I’ve heard that compact fluorescent light bulbs, known for their long life and low energy consumption

I’ve heard that compact fluorescent light bulbs, known for their long life and low energy consumption, contain toxic mercury. Is this true and, if so, what precautions should I take when disposing of them?

—Greg Newswanger, Freedland, MD

Compact fluorescent light bulbs do contain small amounts of mercury vapor, which, when catalyzed by voltage, give off ultraviolet energy, the key building block for generating light. When these bulbs burn out or break, they need to be discarded responsibly so as to avoid unleashing mercury into the environment and food chain.

Mercury—a toxic metal known to cause brain, spinal cord, kidney and liver damage in humans—does not break down easily and, once airborne, often finds its way into groundwater, rivers and the sea, where it can cause a host of contamination issues for wildlife and people alike.

The first thing to do when a compact fluorescent bulb breaks is to open all the windows to disperse any mercury vapor that may have escaped. Then put on gloves, sweep up the fragments, and wipe the area with a disposable paper towel. Using a vacuum is a bad idea, as it will only stir up any lingering airborne mercury. Lastly, the fragments should be sealed into a plastic bag and recycled or disposed of.

The best way to dispose of burned-out or broken compact fluorescent bulbs is to take or mail them (in the sealed plastic bag) to a mercury recycling facility. The website of the Association of Lighting and Mercury Recyclers provides contact information for locating such facilities state by state. If mercury recycling is not an option in your area, the bulb or fragments should be placed in sealed plastic bags and disposed of at your local Household Hazardous Waste (HHW) collection site.

Ironically, compact fluorescent bulbs are responsible for less mercury contamination than the incandescent bulbs they replaced, even though incandescents don’t contain any mercury. The highest source of mercury in America”s air and water results from the burning of fossil fuels, such as coal, at utilities that supply electricity. Since a compact fluorescent bulb uses 75 percent less energy than an incandescent bulb, and lasts at least six times longer, it is responsible for far less mercury pollution in the long run. A coal-burning power plant will emit four times more mercury to produce the electricity for an incandescent bulb than for a compact fluorescent.

CONTACTS: Association of Lighting and Mercury Recyclers, www.almr.org; Earth911.org; EPA Household Hazardous Waste Page, www.epa.gov/epaoswer/non-hw/muncpl/hhw.htm; EPA Fact Sheet: Mercury in Compact Fluorescent Lamps, www.nema.org/lamprecycle/epafactsheet-cfl.pdf