Chemical terrorism: risk modeling proposal for attacks involving ricin in mass gatherings in Brazil

ABSTRACT Mass gatherings are at the center of terrorist strategies and are being repeated more frequently at international level. During the last years, Brazil has been the stage of mass gatherings, and it is supposed to host the Fifa Sub-17 World Cup this year. It is assumed that large exposure in these contexts increases vulnerability to threats, therefore it is necessary that safety planning be supported in risk management studies. It is considered that a greater knowledge of the topic is the first step towards an efficient defense system. This study aims to evaluate the probability of a ricin terrorist attack on a mathematical model. Existing literature shows reports of episodes of use of ricin as a chemical weapon. The choice of ricin is justified because it's a relatively easy biotoxin extraction from castor bean, which is an endemic plant in the Brazilian territory. For such study, we used game theory and the Major probability equation for terrorism risk analysis. The parameters analyzed were the resources of attack, defense, and value of the target. The probability equation has been optimized for defense.