Radiological terrorism can use several modes of deploying radioactive substances in order to cause deliberate radiation exposure, ranging from the intentional covert exposure of large population groups to a strong gamma radiation source, to combining conventional explosives with a suitable radioisotope leading to the intentional dispersal of radioactive aerosols (dirty bomb). The deployment of a radiological dispersal device (RDD) by terrorists is likely to result in relatively low radiation exposure of the targeted population, in most cases insufficient to cause a severe radiation injury. Nevertheless, the social and psychological effects can be severe, particularly in an urban area where a large number of persons may either be actually contaminated or perceive to be contaminated. This paper focuses on the extensive experience gained in the aftermath of the radiological accident which contaminated the Brazilian city of Goiania in 1987. The incident showed the multiple practical difficulties encountered by the professionals and the authorities caring for the radiation victims and addressing the needs of those suspecting to be contaminated, and the reaction by the uncontaminated residents of Goiania. The results of this analysis are used to recommend practically applicable solutions from Lessons Learned:

• Decision-making criteria need to be defined for the early-, intermediate-, and long-term phase of managing the post-attack period, balancing radiation-psychosis, radiation doses, associated health risks, monetary costs and benefits;

• The targeted population needs to be informed early and in a comprehensible manner about clean-up criteria and site restoration concepts, such as exemption, clearance, authorized release, release for restricted use, and optimization in order to assist in calming public radiation fear;

• Proactive planning for optimi management is essential, since many countries are insufficiently prepared for integrating treatment of radiation psychosis with a post-attack dose minimization management;

• Trust-building measures among the inhabitants of the contaminated areas are essential from the onset of managing the aftermath of a radiological terror attack. The population living outside the RDD-affected area needs to be assured that the situation is truly under control by the authorities, e.g., with an adequate quality assurance program for the clean-up and restoration program;

• Authorized groups should be created that can issue certificates of integrity for products and services, thereby reducing the psychological impact of RDD-related terror attacks. Specialized people should be on standby to issue correct press releases, even before reporters arrive on the scene if possible.