Q: I’ve switched to compact fluorescent lightbulbs (CFLs), but I’ve read they contain mercury. Doesn’t that preclude their benefit for the environment, and what about the health hazards? –Sarah, Buffalo, NY

A: We face a classic trade-off dilemma in our choice of light bulbs: does the 2/3 less energy that CFLs use compared to standard incandescents outweigh the mercury pollution they contribute?

CFLs contain small amounts of mercury to allow the bulb to have such a long life. To put the amount in perspective, a CFL has 4 mg of mercury compared to a fever thermometer’s 500 mg. But mercury is highly neurotoxic even at low doses, and the mercury in CFLs surely adds up to be a big problem in the environment because hundreds of millions of fluorescent bulbs are discarded each year.

The best choice for the environment is to choose light-emitting diode (LED) bulbs whenever possible (more about these, below). When comparing CFLs and incandescents the answer is that CFCs are the best win for the environment. According to the U.S. Environmental Protection Agency (EPA), a power plant will emit 10mg of mercury to produce the electricity to run an incandescent bulb compared to only 2.4mg of mercury to run a CFL for the same time. Low-mercury CFLs are now available, and we need to choose those and to dispose of CFLs properly.

If a CFL breaks, the EPA recommended protocol for handling the mercury is not to use your hands or a vacuum cleaner, but to sweep it up, and then wipe the area where it spilled with a damp paper towel. Open nearby windows for ventilation of the vapors.

Recommendations & Resources
* Philips ALTO brand offers low mercury bulbs.

• Green architect Eric Corey reports that one brand of CFLs, Greenlite, can be dimmed, which is good to know for those frustrated because this type of bulb generally can’t be dimmed.
Learn more here.

• LED lighting is incredibly long-lasting and mercury-free. Recent improvements in manufacturing have enabled them to be more practical for the home market. Learn more about LEDs here.

• Contact your local household hazardous waste station or Earth911.org to find out how to dispose of CFLs in your community, and to find out your state’s requirements.

Energy Star’s FAQ’s about CFLs