RADON CHARACTERISTICS

• Colorless
• Odorless
• Tasteless
• Naturally occurring
• Radioactive
• Inert (does not chemically react)
• Noble Gas that occurs in several isotopic forms
• Nine times denser than air
• Soluble in water

The Earth's crust contains small amounts of naturally radioactive materials such as uranium and thorium. Uranium and thorium decay to other radioactive atoms including radium, which then decays to radon gas. Since it is an inert (i.e., chemically stable) gas, radon moves from the soil, where it is produced, and into the air. Radon is a natural part of the earth's atmosphere. The amount of uranium and radium in soil varies greatly with geographic location and soil type. Therefore, the amount of radon gas released to the atmosphere also varies across the United States.

Copyright 2000, Great Lakes Center for Occupational & Environmental Safety & Health, School of Public Health, University of Illinois at Chicago