Radon Testing Season Starts When the Windows Close

Radon is cheap to check and easy to keep putting off. Fall makes it simpler, because a short term test has to run with the windows and outside doors closed, and by the end of September mine are already shut.

The two numbers EPA uses

Fix your home if your radon level is 4 picocuries per liter or higher. That’s the action level. EPA also recommends that you consider fixing between 2 pCi/L and 4 pCi/L, because there is no known safe level of exposure, and it notes that most homes today can be brought down to 2 pCi/L or below. For scale, the average indoor level is estimated at about 1.3 pCi/L, and about 0.4 pCi/L is normally found in outside air.

Why the average says little about your house

Radon comes from the natural breakdown of uranium in soil, rock and water, and it gets into the air you breathe through whatever is under and around the foundation. Two houses on the same street can read differently. EPA’s Massachusetts fact sheet says the Map of Radon Zones was developed to help governments and other organizations target risk reduction activities and resources, that it should not be used to determine if individual homes need to be tested, and that all homes should be tested regardless of zone designation.

Short term or long term

Short term tests remain in your home for two days to 90 days, depending on the device. They’re the quick answer. Long term tests remain more than 90 days and are more likely to tell you the year round average, which matters because levels vary from day to day and season to season.

EPA’s testing steps

Step one is a short term test. If the result is 4 pCi/L or higher, follow up. Step two is either a long term test, for a better understanding of the year round average, or a second short term test if you need results quickly. Step three: if you followed up with a long term test, fix the home when that result is 4 pCi/L or more. If you followed up with a second short term test, consider fixing when the average of the two is 4 pCi/L or higher.

How to run the kit so the result counts

If you are doing a short term test, close your windows and outside doors and keep them closed as much as possible during the test. Heating and air conditioning fans that recirculate air may run. Do not run fans or machines that bring in air from outside. If the test only lasts two or three days, close the windows and doors at least 12 hours before you start, and don’t run it during unusually severe storms or unusually high winds. Place the kit in the lowest lived in level of the home, in a room used regularly like a living room, den or bedroom, but not the kitchen or bathroom. Put it at least 20 inches above the floor where it won’t be disturbed, away from drafts, high heat, high humidity and exterior walls.

If you ever plan to sell

Buyers often ask whether a home has been tested and whether high readings were fixed, and real estate sales happen quickly. EPA’s advice to owners is to test now and save the result in case the buyer is interested in it. Fixing a problem before you list keeps it from becoming a negotiation in the middle of a deal.

Buying or selling in Greater Boston this fall and wondering whether radon belongs on your list? Send me the address and I’ll tell you what to ask for. Diana Kim, REALTOR®, eXp Realty.