PORTLAND – The state’s 39 hospitals are pledging to eliminate the mercury found in their medical equipment and laboratories by 2005.

The pledge is part of a pollution prevention agreement that also calls for the hospitals to cut in half the amount of medical and municipal waste they produce by 2010.

“When [some] types of products are used as directed, the mercury ends up going down the drain with the wastewater, through the sewage treatment system into our rivers and bays,” said Mike Belliveau, toxics project director for the Natural Resources Council of Maine. “Up until this point, it’s been very hard for hospitals to get a handle on that.”

The Maine Hospital Association, the Maine Department of Environmental Protection and the resources council signed the agreement in March, but it wasn’t until last week that all of the hospitals’ chief executive officers had signed on the dotted line and committed themselves to making their facilities more environmentally friendly.

Nationally, hospitals have told the U.S. Environmental Protection Agency that they will take similar steps, but so far that voluntary effort has produced lackluster results.

The Maine agreement is “the most comprehensive statewide hospital agreement to prevent pollution in the country,” Belliveau said.

Mercury is a toxin that is released into the atmosphere from power plants, waste incinerators and industrial processes. It collects in oceans and lakes, where it is ingested by fish and moves up the food chain.

Mercury pollution has become enough of a problem in Maine that the state Bureau of Health has issued fish consumption advisories.

Waste generated by health-care facilities, including hospitals, is among the top three sources of mercury and dioxin pollution in North America.

In addition to thermometers, mercury can be found in hospitals in blood pressure cuffs, fluorescent lights, antibody test kits, hormones, pregnancy tests and other medical supplies. It can also be found in some detergents, bleaches and cleaners.

Eliminating mercury from a hospital’s waste stream is both a matter of rooting it out and changing purchasing practices so that no more of it gets through the front door.