Mercury is a heavy metal. It is the only metal that is liquid at room temperature. It exists in several forms, including elemental mercury, inorganic mercury compounds and organic compounds. Mercury toxicity can occur from any of these and cause a range of symptoms. Several sources of mercury toxicity exist, so being aware of them can help to protect against exposure to mercury.
Elemental Mercury
Elemental mercury, also called quick silver, can be found in thermometers, certain types of switches, fluorescent light bulbs and some medical and laboratory equipment, such as blood pressure meters and barometers. Toys, glazed pottery and other painted items from foreign countries can also contain amounts of mercury. Dental amalgam also has a certain amount of elemental mercury and has been suspected to cause mercury toxicity, however it is approved as a medical device and is currently considered safe by the Food and Drug Administration, although further rulings are pending.
Elemental mercury is also used in folk medicine, particularly in religions such as Santeria, Voodoo and Espiritismo. Commonly referred to "azogue," it is sometimes sprinkled in homes and automobiles.
Usually, due to its slippery nature, elemental mercury will simply roll of the skin or pass through the digestive tract, if swallowed. However, if elemental mercury is aerosolized into tiny droplets it can be inhaled. This can occur when spilled mercury is vacuumed up. Warm conditions can also vaporize mercury, which can then be inhaled.
Symptoms can include a metallic taste in the mouth, vomiting, difficulty breathing, cough and swollen, bleeding gums. Inhaling large amounts of elemental mercury can cause permanent damage to the lungs and even death.
Inorganic Mercury
Inorganic mercury compounds are found in batteries, some disinfectants, fungicides and antiseptics and are used in chemical labs. Inorganic mercury is also sometimes found in folk medicines. Some medicines, particularly nasal sprays and ophthalmic solutions, have minute amounts of mercury compounds, used mainly as preservatives.
If swallowed, inorganic mercury is considered poisonous, causing significant damage to the brain and kidneys. Heavy exposure can result in blood loss, extreme diarrhea, kidney failure and even death.
Organic Mercury
Organic mercury compounds are in some older disinfectants such as Mercurochrome. Burning coal, such as for electric production in power plants, can produce fumes that can be converted to organic mercury by microorganisms. This mercury can work its way into the food chain, where it accumulates until apex predators, such as tuna or swordfish, or even shellfish, develop high levels of mercury. They are then consumed by people, who acquire the mercury.
These compounds can produce illness if breathed, exposed to the skin or eaten over long periods of time. They accumulate in the body and can cause adverse effects years after exposure. Organic mercury compounds can produce neurological symptoms, including numbness, tremors, blindness, memory problems, seizures and death.
Methylmercury, in particular, can cause damage to fetal brain development, resulting in impaired motor and cognitive skills and learning disabilities. Nearly all methylmercury exposure is caused by eating fish or shellfish. Women should avoid eating large amounts of fish or shellfish while pregnant. Small exposures should prove to be no problem.
