A. While it is true that compact fluorescent lights contain small amounts of the toxic metal mercury, using them actually contributes less mercury to the environment than using regular, incandescent bulbs, said Faramarz Vakili, associate director of the UW-Madison Physical Plant.

That's because CFLs consume 75 percent less electricity than incandescent light bulbs, and burning coal for electricity is the biggest source of mercury emissions to our air and water. Consequently, Vakili estimates that a 60-watt incandescent bulb will cause the release of 5.8 milligrams of mercury in 8,000 hours, versus just 1.6 milligrams for an equivalent CFL.

"Even if you assume a compact fluorescent bulb ends up in a landfill, the amount of mercury released is very little, about 0.4 milligrams," said Vakili, who also directs the university's energy conservation initiative, We Conserve. "As a result, something like 72 percent less mercury is released when using compact fluorescent light versus incandescent light."

But CFLs needn't end up in the trash, and in fact many municipalities, including Madison, have banned them from landfills.

"It's important to know that these lights are recyclable and should be recycled," Vakili said.

To do so, people can often return them to stores that sell them, as long as the bulbs aren't broken. To find retailers statewide that accept CFLs for recycling, visit www.focusonenergy.com/Residential/Lighting/cfl_recycling.aspx.

-- Produced in cooperation with University Communications

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