Low-mercury compact fluorescent lamps/lightbulbs (CFLs) do contain a very small amount of mercury (about 3.5 - 4 milligrams, or the amount that would cover the tip of a ballpoint pen) that is sealed in glass tubing. To put this into perspective, old thermostats contain about 500 milligrams (the equivalent of about 125 CFLs), and standard tube shaped fluorescent bulbs contain 8 to 14 milligrams. No mercury is released through CFL use, nor can it escape an unbroken bulb. CFL manufacturers are working to reduce mercury levels even lower. According to ENERGY STAR®, some manufacturers have achieved 1.4 to 2.5 milligrams of mercury per lightbulb.
Now consider that most electricity in the United States is generated by burning coal. The Environmental Protection Agency (EPA) states that for each kWh of electricity generated by burning coal, 1.43 lbs of greenhouse gases, which are responsible for global climate changes, are released. In addition to greenhouse gases, electricity use is also the main source of mercury emission in the U.S.
Power generated by about 617 coal burning plants in the U.S. accounts for roughly 40 percent of our mercury emissions. Coal-fired power plants are the largest human-made source of mercury emissions, because mercury that naturally exists in coal is released into the atmosphere.
By using CFLs properly, the energy reduction reduces the amount of mercury and greenhouse gases that are emitted into the atmosphere by reducing the amount of coal burned. Plus, if CFLs are not broken and are recycled properly, the small amount of mercury they do contain has much less impact on the ecosystem.
If you do choose to use CFLs, be responsible and recycle the bulbs after use.
Some retailers that sell CFLs offer recycling. For more information on how to recycle CFLs, go to the Environmental Protection Agency website.