Andrea,

This could be very serious. You may want to deal with this issue right away.

Perhaps you could call a local poison control center and ask them what to do. The risk is that they may kick you out of your house if they determine that there is real danger.

You could also rent a mercury vapor meter (about $100 per day) and take measurements yourself. If you need contact information for a rental center, just let me know.

Keep us posted.