Add Yahoo as a preferred source to see more of our stories on Google. A-graphic-with-the-words-Radon-Free-and-a-house-outline-are-laid-over-a-field-of-green-grass-and-blue-skies. A silent killer is ...

Radon is a naturally occurring gas that seeps out of rocks and soil. Radon comes from uranium that has been in the ground since the time the earth was formed, and the rate of radon seepage is variable ...