fluoride in tap water

Fluoride: the good, the bad, and the ugly

What is fluoride? Fluoride (F-) is an ion of the element fluorine. It occurs naturally in fresh water, the oceans, and soil. While it is not considered an essential nutrient, fluoride is often added to public drinking water to prevent and reverse tooth decay. In areas that already have naturally occurring fluoride in the water, the amount is adjusted to the optimal level set by the U.S. Department of Health and Human Services, which is usually around 0.7 to 1.2 ppm (ppm = parts per million). Tooth decay is a common health problem that causes tooth pain, tooth loss, and infection, and it may also cause bad breath. Fluoride is said to avert tooth decay by keeping the acid produced by bacteria in plaque from damaging teeth. Besides inhibiting tooth decay, fluoride may also remineralize a tooth’s enamel.

Fluoridation of drinking water

History

In the 1930s, dentists noticed that in certain parts of the United States some people had unusual stains on their teeth. The stained teeth (the staining was later called dental fluorosis, which you can read more about below) also appeared to be less prone to tooth decay. The dentists discovered that the stains were caused by exposure to high levels (1 ppm or greater) of naturally occurring fluoride in the drinking water. In these areas with naturally fluoridated water, people had lower rates of cavities than in areas where the drinking water had very low or no detectable levels of fluoride. Researchers sought a level of fluoride that would hold the severity of dental fluorosis to no more than mild cases while still delivering the added benefit of reduced tooth decay. Many areas began adding fluoride to public drinking water in 1945. Besides public drinking water, fluoride is now added to toothpaste, mouthwash, tablets, gels and foams, floss, and even vitamins. It can also be found in beverages and food prepared with fluoridated water.

Statistics

The CDC reports that 66.2% of people in the United States receive fluoridated water through public water sources. Counties in each state add different levels of fluoride to their drinking water; these levels are usually around 1 ppm and are not to exceed 4 ppm. Some areas have very high levels of naturally occurring fluoride, and the water there is usually monitored to make sure the fluoride does not exceed 4 ppm. Information on which counties add fluoride to their drinking water, and how much, can be found here: http://apps.nccd.cdc.gov/MWF/Index.asp.

Arguments FOR fluoride in drinking water

Fluoridation of drinking water has been hailed by the CDC as one of the greatest achievements of public health because it prevents tooth decay and tooth loss in children and adults regardless of socioeconomic factors or rates of dental care.(1) Many health, service, and professional organizations stand behind fluoridation as a safe and effective way to prevent tooth decay. Fluoride is relatively inexpensive and is reported by the CDC to be completely safe. Fluoridation of public drinking water costs about $0.50 per person per year in most communities. The American Dental Association says that fluoridation is a great investment: for every $1 spent on water fluoridation, $38 is saved on dental care.

teeth with a mild case of fluorosis caused by fluoridated tap water

While high exposure to fluoride may cause dental fluorosis, most cases are mild and barely visible; the effect is simply cosmetic and doesn’t affect a tooth’s function. Some of the earliest studies showed that fluoridated water reduced the total number of cavities in children’s baby teeth by 60% and reduced tooth decay in permanent teeth by 35%.(2) A 2010 study found that adults who were born in a city with fluoridated water experienced less tooth loss.(3)

Adding a small amount of fluoride to water mimics the naturally occurring levels found in places around the world. Fortifying water with fluoride is often compared to fortifying salt with iodine or adding vitamin C to juice or milk. Most water filters do not remove fluoride, because it is often seen as a desirable addition to drinking water. Many communities have voted in favor of adding fluoride to public drinking water.

A recent study examined whether there is a relationship between fluoride exposure and the risk of osteosarcoma (a cancer that starts in the bones). The analysis showed no significant association between bone fluoride levels and the risk of osteosarcoma.(4)

Arguments AGAINST fluoride in drinking water

Many recent studies on fluoride have suggested the need for further research to test whether fluoridation of water is actually necessary and whether it may cause underlying health problems. The bad may outweigh the good. We can see what happens to our teeth when we consume too much fluoride, but we can’t see with the naked eye what too much fluoride does to our bones and the rest of our bodies. There may be fluoride dangers that are not yet known.

Topical use of fluoride that you don’t ingest (such as in toothpaste) does prevent cavities and is said to be safe, but more and more studies are finding that ingesting a lot of fluoride may be harmful to our health. Fluoride has been said to cause Alzheimer’s, hypothyroidism, arthritis, bone cancer, hip and joint problems, brain development problems in children, and more. While we are unsure whether these claims are 100% true, they are concerning and suggest that we should think twice about adding fluoride to our drinking water until more studies prove its absolute safety. The EPA has also stated that excessive exposure to fluoride (over 4 ppm) over a lifetime may cause bone fractures, bone pain and tenderness, and bone disease.(5)

While dentists say that dental fluorosis is simply a cosmetic concern, some studies link it with other issues. For example, many areas in China have high levels of naturally occurring fluoride in their water, and studies have shown that children with dental fluorosis also had lower IQ scores than children who did not show signs of it.(6) An American study that exposed animals to high levels of fluoride found that the fluoride accumulated in brain tissue, possibly causing negative effects on learning and memory.(7)

World Health Organization data comparing fluoridated and unfluoridated countries from 1965 to 2005 show an overall trend in every country toward a reduction in tooth decay. This suggests that water fluoridation is probably not responsible for the reduction in tooth decay.(8)

Others argue that the earlier studies on fluoride safety were conducted with the naturally occurring kind: calcium fluoride. The fluoride added to public drinking water is not calcium fluoride; it is fluorosilicic acid, sodium fluorosilicate, or sodium fluoride, and these compounds are not from pharmaceutical-grade sources. Instead, these chemicals are by-products of fertilizer production and are often purchased from phosphate fertilizer companies. You can find out what type of fluoride is added to your public drinking water here: http://apps.nccd.cdc.gov/MWF/Index.asp.

