DENVER (CBS4)– A simple test that could save lives is being offered free from the Colorado Department of Public Health and Environment. It is part of National Radon Action Month in January.

In Colorado, radon is estimated to cause 500 lung cancer deaths each year and about half of all homes in Colorado have an unacceptable level, according to the state health department.

“They came in and just cut a hole in the slab which I think was about 18 inches or so,” homeowner Rick Varela said.

He moved into his brand new home four years ago but was not able to convince the builder to test for radon. When a neighbor found high levels in their home while trying to sell, he knew it had to be done.

“We were told that a reading as high as we had is the equivalent of smoking several packs of cigarettes a day.”

His average level was a 22.

“You can’t see it, you can’t smell it, you don’t know it’s there unless you measure for it,” Varela said.

He immediately signed up with ace radon to get a mitigation system put in.

“They say the EPA says there’s no acceptable level of radon, the World Health Organization says 2.7,” ACE Radon technician Mike Scroggins said.

Scroggins says radon is everywhere, but levels can be hit or miss.

“Some houses right next door, one will be at 4, one will be at 20… everybody should test,” he said.

According to the Surgeon General the second leading cause of lung cancer in the U.S — and drawing more attention. To help protect Coloradans the state health department is offering free tests and low-income mitigation assistance.

Varela says after his experience it is a cause he can get behind, “A free test is a savings of 150 dollars so i think a lot of people would do it and be motivated to make a change.”

You can sign up for your free radon test here, or for mitigation assistance by visiting the Colorado Department of Public Health and Environment’s website.