What Do Your Ohio Radon Test Results Actually Mean?
A number on a report is only useful if you understand what it means for your family. Here’s a plain-English breakdown of radon levels, risk context, and what action is right for your specific result.
Your radon result — a number in picocuries per liter (pCi/L) — only tells part of the story. Context matters: how long you spend in the tested space, whether you have smokers in the home, and where your number falls on the EPA risk scale. Here’s how to read it clearly.
How it works
Below 2.0 pCi/L — Low risk
Generally considered acceptable. The EPA doesn’t recommend mitigation at these levels. Re-test every 2 years or after any major renovation.
2.0–4.0 pCi/L — Moderate, consider mitigation
Some risk, particularly for smokers or long-term occupants. The EPA recommends “consider fixing” at this level. Many Ohio homeowners in this range choose to mitigate — especially before selling.
4.0–8.0 pCi/L — High, EPA action level exceeded
At or above 4.0 pCi/L, the EPA recommends action. This is the most common range in Ohio homes that test high. Mitigation is strongly recommended and highly effective.
8.0–20.0 pCi/L — Very high, mitigate promptly
Cumulative cancer risk rises significantly at these levels. Schedule mitigation as quickly as practical. This range is not uncommon in Central and Southwest Ohio.
Above 20 pCi/L — Elevated priority
Still mitigatable. Limit time in the affected area — especially the basement — until a system is installed.
Key benefits
Context matters as much as the number
A 3.8 pCi/L result in a basement office where someone works 8 hours daily is very different from the same result in an unfinished storage basement.
Smokers face compounded risk
The combination of smoking and elevated radon is dramatically worse than either alone. Any smoker with results above 2.0 pCi/L should strongly consider mitigation.
Results can change seasonally
Ohio winters often produce higher readings than summer because homes are tightly sealed and the stack effect draws more radon in. A summer result may understate your annual average.
One test isn’t the whole story
Short-term tests are snapshots. For long-term decisions, a 90+ day alpha track test gives the most accurate annual average.
Re-testing after mitigation is essential
Don’t assume a mitigation system is working without verifying. Carl includes a post-mitigation test with every installation.
Your result is covered by our guarantee
If Carl installs a mitigation system and your post-mitigation test shows levels above 4.0 pCi/L, he fixes it at no charge.
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Common questions
My result was 3.8 pCi/L — just under the EPA limit. Do I need to do anything?
3.8 pCi/L is essentially 4.0 pCi/L within measurement precision. If you use the basement regularly, have children, or plan to sell, mitigation is worth considering. The cost is modest and the result is guaranteed.
My upstairs bedroom tested at 1.9 pCi/L. Should I be concerned?
Upper floor levels are typically much lower than basement levels due to dilution. A 1.9 pCi/L reading upstairs is low risk. If you haven’t tested the basement — which is the primary exposure point — that should be next.
I had two tests and got very different numbers. Which is right?
Radon levels fluctuate naturally with weather, barometric pressure, and season. If two tests differ significantly, a third test or a long-term alpha track test gives the most reliable average.
My neighbor tested at 2.0 pCi/L but mine was 7.8 pCi/L. How can houses this close be so different?
Very common. Radon entry depends on your specific foundation, sub-slab material, crack locations, sump configuration, and HVAC pressure differentials. Two adjacent homes on the same street can have dramatically different levels.
After mitigation, my test showed 1.2 pCi/L. Does that mean I’m done forever?
Follow-up testing every 2 years and after major renovation is still recommended. Fan performance can degrade over time, and foundation changes can create new entry points.
What Do Your Ohio Radon Test Results Actually Mean? for your Ohio home?
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