RADON (Rn) GAS
Indoor Radon is the second leading cause of lung cancer in the United States and the leading cause among non-smokers. Smoking, radon, and secondhand smoke are the leading causes of lung cancer.
Radon is generated during radioactive decay of Radium (Ra) which in terms, originates during radioactive decay of Uranium (U) and Thorium (Th). These radioactive elements are usually present scattered in the Earth's crust. The Radon gas escapes through cracks in rocks to the atmosphere. Elevated concentrations of Radon are therefore highly localized and if one zone is affected this does not necessarily mean that neighbors would have the same problem.
The following facts about Radon can be pointed out:
-Radon is a tasteless, colorless, odorless gas.
-It is a proven carcinogen and ranks second only to cigarette smoking as a cause of lung cancer. Smoking increases the risks caused by Radon gas.
-There is a number of radon sampling devices that you can buy, or you can have a professional company conduct tests. The instructions of the manufactures of the testing device must be followed closely.
-Radon is measured in pico Curies per liter (pCi/L). The EPA recommends that remedial action be taken when a residence exceeds a radon level of 4 pCi/L. Normal outside air has a content of 0.1-0.2 pCi/L. Note that the EPA tolerance for remedial action is not a limit for safe level. The health hazards and risks increase as concentration and time of exposure increase.
If you have a Radon problem, it is usually easy and inexpensive to abate. In this case it is recommended to consult an expert. The ways Radon can enter into a house are shown below.
There are three main ways of reducing Radon concentrations in a building: a) Sealing the cracks and holes in foundations where gas can ingress; b) Ventilating (without creating vacuum) the lower level of the building in contact with the soil with fresh outside air in order to remove it; c) Pressurization of the building in order to avoid entrance of Radon gas into it.
A single free copy of the ASTM E-2121 standard is available from EPA’s National Service Center for Environmental Publications or the Agency’s IAQ-Info hotline, 1-800-438-4318. Copies of the standard may be purchased from ASTMI at http:/www.astm.org/
For more information about Radon in indoor air consult: http:/www.epa.gov/radon/
Links are provided as a matter of convenience.
Environmental Issues >