AUGUSTA – Another piece of legislation to keep mercury out of the environment in Maine was signed into law Friday by Gov. John Baldacci, bringing to five the number of newly enacted laws to eliminate the toxic metal.

The latest bill signed by Baldacci calls for reducing the existing mercury emission limit for an individual source from 50 pounds per year to 35 pounds after Jan. 1, 2007, and then to 25 pounds per year after Jan. 1, 2010.

Baldacci marked the occasion by drawing attention to other mercury-reduction bills he has signed in recent days and weeks, saying they move Maine “substantially closer to the goal of eliminating man-made sources of mercury emissions.” He said the Maine laws have become models for other states.

“The effects that mercury can have on your health can range from acne to impaired brain development and everything in between. It depends on the type of mercury and how you came into contact with it,” the governor said.

Other newly enacted Maine laws require manufacturers to set up a system to collect and recycle unused mercury thermostats by offering incentives worth at least $5 per thermostat, and ban the sale of button cell batteries that contain mercury – including consumer products that contain button cell batteries – as of July 2011.

A new law will take initial steps toward recycling of old cell phones, which contain lead, mercury and other materials that can pose health risks if released into the air, water and ground. The final law requires the annual reporting of the volume of mercury amalgam supplied to dentists in the state.

Environmentalists applauded the legislative action to control mercury as precedent-setting.

With passage of the new legislation, “Maine has effectively eliminated all household products that contain mercury from store shelves and the waste stream,” said Brownie Carson, executive director of the Natural Resources Council of Maine. “Maine’s ‘can-do’ common-sense approach is leading the nation in reducing the toxic mercury in our environment.”

The new legislation builds on existing laws such as one that banned the sale of new mercury thermostats as of January 2006.

It’s estimated that 5,600 pounds of mercury are still contained in old thermostats hanging on the walls of Maine homes and businesses, the resources council said.