radon levels illinois 4

https://mighty-wiki.win/index.php/Why_Sub-Slab_Depressurization_Is_the_Standard_for_Radon_Mitigation

Radon levels in Illinois vary significantly by region, with many homes in the northern and central parts of the state testing above the EPA's recommended action level due to underlying geology. Testing your home is the only way to know if elevated levels are present, as radon is an invisible, odorless gas. Winter is an ideal time to test because windows are typically closed, leading to more accurate results. Consider a charcoal canister test or a continuous monitor for reliable data.