Radon
From Conservapedia
Radon is a noble gas. It is not to be confused with radium, an alkali earth metal.
Radon is a radioactive gas which comes from the decay of uranium in the ground. It is a health hazard and causes cancer in people and animals exposed to it. In the United States homeowners are advised by the EPA to test for the presense of Radon and if found to take remedial action.
Radon is most often found in basements or crawl spaces and the remedial action is to vent the area.