Should I give fluoride to my child?

child brushing teeth with fluoride-free toothpaste

If your dentist advises it, or you feel you should give fluoride to your child, it is a good idea to first check the levels of fluoride added to your drinking water. You can access the most recent Consumer Confidence Report from your utility company or check the link provided above. Some areas have high levels of naturally occurring fluoride, so adding more in the form of toothpaste, tablets, or mouthwash is unnecessary and may cause dental fluorosis. It is important to monitor your child’s consumption of fluoride, because too much might cause dental or enamel fluorosis in kids under the age of eight. High levels of fluoride during this period of tooth development may result in blotchy white areas or pits on the tooth’s enamel. There are different degrees of dental fluorosis; severe cases may discolor larger areas of the tooth and turn a more noticeable brown. Consider all sources of fluoride your child might consume, such as drinking water, food, and juice. For example, white grape juice has tested at a fluoride concentration of 2.13 ppm, which is higher than the level recommended by the CDC.(9)

The ADA does not recommend fluoride toothpaste for children under the age of two. For older children, use only a pea-sized amount and make sure they do not swallow the toothpaste. Mouth rinses containing fluoride should not be given to children under the age of six, because the risk of them swallowing it and consuming too much fluoride is high. Swallowing fluoride at 5 mg/kg can be fatal, and symptoms of fluoride toxicity can appear from doses as low as 0.2 mg/kg. Symptoms of fluoride poisoning include gastrointestinal pain, nausea, vomiting, and headaches. A 2004 study concluded that there is no advantage to using fluoride toothpaste over fluoride gels, mouthwash, or varnish.(10) If you do choose to give your child fluoride, this schedule explains how much the ADA recommends for children based on their age: http://ebd.ada.org/contentdocs/6327_Fluoride_Chairside_Tool.pdf.

Various fluoride-free products for your children:

Fluoride substitutes

  • Brushing your teeth after every meal will help keep your breath fresh and reduce the risk of getting tooth decay.

  • Vitamin D: a study analyzing data from 1920 to 1980 showed an association between vitamin D and a 50 percent reduction in tooth decay in children.(11) You can increase your vitamin D level by getting at least 30 minutes of sunshine daily and by taking cod liver oil and other supplements.

  • Xylitol: one study reported that xylitol is capable of remineralizing enamel.(12) This increasingly popular product can be found in gum, toothpaste, and some foods.

If you are looking for a fluoride-free mouthwash, check out our article on homemade mouthwashes.

Removing fluoride from water

If the public drinking water in your area has fluoride added and you would like to remove it, you have a few options. Fluoride is removed from water by reverse osmosis filters and distillation. Keep in mind that most filters, like Brita and PUR, do not remove fluoride. On that same note, boiling or freezing water does not remove it either. Be mindful of bottled water: unless the bottle states that the water is filtered through reverse osmosis, you have to assume that it is from a municipal source and contains fluoride. Fluoride levels in bottled water are not regulated.

Here are some filters that remove fluoride from water:

Fluoride water filter

Fluoride reverse osmosis water filter

Tap Master Water
Filtration System

iSpring Reverse Osmosis
Water Filter System

Conclusion

Most people agree that topical fluoride treatments reduce tooth decay, so using fluoridated toothpaste and mouthwash is relatively safe as long as you don’t swallow it and you rinse your mouth after use. Too much of anything can cause health problems, and fluoride is no exception. Because fluoride is added to most Americans’ drinking water, it is crucial to monitor how much you are consuming. Fluoride is found not only in our drinking water but also in air pollution and on our food from pesticides. Not enough studies have been conducted to show that water fluoridation carries no risk. High levels may be dangerous, so excess fluoride should probably be avoided unless more solid research proves otherwise. The potential dangers of fluoride are real, so research needs to continue.

More resources

To find the levels of fluoride in food and beverages:
http://www.ars.usda.gov/Services/docs.htm?docid=6312

More ways to avoid fluoride:
http://sdsdw.org/avoiding-fluoride/

The American Dental Association’s stance on fluoridation:
http://www.ada.org/sections/professionalResources/pdfs/fluoridation_facts.pdf

Sources

  1. http://www.cdc.gov/fluoridation
  2. http://www.ada.org/sections/professionalResources/pdfs/fluoridation_facts.pdf
  3. Am J Public Health 100(10), 2010.
  4. Kim FM, Hayes C, Williams PL, et al. An assessment of bone fluoride and osteosarcoma. Journal of Dental Research 2011; 90(10):1171-1176.
  5. http://water.epa.gov/drink/contaminants/basicinformation/fluoride.cfm
  6. http://ehp.niehs.nih.gov/1104912/
  7. http://www.scribd.com/doc/15945451/Neurotoxicity-of-sodium-fluoride-in-rats-Phyllis-J-Mullenix-Neurotoxicology-and-Teratology-Vol-17-No-2-pp-169177-1995
  8. http://sdsdw.org/fluoride-facts/world-health-organization-data-tooth-decay-trends/
  9. http://www.ars.usda.gov/Services/docs.htm?docid=6312
  10. http://www.ncbi.nlm.nih.gov/pubmed/14973991
  11. http://www.sciencedaily.com/releases/2012/11/121127130321.htm
  12. http://www.ncbi.nlm.nih.gov/m/pubmed/14700079/