Radon Testing Information

Radon Testing Procedure.

There are several basic types of radon tests available:

Continuous Radon Monitoring:
This is the most accurate representation of the yearly average radon levels in the home with a short term test. Specialized equipment is used to record real-time continuous measurements of radon gas. Air is either pumped or diffuses into a counting chamber. Radon counts are processed by electronics, and concentrations for predetermined intervals are stored in the instrument's memory. They are typically left in place for 3 to 7 days

Short-term canister tests offer a quick and inexpensive way to "screen" for radon in your home. Short-term tests do not measure the annual average level of radon. They are typically left in place for 3 to 7 days.

Long-term tests should be left in place for a minimum of 90 days. Compared to short-term tests, long-term tests provide results that reflect the average amount of radon in the home during the year. The best way to estimate a year-round average is to test for a full year.

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: The amount of radon in homes is usually highest during the heating season. Long-term tests should span both heating and non-heating seasons.

Test location: Radon levels are usually highest on the lowest floor of a home, such as the basement.

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.

Disturbances: Test kits that are disturbed or moved during a test may underestimate the amount of radon in your home.

Timeliness of analysis: Radon test results may not be accurate if you delay sending the test kit to the laboratory as soon as possible after completing the test.

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.

Do I ever need to retest my home?

Yes. You should retest your home every 1-2 years or if you make any major changes to the home, such as building an addition, finishing a basement, buying a new heating system or adding central air conditioning.