According to the La Crosse County Health Department, about 30-percent of the houses in the county have an elevated level of radon.

Radon is an odorless gas that could lead to lung cancer if the concentration is high enough and you’re exposed to it for a long period of time. That's why health leaders are encouraging homeowners to test for radon.

"We’ve got this radon tester," homeowner Peter Nelson says as he takes a small electronic device off the wall. "That’s the thing that I Mostly counted on.”

The United States Environmental Protection Agency (US EPA) recommends fixing your home if your radon level reaches 4 picocuries per liter (pCi/L).

When Nelson began checking the radon levels in his home, he recalls that "some were at 8,9, but there were other times that it was just down to 2 or 3 picocuries per liter. The 8 or 9 was very concerning.”

So Nelson had his house mitigated, meaning he had a system installed that takes the radon from underground and sends it outside his home.

“I anticipated that if we did do radon mitigation,Ii’d want to know afterward that it was doing an adequate job and sure enough our levels went down from 8-9," Nelson said.

His radon level now averages a consistent 1.4, a small level of radon.

Doctors say breathing in a high concentration of radon could lead to lung cancer.

Medical Oncologist Kurt Oettel from Gundersen Lutheran says the second leading cause of lung cancer is radon.

"We can attribute about 15-20,000 cases of lung cancer to radon, but we know that of the 15-20,000, to one degree or another the majority of those, to one degree or another, have a smoking history.”

La Crosse County Environmental Specialist Jim Steinhoff recommends that all homeowners--no matter if they smoke or not--get their home tested for radon.

"It’s very simple to do a radon test," Steinhoff says. "All you do is remove the sampler from the plastic bag. You’d want to put it in the basement only if you spend time down in the basement or you have a finished room.”

After 48-hours you put the test kit in the envelope and mail it off. “In a week or two you’ll get your test results back," Steinhoff says.

Nelson says he’ll occasionally lend his electronic tester to his neighbors so they can check their homes.

“Reading from home to home can be so sporadically different.” Which is why Nelson and the county feel testing your own home is so important.

You can buy a radon test kit from the county health department for six dollars.

So far this year they’ve sold about 700 tests.

For Eau Claire County residents, you can buy a short-term test kit for $7. 37-percent of the homes in the county have elevated levels of radon, 4pCi/L or higher.