Mercury is a naturally-occurring chemical that exists in several forms, metallic (elemental), organic and inorganic. Most health concerns focus on methylmercury in fish, and on metallic mercury, which has been used in many products in the past. Elemental mercury is a shiny, silver-gray liquid metal that scatters into droplets when spilled. At room temperature, liquid mercury will vaporize (evaporate) into air. Mercury vapor cannot be seen or smelled. Common items containing elemental mercury include: thermometers, thermostats, blood pressure units, barometers, gas pressure regulators, florescent light bulbs, and antiques.
Metallic mercury is also called elemental mercury, quicksilver, or simply mercury. It is a shiny, silver-colored metal that is liquid at room temperature. Because mercury has unique properties, it has been widely used in industrial processes, scientific instruments, consumer products, medicine, dentistry, and certain ethnic practices.
Exposure to mercury is a health concern. Exposure to mercury can occur by breathing in mercury vapors, eating or swallowing foods or water contaminated with mercury, or having skin contact with mercury droplets or beads. The route of exposure that poses the greatest risk of health effects is inhalation of mercury vapor. Exposure to mercury can be measured in biological samples.
Mercury is also a concern for the environment. It does not degrade and is not destroyed by burning. In its various forms, mercury cycles through the environment, and some forms accumulate in the food chain (for example, as methylmercury in fish). Mercury's toxicity, persistence and widespread use make proper disposal and recycling essential.
When mercury spills, it must be cleaned up quickly and completely to minimize exposure to toxic mercury vapors. Mercury can be measured in environmental samples. Wastes that contain mercury, or are contaminated by mercury, are regulated and must be disposed of as hazardous waste. Some mercury spills must be reported.
The Department works to prevent mercury pollution. The Partnership to Reduce Mercury in Schools targeted mercury removal in schools. A packet of nine brochures was developed to help school personnel identify mercury sources and reduce or remove the risk of a mercury spill.
Use this Guide to learn about mercury, understand its environmental and health effects, safely manage products and wastes that contain it, and find out what Massachusetts and other states in the region are doing to reduce mercury exposure.
Mercury won't harm you if it stays inside an item. But when a product containing it is broken, thrown in the trash, or poured down the drain, mercury cycles through the environment, polluting air and water, and accumulating in fish.
The National Academy of Sciences estimates that every year in the United States, 60,000 children exposed to mercury in the womb are born with neurological and other problems. These conditions can be permanent and lead to learning and other difficulties.
Even before the 2006 law took effect, MassDEP required power plants to reduce mercury emissions and municipal waste combustion facilities to separate mercury-containing items from the loads of trash sent to them for disposal.
LightRecycle Washington allows Washington residents and businesses to recycle up to 10 mercury-containing lights per day for free at certain locations across the state. Recycling mercury-containing lights is important to protect human health and the health of the environment.
Note on Mercury and Cancer: No human data currently ties mercury exposure to cancer, but the data available are limited. In very high doses, some forms of mercury have caused increases in several types of tumors in rats and mice. When EPA published its Cancer Guidelines in 2005, the Agency concluded that environmental exposures to inorganic mercury and methylmercury are not likely to cause cancer in humans. Technical information about mercury and cancer is available in:
Exposure to methylmercury most commonly occurs when people eat kinds of fish and shellfish that have high levels of methylmercury in their tissues. Almost all people have at least small amounts of methylmercury in their bodies, reflecting the widespread presence of methylmercury in the environment. U.S. Centers for Disease Control and Prevention (CDC) data show that most people have blood mercury levels below levels associated with possible health effects. Methylmercury, however, is a powerful neurotoxin, and people exposed to high levels may experience adverse health effects. If you are concerned about your exposure to methylmercury, you should consult your physician.
Exposures to metallic mercury most often occur when metallic mercury is spilled, or when products that contain metallic mercury break, so that mercury is exposed to the air. If you are concerned about your exposure to metallic mercury, you should consult your physician.
