Potential urban threat after a radiological fire event

Highlights: • A first conservative approach overestimates the consequences. • This view can produce a positive impact on resource allocation. • A coping strategy may arise from an expanded view of the situation. An accident involving both fire and radioactive material might eventually deteriorate into a dual-threat situation. Such scenario connects two important consequences: (a) fire damage and (b) radiation health threat. Computational simulations considering hypothetic fire scenarios in hospitals using radioactive material can provide valuable information about such an event. The initial decision in regards to an emergency response should consider the fire consequences and radiation doses distribution in the environment with consequences appearing at different times. While the fire presents an immediate threat, radiation exposure also creates immediate and future concerns. The purpose of this study is to evaluate leukemia risk from a hypothetical radiological fire event in a hospital operating Cs-137 gamma blood irradiator. The simulation in this study used the Hotspot Health Physics software to generate output data such as total effective dose (TED). The data from HotSpot was then used as an input to the leukemia risk equations from Biological Effects of Ionizing Radiation Committee V and VII (BEIR V and VII) models accordingly. Results suggest that the risks are dependent of wind speed and height of release; however, when age and sex are taken into account different outputs are shown. Also, the risk model can be changed from BEIR VII (low doses) to BEIR V (high doses) as radiation doses rise due to its time-dependent behavior. Such change would bring potential impacts on logistics and risk communication.