In the decade following the September 11, 2001, terrorist attacks, Americans have become more accustomed to the threat of terrorist attacks by weapons of mass destruction (WMD). Training for response to such events is now common for first responders and medical personnel. This chapter will present practical approaches to terrorist attacks involving WMD and explosives, an overview of specific types of explosives, and strategies for dealing with blast and burn injuries in the prehospital setting.

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  Define terrorism, domestic and international.

  
  
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  Discuss specific threats to emergency responders to terrorist events.

  
  
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  Discuss principles and strategies relating to the approach to a possible terrorist attack.

  
  
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  Define the term weapon of mass destruction, and list examples.

  
  
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  Discuss specific issues related to emergency response to various types of WMD events.

  
  
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  Describe explosives and incendiaries and give examples.

  
  
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  Discuss specific medical conditions associated to exposure to explosives and incineraries.

  
  
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  Discuss signs of the possible presence of explosives on a scene (eg, pipe lengths, blasting caps, detonator cord, etc).

Terrorism is any violent act directed against people or property, which is intended to cause damage and/or death, instill fear, and disrupt normal activity among civilians while drawing attention to or furthering a specific nongovernmental group or cause.

Domestic terrorism in the United States refers to activities undertaken in the territorial jurisdiction of the United States which appear to be intended to intimidate or coerce a population or influence governmental policy by mass destruction, assassination, or kidnapping ¹ [18 USC 2331(5)].

International terrorism refers to terrorist activities that would violate American criminal laws or the laws of any state and which occur outside the territorial jurisdiction of the United States or transcend national boundaries in terms of the means by which they are accomplished, the population they are meant to affect, or the locale in which the events occur or where the perpetrators seek asylum. ²

Uses of chemical, biological, radiation, nuclear, and explosive (CBRNE) resources have been well described as possible terrorist scenarios. Explosives have long been weapons of choice for international attacks due to their relative ease of use, low cost, and high impact. In the Middle East, improvised explosive devices (IEDs) and suicide bombings occur with relative frequency. Although there have been fewer explosive attacks in the United States, notable examples from the past two decades include the use of stationary IEDs in the 1993 World Trade Center attack and the Centennial Park bombing during the 1996 Olympic Games in Atlanta, Georgia. Vehicle-borne improvised explosive devices (VBIED) were used in 1995 at the Oklahoma City Murrah Building bombing and the September 11, 2001, attacks on the World Trade Center and the Pentagon. There was also an unsuccessful VBIED attempt in Times Square in 2010. Internationally, explosives were second only to firearms as the most common method of attacks against civilians in 2010 and explosives were responsible for the highest number of civilian casualties. ³ Explosives, as a method of inflicting casualties, is now the leading method of murder chosen by terrorists around the world. ⁴

All of these examples can be considered WMD attacks. The term weapons of mass destruction, however, has become an increasingly political term used to describe conventional and unconventional weaponry used to cause widespread damage or panic. Its connotation suggests terrorism, but it can be applied literally to many circumstances, including traditional warfare. In the immediate aftermath of an event, it may be difficult to determine if the event was intentional or accidental, and that determination may be of secondary importance. Many agencies are now using the more precise term CBRNE to describe chemical, biological, radiological, nuclear, or explosive events in an effort to devise a uniform response to such an event, regardless of its underlying nature. Accidental explosions may occur as a result of industrial accidents, compromised gas pipes, motor vehicle accidents, and many other etiologies. In many parts of the world, death or dismemberment from accidental landmine detonations are still common. ⁵

Unfortunately, terroristic events in the United States are not a new phenomenon. Explosives have been utilized throughout the 20th century to inflict fear in civilian populations. In 1920, a horse-drawn wagon carrying 45kg of dynamite and 230kg of iron sash weights was parked in the financial district of New York City. At noon, on September 16, the explosive-laden wagon, detonated by a timing device, exploded along Wall Street, killing 23 people and injuring 400.

Bath Township, Michigan, was site to multiple bombings in May 1927. The attacks were responsible for the deaths of 45 people. A local farmer, devastated over financial matters, used stockpiled pyrotol and dynamite to blow up his farm, the Bath Consolidated School, and finally himself.

