Thanks to heightened concerns over global warming, everyone's gonzo for going green. As part of the push to be environmentally friendly, tree-huggers, power utilities, and even big-box retailers are pushing the use of compact fluorescent light bulbs (CFLs), which last longer and use less electricity than conventional bulbs.

However, that solution has created another—possibly larger—problem for solid waste managers: mercury. Recycling CFLs is nearing the top of many public works and solid waste manager's to-do lists.

Traditional fluorescent bulbs contain about 12 mg of mercury; CFLs contain about 5 mg. Since mercury has ill effects on humans and animals, regulators want to keep it out of the air and groundwater. To do so, bulbs should be disposed of before they hit a landfill, but no one wants to fund their recycling.

Very few retailers or manufacturers have official collection sites or programs for collecting bulbs of any sort; retailers (like hardware stores) are especially reluctant to collect CFLs because that might lead consumers to believe they'll also handle other hazardous waste, like batteries or electronics. Thus, the burden of handling bulbs falls on the shoulders of public works, which must somehow find funding to handle yet another recycling program.

As a result, only 2% of all bulbs are recycled properly.

Spent or used mercury-containing light products, including fluorescent bulbs, are regulated by the U.S. EPA under the Universal Waste Rule, which is part of the Resource Conservation and Recovery Act, governing hazardous waste. Most states have adopted these rules, and some have taken them even further.