Radon... What is it and should I be concerned?
Should I Test for Radon?
Whether or not to test for radon is a great question and one that gets asked all the time. Maybe you are a first-time home buyer or are someone who has lived in the same house for 30 years. You’ve heard about Radon but are not really sure what all the fuss or you don’t think it applies to your home. The more information you have, the better-informed decision you can make. To help with this, let’s break radon down into three parts.
What is Radon?
Before you can decide anything, let’s explore what Radon is and where it comes from. Radon is a radioactive gas that you cannot see, feel, smell, or taste. It comes from decaying uranium found naturally in the soil. As a gas, the radon moves easily through openings and cracks in a house. Once out of the soil, Radon itself decays, and it’s progeny attach to dust particles that can be inhaled. The inhalation of these particles has been shown to cause lung cancer, and the greater the levels, the higher the risk. Radon is currently the second greatest cause of lung cancer according to the EPA, smoking being the first.
How does it enter my home?
Since radon is a gas, it easily moves through soil as well as small holes, cracks, plumbing penetrations and sump pumps. Differences in air pressure between the basement or crawlspace and the surrounding soil draws radon into the home though these entry points. Because radon can literally be sucked into a home, any home can potentially have a radon problem. All conventional house construction types have been found to have radon levels exceeding the action level of 4 pCi/L. Let’s review the most common types of homes: BASEMENT Radon can enter through floor-to-wall joints, control joints, and cracks in the slab. CRAWLSPACE The vacuums that exist within a home are exerted in the crawlspaces, causing radon and other gases to enter the home from the area below. Even with crawlspace vents, a slight vacuum is still exerted in the crawlspace. Measurements of homes with crawlspaces have shown elevated radon levels. SLAB-ON-GRADE Radon can enter a home regardless of whether it has a basement. Slabs built on grade can have just as many openings to allow radon to enter as do basements. MANUFACTURED HOMES Unless these buildings are set up on piers without any skirting placed around them, interior vacuums can cause radon to enter these types of homes as well.
What really are the risks?
It is estimated that 1 in 15 homes nationwide have levels at or above 4pCi/L, the level at which the EPA recommends taking action to reduce concentrations. The only way to know if there is radon present is to test for it. I like visuals, so I l find the following table helpful to give some perspective to the risk at different Radon levels. (From “A Citizens Guide to Radon”)
I hope this helps answer some of the questions you have about Radon. There is a lot more information available on this subject, and if you would like to learn more, check out the following resources. EPA on Radon InterNACHI's citizen guide to radon