Fluoride Uses Fluorides And Human Health High Concentrations

Where used in very low concentrations (on the order of parts per million), fluorides are used in human health applications; specifically, fluorides such as sodium fluoride ( Na F), sodium fluorophosphate (SMFP), tin (II) fluoride ( SnF₂), and amine fluoride are common ingredients in toothpaste. Many dentists also give their patients semiannual fluoride treatments.

Similarly, many North American municipalities also fluoridate their water supplies, citing effectiveness in reducing tooth decay, safety of fluoridation, and the low cost to do so. The American Dental Association (ADA), World Health Organization (WHO), and some other health organizations recommend fluoridation of municipal water supplies to a level between 0.7 and 1.2 ppm.

When used in very high concentrations (on the order of 10% by volume or higher) , sodium fluoride may be found in rat poisons, insecticides, and wood preservatives.

2 Fluorides and human health

2.1 High concentrations

In high concentrations, as with almost all substances, fluoride compounds are toxic. 5 grams of full strength sodium fluoride will kill most adult humans; a lethal dose is approximately 75mg per kilogram body mass. When ingested directly, fluoride compounds are readily absorbed by the intestines; over time, the compound is excreted through the urine, and the half life for concentration of fluorine compounds is on an order of hours. Implied is that fluoride is taken out of circulation by the body and trace amounts bound in bone. Urine tests are a good indication of high exposure to fluoride compounds in the recent past.

Skin or eye contact with many fluoride compounds (in high concentrations) is dangerous. In case of accidental swallowing, give milkMilk most often means the nutrient fluid produced by the mammary glands of female mammals (including monotremes such as the Australian platypus). It provides the primary source of nutrition for newborns, before they are able to digest more diverse foods., calcium carbonateProperties General Name Calcium carbonate Chemical formula Ca CO Appearance White solid Physical Formula weight 100. 1 amu Melting point Liquifies under high pressure at 1612 K (1339 °C) Boiling point decomposes at 1172 K (899 °C) Density 2. 7 ×103 kg/ m3 or milk of magnesiaMilk of magnesia is a saline-type laxative. The magnesia pulls a saline solution from the bloodstream; this excess fluid produces a flushing effect within the intestines. Available over-the-counter, it is most commonly used in alleviating constipation, bu to slow absorption. Eye or skin contact should be treated by removing any contaminated clothing and flushing with water.

2.2 Low concentrations

Fluoride is best known for its use in small quantities to help reduce Dental cariesDental cavities tooth decay or caries is a disease of the teeth resulting in damage to tooth structure. Causes Dental caries (tooth decay) is one of the most common of all disorders, second only to the common cold. It usually occurs in children and young (cavity) frequency in teeth. A debate continues about whether fluoride ions (F^-) are a trace element beneficial to humans for other reasons.

Fluoride compounds, usually calcium fluoride, are naturally found in low concentration in drinking water and some foods, like tea. Fluoride ions replace hydroxide ions in calcium hydroxyapatite , Ca₅[(PO₄)₃OH], in teeth, forming calcium fluoroapatite , Ca₅[(PO₄)₃F], which is more chemically stable and dissolves at a pH of 4.5, compared to 5.5 pH for calcium hydroxyapatite. This is generally believed to lead to fewer cavities, since stronger acids are needed to attack the tooth enamel. This phenomenon was first recorded by Dr. Harry G. Day at Indiana University Bloomington, and the university first sold the technology to Procter & Gamble to use in crest toothpaste.

The only generally accepted adverse effect of low concentration fluoridation at this time is fluorosis. It is a condition caused by 'excessive' intake of fluorine compounds over an extended period of time, and can cause yellowing of teeth, hypothyroidism, or brittling of bones and teeth. The definition of 'excessive' in the context of fluorosis falls on the order of parts per million and is generally accepted to mean significantly higher than the 0.7 to 1.2 ppm amounts recommended for fluoridated water.

3 See also

Water fluoridation – discusses mass fluoridation and the issues surrounding it.
Fluoride poisoning

3.1 Research sites

Anions

<Hide>

Home > Fluoride

1 Uses