How to Test for Contaminated Indoor Air Quality

Purchase a radon test kit and a carbon monoxide monitor from your local hardware store. Make sure that both say "EPA certified" or "Meets EPA requirements."

Install the carbon monoxide monitor in your home according to the instructions that come with it. Many people install them near a fire alarm in the main story of their house. For additional safety, install one on each floor of your house. If the carbon monoxide levels rise too high, the alarm will go off.

Use your radon test kit. Close all outer doors and windows in your house 12 hours before beginning the test and put the test kit in the lowest floor of the house that is regularly used, in a frequently used room (not a kitchen or bathroom). Put the kit up on a stool or shelf away from heat and humidity, drafts and exterior walls. Leave the radon test in place for three days (or as long as the kit says).

Send the test away to the lab listed on the label. They will send results within a month. If your radon measures 4 pCi/L or more, use another test kit to verify, then contact your state radon office for more information.