Although present in various forms and locations for countless years, terrorism has increasingly been the focus of public concern. Emergency Medical Services (EMS) plays a vital role in responding to, evaluating, and intervening in potentially catastrophic events. EMS often co-manages initial scenes in many medium- to large-scale incidents involving large numbers of casualties. EMS may also manage the scene until state or federal agencies arrive.
Americans will never forget the tragic events of September 11, 2001. More than 3350 people were killed, and more than 10,000 people were injured in an incredibly complicated and choreographed attack. However, not all remember the World Trade Center bombing in 1993 that killed 6 people and injured more than 1000. In April 1995, the federal building in Oklahoma City was bombed, killing 168 people. A pipe bomb was detonated in Centennial Park during the 1996 Olympic Games in Atlanta, Georgia, killing 2 people and wounding 110. The bombing of 4 commuter trains in March 2004 claimed the lives of 190 and injured more than 1800 people in Madrid, Spain. Such events emphasize the potential loss of life and property caused by terrorist activities.
Many authorities consider the United States a continuing high-profile target. For all Americans, the attack on the World Trade Center on September 11, 2001, brought home the tragic realization that America is not immune to terrorism. Philip Stern, an expert on terrorism with the Fairfax Group, said, "As an open society and a democracy, this country is particularly vulnerable. We have free passage, coast-to-coast, anyone can apply for a visa to visit and the population is enormous and diversified."
Such an inviting atmosphere and free society may make terrorist activity inevitable. Many of the terrorist groups of today appear more and more willing to use weapons of mass destruction. Perhaps even more disturbing is the potential for terrorists to utilize more technologically advanced weapons and communications. Access to the Internet and information on the World Wide Web facilitates tremendous technological advancement in destructive potential.
All of these issues underscore the importance of proper education in EMS and advance planning. Terrorist activity may have various mechanisms, including chemical or biological weapons and explosives, as well as new and unanticipated methods of destruction. Full response to a terrorist incident requires in-depth interagency planning involving police; fire; EMS; regional, state, and national emergency organizations; as well as a wide array of ancillary community services. Each agency should be assigned respective roles as soon as possible, well in advance of potential terrorist acts.
For related information, see Medscape's Disaster Preparedness and Aftermath Resource Center.
Weapons of mass destruction (WMD) hold great attraction to terrorists: they have great potential to create fear, both in victims and in the public at large; can be created inexpensively; may be difficult to detect even when being sought; and can be engineered for a delayed onset of symptoms—nerve agents within minutes, vesicants within hours, and biological agents within days. Protecting large populations from exposure to WMD is problematic at best and impossible at worst.
The drawbacks of WMD use are largely ignored by terrorists: contempt for users, retaliation, and prohibition treaties are not priorities for terrorist organizations. Deployment dangers, including injury or even death of deploying persons, are rarely considered risks sufficient to prevent use.
Determining the actual extent of the terrorist threat in the United States is difficult, as it is poorly defined and rapidly changing. James Alan Fox, Dean of Northeastern University's Criminal Justice Program in Boston, believes the 2 current motivations for terrorism are revenge and attention. Either motivation can be justification for exposing large numbers of the populace to a wide variety of dangerous or deadly toxins.
The Morbidity and Mortality Weekly Report, April 21, 2000 states "The public health infrastructure must be prepared to prevent illness and injury that would result from biological and chemical terrorism, especially a covert terrorist attack. As with emerging infectious diseases, early detection and control of biological and chemical attacks depends on a strong and flexible public health system at the local, state, and federal levels."[1]
Effective response to a terrorist incident hinges on comprehensive planning and interagency cooperation. Agencies must address and resolve jurisdictional issues well in advance. After a plan has been devised, it must be updated regularly to reflect changes in resources, population, terrorist activities, or potential targets. Local police, fire, EMS, and Disaster & Emergency Services (DES) agencies should form the first line of response. Other agencies that may be included are as follows:
Depending on the circumstances, state or federal response agencies, such as the Emergency Broadcast System, Federal Aviation Administration, or National Weather Service, may need to become involved. The Federal Bureau of Investigation (FBI) has been designated as lead agency in crisis management response, and Federal Emergency Management Agency (FEMA) is designated as lead agency in consequence management response. The Defense Against Weapons of Mass Destruction Act (Nunn-Lugar-Domenici Bill) of 1996 required the Secretary of Defense to establish a program to advise and train federal, state, and local officials until 1999 and allows the President or Attorney General to request military support for local authorities in chemical/biological incidents.[2]
An act of terrorism in a metropolitan area may cause major health and medical consequences that could easily overwhelm all local health facilities; thus, ongoing contact with state and national agencies is recommended for the additional resources they can provide. The FBI is the federally designated lead agency in a confirmed domestic terrorist event. Depending on location, however, some federal agencies may not be on-site for 24 hours or more.
