Radon Testing and Test Results
MDH recommends that all Minnesota homeowners test their homes for radon. A radon test is the only way to find out how much radon is in your home and if you and your family are at risk. Performing a radon test on your own is easy, inexpensive and takes only a few minutes of your time. The results of a properly performed radon test will help determine if you need to take further action to protect yourself from the health risks of radon. MDH estimates that one in three (1/3) Minnesota homes have radon levels above the Environmental Protection Agency's (EPA) recommended action level.
How do I test for radon?
It is important to follow the instructions that come with the radon test kit. There are two basic types of radon tests available to the public:
- Short-term tests measure radon levels for 2 to 7 days, or use a continuous radon monitor for a minimum of 48 hours, depending on the device. While short-term tests do not measure the annual average of level of radon, they do offer a quick and inexpensive way to "screen" for radon in a home.
- Long-term tests determine the average concentration for a minimum of 90 days. Long-term tests are the best way to estimate the average amount of radon in the home during the year, particularly if a year-long test is done to include both heating and cooling seasons.
Where can I get a radon test kit and how much will it cost?
Radon test kits are sold at some hardware or home supply stores. Your local health department may also offer test kits at reduced prices. For more information on where to obtain low cost radon test kits, see Radon Test Kits.
A radon test kit should cost between $5 and $25, depending on they type of kit. Make sure the price includes laboratory analysis.
If you choose to hire someone to test your home, it will be more expensive. Radon measurement professionals are often used when unbiased third party is needed, such as in real estate transactions.
Go to > top
How much radon in a home is safe?
There is no safe level of radon. Your risk for lung cancer increases with higher levels of radon gas and increased exposure.
The following table estimates your lifetime risk of lung cancer death due to long-term exposure to radon.
| Radon (Annual Average) Level |
Additional Lung Cancer Risk for People Who Never Smoked |
| 20 pCi/L | 36 out of 1,000 |
| 10 pCi/L | 18 out of 1,000 |
| 8 pCi/L | 15 out of 1,000 |
| 4 pCi/L | 7 out of 1,000 |
| 2 pCi/L | 4 out of 1,000 |
Are radon levels regulated?
In Minnesota, radon levels are not regulated. It is up to the homeowner or home buyer to decide what amount of radon is an acceptable risk for your family.
Where should I test?
Test the lowest level of the home that is regularly used. For example, if you spend more than 8 to10 hours a week in the basement, MDH recommends testing the basement.
What factors can influence radon
test results?
- Time of year to test: The amount of radon in homes is usually highest during the heating season. Long-term tests should span both heating and non-heating seasons.
- Weather patterns: Weather patterns can influence how radon gets into your home. Short-term tests should not be conducted during severe weather or unusually high winds.
- Test location: Test the lowest level of the home that is regularly used. For example, if you spend more than 8 to 10 hours a week in the basement, MDH recommends testing the basement.
- Disturbances: Place the test kit at least 20 inches above the floor in a location where it won't be disturbed -- away from drafts, high heat, high humidity and exterior walls. Test kits that are distributed or moved during a test may provide inaccurate results.
- Timeliness of analysis: Once you've finished, reseal the package and send it to the lab specified on the package. Radon test results may not be accurate if the test kits are not sent to the laboratory as soon as possible after completing the test.
Go to > top
What does the recommended action level mean?
The EPA and MDH set the recommended action level for radon at 4.0 picoCuries/liter
(pCi/L). To apply the recommended action level correctly, the results should be based on the annual average level of radon measured in a home. If the annual average
level of radon in a home is above 4.0 pCi/L, the EPA and MDH recommend
that steps be taken to lower it. While
it isn't possible to reduce radon to zero, the best approach is to lower the radon level as much as possible. Any amount of radon, even at or below
the recommended action level, carries some risk.
What do my radon test results mean?
In Minnesota, it is up to the homeowner to decide what amount of radon is acceptable for their home. To help with this decision, the table below provides recommendations based on radon test results and the type of test used. These differ slightly from those of the EPA because they account for the weather extremes and the amount of radon typically found in this state. The advice also clarifies some common mistakes in how people interpret the EPA guidance.
These suggestions assume that the radon tests were conducted properly.
What can I do to lower my risk?
A number of steps can be taken to lower the amount of radon in a home. A quality radon reduction (mitigation) system is often able to reduce the annual average radon level to below 2 pCi/L. Experienced radon mitigation professionals are available and can install appropriate control systems.
How often should I test for radon?
- MDH recommends every Minnesota Home, even those built radon-resistant, be tested for radon.
- You should retest your home every 2 - 5 years and save your results.
- Be sure to rest before and after you make any major structural renovations such as building an addition or finishing a basement. Radon-resistant techniques can be inexpensively included as part of the renovation, if needed.
- You should also perform a radon test after buying a new heating system or adding central air conditioning.
Go to > top