Radon Testing in Columbia, MO

Short-term radon tests run from 2 to 90 days; the tests used in home sales usually run at least 48 hours. For a valid result, the house should be kept closed — windows and exterior doors shut except for normal coming and going — starting 12 hours before the test and throughout it, and the device has to sit in the lowest livable level, away from drafts and exterior walls. Long-term tests run more than 90 days and better reflect year-round average levels, which matters because radon varies by season.

The EPA recommends fixing a home when radon is 4 picocuries per liter (pCi/L) or higher, and suggests considering it between 2 and 4 pCi/L, since there's no known safe level. Zip-code maps show general risk, but neighboring houses in Columbia can test very differently, so a test of the specific home is the only way to know. If a short-term test is high, the EPA suggests a follow-up test before deciding; in a home sale, two simultaneous short-term tests or a continuous monitor are common.