm - 0.480 ppm
20220.364 ppm550.200 ppm - 0.610 ppm
20230.401 ppm220.229 ppm - 0.573 ppm

ppm = parts per million

State, National, and Health Guidelines for Drinking Water

EPA Maximum Contaminant
Level (MCL): 4 ppm

ppm = parts per million

All test results

Date Lab ID Result
2018-05-10E180040760030.240 ppm
2018-05-10E180040760020.370 ppm
2018-10-1564637ND
2018-10-1864636ND
2019-08-1967330ND
2019-08-1967331ND
2020-06-02E20003712002ND
2020-06-23E200039220020.220 ppm
2020-09-02703230.360 ppm
2020-09-02703240.220 ppm
2021-06-08E210036190020.270 ppm
2021-06-08E210036190030.410 ppm
2021-09-14734510.480 ppm
2021-09-14734520.400 ppm
2022-06-09E22010777010.610 ppm
2022-06-09E22010777020.350 ppm
2022-07-28762830.200 ppm
2022-07-28762840.430 ppm
2022-07-28785970.229 ppm
2023-04-18785960.573 ppm
2023-04-1878597-A0.229 ppm