Facts about fluoride and water fluoridation
Water fluoridation is the addition of the chemical fluoride to public water supplies to reduce voids.
About two-thirds of the US population have fluorinated public water, according to the Centers for Disease Control and Prevention (CDC). Of those supplied by municipal water systems, the percentage climbs to 74.6 percent.
What is fluoridation?
Fluoride is an ionic compound derived from fluorine, which is the single most reactive element; it occurs naturally in many rocks. According to the CDC, about 95 percent of the fluoride that goes into public water supplies is made from phosphorite rock.
Fluoride is added to public water supplies at an average concentration of about 1 part per million (1 ppm), or 1 milligram per liter or slightly less. Naturally occurring fluoride concentrations in surface waters depend on the location, but are generally low and typically do not exceed 0.3 ppm. However, groundwater can contain much higher values.
In 2015, the US Department of Health issued a recommendation for the optimal fluoride content in drinking water to prevent tooth decay. This new recommendation applies to a single amount of 0.7 milligrams of fluoride per liter of water, as opposed to the 1962 recommendation of 0.7 to 1.2 milligrams per liter that is the standard today.
The change was recommended because most people in the United States have access to more sources of fluoride than when the guidelines were introduced. “The quantity adjustment is more representative of the current needs of the population. Because of the increased use and availability of other sources of fluoride (toothpaste, mouthwash, etc.) and other improvements in oral health care, these new recommendations were made, ”said Alice Lee, Pediatric Dentist at Montefiore Medical Center in the Bronx, New York.
This is how fluoridation works
Fluoride works by attaching itself to tooth enamel, which, according to Scientific American, is primarily made up of hydroxyapatite, a crystal made up of calcium, phosphorus, hydrogen, and oxygen. By replacing the hydroxyl molecule with hydroxyapatite, fluoride makes the tooth more resistant to acid attacks by bacteria. However, exactly how fluoride protects teeth and how much it protects them is not entirely clear. However, over the past 15 years, research has shown that fluoride acts primarily topically, for example when applied to teeth in fluoride-rich toothpaste.
Tooth decay, if left untreated, can lead to serious health problems such as: B. Infections that can spread to the jaw. According to the CDC, tooth decay has decreased in the US since fluoridation began. But according to the World Health Organization (WHO), it has also decreased in other countries that do not fluoride.
Since its introduction in the 1940s, fluoridation has created a lot of controversy. Proponents of fluoridation say the procedure is “safe and effective” for reducing tooth decay, especially in poor children. Fluoridation of water is advocated by the American Medical Association, the American Dental Association, and the CDC, which lists it as one of the top 10 public health measures of the 20th century.
Those on the other hand say it is an unethical form of mass medication without the consent or knowledge of every individual. Adding fluoride to drinking water does not allow the dosage to be controlled because some people – such as workers and people with kidney problems – drink much more water than others. People who oppose fluoridation also argue that fluoride does not need to be added to the water because toothpaste rich in fluoride is available. The first fluoride toothpaste, Crest, was introduced in 1955.
Anti-fluoride opponents like the Fluoride Action Network cite studies showing that high levels of fluoride have been linked to a number of negative health effects, including bone fractures, thyroid disease, and impaired brain development and function.
A study published in the journal Environmental Health Perspectives in the fall of 2012 found a link between high levels of fluoride, naturally found in drinking water in China and elsewhere in the world, and lower IQs in children. The paper examined the results of 27 different studies, 26 of which found an association between drinking water rich in fluoride and a lower IQ. The mean IQ difference between high and low fluoride areas was 7 points, the study found.
The most obvious health impact from excessive fluoride exposure is dental fluorosis, which can include white streaks in mild cases and brown spots, pits, and broken enamel in severe cases. According to the CDC, in 2010, 41 percent of children ages 12-15 had some form of dental fluorosis.
“The new recommendations will maintain the benefits of fluoride in preventing tooth decay … while reducing the risk of dental fluorosis in younger patients,” said Edward H. Moody, Jr., dentist and president of the American Academy of Pediatric Dentistry (AAPD), told Live Science.
A 2009 study that tracked fluoride exposure in more than 600 Iowa children found no significant association between fluoride exposure and tooth decay. Another 2007 review in the British Medical Journal found that “there have been no randomized trials of water fluoridation,” which is currently the standard for all drugs.
Is Fluoride Bad For You?
It depends who you ask; Fluoride is undoubtedly toxic in certain concentrations. The most comprehensive report on fluoride was published in 2006 by the National Research Council on behalf of the Environmental Protection Agency. This group found that the upper limit for fluoride at 4 ppm was too high to prevent a certain percentage of children from developing severe dental fluorosis and recommended that the EPA lower this limit.
The CDC says the amount it is added to the water (1ppm) is safe and effective. Kerry Maguire of the Forsyth Institute, an independent (not-for-profit) research institute in the United States that specializes in oral health and its connection to general well-being, agrees with the CDC.
“For the children I treat, fluorinated drinking water means fewer cavities that require a visit to the dentist and more time in school,” she said. “As a dentist and scientist – as well as a mother and grandmother – I welcome the CDC’s confirmation of the safety and effectiveness of municipal water fluoridation.”
In 29 of the 30 largest cities, water is fluorinated. The exception is Portland, Oregon. In 2012, for the fourth time since 1956, Portland voters rejected a plan to supply fluoride to the public water supply. Residents have been arguing about fluoridation for weeks.
Additional reporting from Alina Bradford, Live Science Contributor.
correction: This article was updated on June 29, 2015 to include the correct percentage of the US population who have access to fluorinated water.