MINNEAPOLIS (WCCO) — Nearly a third of all Minnesota homes have potentially dangerous levels of radon.

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This month, health officials in Minneapolis want to raise awareness, and make sure every home gets tested. So, on Tuesday, city residents could pick up free radon test kits.

You can’t see it, smell it or taste it, but radon’s threat to your health can be severe.

Next to smoking, radon is the second leading cause of lung cancer in Minnesota. So when Minneapolis announced it was giving away free test kits, people responded.

“My goal this year was to lead a healthier lifestyle, so I’m going to start with my radon testing,” said one woman who got a free test kit Tuesday.

Health leaders say you can test your home as often as you like, but you should do so every two to three years.

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In that time, a home can settle and have its foundation shift and crack, releasing the dangerous gas into the air.

“I have an older house, and I just thought there maybe a chance of structure damage, and it could lead to radon,” said Philip Crawford, of Minneapolis, who also picked up a test kit.

Winter is the best time to test your home, because the furnace is running and the house is usually sealed.

If the three-to-seven day test comes back with high levels, you’ll need a radon mitigation system that pulls radon from the ground below your house, and releases it safely into the air.

The price on those systems is considerable – anywhere from $1,200 or $1,500.

“While that may sound like a lot of money, it is one of the main things you can do to prevent lung cancer,” said Eliza Schell, a Minneapolis code compliance officer.

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If you missed the chance to get a free radon test kit, you can buy one from the city or any hardware store. The cost is usually about $10.