radon retest 2

https://theradonlevelsstlouisinfo.nexorafield.com/posts/understanding-radon-levels-st-louis-homeowners-need-to-know

A radon retest is a follow-up measurement after initial high levels were found, ensuring mitigation efforts actually reduced the radioactive gas in your home. It's a straightforward check—seal windows and doors, then place a test kit in the lowest lived-in area for several days. The result tells you whether your family's exposure is now below the EPA action limit, or if you need further steps to seal cracks or improve ventilation.