Radon is a by-product
of the radioactive decay of uranium, an element that occurs naturally in
the Earth's rocks, sediments and soils.
The Earth's crust
typically contains between 1 and 3 parts per million (ppm) of uranium.
Earth materials with
over 3 ppm uranium are considered potential radon sources, and buildings constructed on top of
such materials may have elevated levels of indoor radon.
|In Ohio, most houses with indoor radon levels above 4 pCi/l are associated with two geologic materials: a rock formation known as the "Ohio Shale," and a soil developed on sediment (called "till") deposited by glaciers during the last Ice Age.|
For more information on the geology of radon in Ohio, Click here