In January 2011, the Department of Health and Human Services (HHS) and the EPA announced that they were proposing decreasing the recommended level from .7 - 1.2 milligrams per liter (mg/L) to .7 mg/L [source: HHS]. Reasons cited for the change include new science (presumably on rising rates of dental fluorosis among children) and prevalence of fluoride in other sources. Let's look at these and other factors affecting how much fluoride might be too much:
- Children 8 Years and Younger: In the U.S., the main health risk of too much fluoride is dental fluorosis (staining and pitting of tooth enamel). Children are especially susceptible because dental fluorosis only affects developing teeth. For this reason, the CDC recommends limiting fluoride containing products and using an alternative source of water for children 8 years and younger if public water supplies contain more than 2 mg/L of fluoride [source: CDC].
- Naturally Occurring Fluoride: The EPA's MCLG (maximum contaminant level goal) for fluoride is 4 mg/L. In some communities, such as the Rocky Mountains, naturally occurring fluoride exceeds this level and water bureaus are actually required to defluoridate public drinking water. Check your water's fluoride level at this site.
- Products Containing Fluoride: The CDC estimates that people get up to 75% of their fluoride intake from drinking water and processed beverages like juice and soda [source: CDC]. Since food, dental products and pesticides may also contain fluoride, it can be relatively easy to exceed the recommended levels of fluoride, especially if you accidentally swallow your toothpaste!
In moderate amounts (.7 to 1.2 mg/L), fluoride helps prevent tooth decay. However, in excess (the level that constitutes excess ranges from more than 1.5 mg/L, according to the World Health Organization, to more than 4 mg/L according to the EPA), dental fluorosis, bone deposits and more serious conditions like skeletal fluorosis can occur [source: WHO]. In places like the United States where fluoride levels are regulated should not exceed the EPA MCLG of 4 mg/L, mild dental fluorosis is the main health risk.
Since dental fluorosis only affects children whose permanent teeth haven't come in yet, parents of children 8 and under should take special care to limit the amount of fluoride their kids ingest. People living in areas with lots of naturally occurring fluoride should also monitor their consumption of fluoride-containing products.
Find lots more fluoride facts on the next page.