How is radon measured and what levels are "too high"?
Radon is measured in picocuries per liter (pCi/L) of air.
No level of radon is considered absolutely safe.
The average indoor radon level is about 1.3 pCi/L.
The U.S. Environmental Protection Agency recommends that action be taken to reduce radon levels if the annual average is 4 pCi/L or higher.
How do you test for radon?
Testing for radon is simple and takes only a few minutes of your time.
Radon test kits are available through the mail and from hardware stores and other retail outlets. Inexpensive short-term and long-term radon test kits can also be ordered through city or county public health departments. For a list of test kit manufacturers and local radon contacts see www.health.state.mn.us/divs/eh/indoorair/radon/rncontacts.html.
Radon test kits are placed in the lowest lived-in level of the home and left for the specified period of time. After that time, the kit is sent to the laboratory for analysis.
There are two common commercially available types of radon test kits:
1. Short-term tests remain in your home for two days to 90 days.
Charcoal canisters and electret detectors are the most commonly used for short-term testing. Because radon levels vary from day to day and season to season, a short-term test is less likely than a long-term test to tell your year-round average radon level.
If the result of a short-term test is 4pCi/L or higher, take a follow-up test to verify results before fixing your home.
2. Long-term tests remain in your home for more than 90 days.
Alpha track and electret detectors are the most commonly used for this type of testing.
A long-term test will give you a reading that is more likely to tell you your home's year-round average radon level than a short-term test.
There are also qualified contractors who can conduct radon tests. Choose a radon contractor who is certified by the National Environmental Health Association (NEHA) or the National Radon Safety Board (NRSB).
Are the tests reliable?
The National Environmental Health Association conducts the Radon Measurement Proficiency (RMP) program to evaluate companies that make and analyze test kits. Look for a test kit from a company that has successfully completed the RMP program.
How long does it take to get the results?
The length of time it takes to get results varies with the laboratory, but generally, you can expect results within a few weeks.