On a national level, the US Government has established the National Disaster Medical System (NDMS). This organization assists in providing medical care and transportation for disaster victims. The NDMS comprises sections of the Department of Health and Human Resources, the Department of Veterans Affairs, the Department of Defense, and the FEMA. Any state can enlist the services of NDMS, which provides assistance at the disaster site, evacuates patients, and finds beds for evacuated patients. Congress also has established a Domestic Preparedness Program that provides enhanced training for local first responders and forms metropolitan medical strike teams in major cities.
In evaluating sites of potential terrorist activity, the release of chemical or biological agents into crowded and contained areas, such as sports stadiums, office or public buildings, and transportation systems (eg, the Tokyo subway Sarin incident) should be considered. Such places provide tempting targets despite on-site security. Rapid identification of the chemical or biological agent is critical to proper disposition of patients and to management of affected areas. Disasters involving hazardous materials (HAZMATs), radioactive materials, or chemical agents may produce unfamiliar medical problems that cannot be identified rapidly in the readily available emergency medicine literature. All possible resources should be used early in the incident to ensure proper identification of the agent and prompt initiation of proper protocols.
Most of the principles of terrorist incident management are similar to the principles in the management of mass casualty incidents. The primary concern in potential terrorist incidents is to secure the area and to ascertain the severity and the nature of the threat. Delayed explosives or materials intended to harm rescue workers may have been planted at the site. A safe scene must be obtained to avoid further endangering survivors and health care workers. Primary and secondary perimeters must be established and secured. It should also be determined if a cleared, downwind perimeter is needed, and one should be established if required.
The Acronym ASBESTOS can be used to remember the important aspects of exposure:
A - Agent(s) - Type and amount of doses
S - State - Liquid, solids, or aerosolized
B - Body sites - Areas of exposure, lungs, skin, or other
E - Effects - Area of effects; local or systemic
S - Severity, of symptoms
T - Timing of events
O - Other diagnoses to consider
S - Synergism - Interaction between multiple agents or coexisting disease[3]
Early involvement of support and ancillary services, mutual aid agencies, and local agencies in the planning process is prudent. After identifying the potential threat, it should be determined which type of protective equipment is necessary. Emphasis must be placed on protection and decontamination of rescuers and victims.
After establishing a decontamination and triage area, rescuers should put on appropriate protective clothing before entering the affected area and beginning rescue efforts. The first focus is on supportive care with emphasis on aggressive airway control and decontamination. Issues associated with simultaneous containment, neutralization, and/or decontamination may be addressed by ancillary agencies. Following initial triage, patients are given primary or aggressive aid depending on their presentation and the resources available. The patients should be decontaminated and transported to a facility that has been informed about the etiology of the incident as soon as feasible. A secure and clean area completes the physical response. Record keeping, analysis of the incident, and investigations conclude the complete response.
While lacking the cachet of nuclear, biological, or chemical weapons, conventional explosives are more likely to be the instrument of a terrorist attack. Ease of obtaining materials and knowledge make conventional explosives more likely a vehicle than other, more difficult to obtain or manufacture agents. Historical analysis consistently demonstrates that the most likely terrorist weapon causing a mass casualty event is a standard explosive device detonated in a crowded area.[4]
An explosive is a normally stable material that, when introduced into a chemical reaction, converts rapidly from a solid or a liquid to an expanding gas. Explosives cause damage primarily through tremendous increases in atmospheric pressure. The initial shock, called the positive pressure wave, is the almost instantaneous increase of pressure from a blast, and the negative pressure wave immediately follows, as the displaced air rushes in to fill the void caused by the initial pressure wave.
