>>64173265
Oh shit. I forgot to mention an important issue that can sometimes (usually most of the time) come up with radon gas. Even if radon is mostly concentrated in the basement, it can have the potential of traveling upwards into higher levels of the home. That air conditioning system you have can pull it further up the house, and even simply opening a window on the top floor can cause a reverse chimney effect. If you see a reading of 140Bq down in the basement, chances are you'll see a reduced amount upstairs as well. I know I was affected, because the readings upstairs was 90Bq.