Metallic Mercury Poisoning

What's the Problem?

Metallic mercury is the pure form of mercury. It is a shiny, silver-white, odorless liquid much heavier than water that is used in thermometers, dental fillings and batteries and is also used in the production of chlorine gas and caustic soda. Exposure to high levels of metallic mercury can permanently damage the brain, kidneys, and developing fetus. Effects on brain functioning may result in tremors, changes in vision or hearing, irritability, shyness and memory problems. Short-term exposure to high levels of metallic mercury vapors may cause effects including lung damage, nausea, vomiting, diarrhea, increases in blood pressure or heart rate, skin rashes, and eye irritation. Skin contact alone does not result in significant mercury absorption into the body, but inhalation exposure to mercury vapor may be likely in environments in which significant skin contact occurs.

Metallic mercury is also used in religious practices in some Hispanic communities. It is sold under the name azogue (pronounced ah-SEW-gay) in stores, sometimes called botánicas, which specialize in religious items used in Espíritismo (a spiritual belief system native to Puerto Rico), Santería (a Cuban-based religion that venerates both African deities and Catholic saints), and voodoo.

The use of azogue is recommended in some Hispanic communities by family members, spiritualists, card readers, and santeros. Typically, azogue is carried on one's person in a sealed pouch prepared by a spiritual leader or is sprinkled in the home or automobile. Some botanica owners suggest mixing it in bath water or perfume and placing it in devotional candles.

Who's at Risk?

Exposure to metallic mercury and the vapors that it releases may result from some dental work and medical treatments or even from a broken thermometer. In addition, workers in chemical and other industries that use mercury may be exposed by breathing contaminated air.

Adults using certain folk medicines or participating in certain religious or ethnic practices may expose themselves and their families to metallic mercury's effects. Because metallic mercury vaporizes into the air at room temperatures, it presents an immediate health risk to anyone spending a significant amount of time in a room where metallic mercury is sprinkled or spilled onto the floor, or where opened containers of metallic mercury are present. The use of metallic mercury in a home or apartment not only poses a threat to persons currently residing in that structure, but also to those who subsequently occupy that dwelling and are unaware of the past mercury use.

Can It Be Prevented?

Yes. First, if possible, avoid using metallic mercury altogether. In addition, take the following precautions:

• Carefully handle and dispose of products that contain mercury, such as thermometers or fluorescent light bulbs.
• Do not vacuum up spilled mercury because it will vaporize and increase exposure.
• If a large amount of mercury has been spilled, contact your health department.
• Teach children not to play with shiny, silver liquids.

Appropriate substitutes are available for nearly all uses of metallic mercury. Make arrangements to safely dispose of whatever metallic mercury you might have. If you do need to use metallic mercury, make sure it is safely stored in a leak-proof container. Keep it in a secure space (e.g., a locked closet) so that others cannot easily get it. Use of metallic mercury in a controlled environment helps to reduce the risk that contamination will occur.

The Bottom Line

Metallic mercury is a hazardous chemical that can cause serious health problems, either short- or long-term. It is best to avoid contact with mercury altogether and all products that may contain mercury should be handled and disposed of carefully.

Anyone who handles mercury is at risk. Over the past two decades, there is a continuing pattern of metallic mercury exposure to children and teenagers who have obtained metallic mercury from school laboratories and abandoned industrial facilities. Exposure of persons using metallic mercury in certain folk medicines or participating in certain ethnic or religious practices is presumed to occur, but the extent of such exposures is unknown. All such exposures should be avoided in the interest of safety.

Case Example

The Johnson family, consisting of a single mother, a 15 year-old son and a 12 year-old daughter live in a non-air-conditioned two-bedroom house in a working class neighborhood on the fringe of what was at one time a booming industrial section of a Midwestern city. The last industrial facility was closed and abandoned three years earlier. The attic of the home has been converted into a bedroom for the son, Rusty. The bedroom includes a single window and a space heater. Rusty has always been an excellent student and has never been a problem to anyone. However, recently he has been behaving strangely. His moods have been erratic and frequently irritable and combative. He has been unable to sleep or to concentrate in school. He has also developed a cough and a strange rash on his hands and feet. His mother suspects drug abuse, so she searches his room one morning and notices several large drops of a silvery liquid near Rusty's bed. Looking under the bed, she finds a small jar lying on its side from which has spilled a larger amount of the silvery liquid. Thinking it might be some kind of drug, she calls the Poison Control Center. The responder tells her it sounds like metallic mercury and instructs her to call the local fire department HAZMAT team and Rusty's doctor immediately. The HAZMAT team arrives and confirms that the substance is indeed mercury. Rusty is immediately taken to the doctor who tests his urine for mercury and discovers that the urine mercury concentration is into the toxic range and could be causing his symptoms. Although they show no signs of mercury intoxication, Mrs. Johnson and her daughter are found to have urine mercury levels above normal as well. Rusty explains that he found the mercury while exploring one of the abandoned industrial facilities nearby. He is treated by his physician, and his urine mercury levels fall to well within the background range within three months. The mother and daughter return to normal background urine mercury levels in just six weeks without treatment. The house is professionally remediated to remove all traces of the mercury.