CFL’s have a downside that is important to know about: they contain a small amount of mercury, a toxic substance. Before you get too upset, here is a quote from the October 2007 article in the Scientific American entitled “Toxic Bulbs”:
Each CFL contains about five milligrams of mercury, about equal to the amount of ink on the tip of a ballpoint pen. Of course mercury does not pose the same kind of risk as, for instance mercury in fish (the U.S. Food and Drug Administration sets a limit of 0.17 milligram in a six-ounce can of tuna). But it can leach out of landfills into water supplies or become airborne if incinerated).
For now at least, most of these bulbs are being thrown into the trash. Limited amounts have started to be recycled, and recycling appears to be the prudent approach for the long run. The Scientific American article quoted above cites a program started in Vermont by True Value Hardware and one in California, by Wal-Mart. One should inquire to the store from which they buy CFL’s, if they take them back for recycling.
For now, it is arguable that CFL usage overall has a reducing effect with respect to mercury output into the environment. At present, discarded CFL’s are projected to yield about 10 tons of Mercury waste annually (Scientific American, “Toxic Bulbs”, Oct. ’07). However, widespread household use of CFL’s could theoretically save as much as 7% of current U.S. electrical usage. http://en.wikipedia.org/wiki/Compact_fluorescent_lamp
Coal fired power plants currently put out about 48 tons of airborne mercury each year. As a result, according to the EPA:
(when coal power is used) the mercury released from powering an incandescent lamp for five years exceeds the total of (a) the mercury released by powering a comparably luminous CFL for the same period and (b) the mercury contained in the lamp”
http://en.wikipedia.org/wiki/Compact_fluorescent_lamp
In otherwords, they calculate that CFL’s, even without recycling, cut down on mercury emissions into the environment by offsetting output from power plants. Additionally, usage of CFL’s will have a large impact in reducing greenhouse gas emissions, particularly carbon dioxide, so overall it still looks like a big positive to switch from traditional incandescent bulbs to CFL’s.
And finally, Scientific American says “And if you break a CFL”:
………Open windows to dissipate mercury vapor. Then While wearing gloves, use sticky tape to pick up the small pieces and powdery residue from the bulb’s interior. Place the tape and large pieces in a plastic bag. After Vacuuming the area, place the vacuum bag inside doubly sealed plastic bags before discarding.
………To find a CFL recycling program in your area, go to www. lamprecycle.org.
Tags: mercury pollution
