Drinking Water: Fluoride
At optimal levels, fluoride in drinking water can be beneficial to dental health. Learn more about fluoride concentration and potential health effects.
Sharon O. Skipton, Extension Drinking Water Educator
Bruce I. Dvorak, Environmental Engineering Specialist
Andy Kahle, Drinking Water Program Specialist, Nebraska Department of Health & Human Services
Wayne Woldt, Extension Water and Environment Specialist
- Sources of Fluoride in Drinking Water
- Indications of Fluoride
- Potential Health Effects
- Testing
- Interpreting Test Results
- Options
- Expert Reports
- Summary
| University of Nebraska–Lincoln Extension and the Nebraska Department of Health and Human Services place a high priority on water quality and jointly sponsor this series of educational publications. |  |
Sources of Fluoride in Drinking Water
Fluoride, a naturally occurring element, exists in combination with other elements as a fluoride compound and is found as a constituent of minerals in rocks and soil. When water passes through and over soil and rock formations containing fluoride it dissolves these compounds, resulting in the small amounts of soluble fluoride present in virtually all water sources.
A study of naturally occurring fluoride in Nebraska’s groundwater reported a range of concentrations from less than 0.1 milligrams per liter (mg/l) to 2.6 mg/l with an average of 0.3 mg/l (Headrick, 1996). According to the study, three areas in Nebraska — the Upper Republican River Valley, Knox County, and the Panhandle — had average concentrations higher than 0.6 mg/l or had average concentrations near 0.6 mg/l with a significant percent of samples over 1.5 mg/l. According to a Nebraska Department of Health and Human Services (DHHS) database and a USGS database used in the Headrick study, counties included in the three areas were: Chase, Dundy, Hayes, Hitchcock, Red Willow, Frontier, Knox, Box Butte, Kimball, Cheyenne, and Scotts Bluff. (Figure 1).
In addition to naturally occurring fluoride, some communities add fluoride to the public water supply, a process known as fluoridation. Nationally, about two-thirds of Americans served by public water systems receive fluoridated water, according to the American Dental Association. Drinking-water fluoridation can be controversial. Opponents argue it violates individual rights and goes against religious beliefs that ban medication. The courts have ruled fluoridation is not an unconstitutional invasion of religious freedom or other individual rights guaranteed by the First, Fifth or 14th Amendments to the U.S. Constitution. The position of the courts is that a significant government interest in health and public welfare generally overrides individual objections to public health regulation.
Opponents also argue that drinking fluoridated water promotes a variety of physical and mental ailments. Since the 1930s, many scientific studies have shown that water fluoridation, at the optimum concentrations recommended for good oral health, has no known harmful effects.
Fluoridation is endorsed by the Centers for Disease Control and Prevention, American Dental Association, and the American Medical Association, as well as numerous national and international health organizations. According to the Centers for Disease Control and Prevention, every dollar spent on fluoridation saves $38 in dental costs. The agency also said Medicaid dental programs cost up to 50 percent less in communities with fluoridated water compared with those with unfluoridated water.
Additional sources of fluoride include foods and beverages and many oral care products, such as toothpastes, mouth rinses, and gels. Topical treatment and supplements are available from physicians and dentists. All potential sources of fluoride should be considered when developing a dental care plan.
Indications of Fluoride
Fluoride in drinking water cannot be detected by taste, sight, or smell. Testing is the only way to determine the fluoride concentration.
Potential Health Effects
As with many substances, potential health effects are directly related to the concentration present. The U.S. Public Health Service, Centers for Disease Control and Prevention and the American Dental Association recommend an optimum level of 1.0 mg/l to ensure potential benefits while minimizing or eliminating potential risks. Fluoride levels in drinking water are discussed in the “Interpreting Test Results” section.
The dental benefits from consuming water containing optimum levels of fluoride are well-documented. Information and recommendations are available in numerous expert panel reports such as those listed on page 4. At optimum levels, fluoride protects against tooth decay. The American Dental Association has stated that fluoride benefits people of all ages. When children are young and their teeth are forming, fluoride makes tooth enamel harder and more resistant to decay-causing acid. Studies indicate that people who drink optimally fluoridated water from birth will experience up to 40 percent less decay over their lifetimes. For adults, fluoride helps repair the early stages of tooth decay even before it becomes visible, a process known as remineralization. For older adults, fluoride can decrease problems with root caries (decay along the gumline).
