I can only hope that this is not an accurate quote, coming from the EPA.
For starters, mercury could not be 'solid waste' for the simple reason that it is a LIQUID.
Secondly, the amount of mercury per thermometer is minuscule, probably 1/10 of 1 gram per thermometer. This would indicate that 170,000,000 mercury-based thermometers are discarded each year, which would be simply unbelievable.
And, even if it were true, check this out:
DEMAND: Manufacturing of chlorine and caustic soda consumes approximately 35 percent of the mercury used in the United States, according to the USGS. Electrical and electronic applications consume 30 percent, and the remaining 35 percent is used for such applications as measuring and control instruments and dental amalgams. An estimated 400 tonnes of mercury were consumed in the United States in 1998, up from 346 tonnes in 1997 but down from earlier years. The value of mercury used in the United States was estimated at $2 million, the USGS said.
Oh, that's right. We can't throw our thermometers away without harming the environment, but a little in our teeth is no problem. /sarcasm