Deep within the ground, naturally occurring uranium in rocks and soil breaks down, releasing a radioactive gas called radon. It rises through the dirt, dissipating into the open air. But when radon brews beneath a home or building, it seeps into the tiniest cracks and holes in the foundation, quickly accumulating in the structure and becoming trapped.
From there, residents can unwittingly inhale the colorless and odorless gas. As the particles further decay, they release bursts of energy that damage the lining of the lungs. Over years, the damage can become substantial enough to cause cancer.
Radon has been a natural risk of living in Indiana and much of the U.S., but awareness is spreading. Just this year, the Monroe County Health Department released an interactive map showing the presence of the gas visually, reiterating the widespread nature of the gas and the necessity of testing.
Bloomington homes are not the only locations contaminated with radon. Nearly one in every three homes tested in Indiana contain dangerous levels of radon — four picocuries per liter or more according to the Environmental Protection Agency — but the gas affects people across the country as well.
Long-term exposure to the gas is the leading cause of lung cancer among nonsmokers; inhaling radon can also increase cancer risks for smokers.
Simeon Baker, a senior environmental health specialist at the MCHD, said the tests that inform the data in the map began in the 1980s, although the map was just uploaded this year. The big takeaway according to Baker is that no matter where you are, you likely have radon — it’s just a matter of how much.
Changes in moisture content, windspeed and seismic activity can all affect the level of radon, Baker said. Often, radon levels can vary widely across a neighborhood.
The state recommends people test their homes each year because levels can change over time. While the county offers free tests that can be ordered online, it stipulates someone must be a homeowner to order a test. Renters in Bloomington can ask their landlords to test for radon or purchase a radon test on their own, but they will have to get their landlord to approve any mitigation.
Anna Killion-Hanson, director of Bloomington Housing and Neighborhood Development, said landlords have no obligation to act if a tenant finds dangerous levels of radon in a home. They are also not obligated to disclose the gas to potential renters.
“There really are no tenant rights in regards to the radon,” she said.
At-home tests can cost as low as $10, but the cost of mitigating radon, which involves sucking the gas from the soil and expelling it outside the home, is much more expensive. It’s generally more difficult and expensive for multifamily units, Killion-Hanson said, which could further disincentivize landlords.
The standard cost of mitigation is $1,500 to $2,000, James Plessinger, who provides radon mitigation through his company Bloom Enviromental, said.
Plessinger said he typically sees radon levels of 7 to 10 pCi/L, but he has seen levels of over 100 on the northwest side of Bloomington. He believes this is due to the proximity to limestone quarries — limestone rock formations tend to contain more radon than other types.
Radon levels of just 4 pCi/L are equivalent to smoking eight cigarettes per day, while inhaling 100 pCi/L amounts to 200 cigarettes per day.
Plessinger has also seen firsthand how levels can vary from home to home. He recalled one house with levels of about 50 pCi/L while a neighbor 40 yards away had 4 pCi/L.
In the past five or six years, Plessinger has seen awareness of the problem rise — what used to be one call a month has quickly become multiple calls a day.
“Everyone in Monroe County should be aware of it,” he said. “Most houses are likely elevated.”
