CDC findings on fluoridated water

Federal agencies including the Centers for Disease Control and Prevention encourage the fluoridation of municipal water supplies for the reduction of tooth decay.

But the CDC also acknowledges that things have changed since the 1940s when the practice started. Through fact sheets on its website, it lists cautions about and problems with the ingestion of too much fluoride, including new indications that mixing instant baby formula with fluoridated water can increase the chance of mild fluorosis, an abnormal mouth condition, in infants.

The Department of Health and Human Services is proposing a reduction in the recommended optimal level of fluoride in drinking water from a range of 0.7 to 1.2 milligrams per liter to 0.7 milligrams.

Here are excerpts about fluoridation from the CDC’s website,, ranging from lifelong-exposure risks to what kind of bottled water to buy to avoid fluoride to sources of the fluoride used in fluoridating water.

Why is the Department of Health and Human Services developing new recommendations for community water fluoridation?

Sources of fluoride have increased since the early 1960s. At that time, drinking water and food and beverages prepared with fluoridated water accounted for nearly all of an individual’s fluoride intake. Today, water is just one of several sources of fluoride. Other sources include dental products such as toothpaste and mouth rinses, prescription fluoride supplements, and professionally applied fluoride products such as varnish and gels.

What is dental fluorosis?

Dental fluorosis is a change in the appearance of the tooth’s enamel. It can result when children regularly consume higher-than-recommended amounts of fluoride during the teeth-forming years, age 8 and younger. Most dental fluorosis in the U.S. – about 92 percent – is very mild to mild, appearing as white spots on the tooth surface that in many cases only a dental professional would notice. Moderate and severe forms of dental fluorosis, which are less common, cause more extensive enamel changes. In the rare, severe form, pits may form in the teeth. The severe form rarely occurs in communities where the level of fluoride in water is less than 2 milligrams per liter.

What are the adverse health effects of excessive fluoride exposure?

Children ... age 8 and younger exposed to excessive amounts of fluoride have an increased chance of developing pits in the tooth enamel. Excessive consumption of fluoride over a lifetime may increase the likelihood of bone fractures, and may result in effects on bone leading to pain and tenderness, a condition called skeletal fluorosis. Severe skeletal fluorosis is a rare condition in the United States. (An Environmental Protection Agency) exposure analysis suggests that the effects on bone in adults are of greatest concern for those living in areas with high natural background levels of fluoride and favoring beverages, such as tea, that are high in fluoride.

Are children or adults exposed to too much fluoride?

Based on the data evaluated in this risk assessment, EPA concludes that it is likely that some children 8 and younger are exposed to too much fluoride at least occasionally while their teeth are forming because of their high fluid intake relative to their body weight and/or because of high natural levels of fluoride in their local drinking water. The impact of overexposure on the risk for pitting of enamel in one or more teeth depends on the frequency and duration of the overexposures.

Is my child getting an appropriate amount of fluoride from drinking water and tooth brushing?

Yes, if you and your child are among the 196 million Americans who receive their water from an optimally fluoridated community water system (0.7 to 1.2 milligrams per liter) and you follow guidelines in your child’s toothbrushing, then it is highly unlikely that your child is receiving too much fluoride. CDC recommends that children under 6 who are using fluoride toothpaste should use a small, pea-sized amount on the brush, spit out the excess paste, and rinse well after brushing. Begin using toothpaste with fluoride when your child is 2 years old. Use toothpaste with fluoride earlier only if your child’s doctor or dentist recommends it. ...

In some regions in the U.S., community drinking water and home wells can contain levels of naturally occurring fluoride that are greater than the optimal levels recommended by the CDC for prevention of tooth decay.

Has the safety of community water fluoridation been evaluated?

The safety and effectiveness of fluoride at levels used in community water fluoridation has been thoroughly documented by scientific and public health organizations using scientific reviews and expert panels.

Are there methods I can use to remove fluoride from my drinking water at home? For example, boiling or use of commercially available water filters and units?

The typical charcoal-based water filtration systems used in most homes do not remove fluoride from water. Boiling water does not remove fluoride. More costly distillation and reverse osmosis are treatment methods that have proven to be effective for removing fluoride to below 4.0 mg/L. If you choose to use home water treatment, make sure that the filter you use is certified to address your concerns.

Infant Formula and Fluorosis:

The proper amount of fluoride at all stages of life helps prevent and control tooth decay. Recent studies have raised the possibility that mixing infant formula with fluoridated water, particularly for infants exclusively on a formula diet during the first year of life, may play a more important role in dental fluorosis development than was previously understood. ...

You can use fluoridated water for preparing infant formula. However, if your child is exclusively consuming infant formula reconstituted with fluoridated water, there may be an increased chance for mild dental fluorosis. To lessen this chance, parents can use low-fluoride bottled water some of the time to mix infant formula; these bottled waters are labeled as de-ionized, purified, demineralized, or distilled.

Health Effects and Environmental Impact

Scientists have found a lack of evidence to show an association between water fluoridation and a negative impact on people, plants, or animals.

Types of Fluoride Additives

The three fluoride additives used for water fluoridation are derived principally from phosphate fertilizer production.

The three additives are:

• Fluorosilicic acid: a water-based solution used by most water fluoridation programs in the United States. Fluorosilicic acid is also referred to as hydrofluorosilicate, FSA, or HFS.

• Sodium fluorosilicate: a dry additive, dissolved into a solution before being added to water.

• Sodium fluoride: a dry additive, typically used in small water systems, dissolved into a solution before being added to water.

Measured Levels of Impurities

Fluoride additives are analyzed for impurities that have been identified as having the potential to occur. Those impurities include arsenic, lead, and radionuclides. ...

Consumers sometimes raise concerns about arsenic in drinking water and the fact that fluoride additives may contain some arsenic. The EPA allowable criterion for arsenic consumption in drinking water is 10 parts per billion. (National Sanitation Foundation) quality testing has found that most fluoride additive samples do not have detectable levels of arsenic. For those samples that do test positive, the arsenic level that an average consumer would experience over an entire year of drinking water at a maximum dosage of 1.2 mg/L fluoride would only be about 1.2% of the EPA allowable amount.

Other impurities in the NSF International-certified fluoride product testing were found to be even lower than the arsenic levels, with only 1%-3% of fluoride products containing detectable levels of metals. The average exposure to a typical consumer would be less than 0.1% of the EPA allowable levels.

Fluoride Additives Are Not Different From Natural Fluoride

Some consumers have questioned whether fluoride from natural groundwater sources, such as calcium fluoride, is better than fluorides added “artificially,” such as FSA or sodium fluoride. Two recent scientific studies ... demonstrate that the same fluoride ion is present in naturally occurring fluoride or fluoride drinking water additives and that no intermediates or other products were observed at pH levels as low as 3.5. In addition, fluoride metabolism is not affected differently by the chemical compounds nor are they affected by whether the fluoride is present naturally or artificially.

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