MINNEAPOLIS (WCCO) — The City of Minneapolis is offering free kits to test the levels of radon in your home.

Radon is the leading environmental cause of lung cancer deaths in the U.S., which kills 21,000 people each year. The Minnesota Department of Health says 40 percent of homes in Minnesota have elevated levels of the gas.

READ MORE: 4 Charged In Metro Area Sex Trafficking Sting

January being National Radon Action Month, the city of Minneapolis is giving out free radon test kits to the first 200 people who apply.

READ MORE: Testimony Continues, Closing Up 1st Week Of Ex-MPD Officers' Federal Trial

You put the self-addressed kit in the mail to be sent to a lab where they’ll test your radon level for you. If a test comes back with high radon levels, it can be fixed.

The free radon test kits are available at the City of Minneapolis Development Review. Once the free radon test kits run out, they will still be available at the same location for $9 each.

MORE NEWS: Apply To ServeMinnesota

You can also check with your county to find test kits. Click here for more information.