TERRORISM RESPONSE / HAZ-MAT
Focus of Terrorism
After a gradual decline in international terrorism from its
peak in the 1970s, the 1990s witnessed an increase in such events. This increase
was not only in total number of incidents, but also represented a shift in
terrorist targets and the methods and weapons used.
Terrorists have shifted their focus from political figures,
governments, and corporations to innocent civilians. Although a terrorist's
weapons of choice remain the AK-47 and pipe bombs, terrorist organizations have
increasingly sought to use more lethal weapons and devices to inflict the
maximum number of casualties, fear, and societal disruption.
Although American citizens have been targeted in the past,
the 1990s also heralded an increase in the frequency and lethality of these
Historically, Americans were attacked overseas,
predominantly in South America or the Middle East, and usually were the victims
of kidnapping, hijacking, or assassination. Numerous events have occurred to
U.S. interests overseas, ranging from the bombings of the U.S. embassies in
Nairobi and Kenya to the attack on the USS Cole.
The first bombing of the World Trade Center in 1993
hallmarked a further shift in terrorist strategy to target American citizens
on U.S. soil. Subsequent attacks, or foiled attempts, included the bombings of
bridges, government buildings (the Murrah Federal Building in Oklahoma City) or
other critical infrastructure and culminated in the multiple aircraft hijacking
and subsequent crashes into the World Trade Center twin towers and the Pentagon
Sept. 11, 2001. This was followed almost immediately by the posting of letters
laden with anthrax spores to members of the government and media
Threat of Terrorism
Terrorists also have sought to use nonconventional and
highly lethal weapons to inflict damage on society.
In 1994, members of the Aum Shinrikyo religious cult,
targeting members of the Japanese court, released the chemical agent sarin at an
apartment complex. This unsuccessful attack was followed in 1995 with a more
successful release in the Tokyo subway system. The result: More than 5,000
people sought evaluation and treatment at local hospitals, and 12 people died
including first responders.
A number of attempts to obtain biological agents, including
ricin toxin and highly lethal bacterial and viral pathogens, have been foiled by
law enforcement or intelligence agencies worldwide, both before and after the
anthrax incidents of 2001.
Hundreds of attempts to smuggle radioactive material have
occurred. It is unknown if other attempts have been successful. In 1995, Chechen
rebels left a container of radioactive cesium-137 in Izmailovsky Park, Moscow.
Records recovered from Al Qaeda caves in Afghanistan in 2001 and 2002 indicate
that terrorist organization's desire to obtain and use this material in weapons.
of mass destruction
than 17 countries are suspected of seeking or have already obtained and
weaponized agents of mass destruction, in violation of international treaties
and conventions. Information from intelligence agencies that Iraq continued its
biological, nuclear, and chemical weapons programs resulted in a pre-emptive
strike by the United States in the spring of 2003. North Korea recently
announced that it possesses an offensive nuclear capability.
Terrorism is not the only threat. A report from the Swiss Reinsurance Co. in
2001 concluded that over the past 20 years, the incidence and consequences of
disasters have doubled, and a significant cause of this increase has been
anthrogenic (man-made) disasters, including those caused by chemical,
biological, radiological, nuclear, or explosive agents, devices, or materials.
Industrial nations have produced in excess of 120,000 different chemicals that
are considered highly toxic to man. These chemicals are ubiquitous in industry,
and many are commonplace in homes and businesses throughout the world.
Significant accidents involving these materials have been responsible for major
societal disruption, disability, and deaths.
The release of methyl isocyanate from the Union Carbide
plant in Bhopal, India, in 1984 caused the immediate death of more than 3,000
people. Countless others suffered temporary or permanent disability.
The derailment of a train carrying toluene, chlorine, and
phosgene near Mississauga, Canada, in 1979 prompted the evacuation of more than
218,000 people, including patients in several hospitals and nursing homes.
In the past 25 years, more than 30 new, highly lethal
infectious diseases have emerged. And numerous bacterial pathogens previously
susceptible to traditional pharmacological treatment have developed resistance
to these traditional antibiotics.
Diseases caused by such viruses as Ebola or Hantavirus have
high mortality rates and no definitive treatment. Plague is still endemic in
parts of the United States.
In addition, new cases of multidrug-resistant tuberculosis
have been documented globally. The outbreak of an avian-borne influenza epidemic
in Hong Kong in 1997 prompted the slaughter of more than 1 million chickens and
other poultry to contain the disease.
Although the 1986 meltdown of the Chernobyl IV nuclear
reactor was an isolated event, several hundred lesser accidents and incidents
have occurred worldwide.
The Chernobyl catastrophe resulted in more than 2,000
near-term deaths and the immediate displacement of over a quarter of a million
people from the contaminated area.
The United States alone has more than 100 such reactors and
boasts a remarkable safety record, but as the 1979 accident at Pennsylvania's
Three Mile Island attests, this country is not immune. More than 40 accidents or
losses involving nuclear weapons have occurred since World War II.
