Cognitive bias and selected atmospheric parameters may severely influence the threat perception in a radiological disaster

The increasing application of nuclear technology worldwide raises the associated risks of such technology being used for harm. This study shows how an urban area affected by a radiological threat can experience the influence of the coupling of cognitive biases and apparently independent environmental variables. The simulated scenario considers the deliberate release of radioactive material over an inhabited urban area through a radiological dispersion device (RDD). The simulation was performed using the computer code HotSpot Health Physics version 3.1.2. A conservative assessment of the situation in its initial phase is developed to better support early decision-making. The influence of human factors through cognitive bias were considered based on the Dunning-Kruger (DK) effect. The results suggest that local atmospheric stability factors and the DK specific coefficients coupling effects should be emphatically considered in the decision process at this early stage. It was also found that there is a coupling between environmental variables and human factors in the perception of radiological risk. The conservative perspective adopted leads to courses of action that can make better use of available resources. Conducting frequent studies, building exercises based on simulated scenarios and testing decision-makers’ capabilities are measures of fundamental importance to improve the effectiveness of response plans.