What Are High Radon Levels? A Guide for Chicagoland Homeowners

Radon in Chicagoland

If you're buying a home, selling one, or have lived in your house for years, you've probably heard someone mention radon testing.

Maybe your real estate agent recommended it before closing.

Maybe a neighbor recently discovered elevated radon levels in their basement.

Or perhaps you've seen stories about radon in Illinois and started wondering whether it's something you should be concerned about.

At Quality Environmental Testing (QET), these are conversations we have every week with homeowners throughout Lockport, Lemont, Homer Glen, New Lenox, Frankfort, Mokena, Orland Park, Tinley Park, Joliet, Romeoville, Darien, and the surrounding Chicagoland communities.

One of the first questions we hear is simple:

"What exactly is radon, and how do I know if my home has too much?"

It's a great question.

After professionally testing homes throughout the Chicagoland area since 2002, we've learned that while many homeowners have heard of radon, very few understand how it enters a home or why one house can test low while the house next door tests well above the EPA action level.

We've tested brand-new homes with elevated radon.

We've tested homes built over 100 years ago with very little.

We've even tested neighboring homes built by the same builder where the results were completely different.

That's why radon testing isn't about guessing.

It's not about what your neighbor's home tested.

It's about your home.

Let's take a closer look at what radon is, why it matters, and how professional testing can give you the answers you need.

What Is Radon?

Radon is a naturally occurring radioactive gas that forms as uranium in the soil and rock beneath us slowly breaks down.

The important thing to understand is that radon is completely natural.

It's found all across Illinois.

Outdoors, it usually isn't a concern because fresh air quickly dilutes the gas.

Inside a home is where things become different.

As radon rises through the soil, it looks for the easiest path into a building. Once it enters your home, it can become trapped and gradually build to higher concentrations.

Because radon has no color, no smell, and no taste, there's no way to know it's present without testing.

How Does Radon Get Into My Home?

One of the biggest misconceptions we hear is that a home must have major foundation cracks to have a radon problem.

That simply isn't true.

Over the years, we've tested beautiful, well-maintained homes with perfectly clean basements that still had elevated radon levels.

Radon only needs a small opening to enter.

Some of the most common entry points include:

• Small cracks in basement floors or foundations

• Expansion joints

• Sump pits

• Floor drains

• Gaps around plumbing pipes

• Utility penetrations

• Crawl spaces

Even homes that appear to be tightly sealed can have elevated radon because modern homes naturally create pressure differences that draw soil gases indoors.

Why Do Some Homes Have High Radon While Others Don't?

This is probably the question we answer more than any other.

"My neighbor tested. Doesn't that mean I'm okay?"

Unfortunately, no.

One thing we've learned after more than two decades of testing homes throughout the southwest suburbs of Chicago is that every home is unique.

We've seen homes less than a block apart with completely different radon levels.

Why?

Because every home sits on different soil conditions, has different foundation construction, different air pressure, different drainage systems, and different pathways where radon can enter.

That's why no map, online estimate, or neighbor's test result can tell you what your home's radon level is.

Only testing your home can answer that question.

What Is Considered a High Radon Level?

Radon is measured in picocuries per liter (pCi/L).

The Environmental Protection Agency recommends taking action when the average radon level in a home is 4.0 pCi/L or higher.

Many homeowners are surprised to learn that there isn't a completely "safe" level of radon.

Instead, the goal is to reduce unnecessary long-term exposure whenever practical.

If your home tests above the EPA action level, a qualified radon mitigation contractor can usually reduce those levels significantly.

Does a New Home Mean Low Radon?

Absolutely not.

In fact, some of the highest radon readings we've encountered have been in newer homes.

People are often surprised by that.

Many assume older homes are more likely to have radon because they may have more cracks or settling.

The truth is that radon comes from the soil beneath the home—not from the age of the home itself.

We've tested:

• Newly built subdivisions

• Established neighborhoods

• Luxury custom homes

• Starter homes

• Homes with basements

• Homes built on slabs

• Homes with crawl spaces

Any of them can have elevated radon.

Why Professional Testing Matters

Since radon can't be seen or smelled, the only reliable way to know your home's level is through testing.

At Quality Environmental Testing, we perform professional 48-hour radon testing using calibrated SunRADON 1028-XP Continuous Radon Monitors.

Unlike simple test kits that provide only a final result, continuous radon monitors record hourly measurements throughout the test.

This allows us to see how radon levels change during the testing period while providing homeowners with accurate, detailed reporting.

After the test is complete, you'll receive an easy-to-read electronic report explaining your results.

If you have questions, we're always happy to walk you through them.

Why Homeowners Choose Quality Environmental Testing

Since 2002, Quality Environmental Testing has helped thousands of homeowners, buyers, sellers, and real estate professionals throughout the Chicagoland area make informed decisions through accurate radon testing.

One thing that makes us different is our independence.

We perform radon testing only.

We do not install radon mitigation systems.

That means our recommendations are based solely on the test results—not on selling mitigation work.

Our job is simple:

Provide accurate testing.

Explain the results clearly.

Help homeowners understand exactly what those results mean.

When Should You Have Your Home Tested?

We recommend professional radon testing if:

• You've never tested your home.

• You're buying or selling a home.

• You've finished your basement.

• You've completed major renovations.

• It's been several years since your last test.

• You want to verify that an existing mitigation system is still working properly.

Because radon levels can change over time, testing isn't just a one-time event for every home.

Final Thoughts

One lesson stands out after more than twenty years of testing homes throughout the Chicagoland area.

Radon doesn't care what your house looks like.

It doesn't matter if it's brand new or one hundred years old.

It doesn't matter if it's the nicest house on the block or the smallest.

And it doesn't matter what your neighbor's home tested.

The only home that matters is yours.

Professional radon testing removes the guesswork and gives you the information you need to make informed decisions for your family.

If you live in Lockport, Lemont, Homer Glen, New Lenox, Frankfort, Mokena, Orland Park, Tinley Park, Joliet, Romeoville, Darien, or the surrounding Chicagoland communities, Quality Environmental Testing is here to help.

With more than two decades of experience, professional-grade equipment, and independent testing you can trust, we're committed to providing accurate results and exceptional service every step of the way.

Because when it comes to radon, peace of mind starts with knowing—not guessing.