Fluoride is found naturally in soil, water, foods, and several minerals, such as fluorapatite and fluorite.
Fluoride concentration in seawater averages 1.3 ppm (parts per million), while in fresh water supplies the natural range is typically between 0.01 to 0.3 ppm. In some parts of the world, fresh water contains fluoride levels which are dangerous and can lead to health problems.
Fluoride is also synthesized in laboratories. Synthesized fluoride is commonly added to drinking water, toothpaste, mouthwashes and various chemical products.
In the following article we will discuss why it is added to drinking water, what its effects are - both positive and negative - and the controversy that surrounds it.
Contents of this article:
Here are some key points about fluoride. More detail and supporting information is in the main article.
- Fluoride is a common, natural and abundant element
- Fluoride can be synthesized in a laboratory
- Tooth decay is reduced in areas with higher natural levels of fluoride in the water supply
- Fluoride protects teeth from decay by demineralization and remineralization
- Children need fluoride to protect their permanent teeth as they are being formed
- People with bridges, crowns and braces might particularly benefit from fluoride
- Excessive levels of fluoride can produce dental fluorosis
- Skeletal fluorosis can be caused by excess fluoride; this can cause damage to bones and joints
- According to WHO, millions of people globally are exposed to excessive levels of fluoride.
Why is fluoride added to drinking water?
Fluoride is added to the water supply, in some regions, in an effort to prevent tooth decay.
In the early 1930s, scientists found that people who were brought up in areas with naturally fluoridated water had up to two-thirds fewer cavities compared to those who lived in areas where the water was not fluoridated.
Several studies since then have repeatedly shown that when fluoride is added to people's drinking water in areas where levels are low, tooth decay decreases.
However, most of the countries in Europe which do not have water fluoridation did not find that their incidences of dental cavities increased. In Germany and Finland, for example, decay rates either remained stable or continued in their downward trend after they stopped adding fluoride to their drinking water.
What does fluoride do?Fluoride is said to protect the teeth in two ways:
- Protection from demineralization - when bacteria in the mouth combine with sugars they produce acid. This acid can erode tooth enamel and damage our teeth. Fluoride can protect teeth from demineralization that is caused by the acid.
- Remineralization - if there is already some damage to teeth caused by acid, fluoride accumulates in the demineralized areas and begins strengthening the enamel, a process called remineralization.
According to the National Health Service, fluoride disrupts the process of tooth decay by:
- Altering the structure of the developing enamel so that it is more resistant to acid attack. These structural changes occur as a child's enamel develops (before he/she is seven years old).
- Providing an environment where better quality enamel is formed, which is much more resistant to acid attack
- Reducing the bacteria's (bacteria in plaque) ability to produce acid, a major cause of tooth decay.
Who needs fluoride?Virtually all public health authorities and medical associations worldwide recommend that children and adults receive a minimum (and maximum) level of fluoride. Children need fluoride to protect their permanent teeth as they are being formed. Adults also need fluoride to protect their teeth from decay.
Several people, especially those at higher risk of tooth decay, benefit from fluoride treatment. Individuals who might benefit from fluoride treatment include those with the following:
- Snacking habits
- Poor dental hygiene
- No (or little) access to a dentist
- Diets that are high in sugars or carbohydrates
- Bridges, crowns, braces, and other restoration procedures
- A history of tooth decay (cavities).
Excess fluoride and health problemsExcess fluoride exposure may come from the following sources:
- Public water fluoridation
- Abnormally high concentrations of fluoride in natural fresh water
- Dentifrice/fluoridated mouthrinse. Young children may swallow it.
- Untested bottled water
- Inappropriate use of fluoride supplements
- Some foods.
Children exposed to high levels of fluorine can experience detrimental effects.
In severe cases of dental fluorosis, the tooth has more evident discoloration and brown markings. The enamel may be rough and pitted, and difficult to clean.
The spots and stains, which are permanent, may eventually darken.
Of greatest concern is the aesthetic changes that occur in the permanent teeth among children who are exposed to too much fluoride between the ages of 20 and 30 months.
According to dentists, the critical period of fluoride exposure is between 1 and 4 years of age - the risk goes away after the age of 8 years. Symptom-severity depends on several factors, including the child's age, weight, degree of physical activity, bone growth, diet and individual response.
Skeletal fluorosisA bone disease caused by too much fluoride. In severe cases, there is damage to bones and joints, as well as pain. High fluorine concentrations in the body lead to hardened and less elastic bones, which increases the risk of fractures.
The bones may thicken and bone tissue accumulates, which contribute to impaired joint mobility. The majority of patients eventually suffer from nausea and possible ruptures of the stomach lining.
In some cases, the thyroid gland may be damaged, resulting in hyperparathyroidism. In hyperparathyroidism the secretion of parathyroid hormones goes out of control, resulting in depletion of calcium in bone structures and higher-than-normal concentrations of calcium in the blood. Lower calcium concentrations in bones make them more susceptible to fractures.
According to UNICEF, fluorosis is endemic in at least 25 countries. The number of people suffering from skeletal fluorosis globally is thought to be in the tens of millions. WHO estimates that 2.7 million people in China have the crippling form of the disease.
Natural water with too much fluoride
Millions of people globally are exposed to high levels of fluoride.
These people are at risk of developing a range of conditions and disorders, ranging from mild dental fluorosis to devastating skeletal fluorosis.
The problem of excessively high fluoride in some waters is largely unrecognized and neglected, and needs to be addressed, WHO stressed.
