Science World Blog Mercury and the Path to Enlightenment
Mercury and the Path to Enlightenment
Last Updated (Wednesday, 24 September 2008 09:47) Written by Raymond Nakamura
The legendary band Queen might be able to function without Mercury, but the energy efficient fluorescent light cannot.
I didn't even know fluorescent lights contained mercury, until I recently looked into how to clean up a broken one. The amount of mercury is considered small — much less than in a thermometer or a dental filling. But then, most thermometers and dental fillings don't use mercury at all any more.
Why Mercury is a Concern
Mercury has many amazing properties, which would be fun to explore, if only it weren't so hazardous to our health. Perhaps the most famous case is Minamata disease, named for a town in southern Japan where residents consumed fish contaminated with mercury from untreated industrial wastes dumped into the bay. I heard it took many years for victims to receive any government assistance. When I passed through MInamata some years ago, it did not seem like an especially cheery place and I didn't go for the seafood, but it now seems to be promoting itself as a model environmental city .
Why Fluorescent Lights Use Mercury
Compact fluorescent lights are new and improved, but on the inside, they mostly work the same way as the long tubes. When electrons in atoms of Mercury (and other gases) floating inside the glass tube get excited by electricity, they give off ultraviolet photons. These photons excite the phosphor, the white powder on the inside of the tube, which then gives off white light.
Why We Use Fluorescent Lights
Fluorescent lights are way more efficient than the old incandescent bulbs because, as you can tell just by feeling them, they don't spend much energy on heat. And new compact fluorescent bulbs have better light quality.
One of the largest sources of mercury is from burning coal, still a major way to generate electricity. Even though BC uses hydro, we also get electricity from other sources as well. Overall, using less electricity should result in less mercury in the environment.
So the world seems complicated and imperfect, but for now, I believe it is better to flick on a fluorescent light than curse the darkness.
