I'm an engineer. I understand quads, kilowatt hours, British Thermal Units, therms, etc. After working here at NRDC in Washington, DC for a while, I have some concept of the importance of a million metric tons of CO2 emissions. And like every American, I know that a billion dollars is too much money to waste. But I have to plead ignorance on what a ton of mercury means for me or the country.

In the context of the proposed rule on lamps from DOE, I know the potential energy, money, and carbon savings are ridiculous. Largest in history. 16 quads, $65 billion, and 800 million metric tons of CO2. Jaw dropping, mind blowing ridiculous. See my last post for more info.

But 11 tons of mercury? What does keeping this pollutant out of the air and water mean in real terms? I'm sure it's a lot of thermometers, but what really?

Since my ignorance on this matter is entirely unforgivable given that some of the leading experts on these topics sit down the hall from me, I decided to find out.

My colleague Susan Keane helped me on the mercury front. She directed me to these stats:

• Coal fired power plants emit roughly 50 tons of Hg into the air annually, so we could save the equivalent of 20% of the annual emissions from this source
• 1 gram of mercury deposited from the air each year onto a 20 acre lake is enough over time to contaminate all the fish in the lake so they are unfit to eat.
• 1 gram of mercury is enough to contaminate 1 ton of fish (at the FDA limit of 1 part per million).

So if we set the standard where we should, we would keep 11 million grams of mercury out of the air and water. This amount, if emitted all at once, could potentially contaminate 220 million acres of lake. Lake Superior is 20 million acres. That's 11 Lake Superiors.

If 1 gram of mercury can contaminate 1 ton of fish, that's 11 million tons of bad fish. Or 121 million Jeremy Pivens. Ok, I know that's not exactly right, but you get the point. These emissions would occur over 30 years, so this comparison is for scale purposes only.

Predictably, I have confirmed my notion that, like the energy, dollar, and carbon savings possible in this rule, the mercury savings defy all comparison. Yes I know that equivalencies like this aren't the best way to document impact since I say they same thing when someone asks me to translate a quad into cars off the road.  This is back of the envelope only and the conclusion is simple - it's a hell of a lot of pollution. If you care about wildlife, lakes, or your own health, then right now you care about general service fluorescent and incandescent reflector lamps. Sorry about that. We will return you to the more interesting topics shortly.

As I mentioned last time, stay tuned to this blog and the ASAP website for more info on how to get involved. After the hearing on Feb 3rd we will provide updates and information on the steps you can take to weigh in.