Not medical advice — for education only. Consult a licensed clinician for diagnosis or treatment.
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EPA Map of Radon Zones

US states by radon zone

A state-level interpretation of the EPA Map of Radon Zones (402-R-93-071). Each state is classified by its predominant county zone. Hover or tap a state to see its average indoor radon (pCi/L) and lung cancer mortality (per 100k) where available.

22
Zone 1 states (highest radon)
23
Zone 2 states (moderate)
6
Zone 3 states (lowest)
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Zone 1 — predicted >4 pCi/L (highest)Zone 2 — predicted 2–4 pCi/LZone 3 — predicted <2 pCi/LClick a state for details.

Source: EPA Map of Radon Zones 402-R-93-071. State-level summary is the modal county zone — within any state, individual counties may fall into a higher or lower zone. Always test the specific home.