Mercury and mercury compounds can be found in air, soil, water, and fish.
What is mercury?
Mercury is a metal that occurs naturally in the environment. It comes in several odorless forms. It can be a shiny, silver-white liquid or a tin-white solid. If it is heated, it becomes a colorless gas. The chemical symbol for mercury is Hg. Mercury may be found in crude oil.
Mercury can combine with other elements, such as chlorine, oxygen, or sulfur, to form inorganic mercury compounds, or salts. Mercury can also combine with carbon to make organic mercury compounds.
Methylmercury is the most common organic mercury compound. It can be formed in water and soil by bacteria. Methylmercury builds up in the tissues of fish. Larger fish tend to have higher levels of methylmercury than smaller fish.
Mercury is used in some thermometers, barometers, vapor and fluorescent lamps, mirror coatings, dental fillings, batteries, pharmaceuticals, and agricultural chemicals. Energy efficient compact fluorescent light (CFL) bulbs contain small amounts of mercury and should be recycled carefully. Mercury salts are sometimes used in skin-lightening and antiseptic creams.
Mercury is used to make electrical equipment, wire, and switching devices; to extract gold and silver from ores; and to produce chlorine gas and caustic soda, a liquid chemical. Mercury compounds were once used in latex paints but were banned from that use in 1990.
You can be exposed to methylmercury by eating fish or shellfish contaminated with mercury. You can also be exposed by having skin contact with mercury.
You can be exposed to mercury by breathing contaminated air at work or by breathing contaminated air from spills, incinerators, and industries that burn fuels that contain mercury.
Exposure to high levels of mercury and mercury compounds can cause mercury poisoning, which can cause death or permanently damage the brain and kidneys. This brain damage can cause tremors, hallucinations, psychosis, changes in vision or hearing, memory problems, loss of appetite and weight, and irritability.
If you are pregnant, repeated exposure to mercury may increase the risk of damage to the fetus or cause miscarriage.
Exposure to high levels of mercury vapor can damage kidneys. It can also irritate lungs and cause depression, inflammation of the gums and mouth, coughing, chest pain, and shortness of breath. Repeated low exposure may cause skin allergies.
Short-term exposure to high levels of mercury vapors can cause lung damage, nausea, vomiting, diarrhea, increases in heart rate or blood pressure, skin rashes, and irritation or cloudiness of the eyes.
If you think you have been exposed to mercury, contact your health care professional.
For poisoning emergencies or questions about possible poisons, please contact your local poison control center at 1-800-222-1222.
This description is based on the information found in the Web links listed with this topic.
Web Links from MedlinePlus (National Library of Medicine)
Cleaning Up a Broken CFL (Environmental Protection Agency)
Map of Releases of Mercury in the United States. TOXMAP (National Library of Medicine)
Mercury (National Institute of Environmental Health Sciences)
Mercury and Health (World Health Organization)
Mercury and Human Health. Enviro-Health Links (National Library of Medicine)
Mercury Compounds. Hazardous Substances Data Bank (National Library of Medicine)
Mercury in Health Care (World Health Organization) (PDF — 32.69 KB)
Mercury In Your Environment (Environmental Protection Agency)
Mercury, Inorganic Compounds. Haz-Map (National Library of Medicine)
Mercury. ToxFAQs (Agency for Toxic Substances and Disease Registry)
Protect Yourself from Mercury in Your Well Water (North Carolina Department of Health and Human Services) (PDF — 826.98 KB)
Last Updated: April 19, 2017