A CBRN event, unlike earthquakes, floods, landslides and anything else you can add to the phenomena that usually refer to the Civil Protection System, spreads over a city that continues to live and could be largely not aware of the situation in place. Excluding nuclear weapons, which trigger clearly visible and mechanically destructive dynamics, C B R presence may also be not noticeable, causing, among other things, considerable difficulties in a timely definition of both the quality of the event and the extension of the phenomena.
