Radon testing when you rent

Radon is a radioactive gas from the soil that you can't see, smell or taste. It seeps into buildings through drains, cracks and other gaps in the foundation, and it's the second leading cause of lung cancer after smoking. Testing is the only way to know the level in your home. Most rental homes are single-family houses or apartments below the third floor, where high radon is most likely. Higher floors can have high levels too, when radon moves through elevator or air shafts.

What you need

• A do-it-yourself radon test kit from a hardware store or a lab, with the lab analysis included
• The kit's instructions

Steps

1. 1

   Ask whether it's been tested

   Ask the owner whether the building has been tested for radon, and ask for a copy of the results if it has. A building that was tested properly may not need another test.

   5 min

2. 2

   Place the kit

   Set the kit on the lowest floor you use regularly, such as a basement you live in, or otherwise the first floor. Put it in a room you use often, like a living room or bedroom, and not the kitchen or bathroom.

   10 min

3. 3

   Keep the house closed

   Keep doors and windows closed as much as you can during the test, since drafts can change the result. Leave the kit in place as long as its instructions say, and at least 48 hours.

   5 min

4. 4

   Send it to the lab

   Reseal the kit and mail it to the lab named on the package. Results usually come back within a few weeks.

   10 min

5. 5

   Retest a high result

   If a short-term test reads 4 pCi/L or higher, do a second test to confirm it, or ask the owner to test further.

   10 min

6. 6

   Check the result and tell the owner

   If the result is 4 pCi/L or higher, send the owner a copy in writing and ask what the owner plans to do. Fixing radon usually means repairs to the building by a trained radon contractor.

   10 min

After you test

In an apartment building, share the results with other residents, since levels can differ from unit to unit. If you later move into a lower floor than the one you tested, test again there. Test again in the future even after a result below 4 pCi/L. How to test your home for radon covers the kinds of test in more detail.