Fluoride in Your Water: Pros and Cons
It seems that recently more attention has been given to fluoride in drinking water and whether or not this element is healthy or harmful. A brief overview of fluoride as well as the pros and cons of water fluoridation are discussed below.
Overview: What is Fluoride?
Fluoride can occur naturally in drinking water and most drinking water supplies consist at least partly of naturally-occurring fluoride. Industries, such as aluminum or fertilizer factories may also contribute to fluoride levels in the drinking water. Most commonly community water systems fortify drinking water by adding fluoride but occasionally the natural levels are too high and water systems must actually decrease the level. The process in which the fluoride levels are adjusted is called community water fluoridation. Though many people are not aware, water fluoridation has been in existence for 67 years since the city of Grand Rapids, Michigan began adding fluoride to municipal water in 1945.
In the early 1900s, dental scientists discovered that in areas where the drinking water contained higher levels of fluoride, residents experienced less tooth decay. After further research it was determined that fluoride in the water helps to prevent tooth decay by preventing de-mineralization, which occurs when acid produced by bacteria in the mouth removes minerals in the tooth. Fluoride also helps to re-mineralize the tooth as well. The potential benefits of community water fluoridation spurred a rapid adoption of this method throughout the country. The Centers for Disease Control (CDC) reported that as of 2010, approximately 73% of the public drinking water systems in the U.S. are optimally fluoridated. Fluoridation is not federally mandated but instead is decided upon by the state or local municipality.
According to the American Dental Association (ADA), the U.S. Public Health Service originally determined that the optimal fluoride level in drinking water is between 0.7 to 1.2 parts per million (ppm). More recently, however, in 2011, the Department of Health and Human Services recommended that the optimal level be reduced to simply 0.7 ppm.
The Pros of Drinking Fluoridated Water
Fluoridation of community water systems is deemed by the CDC to be one of the 10 greatest public health achievements of the 20th century. The ADA also supports fluoridation and mentions that the concept of fortifying water with fluoride is very similar to fortifying milk with Vitamin D or cereal with Folic Acid. When you drink fluoridated water, the fluoride becomes concentrated in the dental plaque which helps prevent breakdown by acid. Fluoride also re-mineralizes the tooth by first attaching or “adsorbing” to the tooth which then attracts calcium molecules and aids in chemical reactions which produce a crystal surface that is more resistant to acid.
By drinking optimally fluoridated water, you can potentially reduce tooth decay in your lifetime by approximately 25%. Water fluoridation is also viewed as an inexpensive process particularly in larger communities, costing approximately 50 cents per person in communities larger than 200,000 people. The ADA also mentions that one dollar spent on fluoridation saves 38 dollars in dental treatments for tooth decay. Another benefit of community water fluoridation is the availability of fluoride delivery to all income levels. Individuals that cannot afford routine dental care do not have to purchase products such as fluoridated toothpaste or fluoride supplements to receive the benefits of fluoridation.
The Cons of Drinking Fluoridated Water
While drinking optimally fluoridated water reduces tooth decay, higher levels of fluoride can cause negative or undesirable effects. The EPA determined that the maximum contaminant level goal (MCLG) for fluoride in drinking water is 4.0 ppm. Consistent lifetime exposure to 4.0ppm or higher fluoride levels can increase the likelihood of developing a condition called skeletal fluorosis which involves bone pain and tenderness in adults. Lifetime exposures to high levels can also increase the likelihood of bone fractures in adults. This MCLG is regulated by the EPA.
The EPA also established a secondary maximum contaminant level (SMCL) of 2.0 ppm for fluoride in drinking water. EPA cannot require that water systems remain under this level but both the EPA and CDC highly recommend remaining below 2.0 ppm to avoid cosmetic effects. Children aged 8 years and younger that are consistently exposed to fluoride levels of 2.0 ppm or higher can develop dental fluorosis which is a change in the appearance of the tooth enamel. Only this age group is at risk because fluoride only affects permanent teeth while they are still developing in the gums. The fluoride can disrupt enamel maturation which causes enamel porosity. The fluorosis can be mild where the teeth have white flecks or spots, frosty edges, or fine lines. More severe forms of fluorosis can result in rough, pitted, or stained teeth. The severity of the fluorosis depends on the amount of fluoride in the water, the duration of exposure (days vs. years), and the susceptibility of the child.
Dental Fluorosis: Increased Risk in Infants
Infants up to the age of 12 months may have a slightly greater risk of dental fluorosis if their main source of nutrition is powdered or liquid infant formula that is reconstituted with fluoridated water. Infant formulas already contain fluoride and the level increases with the addition of fluoridated water. For example, the ADA reported that when water containing 1.0 ppm fluoride is added to a powdered soy-based formula the average concentration of fluoride is 1.07 ppm. Powdered formulas that are either milk or soy-based have the highest fluoride levels while liquid formulas are slightly lower. The levels may be higher if the water used has fluoride levels greater than 1.0 ppm. If your infant is regularly consuming reconstituted infant formula and you are concerned about the risk of fluorosis, you can use ready-to-feed formulas, which have much lower fluoride levels, approximately 0.15 ppm in milk-based and 0.21 ppm in soy-based. Another option is to reconstitute the powdered and liquid formulas with filtered or purified water that either has low concentrations of fluoride or is fluoride-free.
How much fluoride is in your water?
If you would like to know the level of fluoride in your community water system, go to the CDC website titled My Water’s Fluoride, and search for your water district by state and county, or water system ID or name. You can also request a Consumer Confidence Report from your local water supplier. Since fluoride can be naturally-occurring, well water may likely contain fluoride as well. In fact, in 2008 the U.S. Geological Survey reported that 4% of sampled wells had fluoride levels above 2.0 ppm. The EPA recommends that well water should be analyzed by a laboratory every three years.
If you are concerned about drinking fluoridated water, either from the tap or well, you should consider purchasing a water filter that will reduce the fluoride levels.