Radon

The Surgeon General has warned that radon is the second leading cause of lung cancer in the United States. There are currently no conclusive data on whether children are at greater risk than adults from radon. No specific subtype of lung cancer is associated with radon exposure. Only smoking causes more cases of lung cancer.

Radon is a radioactive gas. It is colorless, odorless, tasteless, and chemically inert. Unless you test for it, there is no way of telling how much is present. Radon is formed by the natural radioactive decay of uranium in rock, soil, and water. Naturally existing, low levels of uranium occur widely in Earth's crust, it can be found in all 50 states. Once produced, radon moves through the ground to the air above, some remains below the surface and dissolves in water that collects and flows under the ground's surface.

Members of Andersen Environmental's professional staff are accredited through the National Environmental Health Association (NEHA), as certified Radon Measurement Providers, certified to conduct radon assessments and draft mitigation plans throughout the United States.

Radon Overview

Most indoor radon comes into the building from the soil or rock beneath it. Radon and other gases rise through the soil and get trapped under the building. The trapped gases build up pressure. Air pressure inside homes is usually lower than the pressure in the soil. Therefore, the higher pressure under the building forces gases though floors and walls and into the building. Most of the gas moves through cracks and other openings. Once inside, the radon can become trapped and concentrated.

Openings which commonly allow easy flow of the gases in include the following:

• Cracks in floors and walls
• Gaps in suspended floors
• Openings around sump pumps and drains
• Cavities in walls
• Joints in construction materials
• Gaps around utility penetrations (pipes and wires)
• Crawl spaces that open directly into the building

Radon levels within a building often change on a day-to-day basis. Highest indoor levels are often found during the heating season. Weather conditions, operation of furnaces and fireplaces, and opening/closing of windows and doors are among the factors that cause these patterns.

Short-term sampling canisters are the quickest way to test. These canisters should remain in the building from 2 to 90 days, depending on the device. Because radon levels may fluctuate by as much as a factor of two or three, additional testing is sometimes recommended to better assess the average radon level. Though short-term tests are sometimes used, long-term tests are often recommended.

Long-term tests remain in the structure for more than 90 days. A long-term test gives a reading that is more likely to reflect the building's year-round average radon level than a short-term test. Because of season variations in radon levels, the closer the long-term measurement is to 365 days, the more representative it will be of annual average radon levels.