Missouri — 2.2M metro

Radon in Kansas City,
MO

Missouri's radon map shows the Kansas City metro in a zone of elevated risk. Missouri Department of Natural Resources testing data indicates 30–35% of tested homes in the KC metro exceed the action level, with Johnson County (Kansas) across the border showing even higher rates.

Risk Level

High Risk

2–7 pCi/L

Typical range (area avg.)

EPA action level: 4 pCi/L

Why Kansas City Has High Risk Radon

Kansas City's geology features Pennsylvanian limestones and shales with significant uranium content. The area's famous 'limestone country' creates porous geological pathways that allow radon to migrate freely from bedrock to overlying soils and into homes.

Local Housing and Radon Risk

Kansas City has a large inventory of mid-century ranch homes in Mission Hills, Leawood, and Overland Park (Kansas side). Many Johnson County homes — one of the nation's most tested suburban areas — have documented radon above action levels.

Testing Advice for Kansas City Residents

Kansas City spans two states (Missouri and Kansas), each with separate radon programs. Johnson County (KS) has its own health department radon resources. Missouri buyers should use MDNR-certified contractors; Kansas buyers should use KDA-certified contractors.

How to Test Your Kansas City Home

Step 1: Choose Your Test Type

For initial screening, a charcoal short-term test kit ($12–$25) placed for 48–96 hours provides a quick result. For the most accurate reading, a long-term alpha-track test ($20–$35) left in place for 90+ days accounts for seasonal variation — especially important in Kansas City's climate.

Step 2: Place the Test Correctly

Test in your lowest livable level — basement if you have one, otherwise the first floor. Keep the test 20 inches from the floor, away from windows and exterior walls. Close windows and doors 12 hours before and during the test for accurate results.

Step 3: Interpret Your Results

Below 2 pCi/L: low concern, retest every 2 years. 2–4 pCi/L: consider mitigation, retest in 2 years. 4 pCi/L or higher: the EPA recommends mitigation. Above 8 pCi/L: prioritize mitigation promptly.

Step 4: Hire a Certified Mitigator if Needed

If your test result is at or above 4 pCi/L, hire a certified radon mitigator. In Missouri, always verify your contractor's state certification. Sub-slab depressurization — the most effective mitigation method — typically costs $850–$1,500 installed in the Kansas City area.

Frequently Asked Questions — Radon in Kansas City

Is radon a real problem in Kansas City?

Yes. Missouri's radon map shows the Kansas City metro in a zone of elevated risk. Missouri Department of Natural Resources testing data indicates 30–35% of tested homes in the KC metro exceed the action level, with Johnson County (Kansas) across the border showing even higher rates. The EPA recommends all homes be tested regardless of location — radon levels can vary significantly even between neighboring properties.

How much does radon mitigation cost in this area?

In the Kansas City area, professional radon mitigation (sub-slab depressurization) typically costs $850–$1,500 installed. This is a one-time cost that reduces radon by 50–99%. The system requires minimal maintenance and a mitigator can typically complete the work in 3–5 hours.

Should I test if I have a new home?

Absolutely. New homes built with radon-resistant features still show elevated levels in testing — construction conditions and local geology vary too much to assume any home is safe. Test within the first year of occupancy, especially if your home has a basement.

Can I test radon myself, or do I need a professional?

DIY testing is reliable and recommended as a first step. Short-term kits ($12–$25) and long-term kits ($20–$35) are accurate when placed and returned correctly. Professional testing is only required for real estate transactions in some states. If your DIY test shows elevated levels, use a certified professional for both confirmation testing and mitigation.