Mercury Thermometer Threat

From the WebMD Archives

Nov. 22, 2000 -- From as far east as Boston to as far west as San Francisco -- including many cities in between -- efforts to ban mercury fever thermometers due to health concerns are sweeping through U.S. homes and hospitals.

Once upon a time, mercury thermometers were the most common way to check for fever. Mercury thermometers are made of glass and are the size of a straw, with silvery-white liquid mercury inside. Each fever thermometer contains approximately one gram of mercury. Mercury is poisonous and attacks the body's central nervous system. It can also harm the brain, kidneys, and lungs.

To put things in perspective: One gram of mercury per year leaked into a 20-acre lake is enough to raise the levels of mercury in fish high enough to trigger warnings to consumers. Nationwide, mercury thermometers contribute 17 tons of mercury to solid waste each year.

In efforts to cut back on mercury in the environment and food supply, the Boston City Council recently banned the sale of mercury thermometers in the city. Stores will have approximately two months to clear their inventories of the remaining thermometers, and violators will be fined. There's also a ban on the sale of mercury fever thermometers in Duluth, Minn.; Ann Arbor, Mich.; and several cities and counties in California and Wisconsin. In New Hampshire there's even a state law that prohibits the sale of certain mercury-containing products.

"New Hampshire has the right idea," says Jackie Hunt Christensen, a spokesperson for Health Care Without Harm, a not-for-profit campaign based in Minneapolis that works to eliminate pollution in health care practices. "We need to pass laws at state and federal levels rather than address the issue piecemeal in cities and counties, but we take what we can get."

Other efforts to remove mercury include the "Mercury Thermometers and Family Health in Minnesota" program where mercury fever thermometers are exchanged for mercury-free digital thermometers.

Campaigns to exchange mercury thermometers for digital ones are a "very empowering and a very concrete way to take action to keep mercury out of the environment and out of the food supply," she tells WebMD.

In Washington, D.C., ten of the district's hospitals pledged to phase out their use of mercury products. Each hospital will also host an in-house mercury thermometer roundup to encourage staff to bring in mercury thermometers from their home medicine chests in exchange for a free digital replacement. The campaign also provides hospitals with lists of alternative suppliers of nonmercury medical supplies. Mercury may also be found in blood pressure devices, gastrointestinal tubes, and some batteries. Most of these efforts are also sponsored by Health Care Without Harm.

"We have over 600 hospitals and clinics who have signed a mercury-free pledge," says Health Care Without Harm's mercury coordinator Jamie Harvie.

Retail outlets are getting in on the act as well. "We are extremely pleased with retail response in removing mercury thermometer from shelves and [are] encouraging remaining [retail stores] to make a similar commitment," Harvie says. Eleven leading retailers and manufacturers including Albertson's, Brooks Pharmacy,, and Kmart Corporation have stopped selling the thermometers.

Burned medical waste accounts for 10% of mercury in the air and tossing mercury fever thermometers in the kitchen garbage can is the largest single source of mercury in solid waste, he says.

Still, most human exposure to mercury comes through eating contaminated fish. Pregnant women, women of childbearing age, and young children are particularly at risk from mercury exposure. More than 60,000 children each year may be at risk for learning disabilities because of mercury-contaminated fish eaten by their mothers during pregnancy, according to a report issued by the National Academy of Sciences.

"We are not saying don't eat fish. Instead, learn more about where the hot spots are in local lakes and rivers, consider what type of fish you are eating, and do what you can to keep mercury out of your house," says Hunt Christensen.

Consumers should also remember that "mercury thermometers should never, ever be thrown in the trash, even if they are not broken," Cecilia DeLoach, the D.C. Campaign director Health Care Without Harm, tells WebMD.

"If a mercury thermometer breaks and gets into a carpet, it will vaporize and go into a room and can have health effects on children and others who spend time in the room," she says. The largest risk for mercury exposure is in a small, poorly ventilated room. Even the smallest amount of mercury needs to be treated as a serious issue.

"Bring your mercury thermometer to a household hazardous waste collection facility," she says. "Many state or local agencies operate these facilities as permanent or seasonal collections. Typically, the service is free." For more information on household hazardous waste collections in your area, call your state pollution control, she suggests.

But if a mercury spill should occur, remember the following:

  • Immediately keep all people and pets away from the spill area. To minimize the mercury that vaporizes, turn off any heaters and turn up any air conditioners.
  • Ventilate the area by opening windows and, when possible, keep open for at least two days.
  • Never use a vacuum to clean up a mercury spill. Not only will the mercury contaminate your vacuum, but the heat from the vacuum will evaporate the mercury, further distributing it throughout the house. Similarly, never use a broom to clean up mercury. It will only distribute the mercury into smaller beads, and will contaminate the broom.