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How much mercury do power plants emit to light a CFL? About 50 percent of the electricity produced in the U.S. is generated by coal-fired power plants. When coal burns to produce electricity, mercury naturally contained in the coal releases into the air. In 2006, coal-fired power plants produced 1,971 billion kilowatt hours (kwh) of electricity, emitting 50.7 tons of mercury into the air—the equivalent amount of mercury contained in more than 9 billion CFLs (the bulbs emit zero mercury when in use or being handled). Approximately 0.0234 mg of mercury—plus carbon dioxide, sulfur dioxide and nitrogen oxide—releases into the air per 1 kwh of electricity that a coal-fired power plant generates. Over the 7500-hour average range of one CFL, then, a plant will emit 13.16 mg of mercury to sustain a 75-watt incandescent bulb but only 3.51 mg of mercury to sustain a 20-watt CFL (the lightning equivalent of a 75-watt traditional bulb). Even if the mercury contained in a CFL was directly released into the atmosphere, an incandescent would still contribute 4.65 more milligrams of mercury into the environment over its lifetime. Why do CFLs require mercury to produce light? Compact fluorescent bulbs are made of glass tubes filled with gas and a small amount of mercury. CFLs produce light when the mercury molecules are excited by electricity running between two electrodes in the base of the bulb. The mercury emits ultraviolet light, which in turn excites the tube’s phosphor coating, leading it to emit visible light. How much mercury is contained in a CFL? Each bulb contains an average of 5 milligrams of mercury, “which is just enough to cover a ballpoint pen tip,” says Leslie, associate director of the Lighting Research Center at Rensselaer. “Though it’s nothing to laugh at, unless you wipe up mercury [without gloves] and then lick your hand, you’re probably going to be okay.” What is the proper way to handle a broken CFL? Open the windows and let the room air out for 15 to 30 minutes, then remove as much material as possible without a vacuum cleaner. Using disposable gloves, scoop the glass onto a piece of cardboard and wipe the area with a wet paper towel. For smaller pieces of glass and powder, use duct tape to pull up the fragments and wash your hands after cleaning up the debris. What is the proper method to dispose a CFL? Check if your local recycling center has services available for CFL disposal by calling directly or by visiting Earth 911. Plus, as retail giants such as Home Depot and Wal-Mart amp up their CFL offerings, IKEA recycled 156,301 pounds of CFLs in its 2005 fiscal year with its “Free Take Back” recycling program that puts a collection bin in each store. If that wasn’t enough incentive, officials are looking into providing more consumer bonuses for CFL recycling, Leslie says, and they may even add a deposit value much like cans and bottles. Leslie promises: “Over six months to a year, you will see changes.”