I'm always somewhat annoyed when people and organizations say "CFLs contain a very small amount of mercury sealed within the glass tubing – an average of 4 milligrams. By comparison, older thermometers contain about 500 milligrams of mercury." Or "The 4mg of mercury in CFL's is better for the environment than the 9 milligrams being created per incandescent lamp from coal fired plants."
My response is that the only acceptable amount of mercury (a persistent neuron toxin) for the environment is NO mercury. Because of the mercury hazard - mercury thermometers have been virtually phased out over the last decade. Even when they were being sold they weren't selling at a rate of 400 million per year (U.S. CFL sales 2008) and growing.
Also, only 50% of U.S. energy comes from coal fired plants. The list of counterpoints can go on and one. Bottomline, less mercury is no solution. No mercury should be the goal.
A friend's son sent me this video link. It's an interesting look at a chemical analysis process. Most importantly is the result "concentration of diluted sample was .1 mg/L, so in conclusion sample has a significant amount of mercury".