The second leading cause of lung cancer isn't secondhand smoke; it's radon.
Radon is a naturally-occurring gas that is colorless, tasteless, odorless gas.
"It's not going to make you feel sick," said Patty Lombardo, certified environmental health technician for Polk County. "You can't see it, you can't smell it. It's not going to give you headaches. What it can do is give you lung cancer down the road."
The only way to find out if a home has high levels of radon is to test it. And just because a neighbor's test comes back low doesn't mean your house is safe.
"It has nothing to do with your heat," Lombardo said. "It doesn't have to do with how old your house is. If you're heating your house and it's touching the ground, you should test."
That includes homes with basements, crawl spaces and slabs.
Concrete is no barrier to the gas, which comes from the breakdown of uranium in the soil. The heat in a home can cause a chimney effect, drawing the gas up into the living space. There's always some radon present, but at high levels it can lead to lung cancer.
According to the Wisconsin Department of Health Services, one in 10 homes has high radon levels.
The Polk County Health Department serves as the radon information center for Polk, Douglas, Burnett and Washburn counties. Lombardo said 33 percent of the tests that have been completed in the four-county region have have shown high radon levels. The low number of homes tested could skew that percentage.
Only 13 homes were tested for radon in Douglas County last year, according to Health Officer Kathy Ronchi. Two of them came back with high ratings.
According to Lombardo, there were nine radon tests in Douglas County and 91 in Polk County in 2017. In 2016, 27 of the 73 test results in Polk County showed high levels of radon.
Test results from kits sold at local hardware or big box stores are not included unless residents contact their county health department to report them.
Although the tests are inexpensive - $8 plus postage for shipping - Ronchi said residents have told her they don't want to know what their home's radon level is.
"Some people worry we'll make them do an expensive repair," Ronchi said.
Others are concerned that the test result could affect the possible sale of their home, Lombardo said.
There is no law in Wisconsin requiring a homeowner to fix high radon levels, she said, and it is not a required test for a housing sale. But based on the full disclosure law, if a test has been done you are supposed to let prospective buyers know that you did a test.
It is a fixable problem. A fan is installed to change the air pressure so the house is pushing the soil gas out instead of pulling it in. It generally costs between $800 and $1,200, Lombardo said.
Homeowners can do it themselves, but the state encourages them to have a certified installer put it in.
"Because if you do it incorrectly, you could have a carbon monoxide issue," Lombardo said.
January is National Radon Action Month. Everyone is encouraged to test their home for radon. Winter is the best time to do so because doors and windows are usually closed, trapping the gas in the home. A short-term test takes at least 48 hours and must be mailed to a lab. The results are shared with the health department.
Doctors often ask patients if they smoke, Lombardo said. They don't ask about radon exposure, which is the second-leading cause of lung cancer, topping even secondhand smoke. But it's something residents have the power to prevent.
"It is definitely a fixable thing, that's something we try to encourage people to understand," Lombardo said. "And you do want to know, because it's the second leading cause of lung cancer. Why would you not want to fix that and know that?"
Contact the Douglas County Health Department, 715-395-1304; Polk County Health Department, 715-485-8500; or visit lowradon.org for more information.