Explosives are categorized as either low grade or high grade. Low-grade explosives burn rapidly. Black powder, the original low-grade explosive, served as the basis for the development of smokeless gunpowder and some rocket propellants. Other examples of low-grade explosives are nitrostarch, nitrocellulose, and commercial fireworks.
High-grade explosives, also termed detonating explosives, are more stable than low-grade explosives, frequently requiring trauma or shock for detonation. Nitroglycerin is the original high-grade explosive. Ammonium nitrate is another example of the early types of detonating explosives. Composition B, C-3, C-4, and TNT were developed later. Other examples include Amatol 80/20, RDX, PETN, and dynamite. Initiating high-grade explosives are a separate class of very sensitive high-grade explosives, such as lead styphnate and lead azide.
Explosions in confined spaces are often associated with much higher mortality. Solid surfaces act to reflect and compound the shock waves, causing magnification of the destructive forces. Similarly, blasts that are channeled by alleyways or hallways can have profound impact far outside the normal blast radius because the forces are focused on a smaller area of effect.
Blast injuries can often be categorized as primary, secondary, or tertiary. Primary blast damage is seen as a result of the tremendous pressure changes associated with explosives, in particular high explosives. Bowel, nervous system, cardiovascular system, ears, and lungs are most often affected by the primary blast. Cardiac contusion, esophageal rupture, hemothoraces or pneumothoraces, perforated bowel, arterial gas embolism, or immediate or delayed GI injuries should be suspected as clinically indicated. Burns are also possible, depending on the proximity to the blast.
Secondary blast injuries occur when victims are struck with shrapnel or objects sent airborne during the primary blast. Shrapnel can be the result of environmental objects as innocuous as sticks or rocks, or as malevolent as screws and nuts packed within the primary explosive.
Tertiary blast injuries occur when victims themselves are thrown due to the incredible pressures from the blast. These injuries can include a wide variety of traumatic etiologies similar to a fall of significant magnitude.
"Suicide bombers" often carry a small amount (5-40 lb) of high explosives with an associated detonating device in a clandestine manner seeking to detonate the explosives near a large group of victims. Typical sites include sporting events, restaurants, nightclubs, or other public functions. Shrapnel can serve to extend the injury area, and a suspicion for projectile injuries should be maintained. Extreme care should be exercised in approaching a potential suicide bomber, even if incapacitated. Suspected perpetrators should be evaluated by experienced bomb squad personnel before EMS intervention to ensure a safe environment.
Chemical agents were first used extensively in World War I with dramatic results against unprepared troops. Although far less lethal than conventional explosives, chemical weapons can affect and incapacitate large numbers of troops in a short time. Chemical warfare agents were defined by the United Nations in 1969 as "chemical substances, whether gaseous, liquid or solid, which may be employed because of their direct toxic effects on man, animals, or plants."
The ready availability of precursors of modern chemical weapons and copious documentation on their preparation make the use of chemical weapons for terrorist actions far more likely than use of nuclear or biological weapons. In addition, potential terrorists could easily locate a chemical production facility, sabotage it using chemical or conventional explosives, and allow ambient winds to spread the toxins. The resultant environmental contamination would fulfill many terrorists' objectives of generating fear, trepidation, and panic among the population.
Chemical agents are separated into 2 broad categories: lethal and nonlethal. Lethal agents include cyanides, nerve agents, vesicants, and choking agents. Nonlethal agents include lacrimating, emesis-inducing, and incapacitating agents.
Cyanide compounds
Although they have been used since World War I, cyanide compounds are highly volatile, rendering them less useful than chlorine. The military designates hydrogen cyanide (AC) and cyanogen chloride (CK) as the substances used in warfare. Cyanide and its compounds are among the most rapidly acting chemical agents. Cyanide may be one of the most likely asphyxiant agents used in a terrorist action.[3] Signs and symptoms include air hunger, hyperpnea, apnea, seizures, coma, and death. Cyanide poisoning is treated with a combination of nitrites and thiosulfates. A commercial kit is available, called a Cyanokit. Protective masks, gowns, and gloves are necessary until the patient is completely decontaminated.
