When people think of home health risks, they often picture mold, lead, or carbon monoxide. But there is another threat that's just as dangerous and far more invisible: radon.
Radon is a naturally occurring radioactive gas that seeps into homes from the ground. It's completely invisible, odorless, and tasteless. Long-term exposure can lead to serious health problems. In fact, radon is the second leading cause of lung cancer in the U.S. after smoking, according to the EPA.
Let’s break down what radon gas is, why it matters, and how you can protect yourself and your family from it within your home.
What Is Radon & How Does it Affect Health?
Radon is a naturally occurring radioactive gas that comes from the slow breakdown of uranium found in rocks, soil, and groundwater. Since it’s odorless, colorless, and tasteless, you won’t notice it seeping into your home, but that’s exactly what makes it dangerous.
According to the World Health Organization (WHO), radon is produced continuously in the earth’s crust and moves freely through soil and rock. When pressure builds beneath your home, this invisible gas can enter through:
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Cracks in concrete foundations
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Floor drains and sump pumps
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Construction joints and gaps around service pipes
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Well water (especially in rural homes)
Radon is heavier than air, so it tends to accumulate in lower areas such as basements and crawl spaces. If ventilation is poor, which often happens in colder climates where windows stay shut, the gas gets trapped, gradually increasing your exposure.
Why Radon Is So Dangerous
You might be surprised to know that radon is the second leading cause of lung cancer in the United States, right after smoking. As per the National Cancer Institute (NCI), radon exposure causes around 21,000 lung cancer deaths each year.
According to the CDC, about 1 in every 15 homes in the U.S. has radon levels above the recommended safety limit. Unlike outdoor air, where radon disperses quickly, indoor air can trap this gas for long periods, meaning your risk grows over time.
The scariest part? You won’t feel or see any symptoms immediately. Radon doesn’t cause irritation, coughing, or headaches in the short term. Its impact builds up silently, often going unnoticed until it leads to serious illness years later.
How Radon Affects the Body
When you breathe in radon gas, it quickly breaks down into radioactive particles, which release alpha radiation as they decay. These particles can attach to dust and water droplets in the air and settle in your lungs.
The radiation from these particles damages lung tissue by altering DNA inside the cells. Over years of exposure, radon health effects can lead to lung cancer. Radon exposure doesn’t cause visible symptoms like nausea or fatigue; instead, it’s a slow, cumulative process.
Additionally, if you smoke and also live in a home with elevated radon, your risk is dramatically higher. According to the CDC, smokers exposed to high radon levels have up to 10 times greater risk of developing lung cancer compared to non-smokers.
To put that in perspective, if 1,000 people are exposed to a certain radon level throughout their lifetime, about 62 smokers may develop lung cancer, compared to 7 non-smokers at the same exposure level.
Where Radon Is Most Common
Radon levels vary widely depending on geography, soil composition, and building design. According to the EPA, the following regions are known for higher concentrations:
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Colorado, Minnesota, Iowa, and Pennsylvania are known for their uranium-rich soils and colder climates.
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Areas with granite or shale rock formations, which naturally release more radon.
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Homes with basements or crawl spaces, where the gas collects before moving upward.
Even if your region isn’t marked as high risk, that doesn’t mean your home is safe. Two neighboring houses can have vastly different radon levels based on micro-differences in the soil or construction materials.
That’s why experts emphasize: the only way to know your home’s radon level is to test it.
Testing for Radon in Your Home
Experts say you should test your home every two years or after any major renovation, as changes in ventilation or foundation can alter radon levels. You can find radon detector test kits online or at hardware stores, or you can consult a qualified radon service provider to conduct an assessment. Doing so will aid you in maintaining safe radon levels in your home, resulting in a healthier home environment and reduced risk of radon-related health issues.
If your levels are elevated, there are effective and affordable mitigation options available, including sub-slab ventilation systems and foundation sealing.
Learn how to test for radon in your home: How to Test for Radon
The Bigger Picture: Invisible Indoor Risks
While radon gas is one of the most serious invisible health hazards, it’s not the only one. Many homes can be exposed to high levels of carbon monoxide (CO), volatile organic compounds (VOCs), or mold spores, all of which can affect long-term health. This is why comprehensive home testing is essential. InHaus Lab, for example, offers science-backed in-home assessments that include radon screening along with tests for other indoor air pollutants. They also provide a home health score, a clear and easy-to-understand summary that reflects your home’s overall environmental safety. Their goal is to help families detect and address hidden dangers before they cause harm, giving you peace of mind that your home environment is truly healthy.
What Should You Do Next?
If you’ve never tested your home for radon, now is the time. You can’t see it or smell it, but its effects can be devastating. Whether you’re a homeowner, renter, or planning to buy property, knowing your radon levels is one of the most important steps you can take to safeguard your and your family’s health.
Testing is especially critical if you live in a region known for high radon levels or if your home has a basement. The fix is simple, but only if you know the problem and take action early.
Take the first step towards a healthier home: Schedule your Home Health Assessment
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