That's what one expert equated the levels of radon gas to in Le Mars resident Tom Shrader's home.
"I was kind of outraged to think my grandkids were sleeping in a house with this kind of a radon level," Shrader said. "Before this I didn't even know what radon really was."
It is colorless, tasteless and odorless.
Radon rises through the soil and can seep into homes through cracks and other holes in the foundation, according to the Environmental Protection Agency (EPA).
The EPA recommends fixing one's home if radon levels are higher than 4 picocuries per liter.
Radon is a dangerous gas.
The EPA estimates it causes 21,000 deaths per year.
The gas is the second-highest cause of lung cancer among non-smokers, Shrader noted.
Shrader first began to consider the presence of radon in his home several months ago.
After water damage in his basement, he had asked a business about testing for mold.
Instead, they recommended he test for radon.
When the results came back, Shrader was shocked.
The numbers were much higher than the EPA's recommended level of less than 4.
They showed a level of 40 or higher.
"I was scared and mad, probably at the same time," Shrader said. "Having a newer home I didn't think it would be all that bad."
Experts say that new and old homes can be equally susceptible.
One researcher from Kansas State University, which has an extensive radon program, told Shrader drainage systems around newer homes create a "highway for the radon gas to come through into your home," Shrader said.
"Any house that has a sump pump, chances are it has a high rate of radon," he added. "It's an easier travel route for gas."
Considering the impact on himself, his wife, their children and grandchildren, Shrader chose to have a radon mitigation system installed.
"You need to get it out of the home," he said.
Mitigation of radon usually includes sealing up cracks in basement floor and venting gasses from the soil outside the home
The Shraders installed a PVC pipe with a fan outside the home that constantly vents air from the sump pump area.
After he received his radon test results, Shrader bought a dozen more test kits and shared them with neighbors, family and friends.
"The least one was still higher than the average in northwest Iowa, which is 7.5," he said.
Radon tests are available in Le Mars, including at Plymouth County Farm Bureau, 28 Second St. S.W.
Shrader also spoke to the Le Mars City Council last week to raise awareness about radon.
He asked the council to help educate the citizens of Le Mars about the presence and effects of radon.
He also asked council members to consider adding a requirement for radon mitigation in Le Mars' building code.
With that addition, people building new homes would be required to include a radon mitigation system.
Jason Vacura, Le Mars' code enforcement officer said a radon mitigation requirement is not in the building code because the state has not adopted it as a requirement, but there is already language that could be adopted into city code, he said.
"In the last few times we've adopted code, we've done it word for word as the state has," Vacura said. "Right now it's strictly voluntary whether you do it (add a radon mitigation system to your home)."
Adding a mitigation system can be completed during the construction of the home.
It is more expensive to install a radon mitigation system once a home is built, Shrader said.
He estimated it costs about $1,500 to install a system after a house is built.
Vacura agreed with Shrader that radon is a real issue.
"Everything he said is true -- it is a health concern," Vacura said.