Dirty bomb

The term dirty bomb is most often used to refer to a Radiological Dispersal Device (RDD), a radiological weapon which combines radioactive material with conventional explosives. Though an RDD is designed to disperse radioactive material over a large area, the conventional explosive would likely have more immediate lethal effect than the radioactive material. At levels created from most probable sources, not enough radiation would be present to cause severe illness or death. A test explosion and subsequent calculations done by the Department of Energy found that assuming nothing is done to clean up the affected area and everyone stays in the affected area for 1 year, the radiation exposure would be "fairly high".

References

• Adam Curtis's The Power of Nightmares, Part III -- Video at Information Clearing House