Environmental Health & Engineering, Inc. has completed a detailed evaluation of potential human health risks of naturally occurring radioactive materials in granite countertops. The extensive measurements and rigorous mathematical modeling conducted to date indicate that (i) external doses of ionizing radiation emitted from granite countertops are well below levels that would pose a health concern and (ii) contributions from granite countertops to radon levels in homes are lower than background levels of radon exposure typically found outdoors and indoors.