Understanding radon results
Your result is a number for the test you ran, in that spot, over those days. It is not a grade for your whole city, and one short test is not always the last word.
The follow-up path Minnesota publishes
The Minnesota Department of Health says to complete two tests before you decide on a mitigation system, unless a professional uses a continuous radon monitor in a real estate transaction.
- If the first result is 0 to 1.9 pCi/L, retest every 2 to 5 years.
- If it is 2 to 7.9 pCi/L, do a long-term follow-up test.
- If it is 8 pCi/L or higher, do another short-term test.
Then use the average of the two short-term tests, or the single long-term result. If that result is 4 pCi/L or higher, MDH recommends mitigation. From 2 to 3.9 pCi/L, MDH says you can consider a system. Below 2, retest every 2 to 5 years.
Your state may word this differently. Wisconsin's health department calls levels above 4 pCi/L high. Read your own health department if you do not live in Minnesota.
A very high screening result
Pennsylvania DEP offers a free short-term confirmation kit only when a screening result is greater than 100 pCi/L. That program is not the same thing as the 4 pCi/L action level. Call 800-237-2366 or 717-783-3594 for that specific kit.
Fixing the house
Hennepin County says sealing cracks is part of most radon repairs, and that sealing by itself has not been shown to lower levels in a reliable way. Most fixes use a fan and pipe system. Hire someone licensed in your state. This directory does not book that work, and American Radon Systems does not claim a national license.
More on the action level: what 4 pCi/L means.