[jyl]

The amount of mercury you might realistically ingest after breaking a CFL is about the same as the amount you will ingest from eating a can of tuna.

A CFL has 4-5 mg mercury. If a CFL breaks, a portion of that mercury eventually evaporates. Tests on standard fluorescent tubes showed appx 1/3 of the mercury evaporated gradually over a several day period, with 2/3 remaining in the broken tube. So, break a CFL and take an hour to sweep up and discard the bits, and the amount of mercury that might evaporate into the air during that time is, perhaps, 300 micrograms. The amount that you might inhale is some fraction of that, maybe 100 micrograms.

A typical can of tuna can contain 50-70 micrograms of mercury.