For many, the thought of terrorists detonating a dirty bomb-a radiological dispersal device-is frightening. However, the radiation health risks from such an occurrence are small. For most people directly involved, the exposure would have an estimated lifetime health risk that is comparable to the health risk from smoking five packages of cigarettes or the accident risk from taking a hike. The actual impact of a dirty bomb would be economic and social (NCRP 2001). There would be an economic cost for clean-up as well as a decrease in economic activity in the affected area due to radiation fear. If such a bomb were detonated, those exposed as well as those not exposed would have great concern about potential health effects while seeking medical attention and avoiding the impacted area. This paper discusses the health risks from radiation exposure and compares them to risks from various activities of daily life and to exposure to hazardous chemicals.