(ABC 6 News) – January is Radon Action Month, and health officials are using it to remind everyone to test their homes for radon.

“The only way to know if your house has radon is to test,” said Brenna San Angelo, an Environmental Lab Technician with Olmsted County Public Health.

Radon is a colorless and odorless type of radiation gas found in the soil, that can enter your home through cracks in the foundation.

Breathing in radon for an extended period of time, such as months or years, can cause damage to your lungs.

“It’s the second leading cause of lung cancer over all after smoking, and it’s estimated to cause about 21,000 lung cancer deaths per year in the United States,” said Dan Tranter, Supervisor of the Minnesota Department of Health’s Indoor Air Unit.

About two in five homes in Minnesota test high for radon.

“In southern Minnesota, it can be 50, 60, even 70 percent of homes test high,” said Tranter.

Luckily, testing kits are simple to use. San Angleo explains using an Olmsted County test kit is as easy as unscrewing the top and placing it about three feet away from a window or a wall where it can’t be disturbed by pets, kids or other people. Then leave the device there for about three to five days, put it back in the box it came from and send it back to the county for the lab technicians to calculate.

Experts recommend testing your home every five years, or sooner if you recently had high radon levels. They also say it’s best to test during the winter.

“Because you have your home closed up, the heat is on, so radon levels may be a little bit higher in the winter, but you can test any time of the year,” said Tranter.

Radon levels between two to four picocuries – which is the unit radon is measured in – is a sign that you may want to get a mitigation system to remove the radon from your home. Anything over four picocuries and you should highly consider getting a mitigation system.

“I did get a mitigation system installed in my house. Took about a month until I could get it installed, but I drastically see a difference. It brought my, I was up at about 15 picocuries now it’s about two,” said San Angelo.

MDH has a list of professionals it recommends to help remove the radon from your home.

You can also purchase a test kit from MDH, or pick one up from your local county public health services.

Some counties in Minnesota and Iowa offer free testing kits, while others do require payment.