January 2014 has been designated National Radon Action Month by the EPA.  Learn more about Radon — an invisible, odorless radioactive gas that occurs in nature and is found in homes across the U.S. — and the national effort to take action against it:
http://www.radonmonth.org/
and check out “A Citizen’s Guide to Radon” — http://www.epa.gov/radon/pubs/citguide.html