If your home or workplace has a high level of radon, you should take measures to reduce it. The goals of radon reduction are to:

• Prevent radon from entering the building.
• Vent or remove radon once it has entered the building.

The most common and usually most effective way to prevent radon from entering the home is through sub-slab depressurization, which involves venting air from beneath the foundation. Another way to remove radon-containing air from a building involves placing heavy plastic over the soil in earth-floored crawl spaces and using a fan and pipes or duct work to vent the radon to the outside (from under the plastic). This technique needs to be performed by qualified contractors who have completed training in a national radon proficiency program. You can locate a qualified contractor by contacting your local EPA office (find your regional office by going to the EPA Web site www.epa.gov/iaq/whereyoulive.html) or by calling the EPA National Radon Hotline at 1-800-SOS-RADON (1-800-767-7236).

The first step in reducing the level of radon in your home or office involves simple venting methods. Contact an EPA-qualified contractor to advise you or help you with ventilation of contaminated areas.

Methods of ventilation can include:³

• Opening windows.
• Installing vents in basements or crawl spaces.
• Increasing air movement with ceiling fans.
• Venting air outside the house from sump holes or floor drains.

The balance of air exchange is important to properly remove radon from the home or office. This is why it is essential to have a contractor properly trained in radon reduction to help with ventilation procedures.

Other control methods used to reduce radon include sealing cracks in the foundation or walls and using air cleaners.^{3, 4}

Once radon reduction or prevention procedures are done, the home or building should be retested. You may need to retest the home or building more than once until the radon level falls below the acceptable level of less than 4 pCi/L. It is usually safe to continue living in the home or building while the radon is being vented, but you may want to confirm this with your local EPA office.