University of Wisconsin - Extension

Mercury thermometers are a staple in most medicine cabinets. But if broken, the mercury inside can be hazardous.

"Mercury fever thermometers have been used for decades as a first step on caring for someone who feels sick," explains Steve Brachman, University of Wisconsin-Extension waste reduction and management specialist. "Ironically, the mercury thermometer can be a risk to the health of families and communities. Mercury is a toxic substance that can harm both humans and wildlife."

Mercury thermometers are made of glass the size of a straw, with a silvery-white liquid inside. To function properly, mercury thermometers must be "shaken down" before use, creating a constant high potential for breakage. "Public health officials across the country report a steady stream of concerned calls - more than 18,000 to poison control centers in

1998 alone - of concerned calls from broken mercury thermometers," says Brachman. "Fever thermometers are the largest single source of mercury discarded annually in municipal solid waste, estimated at 17 tons of mercury per year."

Broken mercury thermometers are difficult to clean up. Parents may not know a child broke a thermometer, and mercury from the broken thermometer can soak into carpet or get into cracks in floors. "A single broken fever thermometer, containing 0.5 to 1.5 grams of mercury, is enough to create a health risk if it evaporates into a small, poorly ventilated room," adds Brachman.

To help reduce problems caused by mercury thermometers, many communities are sponsoring mercury fever thermometer exchanges, replacing mercury thermometers with easy-to-use and read non-mercury thermometers. Phasing out the use of mercury in health care is one of seven goals of Health Care Without Harm, the campaign for environmentally-responsible health care. Some communities have gone so far as to ban sales of mercury thermometers.

Brachman encourages community leaders to consider organizing a mercury fever thermometer exchange. The tree main types of exchanges include hospital and other workplace exchanges, school exchanges and community exchanges.

"Mercury thermometer exchanges are worth the effort they take to put together, since the benefits of an exchange are numerous," Brachman says. "When given information about the hazards of mercury thermometers, people are eager to find a safe place to get rid of them."

Mercury being recovered is being recycled. "Mercury-containing items are crushed and heated so the mercury evaporates, separating from the glass and other debris. The gaseous mercury is then condensed back to a liquid state, distilled and used again in new mercury-containing products," explains Brachman.

Two medical facilities in Wisconsin have pledged to become mercury-free: Sacred heart Hospital in Eau Claire and St. Mary's Hospital in Superior. For more information about mercury-free thermometers, organizing a mercury thermometer exchange or mercury collection, call Brachman at (608) 227-3160.