Radon in Soil

Radon Testing–A Homebuyer’s Guide

Many experts recommend a radon test as part of the home inspection. I just wanted to take some time and give a brief overview of radon as it pertains to the home buying and home inspection process. I don’t want to get too technical, and this subject gets technical fast, but I’ll link to some resources that go into greater depth.

So, you’re having a home inspection and your real estate agent recommends a radon test. So, what is radon and why do we care? Radon is an odorless, colorless gas that is produced from the radioactive breakdown chain of uranium naturally occurring in the soil. It is particularly prevalent in areas with granite bedrock, but can be found anywhere. We care about radon because it is the second leading cause of lung cancer in the U.S. after cigarettes.

There is no recognized safe level of radon, but the EPA has set an action level of 4.0 pico Curies per liter of air, abbreviated pCi/L. The definition of a pico Curie is fairly technical and irrelevant to a basic understanding of radon for homeowners. Just know that we want to see a level below 4.0 pCi/L and that if we find a higher level, it’s time to consider remediation.

Radon can be tested in several different ways, in both short-term and long-term tests. In a home buying situation, a short term test is necessary given time line involved. I use a 48 hr activated charcoal test. During the test, windows and doors of the home must be kept closed and no ventilation systems may be run. Normal entrance and exit is fine, as is running heat and A/C units.

After the 48 hour testing period, I’ll pick up the test and send it off to the lab. This takes anywhere from 2-3 business days, depending on the shipping method used. The lab produces an electronic report which I will email to you upon receipt. If the radon level is very low, no action need be taken. If the level is above 4.0 pCi/L, action needs to be taken. A longer term test is a good starting place to get an accurate baseline, followed by remediation and retesting. Remediation may involve a passive or active ventilation system or other measures. Finally, if the radon is less than 4.0 pCi/L, but still above 2.0 piC/L, it’s a good idea to re-test with a long term test.

I hope that gives you a basic understanding of radon testing for home buyers. For more information, visit the EPA.