Ohioans left vulnerable to cancer-causing radon, Dispatch report finds

Radon, a deadly, odorless and colorless gas is lurking inside the homes, schools and workplaces of millions of Ohioans. Most residents have no idea.

In its "Invisible Killer" investigation, The Dispatch set out to test central Ohio homes for radon and see how the state compares to others when it comes to protecting residents from the gas — the leading cause of lung cancer among nonsmokers.

Reporters conducted dozens of interviews with cancer survivors, families who lost loved ones, scientists, lawyers, advocates and researchers and combed through thousands of public records dating back nearly 40 years.

Here's what they found.

Radon awareness is low and so is testing and mitigation

Despite being known about since the 1980s, several Ohioans told The Dispatch they didn't learn of radon's threat until they or a loved one were diagnosed with cancer.

Half of Ohio homes, or 2.5 million households, are estimated to have a radon problem. But, only 67,668 had mitigation systems as of 2021, according to the state's cancer control plan.

The Ohio Department of Health offers free tests to residents, but just a fraction of Ohio households have taken advantage of the program. From 2016 through Oct. 3, 2025, the state had given away 71,434 tests — equal to 1.4% of the roughly 4.9 million households in Ohio.

Ohio fails to protect students and young children from radon

When it comes to kids, Ohio has no laws to protect them from radon.

While the Ohio Department of Health recommends schools test for radon every five years or after renovations, The Dispatch found few districts follow those guidelines.

Columbus City Schools, the state's largest district, does not regularly test its classrooms for radon. And The Dispatch found a hodgepodge of testing in districts across Franklin County, including at least one district that put testing on hold after a levy failed to gain voter approval.

Eleven states require radon testing in schools, according to the Environmental Law Institute. Along with schools, 13 other states also require daycares to test for the dangerous gas.

What the Dispatch found doing its own radon testing

The Dispatch tested 68 central Ohio households. Testing found radon near or above dangerous levels throughout the region, including in some of the wealthiest neighborhoods, in public housing and in rural areas.

With environmental company A-Z Solutions, The Dispatch deployed 128 tests and several continuous radon monitors in the 68 homes during one wave of testing in September and another in early October in Franklin, Delaware and Licking counties. To ensure accurate results, two standard charcoal tests or a test and a continuous monitor were left in most homes.

Fifty-four homes, or 79.4% of those examined, tested positive for radon above the EPA's remediation threshold of 4 picocuries per liter. The Dispatch's results were higher than the 50% of homes the Ohio Department of Health reports test high each year.

From screening to education, many radon changes are needed

The screening guidelines for lung cancer are far more strict than those for any other cancer, experts told The Dispatch.

Only patients aged 50 to 80 who have smoked and have a "20 pack-year history" are eligible for screening, according to the American Cancer Society. Someone who smoked two packs a day for 10 years would qualify for screening, but another person who smoked three packs a day for five years would not.

The tight guidelines mean most people who are diagnosed with lung cancer are not even eligible for screening in the first place, said Dr. David Carbone, head of thoracic oncology and chair of lung cancer research at Ohio State University's James Cancer Hospital.

And, few doctors may be learning much about radon in medical schools.

Renters are at a disadvantage when it comes to radon

Since 1993, Ohio has required home sellers to notify potential buyers of previous radon testing results in their house.

But, The Dispatch found no such protection exists for renters as it does in states like Illinois, Colorado and Maine. Colorado and Illinois also allow tenants to break their lease without penalty if a landlord fails to mitigate for radon once unsafe levels are found. Mitigation typically runs anywhere from $500 to $2,500.

Public housing agencies, such as the Columbus Metropolitan Housing Authority, fail to test every home they own, a review of public records found. CMHA also failed to retest for radon immediately after installing mitigation systems in at least 18 units, The Dispatch found.

Records also showed housing agencies routinely fail to retest for radon in remediated units every two years as suggested by the Centers for Disease Control and Prevention.

Despite suspicions, there's little research linking fracking and radon so far

Hydraulic fracturing, better known as fracking, is the process of pumping high-pressure water below ground to force up natural gas.

Researchers have suspected that along with that fossil fuel, fracking may also result in more radon being released into nearby buildings. But few studies have been done examining whether fracking could lead to higher levels of indoor radon, The Dispatch found.