For a related CME activity, see CME - Acute Cyanide Poisoning: Novel Approaches for Intervention in the Prehospital and Hospital Setting.
Nerve agents
Nerve agents are chemicals that inhibit acetylcholinesterase irreversibly. They combine with acetylcholine (ACH) to prevent transmission at the neuromuscular junction and affect both the sympathetic and parasympathetic nervous systems. Salivation, lacrimation, urination, defecation, and emesis (SLUDGE) are common signs. Muscarinic effects may cause the most serious complications, including bronchoconstriction, laryngospasm, and respiratory depression or arrest. These nerve agents may be delivered by droplet, vapor, or both. Symptoms of skin exposure appear much more slowly than those from inhalation. Onset of symptoms varies from 1 minute to a few hours. If cyanide compounds are inhaled or absorbed through the mucus membranes, death can occur in 1-10 minutes.
Therapy includes atropine sulfate, with as much as 10-40 mg required in some instances. Currently, the US Army uses 2-PAM (pralidoxime chloride), although it is not completely effective. It is least effective against Soman (GD). Pretreatment with pyridostigmine competitively inhibits the nerve agent. Pyridostigmine combines reversibly with ACH, which can resume neurotransmission after disassociation. However, such pretreatment does not protect against seizures.
Current nerve agents include tabun (GA), sarin (GB), soman (GD), and VX. These more potent agents may be the most likely nerve agents to be used in terrorism.[3] Exposure to these agents can cause dramatic and sudden symptoms, especially when vapors or aerosolized agents are used. Transdermal exposure can produce delayed symptoms, as can exposure to limited amounts of either aerosolized or liquid agents.
Local decontamination of these agents includes washing with soap and water. Health care providers should wear full protective gear until the patient is cleared by an environmental health specialist. VX, considered the most toxic of the nerve agents, is also the most difficult to decontaminate because of its low volatility.
Choking agents
Causing pronounced irritation to the upper and lower respiratory tracts, these agents are potentially dangerous because of a period of latency. A victim with dyspnea and mild chest discomfort may deteriorate after several hours to apnea and subsequent death. Chlorine is a widely used chemical that falls into the choking agent class. Chlorine causes upper- and lower-respiratory irritation, lacrimation, chest pain, dyspnea, coughing, laryngeal edema, pulmonary damage, and pulmonary edema.
Treatment is symptomatic with nebulized sodium bicarbonate. Decontaminate by copious flushing of affected areas with water. Medical providers need no special protection from chlorine-exposed patients.
Vesicant agents
Vesicant agents, also termed blistering agents, may be toxic to the lungs, eyes, and mucous membranes. They are named for their tendency to cause blisters. Mustard gas is the best-known vesicant, originally used in World War I. It is a primary tissue irritant and has no significant allergenic component. Lesions are primarily cutaneous, but respiratory, ocular, and GI manifestations may occur, as well as cough, bloody sputum, and dyspnea. Areas of exposure become erythematous and progress to bullae, similar to toxic epidermal necrolysis. Symptoms may not occur for several hours after exposure. No antidote is available.
Other vesicants include sulfur mustard (HD), nitrogen mustard (HN), agent T, and phosgene oxime (CX). Lewisite, unlike mustard and mustard derivatives, causes immediate pain and skin irritation.
Medical providers require protective masks and clothing for patient management. They should decontaminate by blotting and cleansing with soap and water and avoid scrubbing and hot water.
Lacrimator agents
Lacrimator agents (tear gases) are widely used by law enforcement and the military. The most common effects are nasal and ocular discharges, photophobia, and burning sensations in the mucous membranes. Prolonged exposure may produce tightness in the chest, shortness of breath, and malaise and may cause vesiculations or bullae. Physical injuries may be observed from explosive discharge or kinetic effects of projectiles. At least 1 death has been attributed to lacrimator agents.
