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Occupational & Environmental Epidemiology


Radon is a naturally occurring, invisible, odorless gas that comes from natural deposits of uranium in soil, rock, and water. Radon is a radioactive decay product of radium, which is itself a decay product of uranium. Uranium and radium are both common elements in soil.

Radon gas is usually harmlessly dispersed in outdoor air, but when homes or other buildings are built on top of radon-producing geological formations, it can become trapped inside the structure, exposing the people living or working in those buildings to this radiation. Radon can enter the home through cracks in solid floors and walls, construction joints, gaps in suspended floors and around service pipes, cavities inside walls, and the water supply. Long-term exposure to radon at certain levels has been found to cause lung cancer.

Radon is emitted at varying levels and in different locations of North Carolina. The piedmont and mountain counties are estimated to have the greatest proportion of homes with elevated levels of radon.

The U.S. Surgeon General and EPA recommend that all homes be tested be tested for radon. You may do this testing yourself or hire a certified professional. Levels of 4 picocuries per liter (pCi/L) or more require action.

The lead agency for radon-related activities in North Carolina is the N.C. Radiation Protection Section (RPS) of the Division of Health Service Regulation of the Department of Health and Human Services. The RPS is also the sole state agency for the federal State Indoor Radon Grant (SIRG).

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