John Shaffer of Radon Control Services puts stickers next to the manometer that reads the amount of radiation in the house as he installs a radon remediation system Thursday, June 15, in a basement. Shane Potter/Butler Eagle

Present in about 40% of homes in Pennsylvania, radon gas is the second leading cause of lung cancer, but it is easily detected and remediation is relatively inexpensive.

Radon is a colorless and odorless naturally occurring gas formed by the decay of radium atoms from uranium in soil and rock. The amount of radon that escapes from the soil to enter a house depends on several factors including weather, soil porosity and soil moisture, according to the U.S. Environmental Protection Agency.

Pennsylvania has one of the highest incidence of radon among states in the country, according to the state Department of Environmental Protection.

The DEP recommends testing using a kit that can be purchased at hardware or home improvement stores for $20 to $30 or hiring a state certified testing company.

DEP has a directory of certified radon testers and mitigators at www.dep.pa.gov/Business/RadiationProtection/RadonDivision.