These historical examples involve soft targets. Potential targets for a terrorist event are generally categorized as soft or hard. Soft targets are generally undefended and easier to penetrate, like train stations and buses. An attack on these locations may inflict psychological distress and some civilian casualties; however, soft target attacks do not generally result in long-term disruption of daily activity. For example, the multiple London bombings on July 7, 2005, resulted in 52 deaths but the city largely returned to normal function by the next day.

Conversely, hard targets include essential, defended, or fortified infrastructure like military installations and airports which are considerably more protected. Increased security serves both as a deterrent and makes the sites more resistant to successful attacks. ⁶

Nevertheless, a determined individual is all that is necessary to cause massive destruction and carnage. Would-be bombers are able to construct lethal explosives with minimal finances, resources, or expertise. Instructions to manufacture an explosive device are easily obtained via the Internet. If a bomber can obtain the necessary materials, remain inconspicuous, and transport the device, then he or she stands a good chance of deploying the device. For these reasons, it is imperative that civilian medical personnel begin to consider explosions as credible—or even likely—disasters. ^7–10

Twenty-four-hour news coverage now guarantees immediate media attention, and terrorists are acutely aware of how to manipulate propaganda through the media to advance their agendas. By striking highly populated or highly publicized locations, terrorists know they can inflict more casualties and garner more attention.

Medical responders do not have to possess an exhaustive knowledge of explosives. Law enforcement organizations are more appropriate to pursue detailed forensic work regarding explosives. It is important, however, to understand the physics of an explosive device and the resulting aftermath. Knowledge of blast wave mechanics will allow a health care provider to search out blast-related injuries.

In general, explosive materials may be categorized into two types: low grade and high grade. A low-grade explosive is similar to gunpowder including fireworks and nitrostarch. These substances deflagrate, or undergo subsonic combustion, at less than 1000 m/s. This results in a subsonic reaction without a classic blast wave. Conversely, high-energy explosives detonate at about 4500 m/s and produce a supersonic shock wave. ¹¹ Examples of high-grade explosives include trinitrotoluene (TNT), C-4, Semtex, nitroglycerin, dynamite, or ammonium nitrate fuel oil (ANFO).

Detonation of explosive material causes chemical bonds within the material to break down, rapidly converting solid or liquid material to gas. ⁵ The rapid breakdown of bonds creates an exothermic reaction, resulting in a superheated ball of gas. The gas expands outward in a radial pattern, causing a shockwave that propagates through the explosive material. The outwardly expanding wave displaces the surrounding medium, causing an increase in the surrounding atmospheric pressure (the overpressure). An uninterrupted blast wave continues moving outward but dissipates quickly in an open area. Immediately behind the area of increased atmospheric pressure is a zone of negative pressure. This underpressurized area subsequently creates a vacuum (see Figure 77-1). The resulting pressure phenomenon is best summarized by the Freidlander waveform (Figure 77-2). From an explosion, victims can sustain blunt trauma, penetrating trauma, thermal burns, and severe musculoskeletal trauma including amputation. ¹²

Improvised explosive device (IED) is a general term that encompasses a wide range of devices. IEDs may vary in size, shape, and material. In their simplest form, IEDs are essentially any explosive material wired to a trigger device. The common characteristic of all devices is they have been adapted from their original intent. ¹³ A vehicle-borne improvised explosive device (VBIED) is an example of such a device. A VBIED is a vehicle packed with explosive material then detonated in a crowded location or driven to a target site. A home-borne IED is a house or building packed with explosives and detonated when targets approach or enter the structure.

IEDs may also consist of manipulated blast mines, explosive formed projectiles (EFP), and suicide/homicide bombs. ¹⁴ Typically, an IED is a nonstate sponsored explosive constructed out of available materials, most often military ordinance. These devices have recently gained worldwide notoriety as a favorite tool among insurgents in Iraq and Afghanistan.

The type of device a bomber constructs depends on the target and available resources. IEDs are popular because of the ease in which they can be built and concealed. The devices can be hidden along a road or thoroughfare. ¹⁵ Instead of a single device, IEDs may be strung together in a continuous “daisy chain” formation to increase damage and casualties. ¹³

The explosive device may be activated remotely by the bomber or triggered by the victims themselves. An IED is triggered by tripwire, ignition fuse, mercury switch, or depressing a pressure plate. A bomb may also be detonated using a timer, radiofrequency, or cell phone, allowing the bomber to be in a location far from the explosion.

