Know Your Environment. Protect Your Health.

Fluoride

Metropolitan District Commission

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.

 

42

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20180.331 ppm770.0300 ppm - 0.740 ppm
20190.307 ppm73ND - 0.740 ppm
20200.311 ppm73ND - 0.730 ppm
20210.294 ppm73ND - 0.700 ppm
20220.311 ppm73ND - 0.750 ppm
20230.287 ppm73ND - 0.680 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
2018-07-18AE01630GE0.690 ppm
2018-07-18AE01632GE0.740 ppm
2018-07-18AE01640GE0.0300 ppm
2018-07-18AE01641GE0.0400 ppm
2018-07-18AE01637GE0.0600 ppm
2018-07-18AE01636GE0.0400 ppm
2018-07-18AE01631GE0.720 ppm
2019-12-03CE70734ND
2019-12-03CE70735ND
2019-12-03CE70736ND
2019-12-03CE70733ND
2019-12-03CE707410.680 ppm
2019-12-03CE707390.730 ppm
2019-12-03CE707400.740 ppm
2020-12-08IOC1 2006006370.730 ppm
2020-12-08IOC1 2006006110.720 ppm
2020-12-08IOCR 200600614ND
2020-12-08IOCR 200600615ND
2020-12-08IOCR 200600616ND
2020-12-08IOCR 200600617ND
2020-12-09IOC1 2006006030.730 ppm
2021-11-23E300107450 3001074520.680 ppm
2021-11-23I300107476 300107477ND
2021-11-23E300107451 3001074580.680 ppm
2021-11-29E300109635 3001096380.700 ppm
2021-11-29I300109610 300109611ND
2021-11-30I300109649 300109651ND
2021-11-30I300109650 300109657ND
2022-12-08I300283837 300283840ND
2022-12-08300283822 300283825BND
2022-12-15E300287100 3002871020.710 ppm
2022-12-15I300287081 300287084ND
2022-12-15I300287109 300287110ND
2022-12-15E300287072 3002870740.750 ppm
2022-12-15E300287053 3002870550.720 ppm
2023-12-05E300456248 3004562490.680 ppm
2023-12-05I300456268 300456269ND
2023-12-05I300456261 300456262ND
2023-12-05I300456281 300456282ND
2023-12-06E300456222 3004562230.669 ppm
2023-12-06E300456228 3004562290.662 ppm
2023-12-06I300456234 300456235ND