Date Published: 01/09/2009 [Source]
Kentucky has the highest number of homes in the US with elevated radon levels. Experts attribute this to the cave system that the state sits over.
According to Air Chek Inc., a company tests radon readings across the country, 51% of homes in Jefferson County have excess radon levels. In Clark County, Indiana, it's 41%.
Free radon test kits are available from the Kentucky Cabinet for Health and Family Services at (502) 564-4856.