Energy & Environment

Blown Out

Now that "going green" is mainstream, everyone knows the simplest thing to do save the planet: replace incandescent light bulbs with those spiral-shaped compact fluorescent...
by | October 31, 2008

Now that "going green" is mainstream, everyone knows the simplest thing to do save the planet: replace incandescent light bulbs with those spiral-shaped compact fluorescent ones. State and local governments have been giving the energy-efficient bulbs away to promote sustainability, while making the switch to CFLs themselves in government buildings. Meanwhile, hardware stores, pharmacies and general merchandise retailers have been selling hundreds of millions of CFLs since they moved them out of the specialty lighting section and made it easier for consumers to find them on the shelves.

The new bulbs use 75 percent less electricity than incandescent bulbs and last up to 10 times longer. However, there's a big problem with compact fluorescents: The bulbs contain mercury. Although the amount of mercury in a CFL is relatively small, environmental regulators consider breaking one of the bulbs indoors a household hazard that demands special cleanup measures. An even broader problem may emerge perhaps three years from now. That's when the first wave of the recently purchased CFLs will begin burning out, and most likely, wind up smashed in the trash in huge numbers. A lot of mercury will soon be heading to landfills across the country, posing potential risks to both water and air quality.

Some cities, as well as chain retailers such as Home Depot and IKEA, have set up recycling programs specifically aimed at keeping CFLs out of landfills. But those programs aren't attracting many consumers so far. They'll only work if Americans not only break the habit of throwing away blown-out light bulbs but also forge a new habit of bringing used bulbs to a collection site. It's not inconceivable that an increasingly green-conscious public will accept that burden. But persuading them to do so will require a large public education effort around the mercury issue. And so far, that effort has been minimal compared with the campaigns that persuaded so many people to buy CFLs in the first place.

It Adds Up

Elemental mercury is a liquid that releases a colorless, odorless and tasteless vapor when at room temperature. It also is a potent neurotoxin. But inside a CFL, it serves a valuable purpose. When charged with electricity, mercury vapor emits ultraviolet light, which triggers compounds inside the bulb to produce visible light.

Each compact fluorescent light contains about 4 milligrams of mercury. That amount is small compared with the roughly 10 milligrams found in a typical 4-foot fluorescent tube, or the 500 milligrams in a mercury thermometer. But it's the sheer volume of CFLs destined for landfills that is the problem. According to the U.S. government's Energy Star program, sales of CFLs doubled last year, to 290 million -- and that still represents only a 20 percent share in the light bulb market. Joel Hogue, a consultant who specializes in cleaning up mercury-polluted sites, says the cumulative amount of mercury headed to landfills could end up being large. "It adds up quite quickly," Hogue says.

Once mercury reaches a landfill, the risk of its being released remains forever. Over time, the mercury is eaten by bacteria and goes through a process called methylization, which makes it more toxic and dangerous if it leaks out. Such releases don't occur if landfills are operated correctly. But if the protective liners underneath landfills fail, or waste decomposition carries mercury vapor out through gas vents, releases into groundwater or the air are possible.

More attention has been paid to the risks CFLs pose indoors. No mercury is released from the bulbs while they are intact. The problems begin when they break. Last year, the Maine Department of Environmental Protection studied the issue. Researchers wearing hazmat suits smashed different kinds of bulbs on floors covered with everything from hardwood to shag carpeting. They studied how ventilation disperses the mercury vapors. They also looked at how different cleanup methods make the mercury impacts better or worse.

Some of what they found reinforced what was already known -- for example, that cleaning up a broken bulb with a vacuum cleaner makes the mercury problem much worse. But they also found that the worst mercury impacts could be avoided simply by ventilating the room and leaving it for 15 minutes. They also suggested not using CFLs in rooms frequented by infants, small children or pregnant women.

The mercury in CFLs puts environmentalists in a tough spot. On one hand, they don't want to minimize the mercury risk. On the other hand, CFLs pay clear environmental dividends. According to Energy Star, if every American replaced one light bulb with a light bulb that meets its efficiency standards, it would prevent 800,000 cars' worth of greenhouse-gas emissions.

There are upsides in terms of mercury emissions, as well, especially in places that rely on coal to produce electricity. Coal-fired power plants produce more than 40 percent of all domestic, human-caused mercury emissions. And what they release is the more toxic methylmercury. The electricity needed to power one incandescent bulb translates into nearly 14 milligrams' worth of emissions of the "bad" mercury, versus 3 milligrams to power a CFL. Jim Hunt, Boston's chief of environment and energy, says policy toward CFLs must be viewed with the broader environmental spectrum in mind. "One of the most significant sources of man-made mercury in our environment," he says, "is the burning of fossil fuels."

Bulb Collectors

Boston's approach to CFLs is pretty typical among local governments. The city's environmental and energy services Web site promotes changing over to compact fluorescents. It also notes the need to dispose of the bulbs properly. But Boston offers recycling for CFLs only twice a year, during household hazardous waste days. People can bring them to public works yards at other times -- if they're motivated enough to make the trip.

Salt Lake City is making a more ambitious effort. In fact, for area residents, recycling a bulb now is as convenient as returning a library book. The Salt Lake Valley Health Department chose libraries as collection centers because they are located in most neighborhoods. Also, librarians are available to take the bulbs, which is a plus because the department wanted an attended drop-off spot.

Another approach is underway in Berkeley, California. The city recently received a $130,000 grant from the California Integrated Waste management Board to set up a CFL recycling process. The city chose five retailers, including hardware stores and pharmacies, to accept spent bulbs. Officials had to sell store managers on the concept -- some were afraid the recycling container could be vandalized, or put employees at risk of mercury exposure. But Nabil Al-Hadithy, the city's hazardous materials manager, thought it would be impossible to change consumer behavior unless it was as easy to recycle a compact fluorescent as it has finally become to buy one. "If they sell the dang CFL," Al-Hadithy says, "the least they could do is take them back."

Join the Discussion

After you comment, click Post. You can enter an anonymous Display Name or connect to a social profile.

More from Energy & Environment