Yes, CFLs contain mercury. So do laptop computers, TVs, telephones, and tuna fish sandwiches.
On average, CFLs contain 4 milligrams of mercury each (that amount would almost cover the tip of a ballpoint pen). LCD projector TVs, by comparison, contain 500-100 milligrams of mercury. One bite of albacore tuna contains more mercury than a CFL.
Many people think about mercury emissions in a very simplistic manner. (Sure, the mercury in a CFL may be a trace amount, but incandescent light bulbs don’t contain any – which makes incandescent light bulbs better for the environment, right?)
Wrong. The main source of mercury emissions in the U.S. is from coal-fired power plants. They send mercury into the air as pollution. Since CFLs use significantly less energy than incandescents, they actually help decrease mercury emissions in the end. To produce the electricity required for an incandescent light bulb, a coal-fired power plant has to emit 13.6 milligrams of mercury. For a CFL, that emission drops to 3.3 milligrams.
It’s still very important to recycle CFLs for the sake of waste management workers. Those trace amounts have the potential to build up for workers who collect trash from hundreds of houses per day.
However, if you’re questioning the safety of installing a CFL in your home and wondering whether the mercury content is harmful for the environment, just think about a bite of tuna.