The Risk of Lung Cancer from Exposure to Radon in Indoor Air

Tools You Can Use

All homes should be tested for radon. Learn about the health risks associated with radon.

Radon is a colorless, odorless, and tasteless radioactive gas that is formed during the natural breakdown of uranium in soil, rock, and water. It exits the ground and can seep into your home through cracks and holes in the foundation. It can also enter your home in well water.

The National Academy of Sciences (NAS) has estimated that each year in the United States, between 15,000 and 22,000 people die from radon-related lung cancer. Exposure to radon is the second leading cause of lung cancer, after smoking.

The American Society of Home Inspectors (ASHI) recommends that home owners and home buyers test their current or prospective home for the presence of radon gas in indoor air. EPA strongly recommends that steps be taken to reduce indoor radon levels when test results show 4 picocuries per liter (pCi/L) or higher in the air.

In cooperation with EPA's Indoor Environments Division, ASHI created the Radon Mitigation System Inspection Checklist (PDF) (2 p, 43K, About PDF). With just seven inspection elements, the Checklist takes under 15 minutes to complete.

Inspectors can easily integrate radon inspection into a general home inspection. The results tell buyers or owners whether the home has a radon mitigation system, and if so, whether the system is active or passive. Home buyers or owners are encouraged to verify (by using a radon testing kit) that indoor radon levels are below 4 pCi/L, and to consult a qualified mitigator if the inspector notes any apparent deficiencies on the ASHI checklist.

About the Indoor Environments Division | Where You Live | Frequent Questions | A to Z Subject Index

The Risk of Lung Cancer from Exposure to Radon in Indoor Air

Tools You Can Use

Local Navigation