Most patients can be decontaminated fully by undressing, showering, and washing with soap and water. Medical personnel should use protective masks, gowns, and gloves, since lacrimator agents are transmitted by physical contact.
Types of lacrimator agents include bromobenzyl cyanide (CA), ortho-chlorobenzylidenemalonitrile (CS), dibenzoxazepine (CR), 2-chloroacetophenone (CN), chloroacetophenone in chloroform (CNC), and chloroacetophenone and chloropicrin in chloroform (CNS).
Emesis-inducing agents
Emesis agents, also termed nausea gases, are not used routinely in the United States. They produce respiratory and skin irritation effects similar to those of lacrimator agents, as well as profound nausea. Examples of such compounds include adamsite (DM), diphenylcyanoarsine (DC), and diphenylchloroarsine (DA).
No decontamination is required in the field, and diluted bleach solution has proven effective for definitive cleaning. Ordinary clothing protects against these agents; chemical insert masks and standard gloves are adequate.
Incapacitating agents
The possibility of a nonlethal incapacitating agent has long intrigued military commanders. Several agents have been tested, including lysergic acid diethylamide (LSD), mescaline, psilocybin, and psilocin. The only successful agent in production is benzilate (BZ).
BZ is a delayed-onset (1-4 h) agent causing tachycardia, dizziness, vomiting, blurred vision, stupor, confusion, and random activity. Affected persons may be docile, belligerent, stuporous, or confused. They may appear intoxicated.
Decontaminate by washing with soap and water or with dilute bleach solution. Protective masks with charcoal filters provide adequate protection. Gloves are not necessary, since the agent is not absorbed through the skin.
For excellent patient education resources, visit eMedicineHealth's First Aid and Injuries Center. Also, see eMedicineHealth's patient education articles Chemical Warfare and Personal Protective Equipment.
The Biological and Toxin Weapons Convention of 1972 banned the development, production, and stockpiling of biological weapons not required for peaceful intentions. The United States, United Kingdom, Soviet Union, and 67 other nations signed this document. Despite the fact that no biological agents have been used officially in warfare to date, the prospect of their use raises many concerns. Terrorism's history suggests the potential for the use of biological agents. Many authorities fear the use of biological agents more than the use of chemical agents because antidotes and specific countermeasures are available for some chemical weapons. Use of biological agents in terrorist acts potentially could cause tens of thousands of casualties and cost the US economy billions of dollars.
Various scenarios involving use of biological weapons are possible, from a sudden epidemic to a subacute, prolonged pandemic. Pathogens might be disseminated without anyone's realizing it until after the incubation period ends, by then exposing hundreds or thousands of civilians. Anticipating and controlling the dissemination of biological weapons may be difficult, causing complications for terrorists and intended victims. The effects of a biological agent also could evolve as a slowly developing, hard-to-categorize cluster of widely scattered cases, inadvertently allowing further dissemination of the pathogen until the connection is recognized.
Certain aspects of a disease outbreak may combine to prompt suspicion of terrorist activity, including temporal patterns of illness, selected populations of victims, clinical presentation of illness, certain strains or species of pathogens, geographic location, morbidity or mortality patterns, antimicrobial resistance patterns, residual infectivity, route of exposure, weather or climate conditions, incubation period, or concurrence with other terrorist activities.
Biological agents could prove to be a devastating vector; a release of only 30 kg of anthrax spores could cause as many as 30,000-100,000 deaths; in comparison a 1,000-kg atomic bomb would result in approximately 23,000-80,000 deaths.[2]
The number of potential biological agents is nearly impossible to estimate. Agents range from simple viruses to bacteria and compounds derived from vertebrate animals. Biological agents are classified into 2 broad groups: infectious and noninfectious.
This group includes viruses, bacteria, protozoa, and fungi. The list of potential pathogens is extremely long, although an abbreviated list of agents can be considered that is based on previous use as agents during wartime. The synopsis presented for each disease is meant only as an overview. Consult definitive texts for complete information.
