Above EPA Action Level
This area is in EPA Radon Zone 1 — the highest risk designation. The EPA predicts average indoor radon levels above 4 pCi/L, the action level. The EPA strongly recommends:
- Test all homes immediately with a short-term kit or professional monitor
- If confirmed above 4 pCi/L, install a radon mitigation system
- Retest after mitigation to verify levels are below 2 pCi/L
Risk Factors for 66221
Recommended Actions
Test Your Home for Radon
EPA zone data shows area-level risk. A home radon test measures your actual indoor level.
Radon Risk in Overland Park, KS
ZIP code 66221 is located in EPA Radon Zone 1 — the highest risk designation. The EPA estimates that homes in Zone 1 areas have 4+ pCi/L (likely above EPA action level).
Risk Factors for 66221
- Zone 1 designation — EPA predicts average indoor radon levels above 4 pCi/L, the action level
- Median home age: 2004 — newer construction often includes radon-resistant features
What Is Radon?
Radon is a naturally occurring radioactive gas that seeps from soil through foundation cracks into buildings. It is the second leading cause of lung cancer in the United States (after smoking), responsible for approximately 21,000 deaths per year according to the EPA.
Radon is colorless, odorless, and can only be detected through testing. The EPA recommends testing all homes, regardless of geographic zone, because localized geology can create elevated levels even in Zone 3 areas.
Recommended Actions
- Test your home — Short-term test kits cost $15-30 and take 2-7 days. Long-term tests (90+ days) give more accurate annual averages
- Professional testing — Certified radon measurement professionals charge $150-300 for a comprehensive test with continuous monitoring
- Consider mitigation — Sub-slab depressurization systems cost $800-2,500 installed and reduce radon levels by 80-99%
- Real estate transactions — In Zone 1 areas, radon testing is standard practice during home inspections
About This Assessment
This assessment uses the EPA Radon Zone Map classification for KS, combined with Census housing age data for ZIP 66221. Individual home radon levels can vary significantly within a ZIP code based on soil type, foundation construction, and ventilation. Always test your specific home.
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Frequently Asked Questions
What is a dangerous radon level?
The EPA action level is 4 pCi/L (picocuries per liter). If your home tests at or above this level, the EPA recommends installing a mitigation system. The World Health Organization uses a stricter reference level of 2.7 pCi/L. There is no known safe level of radon exposure — any reduction lowers your lung cancer risk.
How do I test for radon?
Short-term test kits (2–7 days) cost $15–$30 and give a quick screening result. Long-term test kits (90+ days) provide a more accurate annual average. Place the kit in the lowest livable level of your home with doors and windows closed. For the most reliable results, follow up a short-term test with a long-term test or hire a certified radon professional ($150–$300).
How is radon mitigated?
The most common and effective method is sub-slab depressurization, where a fan and pipe system draws radon gas from beneath the foundation and vents it above the roofline. Professional installation costs $800–$2,500 and reduces radon levels by 80–99%. The system runs continuously and uses about as much electricity as a light bulb.