Terrorists may utilize shape charges, which add directionality to the blast. Other options include suicide/homicide bomb vest or other garment worn by the bomber, VBIEDs, and a variety of other devices to increase lethality. ^16–18 Each weapon has qualities that a terrorist can take advantage of to accomplish his or her goal and escape detection.

INCENDIARY DEVICES

In addition to explosives, incendiary devices may be deployed to cause damage, inflict casualties, or incite panic. An incendiary device is designed to ignite and cause fire rather than explode. Explosions rarely cause fires because oxygen is depleted during the blast. ¹⁹ Explosives may cause burns because of thermal energy released during the rapid expansion phase of a blast. However, incendiary devices are specifically meant to ignite a fire and usually burn at high temperatures.

A classic example of an incendiary device is a Molotov cocktail (Figure 77-3), which consists of a bottle partially filled with a flammable substance. A rag, doused with a flammable liquid, is shoved into the bottle opening and the rag is lit. When the bottle is thrown, it shatters against a hard surface. The flame ignites the rest of the fluid and the ensuing flames are scattered over a larger area. The resulting fire can trigger an explosion if the open flame contacts other volatile substances.

CHEMICAL, BIOLOGIC, RADIATION, NUCLEAR DEVICES

Today, one of the largest security concerns for the nation is the combination of chemical, biologic, or radioactive substances with explosives. The addition of these agents would compound the fear resulting from an explosion alone. Intelligence agencies have found plans by terrorists to attempt just such an attack. ²⁰ In most cases, an explosion utilizing chemical, biological, or radioactive agents would not result in many casualties; yet an attack involving CRBN would have exorbitant cleanup costs, incite panic, and cause logistical complications especially if it occurs in a highly populated area like New York City. ²¹

A chemical substance, such as chlorine, could potentially be combined with an explosive. Chlorine, as with many chemicals, is transported by trains and trucks across the country. An explosive incident involving a chemical like chlorine could release a gas cloud into an unsuspecting populated area. In this case, because of a moving gas cloud, casualties would be located at the immediate scene, as well as downwind from the incident. This was the case in the Graniteville, SC, chlorine gas spill when a train collision released a gas cloud on January 6, 2005, killing nine people and leading to over 250 people seeking treatment for chlorine exposure. ²²

If a victim is within range of the blast, they will be exposed to typical blast-related injuries as discussed later in the chapter. If a victim is located outside the blast radius, he or she may be exposed to a substances dispersed by the blast. While the effects from exposure will vary by chemical or contaminant, the most likely result will be respiratory and mucosal irritation. Decontamination and removal from the source of exposure should be done as early as possible. Bronchodilators may be beneficial for respiratory distress from pulmonary irritation.

When an explosive device is combined with any radioactive substance, it becomes a radiologic dispersal device (RDD), also referred to as a “dirty bomb.” ²³ An RDD is postulated to be small enough to be portable so as to allow terrorists to remain inconspicuous. The detonation of such a device would not result in a traditional nuclear explosion but would cause panic and uncertainty as well as incur great financial cost to society because of the spread of radioactive contamination.

The effects of a blast following an RDD detonation would be confined to the immediate area and would account for most of the initial casualties. The radioactive substance, however, could be dispersed over a much larger area. ^24–27 Because of their prevalence, the most likely radioactive substances to be incorporated into an RDD are Cs-137, Sr-90, Co-60, Am-241, and Pu-239. ²³ Contamination occurring from the spread of radiation would hinder immediate rescue efforts and evacuation of survivors.

Victims may be grossly decontaminated through removal and disposal of their clothes and copious irrigation. Responders may minimize radiation exposure by following the International Commission on Radiological Protection recommendations including limiting time of exposure, increasing distance from primary contamination, and wearing proper protective and shielding equipment. ^23,28 Victims without injuries but requiring decontamination should not be transported directly to hospitals; instead they should first be directed to a designated screening and decontamination area for proper assessment and decontamination as indicated. ^29,30