When you landfill a used CFL, you aren’t landfilling 5mg of mercury. You are only landfilling what is left when the bulb goes out. Most of the mercury will be bonded to the glass by then. EPA says 14% of the mercury will eventually escape from the bulb if used up, broken, and in a landfill.
And not all of our power is generated from oil. Coal causes at least twice as much mercury pollution escape. Here in Wisconsin, oil is only 1.4% of our electricity. Coal is 65%.
5mg * 14% = 0.7mg of Hg released in a landfill.
8,000 hours use * 13W CFL = 104kWh of electricity.
national average Hg released per kWh produced from all sources of power nationwide is .012mg (EPA)
104kWh * .012mg Hg = 1.25mg Hg released through power consumption.
1.25mg + .7mg = 1.95mg of mercury pollution for 8000 hours of CFL use.
Incandescent bulb contains no mercury.
8,000 hours * 60W incandescent bulb, (equivalent to 13W CFL,) = 480 kWh of electricity.
480kWh * .012 mg Hg = 5.76mg Hg
There you have it. In 8,000 hours of use, (typical lifespan of a CFL,) you will get 1.95mg of mercury pollution from a CFL and 5.76mg mercury pollution from incandescents even if you dump the CFL into a landfill.
Note that some municipalities incinerate trash and this will certainly result in the release of more mercury from a broken CFL when the glass melts I would guess.
As I’ve said, I don’t think the environutalists have done this type of math before. Painting signs is much easier.
And there you got me. I grabbed a statistic for the amount of mercury in oil, which is low because of refining. We burn a lot of coal--you've got the better statistic--and its over a 1000 times higher than the number I found. Thanks.