Fluoride
Michigan State University
Fluoride occurs naturally in surface and groundwater and is also added to drinking water by many water systems. Read More.
Fluoride has been promoted as a chemical that reduces dental cavities. Yet it is now well-established that fluoride primarily exerts its protective effects through topical mechanisms, such as sodium fluoride in toothpaste and mouthwash. In contrast, long-term ingestion of fluoride in water increases dental fluorosis, which includes mottling, pitting and weakening of the teeth. 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 fractures, although these effects may occur at lower doses.
Even fluoride levels of 0.7 ppm, the amount of fluoride in drinking water recommended by the U.S. Public Health Service, can result in too much fluoride for bottle-fed babies. EWG recommends that caregivers mix baby formula with fluoride-free water. The National Toxicology Program is investigating the potential for low doses of fluoride to alter thyroid function and childhood brain development.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2014 | 0.497 ppm | 9 | 8 | ND - 0.850 ppm |
2015 | N/A | 0 | 0 | N/A |
2016 | N/A | 0 | 0 | N/A |
2017 | N/A | 0 | 0 | N/A |
2018 | 0.386 ppm | 34 | 31 | ND - 0.660 ppm |
2019 | 0.235 ppm | 16 | 16 | 0.150 ppm - 0.590 ppm |
ppm = parts per million
State and national drinking water standards and health guidelines
EPA Maximum Contaminant
Level (MCL) 4 ppm
ppm = parts per million
All test results
Date | Lab ID | Result |
---|---|---|
2014-08-21 | LLF34202 | 0.850 ppm |
2014-09-30 | LLF41171 | 0.800 ppm |
2014-09-30 | LLF41172 | 0.760 ppm |
2014-09-30 | LLF41173 | 0.810 ppm |
2014-09-30 | LLF41174 | 0.770 ppm |
2014-10-23 | LLF44199 | 0.170 ppm |
2014-10-23 | LLF44291 | ND |
2014-10-23 | LLF44290 | 0.150 ppm |
2014-10-23 | LLF44292 | 0.160 ppm |
2018-02-28 | LLH68121 | 0.610 ppm |
2018-02-28 | LLH68120 | 0.640 ppm |
2018-02-28 | LLH68124 | 0.590 ppm |
2018-02-28 | LLH68118 | 0.640 ppm |
2018-02-28 | LLH68122 | 0.630 ppm |
2018-02-28 | LLH68123 | 0.630 ppm |
2018-02-28 | LLH68115 | 0.640 ppm |
2018-02-28 | LLH68117 | 0.650 ppm |
2018-02-28 | LLH68113 | 0.630 ppm |
2018-02-28 | LLH68114 | 0.620 ppm |
2018-02-28 | LLH68116 | 0.620 ppm |
2018-02-28 | LLH68112 | 0.620 ppm |
2018-04-26 | LLH77525 | ND |
2018-04-27 | LLH77588 | 0.190 ppm |
2018-04-27 | LLH77587 | 0.420 ppm |
2018-04-27 | LLH77586 | 0.220 ppm |
2018-04-27 | LLH77589 | 0.210 ppm |
2018-04-27 | LLH77592 | 0.660 ppm |
2018-04-27 | LLH77590 | 0.300 ppm |
2018-04-27 | LLH77591 | 0.140 ppm |
2018-05-02 | LLH78373 | 0.270 ppm |
2018-05-02 | LLH78372 | 0.210 ppm |
2018-05-02 | LLH78370 | 0.200 ppm |
2018-05-02 | LLH78369 | 0.200 ppm |
2018-05-02 | LLH78371 | 0.170 ppm |
2018-05-09 | LLH79533 | 0.630 ppm |
2018-05-09 | LLH79534 | 0.640 ppm |
2018-05-17 | LLH81098 | 0.210 ppm |
2018-05-17 | LLH81099 | 0.180 ppm |
2018-05-23 | LLH81944 | 0.200 ppm |
2018-05-23 | LLH81943 | 0.290 ppm |
2018-05-23 | LLH81945 | 0.270 ppm |
2018-07-19 | LLH94101 | ND |
2018-10-23 | LLI12548 | ND |
2019-03-07 | LLI28372 | 0.180 ppm |
2019-03-07 | LLI28373 | 0.150 ppm |
2019-03-07 | LLI28371 | 0.190 ppm |
2019-03-07 | LLI28370 | 0.210 ppm |
2019-03-07 | LLI28374 | 0.590 ppm |
2019-03-20 | LLI30028 | 0.420 ppm |
2019-03-20 | LLI30025 | 0.260 ppm |
2019-03-20 | LLI30026 | 0.180 ppm |
2019-03-20 | LLI30027 | 0.280 ppm |
2019-04-03 | LLI31915 | 0.190 ppm |
2019-04-09 | LLI32595 | 0.170 ppm |
2019-04-09 | LLI32594 | 0.270 ppm |
2019-04-09 | LLI32593 | 0.170 ppm |
2019-04-22 | LLI34143 | 0.150 ppm |
2019-04-22 | LLI34142 | 0.180 ppm |
2019-04-22 | LLI34141 | 0.170 ppm |