Although low levels of fluoride are beneficial, excessive amounts can be harmful. Fluoride in drinking water above optimum levels may produce fluorosis (mottling of teeth). Dental fluorosis appears during tooth formation. The effects can be mild to severe, ranging from barely perceptible white striations or specks on teeth to permanent brown to brownish gray stains on teeth and/or severe pitting. The National Research Council (NRC) conducted a scientific review of research on various health effects, including dental effects, from consuming water with fluoride at the maximum level allowed in public water supplies (four times greater than the recommended optimum level.) They reaffirmed that continued consumption of water containing increasingly higher concentrations of fluoride above optimum levels will generally produce more severe dental fluorosis. While the effect of mild to moderate fluorosis is believed to be cosmetic only, 10 of the 12 committee members concluded that enamel loss and pitting associated with severe fluorosis may increase the risk of tooth decay and infection.
Like other trace elements, excessive quantities of fluoride can result in acute toxicity. Consuming an excessive amount of fluoride (300 to 750 milligrams depending on body weight) in a single dose can result in nausea or vomiting. This level of fluoride intake could occur as a result of some type of accidental? event, such as small children consuming an overdose of fluoride supplements. At the optimum fluoridation level of 1.0 mg/l, an individual would need to ingest 80 to 200 gallons of water in a few hours to reach the acute toxicity level, an amount impossible to drink in that time period.
The possibility of chronic health effects from continuous consumption of drinking water with fluoride above optimum levels has also been studied. The NRC scientific review included research on possible musculoskeletal, reproductive and developmental, neurotoxicity and neurobehavioral, endocrine, and carcinogenicity effects from exposure to fluoride in drinking water at the maximum level allowed in public water supplies (four times greater than the recommended optimum level.) The committee concluded that scientific evidence suggested adverse effects were unlikely, or that evidence is tentative and mixed, for adverse health effects studied, with the exception of bone fractures. While the report’s authoring committee was not in total agreement, the majority concluded that chronic health effects included a likely increase for bone fractures, particularly in those prone to accumulate fluoride into their bones. The level of risk was not quantified.
This publication does not substitute for professional medical advice. If you have any questions or concerns related to potential health effects from consuming fluoridated water, consult your physician.
Testing
Testing Public Water Supplies
The quality of water supplied by public water systems is regulated by EPA under the federal Safe Drinking Water Act. The Nebraska DHHS is responsible for implementing and enforcing Safe Drinking Water Act standards. Under these regulations, public water supplies must be tested for fluoride concentration. If your water comes from a public water supply, contact your water supplier to find out the fluoride level.
Testing Private Water Supplies
Water quality in private wells is not currently regulated in Nebraska; thus, testing a private water supply is not required. All water sources contain some naturally occurring fluoride. If users want to know the concentration of naturally occurring fluoride in a private water supply, they will need to have the water tested at their own expense. The DHHS approves laboratories to conduct tests from drinking water samples. For information on laboratories approved to test for fluoride, contact:
Nebraska Department of Health and Human Services
Department of Regulation and Licensure
Public Health Laboratory
3701 South 14th
Lincoln, NE 68505
(402) 471-2122
Interpreting Test Results
Public Water Supply Test Results
Fluoride guidelines for dental health benefits were established by the U.S. Public Health Service in the 1960s. The recommended level of fluoride in drinking water for dental benefits is 0.7 to 1.2 mg/l. The recommend optimum level for Nebraska is 1.0 mg/l.
Under the Safe Drinking Water Act, the EPA is required to regulate the quality of water supplied by public water systems. EPA standards restrict the total amount of a substance allowed in drinking water, and are designed to prevent undesirable effects that could result from exposure to a substance at concentrations above those allowed. Drinking water standards fall into two categories: Secondary Standards and Primary Standards. Secondary Standards are based on aesthetic factors such as taste, odor, color, corrosivity, foaming and staining properties of water that may affect water’s suitability for drinking and other domestic uses. Primary Standards are based on health considerations and are designed to protect human health. EPA established a recommended Secondary Standard and an enforceable Primary Standard for fluoride in 1986. The Nebraska DHHS enforces Safe Drinking Water Act guidelines in Nebraska’s public water supplies.
The Secondary Maximum Contaminant Level (SMCL) for fluoride is 2.0 mg/l which is equal to 2.0 parts per million (ppm). Water with a fluoride concentration at or below 2.0 mg/l does not present a health risk and should not cause appreciable fluorosis. Mild to moderate fluorosis is not considered a health risk but does have an aesthetic impact on teeth. See the Potential Health Effects Section for more information on fluorosis.
