The Facts About Radon in Homes

Jim Crawford, Field Specialist in Agricultural Engineering University of Missouri Extension, Atchison County

Radon.  Most people are aware that this is a gas that can sometimes present a health hazard inside their home.  However, that is generally the limit of knowledge for most people regarding radon.

Radon is an odorless, colorless, radioactive gas that is caused by the natural breakdown of material that contains uranium.  In the outdoors, radon is diluted to such low concentrations that it is usually harmless.  However, inside an enclosed space such as a home, radon can accumulate to harmful levels.  

Over the past 30 years we have made every attempt to make our homes as airtight as possible to reduce the energy requirements to heat and cool them.  The lack of air transfer between the outside and inside of these airtight, energy efficient homes has caused radon levels (as well as dust and other allergen levels) to increase in some cases.  This is not saying that the energy efficient homes are the only ones affected; the symptoms are just generally noticed quicker in these homes due to the concentration.

The main route of entry for radon into a home is through cracks and openings in walls and floors from the soil under a home.   Radon also can enter water in private wells and be released into the home when the water is used.

Now that we know what radon is and how it enters the home, what are the risks?  The EPA estimates that between 5000 and 20,000 lung cancer deaths a year in the United States are the result of radon exposure.  The greater your exposure to radon the greater your risk of developing lung cancer.

There are two techniques commonly used for detecting radon: Charcoal Canisters and Alpha Track detectors.  Both are exposed to the air in a home for a specific time period and then are sent to a lab for analysis.  Both are commercially available to homeowners, are relatively inexpensive and easy to handle.  The Alpha Track detector allows you to take long term reads while the Charcoal Canister is only for short-term measurements.  Other techniques are available, but they require very expensive equipment and trained personnel.

The screening measurement taken with the Alpha Track and Charcoal Canisters will indicate a potential for a radon problem.  This is because radon levels can vary greatly from season to season as well as room to room.  Depending on the results from these tests, a homeowner may need to have a follow up measurement taken to determine the average radon level in the home.

There are several things that can be done to reduce the radon levels in a home.  Some techniques prevent radon from entering your home and others reduce the levels after the radon has entered.  In almost all cases, preventing the radon from entering the home is the preferred approach.  

If the tests show an elevated level, there are some simple steps you can take to reduce your exposure until the situation can be addressed.

–Stop smoking.  Scientific evidence indicates that smoking may increase the risk of complications from radon exposure.

–Spend less time in areas with higher concentrations of radon, such as basements.

–Open windows and turn on fans to increase the airflow through the house.

The most common solution to prevent entry of radon into your home is called a soil suction system.  This prevents radon from entering your home by drawing the radon from below the house and venting it through a pipe to the outside where it is quickly diluted.

If you would like more information on this topic, University of Missouri Extension guide sheet GO1968 Radon: An indoor health hazard? covers most of the basics of radon.  The Missouri Department of Health and Senior services has an excellent website with lots of information about radon at https://health.mo.gov/living/environment/radon/index.php. There is also a link on their webpage where you can order a free radon test kit.