Fluoride
Desert Water Agency
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 | 0.650 ppm | 1 | 1 | 0.650 ppm |
2015 | 0.590 ppm | 1 | 1 | 0.590 ppm |
2016 | 0.446 ppm | 28 | 27 | ND - 0.780 ppm |
2017 | N/A | 0 | 0 | N/A |
2018 | 0.300 ppm | 2 | 1 | ND - 0.600 ppm |
2019 | 0.383 ppm | 21 | 20 | ND - 0.640 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 |
---|---|---|
2014-06-25 | 3761-060-1045 | 0.650 ppm |
2015-09-23 | 3761-047-1000 | 0.590 ppm |
2016-05-04 | 3761-060-0935 | 0.730 ppm |
2016-05-04 | 3761-043-1030 | 0.760 ppm |
2016-05-11 | 3761-015-1015 | 0.390 ppm |
2016-05-11 | 3761-026-1125 | 0.400 ppm |
2016-05-11 | 3761-022-1045 | 0.300 ppm |
2016-05-18 | 3761-029-1030 | 0.620 ppm |
2016-05-18 | 3761-030-1100 | 0.620 ppm |
2016-06-08 | 3761-024-1015 | 0.480 ppm |
2016-06-08 | 3761-044-0945 | 0.780 ppm |
2016-06-15 | 3761-033-0000 | 0.600 ppm |
2016-06-22 | 3761-046-1030 | 0.300 ppm |
2016-06-22 | 3761-018-1115 | 0.240 ppm |
2016-06-22 | 3761-017-1145 | 0.240 ppm |
2016-06-22 | 3761-008-0945 | 0.460 ppm |
2016-06-29 | 3761-040-1130 | 0.570 ppm |
2016-07-13 | 3761-010-1115 | 0.330 ppm |
2016-07-13 | 3761-020-1200 | 0.280 ppm |
2016-07-13 | 3761-025-0930 | 0.450 ppm |
2016-07-20 | 3761-039-1110 | 0.440 ppm |
2016-07-21 | 3761-031-1025 | 0.190 ppm |
2016-07-27 | 3761-027-1015 | 0.420 ppm |
2016-08-17 | 3761-038-1100 | 0.620 ppm |
2016-08-17 | 3761-034-0950 | ND |
2016-09-07 | 3761-028-1100 | 0.190 ppm |
2016-09-07 | 3761-047-1010 | 0.530 ppm |
2016-09-07 | 3761-032-0930 | 0.490 ppm |
2016-09-29 | 3761-019-0935 | 0.330 ppm |
2016-09-29 | 3761-045-0925 | 0.720 ppm |
2018-07-11 | 3761-037-0745 | 0.600 ppm |
2018-07-11 | 3761-034-1000 | ND |
2019-05-24 | 4790-029-1410 | 0.480 ppm |
2019-05-24 | 4790-060-1345 | 0.460 ppm |
2019-05-24 | 4790-030-0955 | 0.470 ppm |
2019-05-24 | 4790-031-0730 | 0.130 ppm |
2019-05-24 | 4790-043-0930 | 0.640 ppm |
2019-06-19 | 4790-033-1430 | 0.420 ppm |
2019-06-19 | 4790-046-1110 | 0.210 ppm |
2019-06-19 | 4790-026-1300 | 0.170 ppm |
2019-06-19 | 4790-040-1000 | 0.460 ppm |
2019-06-19 | 4790-044-1150 | 0.590 ppm |
2019-07-24 | 4790-031-1030 | 0.160 ppm |
2019-07-24 | 4790-025-1000 | 0.390 ppm |
2019-07-24 | 4790-039-0730 | 0.410 ppm |
2019-07-25 | 4790-024-0200 | 0.390 ppm |
2019-08-06 | 4790-038-1020 | 0.500 ppm |
2019-08-06 | 4790-034-0745 | ND |
2019-08-29 | 4790-045-0940 | 0.330 ppm |
2019-08-29 | 4790-032-1105 | 0.420 ppm |
2019-08-29 | 4790-047-0740 | 0.520 ppm |
2019-08-29 | 4790-019-1025 | 0.600 ppm |
2019-10-17 | 4790-027-0645 | 0.290 ppm |