Anthrax
Bacillus anthracis, the causative organism of anthrax occurs naturally, is relatively easy to access, is very durable; it may live for up to 50 years in soil. Even a small number of anthrax spores, enough to fit on the head of a pin (5,000-8,000 spores), is sufficient to cause the inhalational form of anthrax. The inhalational form of anthrax can be difficult to diagnose in the earliest stages and may be very difficult to treat once clinical signs become apparent. Cutaneous clues are necrotic lesions that spontaneously heal, and inhalation can produce a 1- to 3-day incubation period with fever, dyspnea, necrotizing hemorrhagic mediastinitis, and hypotension leading to death. Death usually occurs in 24-36 hours but may be as long as 7 days. Mortality can reach as high as 95% of inhalational exposures. Standard precautions, including masks, gowns, gloves, and isolation are sufficient. Vaccine is available.
Brucellosis
Highly infectious Brucella species are less commonly fatal than anthrax. Fever, malaise, osteomyelitis, and genitourinary (GU) infections may occur. Endocarditis is typically the cause of death. Standard precautions are sufficient. Precautions against direct contact should be included if draining lesions are present.
Encephalitis viruses
Venezuelan, Eastern, and Western equine encephalitis viruses are likely to be used in weapons. Fever, headache, confusion, obtundation, dysphasia, seizures, paresis, and death may be observed. The Eastern variety has the highest mortality rate at 50-75%. A vaccine for Venezuelan equine encephalitis (VEE) is available, and effective vaccines for the others are currently in development. Standard precautions are sufficient; however, mosquito control is suggested, since mosquitoes are a vector.
Clostridium botulinum
An epidemic of descending and progressive bulbar and skeletal paralysis in afebrile patients may suggest botulinum poisoning. Respiratory failure is the most frequent cause of death. Since an antitoxin is available, standard precautions are sufficient.
Yersinia pestis (plague)
Plague usually manifests as pneumonia, culminating in respiratory failure and shock. A vaccine is available, yet precautions are required against pulmonary and droplet exposure.
Coxiella burnetii (Q fever)
A zoonotic disease with domestic livestock as vectors, Q fever varies in its manifestations. Fever, chills, and headache are the most common symptoms, although malaise, diaphoresis, and myalgia often are observed. Mortality rate is low, even when the disease is untreated. A vaccine is under investigation. Standard precautions are sufficient.
Rift valley fever
A hemorrhagic virus infection, Rift valley fever manifests with symptoms such as malaise, fever, prostration, generalized vascular permeability, and abnormal circulatory regulation. Several different varieties of hemorrhagic viruses are documented, including Ebola. Most are highly infectious and cause morbidity. Some carry high mortality rates. Depending on the strain, a vaccine may be available. Precautions against direct contact are recommended. Additional precautions may be necessary if massive hemorrhage is present.
Smallpox virus
Smallpox may be a viable biological weapon, since the last natural case occurred in 1977 and the smallpox vaccine no longer is produced. Aerosol exposure causes viremia, malaise, fever, headache, delirium, and prolonged rash. Morbidity is caused primarily by secondary bacterial pneumonia. Precautions against aerosol infection are necessary.
Francisella tularensis (tularemia)
Tularemia, a zoonotic disease, occurs in ulceroglandular or typhoidal form. Typhoidal form manifests as fever, prostration, and respiratory symptoms. Mortality rate in typhoidal tularemia is approximately 35%. Standard precautions are sufficient. A vaccine is available as an investigational drug.
Allergic agents come from a variety of sources, including mite and insect particles, feathers, epithelium, hair, urine, feces, and powdered enzymes. Problems caused by these agents may include respiratory symptoms, conjunctivitis, and/or dermatitis.
For excellent patient education resources, see eMedicineHealth's patient education articles Biological Warfare, Anthrax, Plague, and Smallpox.
Responding to a terrorist event can represent a considerable drain on resources for all agencies involved. The potential for death and destruction is tremendous. Agencies responsible for responding to terrorist events can only ensure that appropriate preparations are in place should unforeseen circumstances arise. Extensive preplanning and interagency cooperation is essential in mitigating the effects of terrorist attacks. A prepared and determined populace makes a less inviting target for potential terrorists.