Do compact fluorescent bulbs reduce mercury pollution?
RHONDA SAUNDERS
materials that use toxic subin all 50 U.S. states and 130 counWhen consumers started tossing stances,” she adds. “We need to tries. The authors find that the U.S. burnt-out compact fluorescent look toward safe LEDs [light-emitcould avoid about 25,000 metric bulbs (CFLs) into the trash, they ting diodes] or better CFLs.” tons (t) of mercury emissions ankicked off a compact fluorescent Vicki Calwell, an expert on mernually by switching all incandeskerfuffle. The energy-saving cury in CFLs who is with Ecos Concent bulbs to CFLs by 2012, bulbs with the swirly tops consulting, agrees that the biggest assuming steady growth in lighting tain a small amount of mercury, long-term reductions in mercury demand and a 25% recycling rate. likely too low to pose risks to emissions from lighting will most homeowners but come from reducing merenough to add up to a cury in the bulbs. She notes serious environmental that decreasing mercury problem if people don’t from 5 to 3 milligrams (mg) recycle them. per lamp is equivalent to Now, research published achieving a 40% recycling in ES&T (DOI 10.1021/ rate overnight. es800117h) by researchers In the meantime, CFLs from Yale University is use up to 75% less electricturning the mercury probity than incandescent lightlem on its headsit turns bulbs and last up to 10 out that depending on times longer, according to where you live, you may Energy Star, a U.S. EPA and pump more mercury into Department of Energy effithe atmosphere by flipping ciency-rating program. The on an old-school incandesbulbs contain between 1.4 cent bulb, which doesn’t and 5 mg of mercury, aceven contain mercury, than cording to the program’s by going fluorescent. The website, about the size of extra mercury emissions the dot over an “i” in this attributable to incandessentence. A voluntary cent bulbs come from agreement signed in April burning more mercury2007 by members of the containing coal to power National Electrical Manuthe inefficient lights. facturers Association, a In places that rely heavily trade group, capped the on coal for electricity, such amount of mercury in each as West Virginia or China, bulb at 5 mg. the researchers say switchRobert Hurt, an engineer ing to CFLs can reduce Switching from an incandescent bulb to a CFL reduces at Brown University, has mercury emissions signifi- mercury emissions if the electricity saved comes from coal. developed new nanomatericantly. But cleaner-powPower-plant emissions were calculated using data from als to absorb mercury reered places like California EPA and the U.S. Census Bureau. Mercury savings data are leased by broken CFLs, as and Norway would do bet- from the new ES&T paper. described recently in ES&T ter to stick to incandescent (2008, 42, 5772-5778). bulbs when it comes to re“Neither the [Zimmerman] study By comparison, in a best-case sceducing mercury. “The places nor our recent study in ES&T are nario, U.S. power plants would known for sustainability are the full health-risk assessments, but the have to cut mercury emissions by places that have the potential to do new study does clearly show that 90% to achieve a savings of 17,000 t the most harm by bringing this the use of fluorescents leads to net annually. technology in,” says environmental reduction in mercury emissions Ultimately, a better lightbulb engineer Julie Zimmerman of Yale, and that the benefit varies greatly should both save energy and disa coauthor of the study. by region,” he notes. pense with mercury, Zimmerman The study is the first to rigorsays. “If we want to be truly susously compare mercury emissions —ERIKA ENGELHAUPT tainable, we can’t be dependent on from CFLs and incandescent bulbs
8176 9 ENVIRONMENTAL SCIENCE & TECHNOLOGY / November 15, 2008
10.1021/es8025566
2008 American Chemical Society
Published on Web 09/24/2008
