Fluoride
Mountain View
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 | ND | 1 | 0 | ND |
2015 | 0.588 ppm | 6 | 5 | ND - 0.910 ppm |
2016 | 0.686 ppm | 13 | 12 | ND - 0.870 ppm |
2017 | 0.778 ppm | 13 | 13 | 0.700 ppm - 0.840 ppm |
2018 | 0.839 ppm | 13 | 13 | 0.740 ppm - 0.910 ppm |
2019 | 0.742 ppm | 13 | 13 | 0.420 ppm - 0.900 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 |
---|---|---|
2014-08-25 | Y142390015 | ND |
2015-04-30 | Y151280006 | 0.640 ppm |
2015-08-10 | Y152250027 | ND |
2015-09-23 | Y152710024 | 0.910 ppm |
2015-10-27 | Y153030018 | 0.620 ppm |
2015-11-12 | Y153200021 | 0.740 ppm |
2015-12-15 | Y153520032 | 0.620 ppm |
2016-01-12 | Y160200011 | 0.600 ppm |
2016-02-10 | Y160470029 | 0.580 ppm |
2016-03-15 | Y160810026 | 0.840 ppm |
2016-04-12 | Y161060029 | 0.860 ppm |
2016-05-31 | Y161580014 | 0.870 ppm |
2016-06-28 | Y161870035 | 0.710 ppm |
2016-07-26 | Y162210006 | 0.720 ppm |
2016-08-16 | Y162350051 | 0.790 ppm |
2016-08-29 | Y162450010 | ND |
2016-09-27 | Y162780002 | 0.800 ppm |
2016-10-10 | Y162880023 | 0.780 ppm |
2016-11-08 | Y163140024 | 0.700 ppm |
2016-12-12 | Y163480026 | 0.670 ppm |
2017-01-10 | Y170120044 | 0.780 ppm |
2017-02-15 | Y170480018 | 0.720 ppm |
2017-03-23 | Y170860007 | 0.770 ppm |
2017-04-18 | Y171140008 | 0.840 ppm |
2017-05-09 | Y171350047 | 0.840 ppm |
2017-06-26 | Y171840095 | 0.720 ppm |
2017-07-26 | Y172120026 | 0.760 ppm |
2017-08-15 | Y172290008 | 0.700 ppm |
2017-08-16 | Y172330032 | 0.790 ppm |
2017-09-25 | Y172760005 | 0.800 ppm |
2017-10-24 | Y173030023 | 0.720 ppm |
2017-11-21 | Y173310009 | 0.830 ppm |
2017-12-11 | Y173540047 | 0.840 ppm |
2018-01-30 | Y180360012 | 0.800 ppm |
2018-02-27 | Y180590003 | 0.740 ppm |
2018-03-13 | Y180780018 | 0.840 ppm |
2018-04-10 | Y181070016 | 0.900 ppm |
2018-05-07 | Y181340006 | 0.850 ppm |
2018-06-13 | Y181690025 | 0.870 ppm |
2018-07-10 | Y181970023 | 0.870 ppm |
2018-08-07 | Y182250024 | 0.840 ppm |
2018-09-04 | Y182500003 | 0.850 ppm |
2018-09-06 | Y182530025 | 0.910 ppm |
2018-10-08 | Y182890042 | 0.870 ppm |
2018-11-06 | Y183170032 | 0.810 ppm |
2018-12-17 | Y183600001 | 0.760 ppm |
2019-01-09 | Y190140047 | 0.750 ppm |
2019-02-19 | Y190560006 | 0.740 ppm |
2019-03-13 | Y190770034 | 0.790 ppm |
2019-04-10 | Y191050038 | 0.760 ppm |
2019-05-07 | Y191330024 | 0.760 ppm |
2019-06-11 | Y191680004 | 0.830 ppm |
2019-07-10 | Y191960035 | 0.420 ppm |
2019-08-05 | Y192250038 | 0.700 ppm |
2019-09-03 | Y192540010 | 0.710 ppm |
2019-09-10 | Y192550006 | 0.730 ppm |
2019-10-10 | Y192880016 | 0.730 ppm |
2019-11-13 | Y193220019 | 0.900 ppm |
2019-12-10 | Y193470050 | 0.820 ppm |