Frequently asked questions about Radon
- What is radon?
- How does radon cause cancer?
- Where does radon come from?
- How does radon enter homes?
- How is radon detected?
- When are radon levels highest?
- What if my house has been vacant for months?
- Where can I find more information?
Radon is a naturally occurring radioactive gas without color, odor or taste. Radon is one stage in the decay process of uranium. When one element “decays” and becomes a different element altogether, it gives off radiation in the form of alpha and beta particles and gamma rays. Radon exists as a gas for slightly less than 4 days. It then decays and smaller energy particles are formed which also decay very rapidly. The alpha particles in the air are the real concern as they are heavy enough to penetrate a layer of skin. Long term exposure to high levels of radon gas can cause damage to sensitive lung tissue that can then lead to lung cancer.
These radon decay products, called “daughters,” attach themselves to dust particles floating in the air. When inhaled they can become lodged in the lung tissue. As these radon daughters decay, emitting the tiny bursts of energy, they can damage that lung cell tissue. Prolonged exposure can cause lung cancer. Scientific research indicates that at least a 10 to 20 year incubation period is required before a lung cancer develops.
Scientists estimate that indoor radon is the number one cause of lung cancer in non-smokers and the number two cause of lung cancer (after smoking) in the United States. Up to 21,000 Americans may die each year as a result of radon exposure. The EPA considers radon to be the most significant environmental health risk we face today.
Where does radon come from?
Radon comes primarily from the soil under a building. Radon can be found almost everywhere because radium (the “parent” of radon gas) is present in most soils. Average concentrations of radon are usually low, and small amounts of radon are measurable in the air. However, when homes, schools and buildings are erected over a source of radon, the gas can become trapped and elevated inside the building. The highest levels are usually detected in the basement, however heating and air conditioning systems and whole house vacuum systems can quickly spread radon to other parts of a building.
Radon usually enters buildings mixed with other gasses from the soil. Usual entry points are open sumps, cracks in floors and cinder block walls, openings in floors (from electrical, plumbing and other penetrations), floor drains, etc. Radon is literally pulled, or sucked into the building due to what is called the “stack effect.” Warm, heated air inside the building will rise and exit at higher elevations. This loss of air requires make up air which often comes from the soil through the above mentioned areas. Other exhausting appliances (such as fireplaces, dryers, bathroom fans, etc.) can also increase the rate of radon entry.
One of the most common radon test types is the activated carbon test. Using this technique, a small canister of activated charcoal is placed in the lowest livable area of a home or commercial building (the basement, if you have one) for several days. After exposure, the canister is sealed and sent to a laboratory for analysis. Charcoal canister tests help you determine the radon concentration present at the time of the test.
Other test devices include electronic continuous radon monitors (CRM’s), which can be used to detect and document radon levels on an hourly basis. This type of test is especially valuable when you are involved in purchasing a home and want to prevent tampering with the test device. Certain monitors can also be used to locate primary radon entry points.
Radon levels are highest in the winter by a factor of two to three times over summertime readings.
Unlike natural gas, carbon monoxide or other toxic airborne gasses, radon does not continue to build in concentration. Because ½ the radon “decays” every 3.8 days, an equilibrium is reached and radon levels remain fairly constant. Testing any home requires that the building be kept closed for a period of time before and DURING the test, negating the concern that the house has been vacant and closed up for a long period.
The Environmental Protection Agency’s website is an excellent source of information. Just click on our radon van icon and you will be directed to this site.