Radon Levels in Missouri
Missouri is classified as an EPA Zone 1 state with a high risk for radon. Average indoor radon levels range from 2 to 6 pCi/L, and approximately 33% of Missouri homes test above the EPA action level of 4.0 pCi/L.
Missouri Radon Summary
High Radon Risk State
Missouri is among the higher-risk states for residential radon. The Missouri Department of Health strongly recommends that all residents test their homes. If you have not tested your home, consider ordering a test kit or radon detector today.
Key Facts About Radon in Missouri
- Missouri has significant radon risk throughout the state
- The Ozark region in southern Missouri has uranium-rich bedrock
- Missouri DHSS operates an active radon awareness program
- Missouri requires radon disclosure in real estate transactions
Missouri Testing Requirements & Recommendations
Missouri requires disclosure of known radon information in home sales. Testing strongly recommended.
Missouri has trained and certified radon mitigation professionals statewide.
Major Cities in Missouri
Radon levels can vary significantly within Missouri depending on local geology. All residents — regardless of city — should test their specific home, as neighborhood-level radon varies independently of broader state and county averages.
What Should Missouri Residents Do?
Test Your Home
Use a short-term charcoal test kit ($15–$25) for an initial reading, or a continuous radon detector for ongoing monitoring. Test in your basement or lowest livable area.
Understand Your Result
If your result is below 2.0 pCi/L: monitor periodically. Between 2.0–4.0 pCi/L: consider mitigation. Above 4.0 pCi/L: the EPA recommends mitigation. Above 8.0 pCi/L: take action promptly.
Hire a Certified Contractor if Needed
Look for NRPP or NRSB-certified radon mitigation contractors in Missouri. Mitigation systems typically cost $800–$2,500 and can reduce radon levels by 50–99%.
Verify with a Follow-Up Test
After mitigation, test again to confirm the system is working. Retest every 2 years, or after significant home renovations.
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