Mercury is as deadly as it is beautiful. Unfortunately, our cheap electric power means mercury levels are building up throughout our food chain, most notably in carnivorous fish, like tuna. Our friends over at Grist have eloquently answered a very frequently asked -- and very valid -- question: does the mercury content in compact fluorescent light bulbs, or CFLs, offset the energy savings? The answer, we're glad to report, is unequivocal. The CFL, even though it does contain mercury, is absolutely greener, because producing electrical power releases mercury directly into the atmosphere. So with that resolved, switch away, unencumbered. Just remember to dispose of spent bulbs properly and none of the mercury will escape into the environment. For more information on CFLs, check out these posts in the AT archive: • Compact Fluorescents… With Confidence • Danny Seo's favorite CFL • …and some great tips from our loyal readers.