City bans medical devices that contain mercury
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* Barbara Sibbald

Duluth, Minn., has become the first city in North America to ban the sale of medical equipment that contains mercury, including sphygmomanometers and thermometers. “Mercury pollution is a public health concern,” says Duluth council president Donny Ness. “This is one step toward protecting our citizens.”

![Figure1](http://www.cmaj.ca/https://www.cmaj.ca/content/cmaj/168/1/78.1/F1.medium.gif)

[Figure1](http://www.cmaj.ca/content/168/1/78.1/F1)

Figure. **Is medicine a source of mercury pollution?** Photo by: Canapress

The move came in the midst of controversy over the accuracy of aneroid sphygmomanometers, one alternative to the mercury devices. In September the US Food and Drug Administration cautioned that if the aneroid cuffs aren't calibrated regularly, they are prone to error. The American Heart Association says mercury cuffs also require regular calibration; it “encourages” use of mercury devices until others have received better validation.

A study of the Mayo Clinic's aneroid replacement program (*Arch Int Med* 2001;161[5]:729-31) determined that “a carefully maintained aneroid sphygmomanometer is an accurate and clinically useful means of indirect blood pressure measurement.”

The push to replace mercury sphygmomanometers in the US began in June 1998, when the Environmental Protection Agency and the American Hospital Association agreed to limit the amount of mercury waste produced in hospitals by 2005. At the time the US Centers for Disease Control and Prevention reported that 10% of American women of child- bearing age had mercury concentrations above the level considered safe for the developing fetus. Other organizations have since joined the US effort. Canadian environmental groups have called for similar action here, but without success.

The FDA says exposure to mercury from sphygmomanometers is rare, although the Mayo Medical Center documented 50 spills in a 2-year period that resulted in US$26 000 in clean-up costs. The alternatives are aneroid and electronic devices.

In August the US Senate unanimously passed a bill banning the sale of mercury thermometers. Ten states have already banned the sale of mercury thermometers for testing body temperature, and 11 of the top 15 national retailers have stopped selling them. In July 2001, the American Academy of Pediatrics called on doctors and parents to stop using them.

However, even though medical devices containing mercury can cause pollution, they are a relatively minor source when compared with electricity producers. It is estimated that coal-fired power plants in the US release 51 tons of mercury into the atmosphere there every year, accounting for about one-third of the country's yearly airborne emissions. — *Barbara* *Sibbald*, CMAJ