Fluoride
Dover Air Force Base
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 | 0.728 ppm | 27 | 27 | 0.550 ppm - 1.10 ppm |
2015 | 0.910 ppm | 16 | 16 | 0.450 ppm - 1.01 ppm |
2016 | 0.848 ppm | 13 | 12 | ND - 1.03 ppm |
2017 | 0.988 ppm | 14 | 14 | 0.670 ppm - 1.16 ppm |
2018 | 0.946 ppm | 13 | 13 | 0.870 ppm - 1.10 ppm |
2019 | 0.824 ppm | 13 | 13 | 0.732 ppm - 0.909 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 |
---|---|---|
2014-01-23 | S402678 | 0.810 ppm |
2014-01-27 | S402676 | 0.800 ppm |
2014-01-30 | S402682 | 0.940 ppm |
2014-02-26 | S402702 | 0.600 ppm |
2014-02-26 | S402699 | 0.850 ppm |
2014-03-24 | S402725 | 0.680 ppm |
2014-03-24 | S402716 | 0.600 ppm |
2014-04-02 | S402730 | 0.650 ppm |
2014-04-21 | S407238 | 0.550 ppm |
2014-04-21 | S402740 | 0.620 ppm |
2014-05-07 | S402755 | 0.590 ppm |
2014-05-30 | S402775 | 0.570 ppm |
2014-06-26 | S402790 | 0.640 ppm |
2014-07-07 | S575368 | 0.650 ppm |
2014-07-28 | S575393 | 0.640 ppm |
2014-08-20 | S575352 | 0.640 ppm |
2014-08-26 | S575353 | 0.640 ppm |
2014-09-02 | S575402 | 0.640 ppm |
2014-09-17 | S575472 | 0.630 ppm |
2014-09-22 | S575482 | 0.620 ppm |
2014-09-24 | S575476 | 0.610 ppm |
2014-10-08 | S573378 | 0.580 ppm |
2014-11-05 | S589465 | 1.08 ppm |
2014-11-10 | S575410 | 1.10 ppm |
2014-11-17 | S251491 | 1.000 ppm |
2014-12-03 | S589556 | 0.950 ppm |
2014-12-31 | S447362 | 0.970 ppm |
2015-01-06 | S589668 | 0.980 ppm |
2015-01-21 | S588733 | 0.970 ppm |
2015-02-02 | S603195 | 0.940 ppm |
2015-02-18 | S403132 | 0.960 ppm |
2015-03-03 | S603364 | 0.960 ppm |
2015-04-06 | S616765 | 0.990 ppm |
2015-05-01 | S617002 | 0.890 ppm |
2015-06-02 | S639957 | 0.920 ppm |
2015-07-09 | S640359 | 0.910 ppm |
2015-08-05 | S640454 | 0.450 ppm |
2015-08-26 | S640538 | 0.750 ppm |
2015-09-21 | S640620 | 0.980 ppm |
2015-10-01 | S640050 | 0.980 ppm |
2015-11-02 | S629147 | 1.01 ppm |
2015-12-01 | S643149 | 0.940 ppm |
2015-12-08 | S654791 | 0.930 ppm |
2016-01-05 | S624999 | 0.960 ppm |
2016-02-02 | S640665 | 0.890 ppm |
2016-02-29 | S659170 | 0.860 ppm |
2016-03-01 | S659174 | 0.610 ppm |
2016-04-04 | S629165 | 0.880 ppm |
2016-05-19 | S640319 | 0.970 ppm |
2016-06-20 | S671570 | 1.000 ppm |
2016-07-20 | S671574 | 1.03 ppm |
2016-08-16 | S671721 | 0.970 ppm |
2016-09-26 | S679693 | 1.02 ppm |
2016-10-19 | S679694 | 0.970 ppm |
2016-11-22 | S671603 | ND |
2016-12-21 | S671606 | 0.870 ppm |
2017-01-31 | S671735 | 0.850 ppm |
2017-02-28 | S671742 | 1.04 ppm |
2017-03-09 | S679745 | 0.980 ppm |
2017-04-04 | S694204 | 1.05 ppm |
2017-05-18 | S694218 | 0.920 ppm |
2017-06-12 | S694320 | 1.01 ppm |
2017-07-18 | S737359 | 0.980 ppm |
2017-07-18 | S730791 | 0.980 ppm |
2017-08-16 | S737465 | 1.09 ppm |
2017-09-07 | S757441 | 1.16 ppm |
2017-10-09 | S757403 | 1.03 ppm |
2017-11-02 | S757416 | 0.670 ppm |
2017-11-13 | S757493 | 1.000 ppm |
2017-12-06 | S757505 | 1.07 ppm |
2018-01-16 | S757708 | 0.980 ppm |
2018-01-17 | S769445 | 0.970 ppm |
2018-02-06 | S757768 | 0.870 ppm |
2018-03-08 | S757788 | 1.10 ppm |
2018-04-03 | S759331 | 0.967 ppm |
2018-05-15 | S759350 | 0.990 ppm |
2018-06-25 | S757795 | 0.985 ppm |
2018-07-05 | S759484 | 0.893 ppm |
2018-08-02 | S694295 | 0.911 ppm |
2018-09-17 | S759569 | 0.936 ppm |
2018-10-08 | S759588 | 0.902 ppm |
2018-11-06 | S759641 | 0.874 ppm |
2018-12-04 | S811834 | 0.921 ppm |
2019-01-02 | S759673 | 0.732 ppm |
2019-02-19 | S759629 | 0.899 ppm |
2019-03-07 | S824253 | 0.821 ppm |
2019-04-03 | S759686 | 0.750 ppm |
2019-05-02 | S759698 | 0.872 ppm |
2019-06-06 | S759284 | 0.852 ppm |
2019-06-18 | S848051 | 0.909 ppm |
2019-07-30 | S757554 | 0.817 ppm |
2019-08-08 | S759734 | 0.827 ppm |
2019-09-09 | S759706 | 0.817 ppm |
2019-10-03 | S759711 | 0.848 ppm |
2019-11-05 | S895867 | 0.816 ppm |
2019-12-02 | S919986 | 0.753 ppm |