January is National Radon Action Month, and according to the U.S. Environmental Protection Agency (EPA) more than 8 million U.S. homes have indoor concentrations of radon that exceed safe levels. In some states nearly 40% of all homes exceed safe levels.
What is radon?
Radon is a naturally forming, radioactive, colorless, odorless and tasteless gas. It is found in almost all soil, and is produced by a natural process as uranium breaks down into radium and then into radon gas. Radon in turn breaks down into solid radioactive elements known as “radon progeny” (such as polonium – 218) that attach to airborne particles.
Radon enters a home through cracks in the floor or walls of the basement or foundation. In one EPA study, nearly a third of homes tested (in seven states) had radon levels exceeding the EPA’s recommended safe level. Radon contamination is found in every state, according to the EPA.
Radon and your health
Because they are radioactive, radon and radon progeny emit alpha particles, a high-energy radiation that damages DNA in human cells and causes lung cancer. When radon is inhaled, particles become lodged in the lungs where they continue to emit alpha particles. Radon exposure is the second leading cause of lung cancer among nonsmokers in the U.S., after secondhand smoke exposure. The National Science Foundation puts the annual U.S. death toll from radon exposure at 20,000. Many of these victims never smoked.
Some studies have also suggested a link between radon and leukemia, though the National Cancer Institute notes the evidence remains inconclusive.
What you can do
Here are a few simple steps you can take to control radon levels in your home and help protect those you love:
- Test for Radon. The first step in managing the risk of radon is to have your home tested. Every home is unique, and a home with dangerous radon levels can be next door to a home with virtually no radon. Any radon level higher than 4 picocuries per liter is considered by health authorities to be unsafe. Testing should always be conducted by a qualified contractor, and should include both short-term and long-term testing. State and federal health agencies can recommend a qualified testing company in your area. The EPA offers more information on radon and radon-testing companies at its website (see link below).
- Mitigate Radon. A qualified radon mitigation contractor will help you determine the most effective radon reduction techniques for your home. These techniques include:
Sealing cracks. Since radon enters your home through cracks in the floor and walls of the foundation, sealing cracks and leaks is an important first step. However, sealing cracks will limit but not completely stop the flow of radon into a home.
Suction. Pipes inserted into or below the foundation slab are connected to a vent fan that pulls radon from below the house and out into the open air.
Depressurization. This generally involves drilling a hole in the basement floor and extending a pipe beneath the slab of the house. The pipe runs up through the home and then vents outward with the help of an inline fan.
Ventilation. Installing a heat recovery ventilator increases ventilation by drawing outside air into the house and expelling radon-contaminated air. Air is warmed or cooled as needed, and air filtration can be added to filter the outdoor air coming in.
Filtration. Research by the American Association of Radon Scientists and Technologists showed that even standard HEPA filters can reduce radon by as much as 85%. The U.S. EPA does not generally recommend air cleaning to control radon because most filtration systems, even HEPA filters, are incapable of stopping the tiniest particles to which radon progeny adhere. IQAir HyperHEPA filtration, on the other hand, filters particles down to 0.003 microns – the smallest particles that exist.
For whole-house air filtration of potentially radioactive particles of all sizes, IQAir recommends the high-performance Perfect 16 whole-house system. For specific areas within a home or for homes without centralized heating or cooling systems, the HealthPro Plus and the GC MultiGas systems are recommended.
If a mitigation specialist recommends overpressure, an IQAir InFlow or OutFlow Kit can be combined with an IQAir room air purifier to draw outdoor air into the indoor environment, creating overpressure in the process.
The EPA Map of Radon Zones (http://www.epa.gov/radon/zonemap.html) can help you determine the potential radon risk where you live, but the EPA recommends that every home should be tested for radon. For more information on radon health effects and reduction programs, visit the EPA’s Radon Home Page (http://www.epa.gov/radon/).