Not a lot -- in fact just a miniscule amount -- probably just the amount that used to go into vaccines. I guess the mercury industry found another market (no wonder they folded on the vaccine issue) So we're still not rid of mercury in our environment even though it's been proven over and over how toxic it is
from https://www.ecy.wa.gov/programs/swfa/recyclefaq.htmlHousehold Hazardous Waste
Q. Why should I recycle my compact fluorescent lights and fluorescent tubes?
A. Compact fluorescent lights (CFLs) and tubes come in various shapes and sizes. CFLs contain small amounts of mercury (about as much as the ink on the tip of a ball point pen). If the lights are broken, mercury vapor can enter the environment and settle into surface waters, where it can turn into highly toxic methylmercury. Fish and other wildlife can then ingest the mercury and pass it up the food chain to humans. Once mercury is in the food chain, it is almost impossible to remove. The U.S. Environmental Protection Agency estimates that 600 million fluorescent lights are disposed of annually, with over 80 percent ending up in landfills. Because mercury persists in the environment, you must not throw away CFLs with your regular garbage. Instead, recycle them at your local household hazardous waste facility, so the mercury, aluminum, glass, and phosphor can all be safely recovered.
Q. What should I do if a compact fluorescent light or fluorescent tube gets broken?
A. If a light breaks, put on protective gloves and carefully sweep up all of the glass fragments and any powder with a disposable hand broom and dust pan. Place the broken pieces of glass in a rigid food storage container with a snap on lid. Place the disposable hand broom and dustpan in a plastic bag and wipe the area with a damp paper towel. Put the used towel in the plastic bag as well and then place everything in a five-gallon bucket or container with a lid. The greatest potential hazard in this situation is being cut by the broken glass. Ventilate the area well. Make sure to never use the vacuum cleaner because you would contaminate your vacuum and the mercury could become airborne. Dispose of the waste at your local household hazardous waste facility.