We learned today that our house "to be" has, what is considered to be, a very high level of radon (did you know the Surgeon General has warned that radon is the second leading cause of lung cancer in the United States today?).
I, of course, obsess about this kind of thing (which drives Hubs crazy). Why is it worth obsessing over? Because it is invisible, tasteless and odorless (just like pesticides).
After talking with the US EPA, the Colorado Department of Health, and a local radon removal specialist, I am happy to report that they all concur - radon is extremely common in Denver. The issue can be resolved by installing a ventilation system that pushes the gases outside.
For fun reading about radon, visit: http://www.epa.gov/radon/