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EWG's Tap Water Database — 2019 UPDATE

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Fluoride

Carroll-Boone Water District

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.

 

36

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND10ND
2013ND10ND
2014ND10ND
20150.380 ppm85ND - 0.700 ppm
20160.608 ppm12120.510 ppm - 0.690 ppm
20170.645 ppm13130.450 ppm - 0.770 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
2012-04-18121110003ND
2013-04-09131020003ND
2014-04-07141000029ND
2015-05-12Y151350001ND
2015-06-09Y151670004ND
2015-07-20Y152020023ND
2015-08-20Y1523600300.490 ppm
2015-09-22Y1527100190.630 ppm
2015-10-19Y1529900080.700 ppm
2015-11-03Y1531300010.600 ppm
2015-12-15Y1535700080.620 ppm
2016-01-04Y1600800290.650 ppm
2016-02-09Y1605300140.600 ppm
2016-04-13Y1610600520.690 ppm
2016-04-19Y1611200130.670 ppm
2016-05-19Y1615200090.590 ppm
2016-06-14Y1617900220.660 ppm
2016-07-19Y1620700350.660 ppm
2016-08-16Y1623500500.600 ppm
2016-09-14Y1626400420.570 ppm
2016-10-19Y1630200180.560 ppm
2016-11-09Y1632100050.510 ppm
2016-12-13Y1635000300.540 ppm
2017-01-17Y1702000100.510 ppm
2017-02-14Y1704800160.450 ppm
2017-03-22Y1708600060.580 ppm
2017-04-20Y1711400350.700 ppm
2017-04-27Y1711800070.570 ppm
2017-05-22Y1715000050.660 ppm
2017-06-21Y1717700360.690 ppm
2017-07-12Y1719800620.690 ppm
2017-08-16Y1723300240.650 ppm
2017-09-05Y1725400340.650 ppm
2017-10-16Y1729600170.760 ppm
2017-11-16Y1732400320.700 ppm
2017-12-07Y1734500640.770 ppm