Well, it looks like someone has finally noticed that granite actually contains small quantities of Uranium which decay into Radon gas.

Ummm…I’ve know that for years, but I went to school in New England, where granite is a major source of Radon.

Had a discussion with Harry Stubbs, pen name Hal Clement, where he said that his being in a trench about a mile from a nuclear blast in the 1950s exposed him to less radiation than hanging in his basement..He ran the numbers for us, actually.

The amount of radiation is small, but it might effect resale value, so if you are getting the counters installed, you might want to have a technician measure the radiation level before installation.