A recent New York Times Article discusses the fact that some granite counter tops have been found to emit radon gas. The article was prompted by an incident that occurred in New Jersey where a family’s summer home was found to have high levels of radon gas in a routine home inspection. Radon Gas is the second most frequent cause of lung cancer, after cigarette smoking, and radon-induced lung cancer is thought to be the 6th leading cause of cancer death overall.

Allegations that granite countertops may emit dangerous levels of radon and radiation have been raised periodically over the past decade, mostly by makers and distributors of competing countertop materials. The Marble Institute of America has said such claims are “ludicrous” because although granite is known to contain uranium and other radioactive materials like thorium and potassium, the amounts in countertops are not enough to pose a health threat.

The Environmental Protection Agency has received many calls from concerned homeowners and radon inspectors looking for guidance on this issue. The end result is that there are over 900 different types of granite available in the United States from around the world.  While it is still unknown what levels of radon exposure cause cancer, the EPA standard since 20034 pCi/L in indoor air.