Radon Testing  

EPA Recommends
  1. Test your home for radon - it's easy and inexpensive. Start with a short-term test. You can Contact Us to Help Arrange Radon Testing
  2. If your result is at or above 4 pCi/L,  follow up with either a long-term test or another short-term test.
  3. Average the results of the tests.  Fix your home if your average radon level is 4 pCi/L or higher.

Radon levels less than 4 pCi/L still pose a risk, and in many cases can be reduced.

You can't see radon, but it's not hard to determine if you have a radon problem. Testing for radon is easy and should only take a few minutes of your time.

For airborne radon, you can choose either a short-term test, usually 2-7 days, or long-term, test, usually 3 months to a year. The short-term measurement gives a quick snap shot of your radon levels, while a long-term measurement captures the seasonal variations and lets you know what levels you are living with for an extended period of time. For waterborne radon, you will need to collect a water sample from a household faucet.

How to Test for Radon

Hire a Professional

If you are concerned about performing the test yourself or if you are buying or selling a home, you can hire a certified radon measurement professional to do the testing for you. To find a professional you can contact your state radon office to obtain a list of qualified testers.  (See the left-side bar for links to the California state radon sites.)  Another option is to  contact a private radon proficiency program the  for lists of privately certified radon professionals serving your area.   You can Contact Us to Help Arrange Radon Testing


Common Types of Radon Tests
Short Term Testing

The quickest way to test is with short-term tests. Short-term tests remain in your home for two days to 90 days, depending on the device. "Charcoal canisters," "alpha track," "electret ion chamber," "continuous monitors," and "charcoal liquid scintillation" detectors are most commonly used for short-term testing. Since radon levels tend to vary from day to day and season to season, a short-term test is less likely than a long-term test to tell you your year-round average radon level. If you need results quickly, however, a short-term test followed by a second short-term test may be used to decide if you need to to fix your home.

Long Term Testing

Long-term tests remain in your home for more than 90 days. "Alpha track" and "electret" detectors are 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.  these tests give you a better idea of your long term exposure.  Click here to see the health risks associated with Radon exposure.


What do the results mean?

The amount of radon in the air is measured in "Pico curies per liter of air" or "pCi/L".  The average radon level is estimated to be about 1.3 pCi/L indoors, and about 0.4 pCi/L outdoors. Radon levels fluctuate naturally. An initial test might not be an accurate assessment of your home's average radon level. Transient weather can affect short-term measurements.

If you are buying
    a Property

Purchasers of real estate are advised to delay or decline a purchase if the seller has not successfully reduced the radon levels to 4 pCi/L or less. Most homes today can be reduced to 2 pCi/L or below. 

If the results of your first test were:
  • between 2 and 8 pCi/L, you have the choice of testing method. If results are needed quickly, use a short-term (2-7 days) device. For a better understanding of your home's year-round average, use a long-term (3-12 months) device.
  • higher than 8 pCi/L, it is recommended that you test again using another short-term test device. The higher the radon concentration above 8 pCi/L, the sooner you should conduct a retest. 
  • higher than 10 pCi/L, warrant only another short-term test so that abatement measures are not unduly delayed.  

See the Radon risk tables for the health risks associated with long term exposure to Radon.

Average Exposure

Once you have conducted a second test, average the results to determine your average exposure to radon gas. 

Average Over 4.0 pCi/L
  • If you are involved in a real estate transaction, the EPA recommends fixing the house prior to sale if the average of your original and follow-up tests are 4.0 pCi/L or higher.
  • If you chose a long-term device for your second test, the EPA recommends fixing your home if the follow-up result is 4.0 pCi/L or higher.
  • If the results of your follow-up test with a  short-term test are still 4.0 pCi/L or higher, you are urged to consider fixing your home.

Sometimes short-term tests are less definitive about whether or not your home is above 4 pCi/L. This can happen when your results are close to 4 pCi/L. For example, if the average of your two short-term test results is 4.1 pCi/L, there is about a 50% chance that your year-round average is somewhat below 4 pCi/L. However, EPA believes that any radon exposure carries some risk - no level of radon is safe. Even radon levels below 4 pCi/L pose some risk, and you can reduce your risk of lung cancer by lowering your radon level.

Average Under 4 pCi/L

Even if your test result is below 4 pCi/L, you may want to test again sometime in the future. Keep in mind that radon levels less than 4 pCi/L still pose a risk, and in many cases can be reduced.   The EPA recommends fixing your house if your average results are between 2 and 4 pCi/L.

Yes!  Most homes can be fixed. 

If you have performed a follow-up test and your radon level needs to be reduced, you have several options. With today's technology the radon level in most homes can be reduced to under 2 pCi/L.

Radon Mitigation Options..... Next