Radon comes from the natural radioactive breakdown of uranium in soil, rock, and water. Radon is an invisible, odorless, tasteless gas that moves through the ground to the air above. It enters buildings from cracks in solid floors or walls, construction joints, gaps in suspended floors, as well as around service pipes, cavities inside walls, and the water supply. Two houses side-by-side can have very different radon levels due to the geology below the individual homes, including the types of soil and rock and the cracks and fissures.
Radon in Boulder County
Naturally existing low levels of uranium occur widely throughout the earth's crust. Radon is found in all 50 states, and is prevalent in Colorado. The EPA has ranked Boulder County as "Zone 1," which means the average house will likely exceed the EPA's action level of 4.0 pCi/L.
Radon can be found in any building, but homes are the most concerning since that is where families spend the most time. Find out if your home has radon.
Radon Exposure & Cancer
Radon is the leading cause of lung cancer among non-smokers. It is estimated to cause about 21,000 lung cancer deaths per year.
When air containing radon gas is inhaled, sensitive tissue can be exposed to alpha radiation, causing damage that increases the risk of cancer.
The Iowa Radon Lung Cancer Study tracked nearly 1,000 women who had lived in their homes for more than 20 years. The results of the case-control study (after adjusting for age, smoking, and other factors) indicated that a 20-year exposure of radon levels at the EPA guideline of 4.0 pCi/L yielded an increased lung cancer risk of 50%.
As Radon Decays, the Alpha Particles Released Are Strong Enough to Pit Plastic
The greatest exposure to alpha radiation for the average person comes from the inhalation of radon and its decay products.
Alpha particles, as defined by the EPA, are “a type of ionizing radiation ejected by the nuclei of some unstable atoms." If alpha particles have been inhaled, sensitive living tissue can be exposed to alpha radiation. The resulting damage increases the risk of cancer. In fact, alpha radiation is known to cause lung cancer in humans when alpha particles are inhaled.
This picture shows a plastic chip from a passive radon test. This piece of plastic is magnified only 100 times and shows the damage to the plastic as a result of exposure to alpha particles after just 3 months exposure at 4 pCi/L.
For more information, see www.epa.gov.
Information from National Association of Counties, March 2006 County IAQ Newsletter