Consider the old incandescent lightbulb. It has stood us in good stead for more than a century, but, let's face it, now deserves to be retired in favor of more energy efficient technology. I'm in favor of saving energy and, especially, money, and I'm also in favor of switching to new technologies that are improvements over old, antiquated ones. (Though I sometimes do miss the typewriter.) The incandescent bulb uses a mere 10% of the energy passing through it to generate actual light; most of the rest escapes as heat, which is undesirable save for perhaps in the dead of winter and/or if you have an EasyBake Oven. (The Environmental Defense Fund's Fred Krupp not inaccurately described incandescents as "little heaters that put out a little light.") The "new and improved" lighting technology is the compact fluorescent light (CFL) bulb, but, to be honest, I have never really seen the CFL as anything more than a transitional lighting technology—a stopgap measure until LED-based lightbulbs become cost-effective. (Likewise, I always disliked fax technology and never thought of the fax machine as anything other than a transitional technology between mailing and e-mailing. But anyway...) Happily, LEDs are coming to market fairly swiftly, and while they are still pretty pricey, costs are coming down. Some people claim that CFL light is inferior to incandescent light (though I have never had a problem with it), and I do grant that some people are sensitive to the high-frequency flicker (an old issue with the long tubular fluorescent bulbs that have lit our offices and other commercial spaces for decades). There is also the argument that CFLs don't last as long as is claimed. But my real beef with CFLs has been the mercury issue. CFL blubs use an electric current to stimulate mercury vapor, which produces ultraviolet light, which then is converted into visible light by striking a fluorescent coating (called phosphor) lining the inside of the bulb. The problem is that mercury is a highly toxic element that is liquid at room temperature, as many of us who have ever inadvertently (or perhaps advertently) broken a thermometer know. Mercury is also a pollutant which can contaminate groundwater as well as other species such as food fish (mercury poisoning from tuna and other fish is a health hazard). Thus, CFL bulbs need to be disposed of carefully and not just tossed in the trash. And, should a bulb break, a special cleanup procedure needs to be performed. I'm less worried about the health hazard of the mercury--after all, a CFL bulb doesn't contain that much mercury, just a scant 0.000176 ounce (or 5 milligrams), 100 times less than what old thermometers used to contain (and, aside from Uncle Fester, not many of us put light bulbs in our mouths). I've always found the special disposal process the most objectionable part of the CFL experience. It's a small price to pay--and not too onerous--but I'm still eager to switch to something better. However, a new study sheds new li-- er, I mean, raises new potential issues with CFLs. The issue? Ultraviolet (UV) light. Remember how the CFL works: UV light excites the phosphor to generate visible light, right? Technically, the phosphor coating is supposed to absorb all the UV light, but during manufacture (particularly when the bulbs are bent or coiled) bits of the coating can flake off, creating "bald" areas that allow small bits of UV light to escape the bulb. The problem, as you may have grokked by now, is (via The Green Grok):

The researchers found further that exposing living skin cells to the CFL produced damage consistent with UV radiation, and that the damage was enhanced in the presence of titanium dioxide — a compound often present in skin care products. They conclude that “UV radiation emanating from CFL bulbs (randomly selected from different suppliers) as a result of defects or damage in the phosphorus coating is potentially harmful to human skin.”

Now, before we all start screaming "CFLs cause cancer!" let's clarify (emphasis added):

Tatiana Mironova, co-author of the [CFL-UV] study, told Media Matters that “there is no link in scientific literature between CFL exposure and cancer.” And dermatologist Dr. Howard Brooks explained that CFLs emit “such a small amount” of UV rays that they “shouldn’t be a risk.” Dr. Brooks said that skin damage would only be a concern after “prolonged exposure,” such as sitting directly underneath a desk lamp for an extended period of time.

I'm not one to panic and start throwing away (carefully, of course) all the CFL bulbs in the house. But it does offer a bit more impetus to keep an eye out for alternatives to CFLs. (There are halogen lamps--hotter, but more efficient, than incandescents, but not as efficient as CFLs.) So I still say let us look to the LED—more efficient, safer, and longer-lasting. Well, except for one bulb that has been burning for 100 years and, of course, the pride of Livermore, Calif., the Centennial Light Bulb, which has burned continuously for 110 years.