The Primary Maximum Contaminant Level (MCL) for fluoride in drinking water is 4.0 mg/l which is equal to 4.0 ppm. Daily consumption of water with a fluoride concentration at 4.0 mg/l was believed to not present a health risk based on best available science at the time of the MCL enactment. National Research Council Report (2006) concluded that exposure at the current MCL puts children at risk for developing severe fluorosis that may compromise tooth function, and could put adults at increased risk of bone fracture, especially in those prone to accumulate fluoride into their bones. It is important to note that the allowable MCL is nearly four times the optimum concentration recommended by the U.S. Public Health Service and the Nebraska DHHS.
Nebraska Legislative Bill 245 passed in 2008 requires all Nebraska public community water supplies serving populations over 1,000 to fluoridate “in the amount and manner prescribed by the rules and regulations of the Department of Health and Human Services Regulation and Licensure” by June 1, 2010, unless citizens of the community opt out through a ballot vote prior to that date. Fluoridation is not required for water supplies that have naturally occurring fluoride at optimum levels. The DHHS Department of Dental Health recommends a fluoride concentration of 0.7 to 1.5 mg/l to ensure potential benefits while minimizing or eliminating potential risks. At the time of bill passage, 62 Nebraska communities with populations over 1,000 did not fluoridate their water and did not have naturally occurring fluoride in the water.
In the summer of 2008, DHHS reported that Nebraska public water supplies with naturally occurring fluoride at or above 0.7 mg/l include:
| Abie Alliance Bartley Benkelman Big Springs Broadwater Bushnell Cambridge Ceresco Chappell Clarks Craig Culbertson Dix |
Grant Gurley Haigler Hayes Center Hemingford Henry Imperial Indianola Jackson Lebanon Lyman McCook Morrill Oakland |
Omaha Tribal Utilities Oshkosh Palisade Ponca Sarpy Co. SID #158 - Tiburon Stockville Stratton Trenton Uehling Verdel Walthill Wauneta Winnebago |
In the summer of 2008, DHHS reported that the following Nebraska public water systems fluoridate their water supply. Some Nebraska communities buy their water supply from a utility rather than operate their own water system. Communities that buy fluoridated water are indented and italicized and listed under the public water supply from which their water is obtained. It is anticipated that this list will change as LB 245 is implemented.
| Adams Albion Allen Arlington Auburn Bassett Beatrice State - Developmental Center Blair Kennard Shannon Estates Washington Co. RWD #2 Country Estates MHP Bloomfield Blue Hill Cedar-Knox RWP Crofton Fordyce St. Helena Obert Coleridge Columbus Cook Creighton Elgin Elmwood Emerson Fairbury Little Blue NRD RWD #1 Falls City Richardson County RWD #2 Salem Verdon Rulo | Fremont Meadowbrook MHP Fullerton Gering Gordon Hallam Hartington Hickman Holdrege Humphrey Kearney Laurel Lincoln Lindsay Louisville Lyons Macy Magnet Metropolitan Utilities District Bellevue Bennington Elkhorn LaVista Maplewood Estates MHP Omaha Papio-Missouri River NRD - Washington County Fort Calhoun Paradise Lakes Ralston Waterloo Minden Nebraska City Otoe County RWD #1 | Neligh Nelson O’Neill Ogallala Osmond Papillion Pender Papio-Missouri River NRD - Thurston Co. Plattsmouth Cass County SID #7 - Swallow Hills Cass County RWD #1 Murray Nehawka Red Cloud Rushville Scribner Shelby South Sioux City Springfield Stella Superior Syracuse Tecumseh Johnson County RWD #1 East Tilden Utica Valley Valparaiso Wausa Waverly Wayne West Point |
Private Water Supply Test Results
EPA and Nebraska regulations do not apply to private drinking water supplies. Thus, fluoride concentration in private drinking water is not regulated. It is highly unlikely that naturally occurring fluoride concentrations would occur above the concentration allowed in a public water supply. If naturally occurring fluoride concentrations are found to be above the optimum or desired level, users might voluntarily consider reducing the fluoride concentration.
