Fluoride
Iowa Lakes Regional Water
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 | N/A | 0 | 0 | N/A |
2015 | N/A | 0 | 0 | N/A |
2016 | ND | 5 | 0 | ND |
2017 | 0.318 ppm | 10 | 7 | ND - 0.590 ppm |
2018 | 0.388 ppm | 11 | 10 | ND - 0.512 ppm |
2019 | 0.462 ppm | 12 | 12 | 0.388 ppm - 0.520 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 |
---|---|---|
2016-01-19 | 16001297-95835 | ND |
2016-06-21 | 16010655-106748 | ND |
2016-08-02 | 16013337-109963 | ND |
2016-11-03 | 16019625-117590 | ND |
2016-12-20 | 16023152-122198 | ND |
2017-01-23 | 17001556-124919 | ND |
2017-02-27 | 17003842-127762 | ND |
2017-03-21 | 17005543-129883 | 0.590 ppm |
2017-06-20 | 17012048-137732 | 0.372 ppm |
2017-07-25 | 17014479-140609 | 0.414 ppm |
2017-08-08 | 17015441-141771 | 0.394 ppm |
2017-09-19 | 17018723-145578 | 0.497 ppm |
2017-10-09 | 17020589-147736 | 0.515 ppm |
2017-11-27 | 17024287-152140 | ND |
2017-12-12 | 17025725-153870 | 0.397 ppm |
2018-01-16 | 18001339-156699 | 0.377 ppm |
2018-03-20 | 18005207-161577 | 0.449 ppm |
2018-04-24 | 18008030-164947 | 0.442 ppm |
2018-05-01 | 18008513-165495 | 0.472 ppm |
2018-06-19 | 18011872-169602 | 0.357 ppm |
2018-07-10 | 18013298-171382 | 0.405 ppm |
2018-08-07 | 18015365-173964 | 0.342 ppm |
2018-09-25 | 18018875-178150 | 0.428 ppm |
2018-10-16 | 18020502-180289 | 0.512 ppm |
2018-11-28 | OE743969 | 0.480 ppm |
2018-12-19 | 18026811-187871 | ND |
2019-01-14 | 19001559-190947 | 0.478 ppm |
2019-02-18 | OE771947 | 0.500 ppm |
2019-03-18 | 19008016-199056 | 0.388 ppm |
2019-04-22 | 19011758-203670 | 0.407 ppm |
2019-05-07 | 19013832-206329 | 0.451 ppm |
2019-06-25 | 19018520-212363 | 0.441 ppm |
2019-07-23 | 19021433-216008 | 0.452 ppm |
2019-08-20 | 19024305-219685 | 0.456 ppm |
2019-09-23 | OE869664 | 0.460 ppm |
2019-10-24 | OE884594 | 0.500 ppm |
2019-11-25 | OE898017 | 0.490 ppm |
2019-12-16 | OE906115 | 0.520 ppm |