WHO says that guidance is needed on fluoride levels, because it is found in natural waters at various levels of concentration. Low fluoride levels benefit human health by protecting the teeth, but high concentrations can lead to serious diseases, such as "skeletal fluorosis which has devastated some communities". Over 10 million people in China are thought to suffer from skeletal fluorosis.
Nobody knows how many people globally suffer from skeletal fluorosis or dental fluorosis. We know that water is usually the main source of fluoride exposure. Exposure to fluoride from diet or burning high fluoride coal are also sometimes important contributors.
High concentrations of fluoride occur in several parts of the world, including southern Asia, the Eastern Mediterranean and Africa. There is an area that extends from Turkey and stretches all the way to China (via Iraq, Iran, Afghanistan, India and northern Thailand) where water fluoride levels are high.
In some arid parts of Africa where fluoride levels in water are high, there are no alternative sources of water.
WHO says the suffering caused by excessively high levels of fluoride in water can be prevented. "Although removal of excessive fluoride from drinking-water may be difficult and expensive, low-cost solutions that can be applied at a local level do exist." The following procedures may be used to reduce fluoride levels in water:
- Crushed clay pots
- Bone charcoal
- Contact precipitation
- Absorptive filters (activated alumina).
WHO published a reference source titled Fluoride in Drinking-Water. It is said to be "an invaluable reference source for all those concerned with the management of drinking-water containing fluoride and the health effects arising from its consumption, including water sector managers and practitioners as well as health sector staff at policy and implementation levels."
Concerns surrounding water fluoridationA growing number of people are asking why we are being "medicated" in such large numbers without being consulted first. Surely, if fluoride is a medication and is being added to our water supply, shouldn't this occur with our approval?
There is also concern that perhaps it is not possible to accurately control exactly how much fluoride people receive, or monitor their response.
Not all studies regarding water fluoridation have produced encouraging results:
Not all scientists agree on the benefits of fluoride.
Their study was published in the July 2012 edition of Environmental Health Perspectives.
Keep fluoride concentrations in drinking water at the lower end of recommended levels - despite claiming that the fluoridation of drinking is seen as "one of the ten great public health achievements of the 20th century", the US Department of Health and the US Environmental Protection Agency announced in January 2011 that they would like to set the recommended level of fluoride at the lowest end of the optimal range to prevent tooth decay.
Some have wondered why US public health authorities would suddenly decide to bring fluoride levels down - was it pressure from a growing number of people who have been campaigning against water fluoridation? The HHS said it was to make sure that the incidence of dental fluorosis among children is kept to a minimum. The HHS said that the recommended range from 0.7 to 1.2 milligrams of fluoride per liter of water should be altered to just 0.78 milligrams, with no upper limit.
Some people dispute fluoridation's protection from cavities - New York State Coalition Opposed to Fluoridation, Inc., in 2007, quoted a study that reviewed English-language fluoridation studies from January 2001 to June 2006 which found "Several epidemiological studies conducted in fluoridated and non-fluoridated communities suggest that [fluoridation] may be unnecessary for caries prevention...".
New York State Coalition Opposed to Fluoridation also reported that:
- Women who avoided fluoride were less likely to develop anemia during pregnancy, had a lower risk of giving birth prematurely, and gave birth to heavier babies. Fluoride was found to be linked to gum disease, according to an article published in the Indian Journal of Dental Research.
- Violates Article 35 of the European Charter of Fundamental Rights
- Is a banned substance according to the UK Poisons Act of 1972
- Violates Articles 3 and 8 of the Human Rights Act
- Raises issues under the UN Convention on the Rights of the Child.
"There is little conclusive evidence that fluoride reduces the incidence of dental caries (tooth decay) but it is known to increase dental fluorosis (mottled and pitted teeth).
Mass studies from the US, Canada and New Zealand show little difference in levels of decayed, missing and filled teeth (DMFT) between fluoridated and non-fluoridated areas. However, a third of children in fluoridated West Midlands suffer from dental fluorosis."
Official scientific opinion on fluoridationThe use of adding fluoride to drinking water - water fluoridation - is endorsed by the WHO (World Health Organization), AMA (American Medical Association), BDA (British Dental Association), and the ADA (American Dental Association).
According to the American Dental Association's web page titled "ADA Fluoridation Policy & Statements":
"The American Dental Association unreservedly endorses the fluoridation of community water supplies as safe, effective and necessary in preventing tooth decay. This support has been the Association's position since policy was first adopted in 1950."
Adding fluoride to the water is endorsed by the WHO, among others.
The aim being to prevent tooth decay. The ADA says that "water that has been fortified with fluoride is similar to fortifying milk with Vitamin D, table salt with iodine, and bread and cereals with folic acid".
The National Health Service (NHS), UK, quoted a UK study which compared levels of tooth decay among very young children in areas where drinking water was not fluoridated to those living in areas where fluoridation occurred.
The researchers found that there was 60% less tooth decay among the children living in the fluoridated water areas.
According to Health Canada "The optimal concentration of fluoride in drinking water for dental health has been determined to be 0.7 mg/L for communities who wish to fluoridate. This concentration provides optimal dental health benefits and is well below the MAC to protect against adverse effects."
Canadian Dental Association President Dr. Ron G. Smith described water fluoridation as one of the greatest preventative measure we have in the fight against dental decay. "There is clear evidence that fluoride helps natural tooth enamel remineralize and jurisdictions around the world support water fluoridation, as do we. It is important that everyone understands the facts and the benefits of fluoride."
The Australian Department of Health and Ageing confirmed that according to the most up-to-date evidence, fluoride in the water system is safe and effective for people of all ages.
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