They are the little light bulbs that could change the world. Compact fluorescent bulbs use about 75% less energy than their traditional incandescent cousins, and the US Department of Energy estimates that if every home in the country installed just one of them, it would save $600 million in annual energy costs. It's little wonder that compact fluorescent light bulbs, or CFLs, have become a quick and easy way for home owners to "go green." But how environmentally friendly are CFLs? There is no denying the potential energy savings. That translates to a reduced need for power generation at the coal fired power plants, which in turn means fewer tons of toxic pollutants like mercury in the air. But CFL's actually contain mercury, which is a highly efficient conductor of electricity. Recycling officials worry that as more Americans make the switch to the energy saving bulbs, that more of them will end up in land fills, eventually releasing that mercury in the environment. Vanderburgh County Solid Waste District Recycling Coordinator Jim Daniels says switching to CFLs means thinking more about what happens to them when they eventually burn out. "The big trick," says Daniels, "is when that item that mercury in it is at the end of it's life, dispose of it properly." CFLs last six to ten times as long as incandescent bulbs, so the need to replace them is infrequent. But there is not a recycling center in Evansville that takes the bulbs year round. Daniels says that may be coming, but in the mean time, making the simple step of holding the bulbs until the Solid Waste District conducts it's annual Tox Away Day is the Earth friendly way to go. During those toxic waste collection days, the district will take CFLs and other fluorescent bulbs, and send them off to a processing and recycling center in Cincinnati. For more information on CFLs, check out the US Department of Energy web site.