If you are worried about mercury perhaps you ought to consider the following:
The largest source of man-made mercury in the environment from from burning coal in coal-fired power plants.
If you compare the 3.5 mg that are in a fluorescent bulb that is the equivalent of a 100 watt incandescent you would find that electricity generated by coal would account for about 12mg of mercury released into the environment.
Since 50% of US electricity is generated by coal, that means by switching the fluorescent you reduce the amount of mercury in the environment by about 2.5 mg per light bulb.
Moreover, it is also possible to actually properly dispose of fluorescents whereas it is awful tough to get rid of the mercury released as a gas.
So now you can sleep better knowing that your mercury balance is actually better.
Someone should tell the Chinese. I suspect that all power plants will be forced to put on bag houses soon. It seems that we are not seeing Hg coming out of stacks with these bag houses. Let's put it in the flyash and bottom ash and sequester it in cement.