According to the Environmental Protection Agency, radon contamination causes nearly 20,000 deaths a year. Thing is, you can test for and “fix” this very serious problem quite easily. Here’s what you do.

How Do You Test for Radon?

All homes should test for radon, regardless of geographic location; homes with elevated radon levels have been identified across the country. If you haven’t checked for radon in the past two years, or if you’ve done some remodeling since the last time you did, pick up an Accu-Star certified radon test from your local home center. Available in both short-term and long-term monitoring, the tests are easy to use and require minimal setup. “The test is cheap and reliable—it doesn’t take rocket science,” says Bill Wehrum, an administrator at the EPA’s Office of Air and Radiation.

High Levels and How to Get Rid of It

If you do find high levels of the gas above 4 picocuries per liter of air (pCI/L), you should immediately call your state EPA office for a list of qualified mitigation contractors in your area. While some of the solutions are simple, it is not a DIY job. “If you don’t do it right, you might actually increase the level of radon or compromise the air quality in your house,” says Wehrum. A radon mitigation contractor will be able to tell you what kind of radon control system (active or passive and sub-slab, sump hole or block wall suction) will be most effective for you based on where you live and what kind of foundation you have. They should also be able to provide tips for keeping your home safe, such as continually checking for and sealing up cracks in your foundation. Be sure to test your home again once any work is completed and continue to do so periodically to ensure your mitigation system is working.

How to Prevent Radon

If you’re building a home, you can save yourself loads of worry—and money later on down the road—by installing a passive radon control. Here’s how:

Install a layer of gas-permeable aggregate, such as four inches of gravel, beneath the slab or flooring system of your home if you don’t have a crawlspace. Cover this layer or your crawlspace floor with plastic sheeting to stop radon gas from moving past that level and into your home. Seal and caulk all cracks in your foundation and walls. Not only will this help prevent entry of radon, but it’ll add to the energy efficiency of your home. Run a three to four-inch gas-tight pipe from the first layer or crawlspace to the roof. This will safely vent gases from the soil to the outside. Wire in an extra circuit to the attic so that a vent fan can be installed to turn the pipe into a vacuum cleaner, or an active radon control system, which routes the gas out of your home.