Elemental mercury is the metallic form of mercury—a silvery, odorless liquid metal. When heated, it is a colorless, odorless gas. Elemental mercury can transform into various mercury compounds, and it can change phases between solid, liquid and gas. Once in the environment, mercury is persistent: it never goes away.
Mercury is used in measurement devices and in electronic and electrical applications—thermostats, thermometers, lighting, switches, and batteries. It is part of the silvery material used to fill teeth, and it is used in gold mining.
People are exposed to elemental mercury by breathing it in vapor form. Exposure to elemental mercury can result in the following symptoms: tremors, mood swings, insomnia, neuromuscular changes, headaches, and/or cognitive impairment. The Centers for Disease Control and Prevention provides a comprehensive description of the health effects of elemental mercury. (People are also exposed to mercury by eating fish contaminated with methylmercury. See Mercury in fish and Health effects of mercury.)
Residents of King County can bring elemental mercury to household hazardous waste facilities for free disposal. Transport liquid mercury safely in a non-metal container with a lid. (Don't use metal containers because the metal could react with the mercury.)
Businesses can dispose of mercury through a mercury reclamation facilityor a hazardous waste management company. (see Fluorescents and Thermostats).
The Washington State Mercury Education and Reduction Act (MERA) of 2003 (Revised Code of Washington 70.95) prohibits K-12 schools from purchasing bulk elemental mercury and mercury compounds for the science lab. The Act requires schools to remove and properly dispose of bulk elemental mercury and mercury compounds. It went into effect January 1, 2006.
In King County, schools can dispose of mercury through a mercury reclamation facilityor a hazardous waste management company.
For more information contact Taylor Watson, Health and Environmental Investigator, at taylor.watson@kingcounty.gov.