January is Radon Action Month, and the Berrien County Health Department is urging residents to test their homes for radon by offering free testing kits.

Radon is an odorless, invisible radioactive gas found at elevated levels in an estimated one in four Michigan homes.

It’s the second-leading cause of lung cancer in the U.S., behind smoking, and the only way to detect it is through testing.

Free kits are available throughout January at health department offices in Benton Harbor and Niles during regular business hours, while supplies last.

One kit is available per household for both homeowners and renters. Health officials recommend testing every two years, since radon levels can change over time.