Fluoride
City of Greenville
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 | N/A | 0 | 0 | N/A |
2015 | N/A | 0 | 0 | N/A |
2016 | 0.651 ppm | 8 | 8 | 0.330 ppm - 1.33 ppm |
2017 | N/A | 0 | 0 | N/A |
2018 | N/A | 0 | 0 | N/A |
2019 | 0.576 ppm | 9 | 9 | 0.427 ppm - 0.873 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 |
---|---|---|
2016-12-12 | 161213-205IN | 0.549 ppm |
2016-12-12 | 161213-200IN | 0.781 ppm |
2016-12-12 | 161213-199IN | 1.33 ppm |
2016-12-12 | 161213-198IN | 0.330 ppm |
2016-12-12 | 161213-197IN | 0.643 ppm |
2016-12-12 | 161213-196IN | 0.452 ppm |
2016-12-12 | 161213-192IN | 0.562 ppm |
2016-12-12 | 161213-191IN | 0.558 ppm |
2019-04-09 | 190410-038IN | 0.873 ppm |
2019-04-09 | 190410-037IN | 0.548 ppm |
2019-04-09 | 190410-036IN | 0.427 ppm |
2019-04-09 | 190410-035IN | 0.652 ppm |
2019-04-09 | 190410-034IN | 0.431 ppm |
2019-04-09 | 190410-033IN | 0.582 ppm |
2019-04-09 | 190410-032IN | 0.439 ppm |
2019-04-09 | 190410-031IN | 0.555 ppm |
2019-12-03 | 191204-010IN | 0.674 ppm |