|Fluorescent light bulbs use less electricity than incandescent light bulbs, resulting in fewer emissions associated with electricity generation from power plants. All fluorescent lamps, however, contain mercury. Most compact fluorescent lamps (CFLs) contain 3 to 5 milligrams of mercury, with some of the newer models having as little as 1 to 3 milligrams.
Mercury is a toxic metal associated with contamination of water, fish, and food supplies, and that can lead to adverse health affects in humans. While incandescent light bulbs do not contain mercury, fossil-fuel power plants can emit 6 to 7 more milligram of mercury into the atmosphere generating the electricity needed for an incandescent lightbulb compared to the electricity needed for a compact fluorescent.
There is not a risk of mercury exposure from an intact CFL, but fluorescent lamps should not be disposed of with regular trash, but should be disposed of in accord with local laws and regulations. Indeed, in many places, such as California, it is simply illegal to throw fluorescent lamps away. Expired compact fluorescents should be taken to a local recycling center, to your community's hazardous waste collection event, or to a local retailer that will accept spent CFLs for recycling. "Mail order" fluorescent recycling boxes may also be ordered through EFI.
Additional Information: Energy Star Mercury Fact Sheet (pdf)
Additional Information: Earth911.com
Additional Information: LampRecycle.org
Additional Information: How
to Dispose of Compact Fluorescent Lamps (pdf)
Additional Information: Recycleabulb.com CFL Recycling Locations