Radon gas in homes: What to know
How to detect and treat your home for this colorless, odorless and dangerous gas.
What is radon gas?
Radon is gas that is colorless, tasteless, odorless and deadly. Radon is responsible for around 21,000 lung cancer deaths yearly and is the second-leading cause of lung cancer among nonsmokers in the United States.
Radon comes from the decay of uranium in soil. It can enter your home through cracks in the foundation or other openings. Once inside, radon builds up, causing a larger problem. And while its mitigation is not covered by homeowners insurance, any home may have a radon problem, and the worst thing you can do is ignore it.
"The biggest danger is assuming there's not a problem because you don't notice a problem," says Jay Solomon, natural resource, environment and energy educator with the University of Illinois Extension.
So, is radon dangerous? Yes. However, identifying radon is possible. Target this hidden hazard and help take action with these tips.
Radon gas testing
The only way to know if you have radon is to test your home. Radon test kits are easy to use, inexpensive and only take minutes to set up. The most common tests measure radon levels over a two- to seven-day period. Depending on the type of home radon test you use, you may be able to gather results within a couple of days. After submitting your results, you're typically notified about the outcome within two weeks. For more accurate results, follow the instructions on the radon test kit package.
Know your radon gas numbers
Radon is measured in picocuries per liter of air (pCi/L), and "more than likely, your test will yield a positive result," Solomon says. The national average indoor radon level is 1.3 pCi/L. The EPA's recommended action level is 4 pCi/L. If your test yields 4 pCi/L or higher, it's wise to take a second test to confirm.
Take action with a radon mitigation system
If your test results are high, you'll want to invest in a radon reduction system. In 2025, a base system can range in cost from $1,000 to $2,500, Solomon says, and you'll pay more for advanced systems. Check out your state’s radon program and look for licensed radon mitigation contractors. Gather several estimates and obtain references to get a good sense of your preferred contractor for the job.
Keep testing for radon
Solomon recommends testing your home every few years. “As subsoil condition change under your home over time, the level of radon gas entering the home may increase,” he says. For instance, Illinois recommends testing every two years, plus or minus a season. "If you tested in summer before, test in the spring, fall or winter next time," says Solomon.
Radon exposure symptoms and impact
It can be difficult to determine if a single symptom was or wasn’t caused by radon exposure. This is why testing for radon in a home can be so important. Symptoms of radon gas exposure can include shortness of breath, the development of a cough or the exacerbation of an existing one, a sense of tightness or pain in the chest, difficulty swallowing – sometimes expressed as the throat or gullet feeling constricted or smaller – and hoarseness of the throat. Long-term radon exposure can cause lung cancer. If you suspect you may have been exposed to radon, it’s important to discuss this with your doctor and explore the possibility of getting tested.
Other measures to help reduce radon gas in your home
If you’re concerned about possible radon exposure in your home, there are additional measures you can take to help prevent radon buildup. One potentially effective approach is to improve ventilation by using fans and opening windows to help increase airflow throughout your home. If radon is seeping up from beneath your home, another approach you can take is to seal cracks in the floor, walls and basement with caulk or plaster. Sealing can potentially prevent radon from entering your home or limit its further flow once inside. Avoid smoking inside your home, smokers are at substantially higher risk of lung cancer from radon and the smoke can erode the sealing used to prevent radon buildup.
If you’re in the planning or construction phase of building a new home, you may want to consider incorporating radon-resistant construction into the design of your home. A home built with radon prevention in mind may cost less in the long run compared to retrofitting solutions for radon issues down the road.
Radon is a serious hazard. Be safe, be diligent and treat radon exposure with the serious consideration it warrants.
The information in this article was obtained from various sources not associated with State Farm® (including State Farm Mutual Automobile Insurance Company and its subsidiaries and affiliates). While we believe it to be reliable and accurate, we do not warrant the accuracy or reliability of the information. State Farm is not responsible for, and does not endorse or approve, either implicitly or explicitly, the content of any third-party sites that might be hyperlinked from this page. The information is not intended to replace manuals, instructions or information provided by a manufacturer or the advice of a qualified professional, or to affect coverage under any applicable insurance policy. These suggestions are not a complete list of every loss control measure. State Farm makes no guarantees of results from use of this information.
