Here are some useful links for any homeowner
U.S. Environmental Protection Agency
…to protect human health and the environment. A wide variety of topics are available including, lead, radon, mold, asbestos, human health, etc.
http://www.radon.com/
Excellent radon information center.
http://www.epa.gov/iaq/states/minnesota.html
Indoor air quality information on mold, radon, carbon dioxide, tobacco smoke, homes, schools, and other indoor air quality topics.