Analysis of a dirty bomb attack in a large metropolitan area: simulate the dispersion of radioactive materials

The potential for a radiological or nuclear attack has been widely acknowledged in the last two decades. The use of a dirty bomb by terrorist organizations is considered to be a credible threat for which policymakers and relevant security agencies must prepare. Radioactive materials are stored in thousands of facilities around the world and may not be adequately protected against theft. This article analyzes a hypothetical dirty bomb attack in a large metropolitan area, evaluating the radiation dose to the involved population. The dispersion of radioactive materials is simulated using HOTSPOT code, considering a number of possible radionuclides (alpha, beta and gamma emitters) and scenarios. The findings of the present study corroborate and extend previous research demonstrating that it is unlikely that the atmospheric dispersion of radioactive material contained in a dirty bomb would produce deterministic effects in the exposed population. The radioactive material would be dispersed into the air resulting in relatively low doses. However, depending on the situation, the explosion of a dirty bomb is likely to contaminate properties (rendering them temporarily uninhabitable), thereby requiring potentially costly cleanup. Furthermore, due to the general fear of radiation, pervasive psychological effects are expected.