Detection of IEDs presents a real challenge for security screeners, employees, first responders, and military personnel. Training security guards, airport staff, and other personnel to be alert for suspicious behavior and IED indicators is the most common and best defense. Various bomb detection technologies continue to be developed for use in high-risk areas or situations such as airports and high profile events. These technologies include "trace detectors" that identify trace amounts of commonly used explosives in the air, and "millimeter-wave technology" that detects dense objects, hidden under clothes. Explosives-detection dogs, trained to detect and locate chemical explosives, are used in many security scenarios.
The extent of damage caused by an IED depends on its size, construction, and placement, and whether it incorporates a high explosive or propellant. Vehicle bombs can carry significantly more explosive material, and therefore do more damage.
Damage to Structures and Infrastructure
An explosion in or near a building or public transportation venue may blow out windows, destroy walls, and shut down building systems. Exit routes may be disrupted or destroyed, and smoke and dust may travel upward through stairways and elevator shafts, making navigation difficult. Building failure may result in the release of hazardous materials used within the building or incorporated within its structure. An IED attack may cause disruptions in municipal services such as electricity, water, communications, and transportation, which may continue for days to weeks after an attack. Individuals and businesses should have a plan for addressing these interruptions.
The Possibility of Secondary Devices and/or Multiple Explosions A known bomber tactic is to use a distraction, such as gunfire, small bombs, or other surprises, to attract bystanders to a window, a doorway, or outside, and then to detonate a second destructive device at the gathering point. In an attack, there may be bombings at multiple locations. Rescue efforts can be hampered by the need to respond to more than one site.
The explosion of a bomb can cause secondary explosions if gasoline, natural gas, or other flammable material is ignited. Secondary hazards can include fire with possibly toxic smoke, disruption of electric power, ruptured natural gas lines and water mains, and debris. There can be loss of traffic control in the area of the blast with possible traffic accidents involving fleeing citizens.
Immediate Health Effects
Explosions create a high-pressure blast that sends debris flying and lifts people off the ground. The type of injuries and the number of people hurt will vary depending on the physical environment and the size of the blast, the amount of shielding between victims and the blast, fires, or resulting structural damage, and whether the explosion occurs in a closed space or an open area. Injuries common to explosions include:
- Overpressure damage to the lungs, ears, abdomen, and other pressure-sensitive organs. Blast lung injury, a condition caused by the extreme pressure of an explosion, is the leading cause of illness and death for initial survivors of an explosion.
- Fragmentation injuries caused by projectiles thrown by the blast
- Impact injuries caused when the blast throws a victim into another object
- Thermal injuries caused by burns to the skin, mouth, sinuses, and lungs
- Other injuries including exposure to toxic substances, crush injuries, and aggravation of pre-existing conditions