What’s Lurking in Your Countertop?

Who knew that granite countertops can emit dangerous levels of radon and radiation? It's rare, but here's an excerpt from one woman who had some seriously dangerous counters:

The E.P.A. recommends taking action if radon gas levels in the home exceeds 4 picocuries per liter of air (a measure of radioactive emission); about the same risk for cancer as smoking a half a pack of cigarettes per day. In Dr. Sugarman’s kitchen, the readings were 100 picocuries per liter. In her basement, where radon readings are expected to be higher because the gas usually seeps into homes from decaying uranium underground, the readings were 6 picocuries per liter.