Since radon is a by-product of disintegrating rock, it is more likely to be present in rocky areas or where subterranean rock formations are known to exist, especially granite.

During a natural geologic process, rock becomes fractured and small amounts of radon are emitted. Because radon is a gas that ...

What is Radon?  Radon is an odorless, colorless, tasteless gas that is naturally present in our atmosphere. This radioactive gas is a byproduct of disintegrating rock in the ground. As the rock splits and crumbles, it releases radon gas into the air. The half-life of radon is 3.8 ...