Fluoride
City of Lawrence
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 |
---|---|---|---|---|
2013 | N/A | 0 | 0 | N/A |
2014 | 0.384 ppm | 16 | 16 | 0.190 ppm - 0.500 ppm |
2015 | 0.339 ppm | 10 | 10 | 0.220 ppm - 0.550 ppm |
2016 | 0.313 ppm | 10 | 8 | ND - 0.630 ppm |
2017 | 0.303 ppm | 9 | 8 | ND - 0.430 ppm |
2018 | 0.380 ppm | 10 | 10 | 0.260 ppm - 0.600 ppm |
2019 | 0.321 ppm | 18 | 18 | 0.160 ppm - 0.500 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 |
---|---|---|
2014-02-12 | FEB2014-GENCHEM | 0.500 ppm |
2014-02-12 | FEB-14-GENCHEM | 0.300 ppm |
2014-02-12 | 60659 | 0.310 ppm |
2014-02-12 | 60656 | 0.420 ppm |
2014-04-17 | 98228 | 0.430 ppm |
2014-04-17 | 98229 | 0.400 ppm |
2014-04-17 | 98230 | 0.450 ppm |
2014-04-17 | 98231 | 0.380 ppm |
2014-05-21 | MAY2014-GENCHEM | 0.400 ppm |
2014-05-21 | MAY-14-GENCHEM | 0.400 ppm |
2014-08-13 | AUG2014-GENCHEM | 0.400 ppm |
2014-08-13 | AUG-14-GENCHEM | 0.400 ppm |
2014-08-20 | 178434 | 0.450 ppm |
2014-08-20 | 178433 | 0.360 ppm |
2014-10-23 | 218435 | 0.350 ppm |
2014-10-23 | 218434 | 0.190 ppm |
2015-01-12 | 260483 | 0.430 ppm |
2015-01-12 | 260484 | 0.550 ppm |
2015-04-01 | 303912 | 0.240 ppm |
2015-04-01 | 303911 | 0.240 ppm |
2015-04-21 | 316510 | 0.430 ppm |
2015-04-21 | 316463 | 0.420 ppm |
2015-08-10 | 381796 | 0.340 ppm |
2015-08-10 | 381795 | 0.220 ppm |
2015-11-03 | 421424 | 0.290 ppm |
2015-11-03 | 421425 | 0.230 ppm |
2016-02-16 | 493933 | 0.310 ppm |
2016-02-16 | 493932 | 0.630 ppm |
2016-05-04 | 538522 | 0.410 ppm |
2016-05-04 | 538521 | 0.410 ppm |
2016-05-04 | 538520 | 0.380 ppm |
2016-05-04 | 538519 | 0.380 ppm |
2016-07-21 | 587475 | 0.430 ppm |
2016-07-21 | 587474 | 0.180 ppm |
2016-10-17 | 644732 | ND |
2016-10-17 | 644733 | ND |
2017-01-11 | 679769 | ND |
2017-01-11 | 679768 | 0.360 ppm |
2017-04-04 | 733918 | 0.360 ppm |
2017-04-04 | 733917 | 0.280 ppm |
2017-04-25 | 746985 | 0.290 ppm |
2017-04-25 | 746983 | 0.320 ppm |
2017-07-05 | 788887 | 0.370 ppm |
2017-07-05 | 788886 | 0.320 ppm |
2017-11-15 | 878906 | 0.430 ppm |
2018-01-03 | 899749 | 0.440 ppm |
2018-01-03 | 899748 | 0.600 ppm |
2018-04-27 | 938150 | 0.300 ppm |
2018-04-27 | 938149 | 0.320 ppm |
2018-05-02 | 938152 | 0.290 ppm |
2018-05-02 | 938151 | 0.400 ppm |
2018-07-03 | 1001333 | 0.260 ppm |
2018-07-03 | 1001332 | 0.320 ppm |
2018-10-09 | 1058335 | 0.480 ppm |
2018-10-09 | 1058336 | 0.390 ppm |
2019-01-02 | 1097376 | 0.410 ppm |
2019-01-02 | 1097375 | 0.320 ppm |
2019-02-14 | 2019-02-14 GEN T | 0.400 ppm |
2019-02-14 | 2019-02-14 GEN T | 0.500 ppm |
2019-04-15 | 1138988 | 0.260 ppm |
2019-04-15 | 1138989 | 0.340 ppm |
2019-04-15 | 1138990 | 0.290 ppm |
2019-04-15 | 1138991 | 0.230 ppm |
2019-05-14 | 2019-05-14-GEN-T | 0.200 ppm |
2019-05-14 | 2019-05-14-GEN-T | 0.300 ppm |
2019-07-30 | 1213997 | 0.170 ppm |
2019-07-30 | 1213996 | 0.160 ppm |
2019-08-07 | 2019-08-07-GEN-T | 0.200 ppm |
2019-08-07 | 2019-08-07-GEN-T | 0.200 ppm |
2019-10-07 | 1253193 | 0.420 ppm |
2019-10-07 | 1253192 | 0.480 ppm |
2019-11-18 | 2019-11-18-GEN-T | 0.400 ppm |
2019-11-18 | 2019-11-18-GEN-T | 0.500 ppm |