Fluoride
Nashville Water Department #1
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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2014 | 0.381 ppm | 33 | 33 | 0.0380 ppm - 0.843 ppm |
| 2015 | 0.447 ppm | 33 | 33 | 0.00500 ppm - 0.736 ppm |
| 2016 | 0.618 ppm | 36 | 36 | 0.518 ppm - 0.723 ppm |
| 2017 | 0.616 ppm | 32 | 32 | 0.0680 ppm - 0.715 ppm |
| 2018 | 0.631 ppm | 36 | 36 | 0.513 ppm - 0.765 ppm |
| 2019 | 0.639 ppm | 33 | 33 | 0.494 ppm - 0.813 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 | Result |
|---|---|
| 2014-01-08 | 0.0620 ppm |
| 2014-01-08 | 0.562 ppm |
| 2014-01-08 | 0.601 ppm |
| 2014-02-11 | 0.0380 ppm |
| 2014-02-11 | 0.718 ppm |
| 2014-02-11 | 0.629 ppm |
| 2014-03-11 | 0.0420 ppm |
| 2014-03-11 | 0.317 ppm |
| 2014-03-11 | 0.617 ppm |
| 2014-04-16 | 0.0650 ppm |
| 2014-04-16 | 0.644 ppm |
| 2014-04-16 | 0.653 ppm |
| 2014-05-14 | 0.0480 ppm |
| 2014-05-14 | 0.602 ppm |
| 2014-05-14 | 0.784 ppm |
| 2014-06-23 | 0.0610 ppm |
| 2014-06-23 | 0.843 ppm |
| 2014-06-23 | 0.692 ppm |
| 2014-08-13 | 0.0740 ppm |
| 2014-08-13 | 0.837 ppm |
| 2014-08-13 | 0.365 ppm |
| 2014-09-09 | 0.0650 ppm |
| 2014-09-09 | 0.788 ppm |
| 2014-09-09 | 0.0740 ppm |
| 2014-10-14 | 0.0520 ppm |
| 2014-10-14 | 0.645 ppm |
| 2014-10-14 | 0.0630 ppm |
| 2014-11-11 | 0.0590 ppm |
| 2014-11-11 | 0.0800 ppm |
| 2014-11-11 | 0.709 ppm |
| 2014-12-09 | 0.0600 ppm |
| 2014-12-09 | 0.633 ppm |
| 2014-12-09 | 0.0930 ppm |
| 2015-01-13 | 0.00500 ppm |
| 2015-01-13 | 0.573 ppm |
| 2015-01-13 | 0.596 ppm |
| 2015-03-10 | 0.0350 ppm |
| 2015-03-10 | 0.294 ppm |
| 2015-03-10 | 0.659 ppm |
| 2015-04-15 | 0.00500 ppm |
| 2015-04-15 | 0.736 ppm |
| 2015-04-15 | 0.435 ppm |
| 2015-05-12 | 0.0340 ppm |
| 2015-05-12 | 0.541 ppm |
| 2015-05-12 | 0.697 ppm |
| 2015-06-09 | 0.0540 ppm |
| 2015-06-09 | 0.696 ppm |
| 2015-06-09 | 0.681 ppm |
| 2015-07-15 | 0.383 ppm |
| 2015-07-15 | 0.651 ppm |
| 2015-07-15 | 0.641 ppm |
| 2015-08-11 | 0.528 ppm |
| 2015-08-11 | 0.554 ppm |
| 2015-08-11 | 0.527 ppm |
| 2015-09-08 | 0.602 ppm |
| 2015-09-08 | 0.686 ppm |
| 2015-09-08 | 0.599 ppm |
| 2015-10-13 | 0.498 ppm |
| 2015-10-13 | 0.540 ppm |
| 2015-10-13 | 0.0500 ppm |
| 2015-11-10 | 0.595 ppm |
| 2015-11-10 | 0.596 ppm |
| 2015-11-10 | 0.0570 ppm |
| 2015-12-08 | 0.583 ppm |
| 2015-12-08 | 0.0450 ppm |
| 2015-12-08 | 0.582 ppm |
| 2016-01-12 | 0.618 ppm |
| 2016-01-12 | 0.569 ppm |
| 2016-01-12 | 0.614 ppm |
| 2016-02-09 | 0.585 ppm |
| 2016-02-09 | 0.629 ppm |
| 2016-02-09 | 0.598 ppm |
| 2016-03-02 | 0.518 ppm |
| 2016-03-02 | 0.616 ppm |
| 2016-03-02 | 0.565 ppm |
| 2016-04-12 | 0.586 ppm |
| 2016-04-12 | 0.590 ppm |
| 2016-04-12 | 0.590 ppm |
| 2016-05-10 | 0.610 ppm |
| 2016-05-10 | 0.664 ppm |
| 2016-05-10 | 0.636 ppm |
| 2016-06-14 | 0.600 ppm |
| 2016-06-14 | 0.660 ppm |
| 2016-06-14 | 0.692 ppm |
| 2016-07-12 | 0.584 ppm |
| 2016-07-12 | 0.688 ppm |
| 2016-07-12 | 0.664 ppm |
| 2016-08-08 | 0.607 ppm |
| 2016-08-08 | 0.682 ppm |
| 2016-08-08 | 0.723 ppm |
| 2016-09-13 | 0.608 ppm |
