I just did a series of presentations in Tempe, AZ, had a wonderful time, hope to post more.
One night, the question of mercury in compact fluorescent bulbs generated a bit of discussion.
Sources of Mercury Emissions include coal power plants (utility boilers), cement, landfills, etc. The addition of mercury to the environment is declining; after peaking in 1960, emissions have fallen more than half. US emissions dropped by 1/3 just in the 1990s. This is because mercury use is less common.
The contribution of mercury from compact fluorescents is small, smaller than the contribution of incandescent bulbs lit in part by coal power.
Heavy metal poisoning can be serious, that said, I’m not sure why mercury has grabbed the public interest, though I see environmentalist groups pushing this concern. Not to mention the US government’s focus on cleaning up coal emissions of mercury, with less public discussion of the more potent killers from coal power. While coal is the single biggest contributor to mercury in the air, mercury is far down the list of coal’s sins. Carbon dioxide, causing climate change, particulates, killing some 30,000 Americans annually and hundreds of thousands of Chinese, and ozone, killing 1,000 Americans annually and ?? Chinese, certainly are more important than mercury. Incandescent bulbs use about 4 times the electricity and create 4 times the number of deaths and illnesses, of which mercury is a minor portion.
Compact fluorescent bulbs save lives.
Incandescent bulbs are costly. If your electricity is made from coal or natural gas, incandescent bulbs are important contributors to mortality rates, environmental destruction, and a small increase in mercury emissions (though larger than the contribution from compact fluorescents).
Switching your bulbs to compact fluorescent is a good idea!
Dispose of your light bulbs as specified locally. In some places, this means collecting them until other stuff is taken in for processing. In others, it means throwing compact fluorescents out with the trash, unless you generate more than 100 kg in hazardous waste/month.
How dangerous is mercury?
It, along with cadmium, arsenic, and lead, would not be commercially affordable if they had to meet the same standards as uranium. That said, avoid breaking CFL’s regularly and there shouldn’t be too much problem. The old mercury thermometers had between 10 and 800 times as much mercury as a compact fluorescent bulb. The Japanese problems with mercury poisoning from fish occurred after industrial dumping. Don’t go out of your way to eat mercury, but don’t worry too much about the levels of mercury in CFL’s either.