Radon Levels in Marion County, Iowa
The average indoor radon level in Marion County is 8.5 pCi/L — about 6.5× the U.S. average of 1.3 pCi/L, and above the EPA action level of 4.0 pCi/L (CDC National Environmental Public Health Tracking Network, 2008–2017). That means the typical home here tests high enough that the EPA recommends installing a radon mitigation system — testing is strongly advised across Pella and the rest of the county.
Marion County Radon, in Context
Source: CDC National Environmental Public Health Tracking Network — mean pre-mitigation radon level in tested buildings, Iowa, 2008–2017. Classification: Elevated (above EPA 4.0 action level).
What This Means for Marion County Homeowners
Because the county average sits above the EPA's 4.0 pCi/L action level, radon mitigation is commonly needed here. The fix is routine: an NRPP-certified contractor installs an active sub-slab depressurization system that vents soil gas above the roofline, typically reducing indoor radon by 70–99%. Either way, Iowa Radon Experts routes you to a verified Iowa partner contractor for testing or mitigation.
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Test or Mitigate Radon in Marion County
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