Testing Your Home for Radon

Radon is an odorless, tasteless and invisible gas that is released by the decay of uranium, a naturally occurring rock in our soil. When radon is released from the ground, it can seep through cracks in the foundation of a home. Breathing in radon can damage cells in the lungs and can lead to lung cancer. Radon exposure is the second leading cause of lung cancer in the United States and is responsible for more than 21,000 lung cancer deaths each year.

Testing your home for radon is the only way to determine if you and your family are at risk for radon exposure. It is important to test your home every two years. You can do it yourself or hire a licensed radon measurement professional.

How does radon get into your home?

  • Cracks in solid floors
  • Construction joints
  • Cracks in walls
  • Caps in suspended floors
  • Caps around service pipes
  • Cavities inside walls
  • A ground water supply

How do I test my home?

You can test your home with an inexpensive kit available at most hardware stores. Some of the most commonly used devices are charcoal canisters, alpha track, electric ion chamber, continuous monitors and charcoal liquid scintillation. Keep doors and windows closed 12 hours before and during the test.

There are short-term testing devices that are used between two and 90 days and are good if you need quick results. Long-term devices remain in the home for more than 90 days and will provide a more accurate radon average because the amount of radon in your home varies from season to season.

Where should the detector kit be placed?

Kits should be placed in any livable room where the foundation has direct contact with soil, for example, basements and rooms above crawl spaces. Kits should also be placed in rooms that are the lowest area suitable for occupancy, such as a family room, bedroom, den, playroom, etc. Make sure the test is placed:

  • Where it won’t be disturbed
  • Three feet from outside doors or windows
  • Out of direct flow from an air duct
  • One foot from exterior walls
  • 20 inches to six feet from the floor
  • Four inches from other objects
  • Four feet from heat or direct sun

What do I do with the results?

If test results are above 4.0 pCi/L, it is recommended that you have your home mitigated. The Illinois Emergency Management Agency has a list of professional radon mitigaters trained to reduce radon levels.

Radon Resources

Click the red links below to visit recommended radon sites and resources.

United States Environmental Protection Agency (EPA)

A Citizen’s Guide to Radon
An overview of how to protect yourself and your family from radon, how to test your home, myths and facts about radon, and a list of resources.

A Consumer’s Guide to Radon Reduction: How to fix your home
A guide to reducing radon levels in your home, choosing a qualified radon mitigation contractor, reducing radon at work, and maintaining a radon reduction system.

A Home Buyer’s and Seller’s Guide to Radon
A guide to testing a home for radon, buying or building a home, selling a home, radon-resistant homes, and radon mitigation.

Illinois Emergency Management Agency (IEMA)

The ABCs of Radon in Illinois: What every family should know – Also available in Spanish.
An overview of testing a home for radon, where radon comes from, radon zones in Illinois and radon mitigation systems.

Guidelines for Home Environment Radon Measurements
A guide to buying and using long-term and short-term radon tests, how to test your home, and what to do with test results.

Radon Guide for Tenants
A guide for people who rent houses, apartments and condominiums explaining what radon is and how to find out if there is a radon problem in the residence.

Radon Testing Guidelines for Real Estate Transactions
A guide to testing a home for radon before buying or selling.

Guide to Radon Mitigation
A guide to various methods of radon mitigation in homes.

IEMA Radon Measurement Laboratories and Low Cost Detectors
IEMA’s listing of licensed laboratories and test kits that have demonstrated accurate radon measurement.