Fluoride is important to strong teeth and bones, but too much fluoride can be toxic. Toothpaste, drinking water, some pesticides and cleaning products contain significant amounts of fluoride. Here are the causes, symptoms and treatment of fluoride poisoning.
Fluoride is a reduced form of the chemical element fluorine. Fluoride occurs naturally in food and water, and in the earth’s crust. In the human body, 95% of fluoride is in the bones and teeth. While fluoride can help prevent cavities, an excess of fluoride can have serious health effects.
Fluoride first attacks the stomach, invading the intestinal mucosa and creating hydrofluoric acid. Hydrofluoric acid is strong enough to dissolve glass.
Early symptoms of fluoride poisoning usually occur soon after ingestion. Later, toxic levels of fluoride can inhibit the body’s ability to use nutrients such as calcium and potassium. Fluoride poisoning can cause chronic damage to the nervous system, as well as the stomach, heart and other vital organs. In some cases, fluoride poisoning is fatal.
In adults, the estimated lethal dose of fluoride is 5-10 g, or 32-64 mg per kilogram of body weight. In children, a lethal dose of fluoride is 16 mg/kg.
Fluoride in Toothpaste
Toothpaste typically contains 1 mg/g of fluoride. Fluoride in toothpaste may appear as:
- sodium monofluorophosphate
- sodium fluoride
- stannous fluoride
- amine fluoride
Fluoride poisoning often affects children. Less than half a tube of toothpaste can be fatal to a child under two years old.
Causes of Fluoride Poisoning
Causes of fluoride toxicity in children and adults may include:
- ingestion of toothpaste
- excess dietary supplements (sodium fluoride)
- ingestion of insecticides or rodenticides (such as sodium fluoroacetate)
- malfunction of city water fluoridation equipment
- glass-etching chemicals
- chrome cleaners such as ammonium bifluoride
- automobile wheel-cleaning products
- metal cleaners
- industrial exposure
- volcanic eruption
Decaffeinated tea or coffee has higher amounts of fluoride than regular coffee or tea. In cookware, non-stick coatings such as Teflon™ contain fluoropolymers.
Flouride poisoning often occurs concurrently with iodine deficiency. Some sources suggest that low levels of iodine can cause toxic amounts of fluoride in the body.
Symptoms of Fluoride Poisoning
Early symptoms of fluoride poisoning usually appear within a few minutes of exposure or ingestion. Initial symptoms of fluoride toxicity may include:
- abdominal pain
- dysphagia (difficulty swallowing)
- mucosal damage
Later symptoms of fluoride poisoning may include:
- hyperkalemia (potassium overload, causing heart problems)
- hypocalcemia (low levels of calcium)
- hypoglycemia (low levels of blood glucose)
- hypomagnesemia (low magnesium levels in the blood)
- muscle weakness
- muscle spasms or contractions
- hyperactive reflexes
- paresthesia (numbness and tingling)
- in severe cases, multi-organ failure
Death by fluoride poisoning may occur due to:
- cardiac arrest
- widening of QRS (electrical conduction system of the heart)
Long-term ingestion of fluoride, as in swallowing toothpaste, can cause dental fluorosis. The ameboblasts or cells which produce tooth enamel become damaged, resulting in discoloration of the teeth. Discoloration ranges from white spots in mild cases, to brown or black stains in more severe forms.
Treatment of Fluoride Poisoning
Fluoride poisoning can be fatal. If you suspect fluoride poisoning, identify the source and contact a poison control center or hospital immediately.
Emergency care of fluoride toxicity includes:
- cardiac monitoring
- dosage with milk, calcium carbonate, and aluminum- and magnesium-based antacids (hydroxides) to bind fluoride
- gastric lavage (gastric irrigation or stomach pumping)
- test for hypocalcemia
- calcium IV for patients with arrhythmia or cardiac symptoms
Non-emergency medical treatment and aftercare may include monitored doses of calcium chloride or calcium gluconate (kalcinate). Calcium chloride treats calcium deficiencies caused by fluoride poisoning. Calcium gluconate helps stabilize nerve, muscle and cardiac function due to potassium deficiency.
Although fluoride poisoning is serious, most cases are mild. Death by fluoride poisoning is rare.