About two in every five homes have dangerous levels of radon, so every home should be tested.

Radon is the leading environmental cause of cancer deaths in the United States and the leading cause of lung cancer among nonsmokers. Fortunately, the risk is largely preventable, by testing homes and fixing radon problems.

Radon is an odorless, colorless and tasteless radioactive gas that occurs naturally in Minnesota soils. It can enter into all kinds of homes through cracks or openings in walls or foundations. The only way for residents to know if their homes have radon is by testing. Radon is...