In high concentrations, soluble fluoride salts are toxic. Referring to a common salt of fluoride, NaF, the lethal dose for most adult humans is estimated at 1-10 grams.^[1] A lethal dose is approximately 28 mg per kilogram of body mass.^[2]

Like most soluble materials, fluoride compounds are readily absorbed by the intestines and excreted through the urine. Trace amounts are incorporated in bone. Urine tests have been used to ascertain rates of excretion in order to set upper limits in exposure to fluoride compounds and associated detrimental health effects.^[3]

Skin or eye contact with many fluoride salts (in high concentrations) is dangerous.

Organofluorine compounds feature very stable C-F bonds and do not release fluoride ions (F^-) or cause fluoride poisoning. Organofluorine compounds are pervasive in drugs, e.g. Prozac, as well as many kinds of materials such as freons and Teflon.

Fluorosis

Although there is some contradictory evidence on the issue,[1] the only generally accepted adverse effect of high concentration water fluoridation at this time is dental fluorosis. It is a condition caused by 'excessive' intake of fluoride ions over an extended period of time during tooth development (before teeth erupt into the mouth), 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 (ppm) and is generally accepted to mean significantly higher than the 0.7 to 1.2 ppm amounts recommended for fluoridated water. Fluoride in small amount is considered by most dentists to be beneficial to teeth (see Fluoride therapy).

Gastro-intestinal inflammation

One of the side effects of fluoride poisoning is gastro-intestinal inflammation as fluoride toxicity has a corrosive effect on the mucous membrane which line the gut.^[4] Among the potential metabolic disturbances reported caused by fluoride toxicity is the increased impact of the natural plant toxin, salicylate,^[4], which may have particular significance in subgroups who already have high incidence of salicylate intolerance such as the ADHD and autism populations (see Autism therapies).

Lethal levels in swallowing toothpaste

As of April 7th, 1997, the United States FDA (Food & Drug Administration) required that all fluoride toothpastes sold in the U.S. carry the following poison warning:

WARNING: Keep out of reach of children under 6 years of age. If you accidentally swallow more than used for brushing, seek professional help or contact a poison control center immediately.

Potentially fatal dose = 5 mg of fluoride per kg of bodyweight.

Ingestion of fluoride can produce gastrointestinal discomfort at doses at least 15 to 20 times lower (0.2-0.3 mg/kg) than doses which can kill (Gessner 1994;^{[citation needed]} Akiniwa 1997^{[citation needed]}). A 2-year-old, for example, may experience gastrointestinal distress if they ingest a mere 2 to 3 percent of flavored toothpaste.

All or part of this article may be confusing or unclear. Please help clarify the article. Suggestions may be on the talk page. (October 2008)

Between 1989 and 1994, over 628 people - mostly children - were treated after ingesting too much fluoride from their toothpaste. Gastrointestinal symptoms appear to be the most common problem reported (Shulman 1997).^{[citation needed]}

Possible sources

Historically, most cases of fluoride poisoning have been caused by accidental ingestion of insecticides or rodenticides.

• Glass-etching or chrome-cleaning agents like ammonium bifluoride
• Industrial exposure to fluxes used to promote the flow of a molten metal on a solid surface.
• Insecticides or rodenticides containing sodium fluoride
• Fluoride in volcanic ejecta, for example in cattle grazing after a 1845 - 1846 eruption of Hekla, and the 1783-1784 flood basalt eruption of Laki
• In metal cleaners
• In fluoride toothpaste

Chronic toxicity

This article is focused on acute toxicity: the results of ingesting a large amount of fluoride in a short period of time. Chronic toxicity, the result of ingesting small amounts of fluoride over a long period of time, results in dental fluorosis and skeletal fluorosis^[5][6].

Symptoms of acute toxicity

Fluoride toxicity is characterized by a variety of signs and symptoms. Symptom onset usually occurs within minutes of exposure. Severity of symptoms can depend on the amount of fluoride ingested.^[7]

Symptoms of fluoride poisoning point towards some kind of profound metabolic dysfunction, very similar to the symptoms of hypothyroidism.^[8]

Gastrointestinal

When poisoned by fluoride, gastrointestinal signs predominate.

• Abdominal pain
• Diarrhea
• Dysphagia
• Hypersalivation
• Mucosal injury
• Nausea
• Vomiting

Electrolyte abnormalities

• Hyperkalemia
• Hypocalcemia
• Hypoglycemia
• Hypomagnesemia

Neurologic effects

• Headache
• Hyperactive reflexes
• Muscle weakness
• Muscular spasm
• Paresthesia
• Seizures
• Tetanic contractions
• Tremor

Cardiovascular

• Cardiac arrest
• Shock
• Widening of QRS
• Various arrhythmias

Method of action

Ingested fluoride initially acts locally on the intestinal mucosa. It can form hydrofluoric acid in the stomach, which leads to gastrointestinal irritation or corrosion^[9]. After ingestion, the gastrointestinal tract is the earliest and most commonly affected organ system.

Treatment

In case of accidental swallowing, give milk, calcium carbonate or milk of magnesia to slow absorption. Eye or skin contact should be treated by removing any contaminated clothing and flushing with water.

References

External links

• "287" The Body Burden Movie for Theatrical Release 2008 will cover fluoride poisoning
• The "287" Body Burden blog
• Fluoride Action Network An international coalition seeking to broaden public awareness about the toxicity of fluoride compounds and the health impacts of current fluoride exposures.
• eMedicine article about Fluoride Toxicity by Geoffrey Nochimson, MD
• Acute fluoride poisoning from a public water system. Gessner BD, Beller M, Middaugh JP, Whitford GM.
• Re-Examination of Acute Toxicity of Fluoride, by Kenji Akiniwa, Tokyo, Japan
• Website of the "Parents of Fluoride poisoned children" foundation
• [2] fluoride may be used reliably to reduce thyroid function. This is therapeutic with hyperthyroidism.
• [3] Since fluorides reduce thyroid function, the full list of conditions associated with hypothyroidism(177 conditions) is also present in fluoride poisoning.
• impact of fluoride toxicity on salicylate levels and gut inflamation