OK, go ahead, make the required "gas" jokes.
Now down to business: Your basement might be filled with radioactive gas, and that gas might be creeping upstairs into your living room, kitchen and lungs.
It's called radon, and it's a substance that goes through bouts of celebrity—occasionally appearing as the media's Scary Thing of the Week. Then radon disappears, as though the problem has been taken care of.
The Environmental Protection Agency has declared January "National Radon Action Month," and it's a good time for Wisconsin residents—especially those living in Southern Wisconsin—to test their homes.
Radon is a naturally occurring gas that enters homes through the ground.
"The house acts like a little jar, holding the gas in," said Tim Banwell, Rock County Health Department environmental health director.
The gas is a "very weak" radioactive source.
"The skin deflects it," Banwell said. "But it gets deep into the lungs, into the alveoli—the parts of the lungs that look like little clusters of grapes. They're only about one-cell thick."
After smoking, radon is the leading cause of lung cancer.
Here's why local residents need to be particularly concerned: The EPA has established three zones for radon levels. The zones are based on indoor radon measurements, geology, aerial radioactivity, soil permeably and foundation types.
All of Wisconsin's 72 counties are in zones No. 1 and No. 2, the zones with the highest radon levels. Rock, Walworth, Green, Dane and Jefferson counties are in zone No. 1.
Zone 1 counties have a predicted average indoor radon screening level at greater than 4 picocuries per liter. In non-scientific terms, that means they have the highest potential for having radon gas levels above the amount considered safe.
How did we get so lucky?
"Uranium turns into lead naturally, but it's a very long decay process," said Banwell. "Radon is part of the normal process of decay."
Now think about where we live.
"There were significant lead deposits out west of us in Mineral Point," Banwell said.
Locally, about 44 percent of all homes tested have elevated levels of radon, Banwell said.
"It's really hard to know which home will be impacted," he said. "You can have one home that will test high, and the one right next to it will test low."
The health department hopes to do more radon outreach this year.
Banwell would like to see more testing done, especially in the western part of the county.
The Rock County Health Department sells radon-testing kits for $11 and $25, including lab analysis. Kits also can be purchased at hardware stores, but consumers should check if the cost includes lab analysis.
If elevated radon levels are found in a home, remediation usually costs between $500 and $800. Some homes might need more extensive systems costing up to $1,500, said Tim Banwell, Rock County Health Department environmental health director.
Remediation consists of running a PVC pipe from beneath the basement floor and venting the gas outside the home.
Health department's offices are located at 3328 N. Highway 51, Janesville, and 61 Eclipse Center, Beloit.
For more information, call (608) 757-5440 or (608) 364-2010.