The Problem: Each year, tons of radioactive materials are shipped across thousands of miles to the WIPP site in Carlsbad, New Mexico. Many citizens of New Mexico are concerned about the environmental safety of transporting and storing these materials. Some protesters are afraid for our future, while government leaders and scientists assure us there is little to fear. Who is right? How long will the materials be radioactive? What information is needed to decide how much is safe? Understanding half-life will help us in answering these questions.