What to do if radon levels in your home are high

Radon is an odorless, colorless, and tasteless radioactive gas, produced naturally by the decay of uranium. Radon particles can be trapped in the lungs when inhaled, and prolonged exposure can damage the tissue of the lungs, potentially leading to lung cancer. In the US, radon is second only to smoking as a cause of lung cancer. 

Because radon exposure causes no irritation or immediate health effects, exposure usually goes unnoticed until there are more serious health consequences. It’s especially dangerous for children, whose faster respiration and smaller lungs translate to higher doses even at the same concentration. 

If you have tested your home for radon and found that the levels are higher than recommended–4 pCi/L or higher–there are steps you can take to reduce concentrations of the gas (and lower the associated risks): 

• Find a state-certified radon mitigation contractor: If you’re planning to undertake larger home repairs (see some options below), it is always best to use a certified radon mitigation contractor. Radon mitigation requires special knowledge and skills, and a contractor without special training might worsen the problem.^[1] The EPA maintains a list of contactors by state; this is a good starting point for finding a certified professional near you. 
• Choose the best mitigation system for your home: Where your house is located, how it is constructed, and environmental factors in your area will all help determine the best radon reduction option. Some form of subslab depressurization is usually the most common and most reliable form of radon reduction, and involves installing suction pipes beneath the foundation of the home (these are usually attached to a fan system that vents to the outdoors). Ventilating a crawl space, house or room pressurization, or a heat recovery ventilator are alternate options you may want to consider. Make sure to take associated increases in utility costs into account when choosing the best mitigation option for you.
• Open windows and doors: Radon builds up in the air, but adequate ventilation can help reduce the concentration to safe levels. Fans and vents can help with this process. It should be noted this is at best a temporary solution and should not take the place of a more permanent radon mitigation plan. 
• Seal your foundation: Sealing cracks and entry points in your home–particularly the foundation–is an important part of any radon mitigation strategy. Plaster, caulk, and other sealants can all achieve this goal.

Test again: Your contractor should test once work is complete to demonstrate the solution’s effectiveness. Additionally, you may want to test more frequently in the future to ensure that your system is still working as expected.