| 2016-09-13 | 0.630 ppm |
| 2016-09-13 | 0.715 ppm |
| 2016-10-12 | 0.589 ppm |
| 2016-10-12 | 0.602 ppm |
| 2016-10-12 | 0.682 ppm |
| 2016-11-07 | 0.645 ppm |
| 2016-11-07 | 0.631 ppm |
| 2016-11-07 | 0.610 ppm |
| 2016-12-13 | 0.527 ppm |
| 2016-12-13 | 0.564 ppm |
| 2016-12-13 | 0.550 ppm |
| 2017-01-19 | 0.590 ppm |
| 2017-01-19 | 0.574 ppm |
| 2017-01-19 | 0.621 ppm |
| 2017-02-14 | 0.612 ppm |
| 2017-02-14 | 0.626 ppm |
| 2017-02-14 | 0.620 ppm |
| 2017-03-15 | 0.615 ppm |
| 2017-03-15 | 0.623 ppm |
| 2017-03-15 | 0.622 ppm |
| 2017-04-12 | 0.654 ppm |
| 2017-04-12 | 0.701 ppm |
| 2017-04-12 | 0.715 ppm |
| 2017-05-10 | 0.638 ppm |
| 2017-05-10 | 0.666 ppm |
| 2017-05-10 | 0.0680 ppm |
| 2017-06-07 | 0.574 ppm |
| 2017-06-07 | 0.659 ppm |
| 2017-06-07 | 0.705 ppm |
| 2017-07-12 | 0.603 ppm |
| 2017-07-12 | 0.667 ppm |
| 2017-07-12 | 0.690 ppm |
| 2017-08-23 | 0.628 ppm |
| 2017-08-23 | 0.614 ppm |
| 2017-09-25 | 0.608 ppm |
| 2017-09-25 | 0.624 ppm |
| 2017-09-25 | 0.624 ppm |
| 2017-10-24 | 0.641 ppm |
| 2017-10-24 | 0.650 ppm |
| 2017-10-24 | 0.618 ppm |
| 2017-11-14 | 0.640 ppm |
| 2017-11-14 | 0.612 ppm |
| 2017-11-14 | 0.604 ppm |
| 2018-01-18 | 0.538 ppm |
| 2018-01-18 | 0.513 ppm |
| 2018-01-18 | 0.524 ppm |
| 2018-02-13 | 0.756 ppm |
| 2018-02-13 | 0.642 ppm |
| 2018-02-13 | 0.636 ppm |
| 2018-03-19 | 0.638 ppm |
| 2018-03-19 | 0.612 ppm |
| 2018-03-19 | 0.618 ppm |
| 2018-04-23 | 0.610 ppm |
| 2018-04-23 | 0.627 ppm |
| 2018-04-23 | 0.621 ppm |
| 2018-05-23 | 0.609 ppm |
| 2018-05-23 | 0.611 ppm |
| 2018-05-23 | 0.610 ppm |
| 2018-06-21 | 0.587 ppm |
| 2018-06-21 | 0.658 ppm |
| 2018-06-21 | 0.665 ppm |
| 2018-07-19 | 0.611 ppm |
| 2018-07-19 | 0.709 ppm |
| 2018-07-19 | 0.672 ppm |
| 2018-08-22 | 0.765 ppm |
| 2018-08-22 | 0.702 ppm |
| 2018-08-22 | 0.682 ppm |
| 2018-09-24 | 0.650 ppm |
| 2018-09-24 | 0.678 ppm |
| 2018-09-24 | 0.622 ppm |
| 2018-10-22 | 0.611 ppm |
| 2018-10-22 | 0.611 ppm |
| 2018-10-22 | 0.654 ppm |
| 2018-11-26 | 0.620 ppm |
| 2018-11-26 | 0.684 ppm |
| 2018-11-26 | 0.606 ppm |
| 2018-12-10 | 0.572 ppm |
| 2018-12-10 | 0.590 ppm |
| 2018-12-10 | 0.606 ppm |
| 2019-01-15 | 0.605 ppm |
| 2019-01-15 | 0.519 ppm |
| 2019-01-15 | 0.516 ppm |
| 2019-02-19 | 0.638 ppm |
| 2019-02-19 | 0.494 ppm |
| 2019-02-19 | 0.543 ppm |
| 2019-03-19 | 0.613 ppm |
| 2019-03-19 | 0.611 ppm |
| 2019-03-19 | 0.525 ppm |
| 2019-04-15 | 0.604 ppm |
| 2019-04-15 | 0.654 ppm |
| 2019-04-15 | 0.652 ppm |
| 2019-05-23 | 0.585 ppm |
| 2019-05-23 | 0.689 ppm |
| 2019-05-23 | 0.696 ppm |
| 2019-07-22 | 0.686 ppm |
| 2019-07-22 | 0.765 ppm |
| 2019-07-22 | 0.747 ppm |
| 2019-08-14 | 0.682 ppm |
| 2019-08-14 | 0.752 ppm |
| 2019-08-14 | 0.688 ppm |
| 2019-09-23 | 0.707 ppm |
| 2019-09-23 | 0.813 ppm |
| 2019-09-23 | 0.702 ppm |
| 2019-10-23 | 0.690 ppm |
| 2019-10-23 | 0.680 ppm |
| 2019-10-23 | 0.690 ppm |
| 2019-11-18 | 0.590 ppm |
| 2019-11-18 | 0.560 ppm |
| 2019-11-18 | 0.580 ppm |
| 2019-12-18 | 0.634 ppm |
| 2019-12-18 | 0.602 ppm |
| 2019-12-18 | 0.576 ppm |