Quicksilver

CFLs contain mercury. Specifically, they send electricity through a mercury vapor to generate UV light, which then reacts with the flourescent coating on the inside of the bulb to produce visible light.

The fact that CFLs contain mercury has been a recurring theme on the afternoon talk show on KOH recently, parroting a member of Congress who paraded this fact around as though light bulb makers want to poison the country.

Yes, there is mercury in CFLs. But guess what - if you use a regular incandescent light bulb, powered by the most common source of electricity in the country - coal (a fuel source, ironically, the host praised in the same breath as the denouncing of MERCURY!!!!!!!) - you release more merurcy into the environment then if you were to toss your CFL in a landfill.

And you not only release more, you release about 3.5 times as much overall, and 14 tiems as much as is likely to be released by the bulb itself (0.4 mg, or about 11% of the mercury inside). Using incandescent light bulbs instead of a CFL over the life of the bulb will release 5.6mg of mercury into the air at coal-fired power plants. The power for the CFL would release 1.2 mg. Even if ever miligram of mercury in the bulb (4mg) were released while somehow still running a full 8,000 hours of power, in a contrary-to-physics worst-case scenario, the CFL still beats the incandescent bulb in mercury emissions, 5.2 to 5.6. But all of this neglects to mention that airborne mercury (mostly from coal plants, which then rains into the seas and accumulates in fish where it is ingested by humans) is the leading cause of human mercury poisoning.

Even this host can answer the following question: what's more mercury? 5.6 mg or 0.4 mg?

And, in related news, Home Depot is launching a CFL recycling program, to minimize the already lower-than-incandescent release of mercury into the environment (rather, to attract people into its stores. That other stuff is, of course, a nice side-effect).