Rural and suburban population surge following detonation of an improvised nuclear device: a new model to estimate impact.

Background: The objective of the study was to model urban evacuation into surrounding communities after the detonation of an improvised nuclear device (IND) to assist rural and suburban planners in understanding and effectively planning to address the effects of population surges.

Methods: Researchers developed parameters for how far evacuees would travel to escape disasters and factors that would influence choice of destination from studies of historical evacuations, surveys of citizens' evacuation intentions in hypothetical disasters, and semistructured interviews with key informants and emergency preparedness experts. Those parameters became the inputs to a "push-pull" model of how many people would flee in the 4 scenarios and where they would go.

Results: The expanded model predicted significant population movements from the New York City borough of Manhattan and counties within 20 km of Manhattan to counties within a 150-mi radius of the assumed IND detonation. It also predicted that even in some communities located far from Manhattan, arriving evacuees would increase the population needing services by 50% to 150%.

Conclusions: The results suggest that suburban and rural communities could be overwhelmed by evacuees from their center city following an IND detonation. They also highlight the urgency of educating and communicating with the public about radiation hazards to mitigate panic and hysteria, anticipating the ways in which a mass exodus may disrupt or even cripple rescue and response efforts, and devising creative ways to exercise and drill for an event about which there is great denial and fatalism.