Some people who drink water containing inorganic mercury substantially in excess of the maximum contaminant level (MCL)maximum contaminant level (MCL)The highest level of a contaminant that EPA allows in drinking water. MCLs ensure that drinking water does not pose either a short-term or long-term health risk. EPA sets MCLs at levels that are economically and technologically feasible. Some states set MCLs which are more strict than EPA's. for many years could experience kidney damage. If you are concerned about an exposure to inorganic mercury, you should consult your physician.
We work with the Washington State Department of Health, along with industry and environmental stakeholders, to identify and take action to phase out the use, release, and exposure to mercury in Washington. Working with partners, we've developed a chemical action plan to reduce or eliminate the use of this substance.
Mercury that is released to land, air, or water can eventually find its way to lakes, rivers, and the ocean. Eating fish is one of the most common ways people are exposed to mercury. Methylmercury builds up in the aquatic food chain as organisms are eaten by larger ones. Fish at the top of the food chain, like tuna, contain much higher concentrations of mercury than the surrounding water.
All forms of mercury are toxic to people and other animals. Mercury affects the brain and nervous system, damages the kidneys and liver, and has been linked to cancer. Children are especially at risk because their brains and bodies are still developing. Many of the health effects of mercury are permanent.
The chemical action plan for mercury found that Washington can reduce mercury pollution by focusing on improving waste disposal, management, and recycling. The Legislature has passed laws to reduce the sale of mercury-containing products and worked with power companies to phase out coal-fired power plants. We worked with dentists to install amalgam separators and with auto recyclers to collect mercury switches from older cars.
Small-scale gold refining is a major cause of air pollution from mercury. EPA helped design a low-cost mercury capture system that is simple to build and install, uses locally available materials, and reduces mercury emissions by at least 80%.
Elemental or metallic mercury is a shiny, silver-white metal, historically referred to as quicksilver, and is liquid at room temperature. It is used in older thermometers, fluorescent light bulbs and some electrical switches. When dropped, elemental mercury breaks into smaller droplets which can go through small cracks or become strongly attached to certain materials. At room temperature, exposed elemental mercury can evaporate to become an invisible, odorless toxic vapor. If heated, it is a colorless, odorless gas. Learn about how people are most often exposed to elemental mercury and about the adverse health effects that exposures to elemental mercury can produce.
In its inorganic form, mercury occurs abundantly in the environment, primarily as the minerals cinnabar and metacinnabar, and as impurities in other minerals. Mercury can readily combine with chlorine, sulfur, and other elements, and subsequently weather to form inorganic salts. Inorganic mercury salts can be transported in water and occur in soil. Dust containing these salts can enter the air from mining deposits of ores that contain mercury. Emissions of both elemental or inorganic mercury can occur from coal-fired power plants, burning of municipal and medical waste, and from factories that use mercury. Inorganic mercury can also enter water or soil from the weathering of rocks that contain inorganic mercury salts, and from factories or water treatment facilities that release water contaminated with mercury.
Although the use of mercury salts in consumer products, such as medicinal products, have been discontinued, inorganic mercury compounds are still being widely used in skin lightening soaps and creams. Mercuric chloride is used in photography and as a topical antiseptic and disinfectant, wood preservative, and fungicide. In the past, mercurous chloride was widely used in medicinal products, including laxatives, worming medications, and teething powders. It has since been replaced by safer and more effective agents. Mercuric sulfide is used to color paints and is one of the red coloring agents used in tattoo dyes.
Human exposure to inorganic mercury salts can occur both in occupational and environmental settings. Occupations with higher risk of exposure to mercury and its salts include mining, electrical equipment manufacturing, and chemical and metal processing in which mercury is used. In the general population, exposure to mercuric chloride can occur through the dermal route from the use of soaps and creams or topical antiseptics and disinfectants. Another, less well-documented, source of exposure to inorganic mercury salts among the general population is from their use in ethnic religious, magical, and ritualistic practices and in herbal remedies.
When inorganic mercury salts can become attached to airborne particles. Rain and snow deposit these particles on land. Even after mercury gets deposited on land, it often returns to the atmosphere, as a gas or associated with particles, and then redeposits elsewhere.