About Radon Gas
Radon is a naturally occurring gas that seeps out of rocks and soil. Radon is an element in the periodic table. It comes from uranium that has been in the ground since the time the earth was formed. The rate of radon seepage is quite variable, partly because the amounts of uranium in the soil vary considerably. Radon flows naturally from the soil into outdoor air. Typically, radon will quickly dissipate in outside air, but it can build up to dangerous concentrations when trapped indoors and unable to disperse. Some underground mines, especially uranium mines, contain much higher levels of radon.
Although radon is chemically inert and electrically uncharged, it is radioactive, which means that radon atoms in the air can spontaneously decay, or change to other atoms. When the resulting atoms, called radon progeny, are formed, they are electrically charged and can attach themselves to tiny dust particles in indoor air. These dust particles can easily be inhaled into the lung and can adhere to the lining of the lung. The deposited atoms decay, or change, by emitting a type of radiation called alpha radiation, which has the potential to damage cells in the lung. Alpha radiation can disrupt the DNA of these lung cells. This DNA damage has the potential to be one step in a chain of events that can lead to cancer. Alpha radiation travel only extremely short distances in the body. Thus, alpha radiation from the decay of radon progeny in the lungs cannot reach cells in any other organs, so it is likely that lung cancer is the only potentially important cancer hazard posed by radon.
Radon can build to dangerous levels in the home; especially homes built in the last 30 years. Newer homes are typically built more energy efficient. This is good for the environment, but can be bad for indoor air quality unless properly mitigated for in advance. Newer homes are built “tighter” than older homes, which can sometimes trap VOCs and dangerous gases like radon. VOCs can off-gas from paint and furnishings in the home and can typically be mitigated by an HVAC professional. Radon, however, seeps up from the soil, through cracks in the foundation, and finds its way into homes where it is recirculated and can accumulate to dangerous levels. Typically, an HVAC system will not mitigate radon effectively.
The most common way to mitigate radon in the home is through a technique called “sub-slab depressurization”. By drilling a hole in a foundation and creating a suction pit (or sealing a crawlspace with radon barrier), a system can be created that pulls air from the soil and exhausts it out the roof of a home. This way, radon never has a chance to get trapped inside! There are many different types of sub-slab depressurization techniques, which is why it is important to have a trained and certified mitigator install a system. Qualified mitigators in the United States can be found in the AARST-NRPP website located on the right hand side of this page. Confident and determined do-it-yourselfers can often install their own systems with phone support from PDS and a copy of the book Protecting your Home from Radon available here.
Radon is colorless, odorless and undetectable by the naked eye. It is important to test your living space at least once every two years. Fortunately, radon is easy to mitigate for and one of the most inexpensive ways to improve your home and health.
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