Options
Options for Adding Fluoride to Public Water Supplies
To add fluoride to the drinking water, a public water supply will need to add it at each point of entry to the water system. A point of entry is where the water from at least one well or treatment plant is connected to the distribution system. To add fluoride at entry points, chemical feed equipment and tanks, safety equipment, and modifications to the distribution system pipes will be required. If suitable space to house the feed equipment is not available near the point of entry, modifications to a building or a new building will be required. Nebraska public water supplies that do not currently chlorinate water will not be required to add chlorine if fluoride is added.
The costs of adding fluoride to a public water supply depend upon the specific situation for each system. Generally costs will be greater if a system has a large number of points of entry, must add a building to house the fluoride supply equipment, must hire additional staff to operate the fluoride feed system, and/or must treat a larger volume of water. For most communities in Nebraska, the installation cost per point of entry generally will range from $20,000 to $40,000 if a building and additional water piping are required. Point of entry installation costs may be higher for communities needing larger buildings. In addition, there will be an ongoing operating cost. The annual operating cost (fluoride solution, monitoring, and maintenance) generally will be in the range of $10 to $40 per million gallons of water treated. Operating costs will be lower for larger communities and those with fewer points of entry. Operating costs may be higher for communities that must hire additional staff to operate the fluoridation equipment.
Options for Adding Fluoride to Private Water Supplies
It is not practical to fluoridate private drinking water supplies. If the fluoride level is less than desired, bottled water may be a viable option. The U. S. Food and Drug Administration regulates bottled water and allows fluoride in bottled water either from naturally occurring sources or fluoridation. Therefore, some, but not all, bottled water may contain fluoride. Check the label or contact the manufacturer for information on fluoride concentration in the product selected. If the desired fluoride needs cannot be met through the drinking water source, it may be necessary to use fluoride supplements, generally obtained by prescription from a doctor/dentist.
Removing Fluoride From Public Water Supplies
LB 245 requires public water supplies serving populations over 1,000 to provide water with fluoride at optimum levels unless citizens of the community opt out through a ballot and vote. No public drinking water supplies in Nebraska have documented fluoride concentrations above the MCL of 4.0 ppm. Therefore, it is not likely that Nebraska public water supplies will seek options to remove naturally occurring fluoride.
Removing Fluoride at the Tap
If naturally occurring fluoride in public or private water supplies exceeds optimum levels, or if the presence of fluoride in public drinking water through fluoridation is not desired, an alternative drinking water source or water treatment are viable options. An alternative water source for drinking and cooking may be obtained from bottled water. Since bottled water also may contain fluoride, check the label, or contact the manufacturer for information on fluoride concentration in the product selected. Four treatment methods are suitable for removing fluoride from drinking water, including activated alumina filters, distillation, reverse osmosis, and anion exchange. For more information on reverse osmosis or distillation, see Drinking Water Treatment: Reverse Osmosis (G1490) and Drinking Water Treatment: Distillation (G1493). Typically these methods are used to treat water only at one faucet. Treatment units can furnish an adequate supply of defluoridated drinking and cooking water for the home. Work with a reliable, competent water treatment dealer to select the treatment method best for your situation.
Expert Reports
Fluoride in Drinking Water: A Scientific Review of EPA’s Standard; National Research Council; March 2006; (www.nap.edu).
Fluoride Facts; American Dental Association; 2005; (www.ada.org/public/topics/fluoride/facts/index/asp)
Oral Health in America: A Report of The Surgeon General; 2000; (www.nidcr.nih.gov/sgr/sgrohweb/home/htm)
Fluoride In Nebraska Groundwater; Headrick, Jacqueline; 1996; M.S. Thesis; University of Nebraska
Review of Fluoride: Benefits and Risks; U.S. Public Health Service: February 1991; Report of the Ad Hoc Subcommittee to Coordinate Environmental Health and Related Programs; Washington, D.C.
Summary
All water contains naturally occurring fluoride. Fluoride is also added to some public drinking water supplies, a process known as fluoridation. At the optimum level of 1 mg/l, fluoride reduces the occurrence of dental decay. Elevated levels of fluoride in drinking water can cause fluorosis, or mottling of teeth. High levels consumed over a long period can cause chronic toxicity. Extremely high levels, significantly above those found in water, can cause acute toxicity. Tests by reputable, qualified laboratories can determine the concentration of fluoride in drinking water. If fluoride is present above a desirable level, options include using water treatment equipment to remove the fluoride or an alternative water source.This publication has been peer reviewed.
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Index: Water Management
Drinking Water
1998, Revised August 2008
