What is it and where is it found?
Mercury is a natural rock found in the earth’s crust. This rock or ore is mined, crushed and heated to release vapors. The vapors are condensed and collected as a liquid. The liquid is shiny, silver and odorless. It continually emits vapors when exposed to air and when heated it becomes a colorless, odorless gas. Mercury also gets into the environment from coal-fired power plants, cement plants and certain other industries, where it is discharged from smoke stacks into the air. The mercury contamination gets carried in the air and eventually settles down onto the land and into water bodies like lakes, rivers, streams and oceans.
How do people come into contact with it?
The main way people come into contact with mercury is by eating contaminated fish. This is because mercury that ends up in water bodies concentrates in the sediment at the bottom of rivers, streams, lakes and oceans. Once there, a biological process turns it into an especially toxic form of mercury called methyl mercury. The sediment dwelling creatures are eaten by the small fish, which in turn are eaten by bigger fish, and so on up the food chain. The longest living, top predator fish like large mouth bass, tuna, and shark, accumulate the most mercury of all.
Other sources of mercury, and how someone might become exposed, include:
- Mercury from dental work and medical treatments (breathing vapors that are released during dental work or from thimerisol)
- Compact Fluorescent Light bulbs (CFLs) (when broken they release mercury vapors, which can be inhaled);
- Old mercury-containing thermometers (same as above);
- Jobs involving the use of mercury, like dental, health services or chemical industries; (Mainly by breathing vapors);
- High school science labs; (Breathing vapors that may be in the air)
- Rituals that include mercury (again, breathing in the vapors);
- Cosmetics from certain areas of the world that contain mercury (rubbing it into your skin, breathing in the vapors)
- Abandoned mercury mines (coming into contact with contaminated soil, breathing vapors inside mine shafts).
What are the health concerns?
Methyl mercury can damage the developing brain, which can lead to behavior and learning problems later in life. Young children as well as unborn and breast-fed babies are most at risk from mercury contamination. Mercury in a mother’s body passes to the fetus and can cause brain damage, mental retardation, lack of coordination, blindness, seizures, and the inability to speak. Children poisoned by mercury may develop kidney damage and problems with their nervous and digestive systems.
What can I do to protect myself, my family, or my employees?
- It is especially important for women and children to follow local fish consumption advisories.
- In general, younger and smaller fish have less contamination. To view fish consumption guidelines for those who are pregnant, planning to become pregnant, nursing or feeding young children, or are concerned about toxics in fish, click here.
- Properly dispose of mercury-containing thermometers, CFLs, and other hazardous items. View the Oregon Department of Environmental Quality's mercury collection programs.
- Check to see if your child’s high school science lab knows about the U.S. Environmental Protection Agency’s School Chemical Cleanout Campaign.
- Never use mercury at home for rituals. If mercury is ever brought into the home or spilled, call the Oregon Response System at 800-452-0311 or 503-378-6377. Do not touch the mercury, and have all people and pets leave the area until you are sure about the severity of the spill.
- If you accidentally break a Compact Florescent Light bulb (CFL), be sure to follow these safety precautions.
What's being done to protect public health?
Oregon Department of Environmental Quality (DEQ) sponsors mercury clean-up and collection programs. Mercury thermometers, thermostats, and switches can be turned in at local hazardous waste collection locations and events. DEQ will pick up anything that weighs over one pound.
Compact Fluorescent Light bulbs (CFLs) can be recycled at local “big box” and hardware stores or hazardous waste collection sites. Businesses are required to recycle fluorescents bulbs.
Oregon schools are taking measures to eliminate mercury from their schools with the help of EPA and DEQ.
Where can I get more information?
EPA's website on mercury
Oregon DEQ website
Agency for Toxic Substances and Disease Registry website