Explosions at munitions and fireworks plants and other
industrial sites containing highly combustible or explosive materials are
practically a daily phenomenon worldwide.
This course is designed to heighten the participant's
awareness of the clinical and operational medical response to terrorism,
incidents involving the use of weapons of mass destruction (WMD), and disasters
resulting from releases of chemical, biological, or radiological materials or
nuclear or high-yield explosions.
Although there is some overlap among these three phrases,
they are not synonymous, and the preparedness for and response to events of
these types are not identical.
Terrorism may be defined as the unlawful use or threatened
use of force or violence against people or property to intimidate or coerce
civilians or any segment of a government to further political or social
Chemical, biological, radiological, nuclear, or high-yield
explosive (CBRNE) events are incidents whether minor or catastrophic
involving the accidental or intentional release of these materials that harm or
have the potential to harm a society.
WMD are devices capable of a high order of destruction
and/or of being used in such a manner as to destroy large numbers of people.
These can be nuclear, chemical, biological, and radiological materials or
nonconventional or high-yield explosives. This definition, however, excludes the
means of transporting or propelling the weapon where such means is a separable
and divisible part of the weapon.
This course also provides the participant with an overview
of the medical management of incidents involving CBRNE materials. CBRNE
incidents are unique among the types of events EMS personnel may respond to:
This course will not create an expert in CBRNE
Expertise can be gained only through continued and more
detailed education, psychomotor skills training, individual procedures practice,
and integrated exercises with personnel from other agencies that would be
involved with the response to these complex emergencies.
This course will provide all participants with
common, solid baseline knowledge on which to build additional knowledge, skills,
While returning from a patient transport to a nearby
hospital, you are contacted by your service dispatcher to respond to the scene
of an automobile explosion and fire in the parking lot of the football stadium.
The dispatcher informs you that a bystander called 9-1-1, stating that there
appeared to be several people down immediately around the automobile and several
others nearby who seemed to be having difficulty breathing. At least two of
those people had collapsed. Although there was an initial explosion, the
bystander reported no significant fire burning.
The dispatcher informs you that the fire department and
police are on their way and authorizes you to proceed using lights and sirens.
On arrival at the parking lot, approximately five minutes
later, you immediately note that you have arrived prior to other emergency
response vehicles. You also note that:
You have correctly assessed that there is something unusual
taking place. The automobile has not been destroyed, and there is no heavy smoke
or fire, yet people at a distance from the vehicle appear to have been affected
physically by the "explosion." The majority of people affected are to
the south of the vehicle, out to a distance of 25 yards. Glancing at the stadium
flagpole, you note that the wind appears to be blowing in a southerly direction.
The flag is lightly fluttering, indicating a wind speed of 5 -10 mph.
is your initial assessment?
Your assessment is that noxious chemicals may have been
released from or near the automobile.
the scene safe?
Although the wind may have dissipated those chemicals, an
ongoing release may be occurring. If this has been an intentional event, the
possibility of a second release or explosion may exist. The scene is not safe.
is your first priority as initial responder to the scene?
Your first priority, as the initial responder, is to ensure
your own safety, the safety of your crew, and that of bystanders who have not
been affected but are dangerously close to the vehicle. You accordingly position
your ambulance upwind, approximately 100 yards from the vehicle. Your partner
attempts to move the watching crowd farther from the scene while you radio your
and Police Arrive
You inform dispatch of your observations and conclusion:
that this appears to be a hazardous materials incident, there is no fire, and
there are at least 30 people affected. Next, you assist your crew in cordoning
off bystanders. At this time, a fire department pumper and police unit arrive on
More units arrive as the police set up perimeter control.
Meanwhile, the hazardous materials unit from the fire department prepares to
enter the scene. Consider these questions:
Entering the hot zone in OSHA Level A fully encapsulated
suits, each with a self-contained breathing apparatus (SCBA), the hazardous
materials unit personnel ascertain that the victims appear to be suffering from
a chemical exposure. This is most likely a nerve agent or organophosphate
Victims who can walk with assistance are escorted to the
decontamination corridor, while those unable to walk are carried to that
location. A decontamination team begins water wash-down of the victims.
One ambulatory victim staggers out of the hot zone away
from the decontamination corridor, directly toward you and your unit.
Secondary contamination of unprotected
personnel is always a concern prior to decontamination of those individuals. You
notify the incident commander, who directs protected decontamination support
personnel to guide the victim to the decontamination corridor.
Three victims are rapidly processed through decontamination
one ambulatory and two on litters.
Patient A is alert, responsive, and complaining of severe
eye pain and some difficulty breathing. Patient B is actively convulsing.
Patient C has shallow respirations with frothy liquid from his mouth and nose.
He is unresponsive to painful stimulation.
Consider these questions:
In a mass-casualty setting, use the Simple Triage and Rapid
Treatment (START) algorithm, and triage Patients B and C as immediate and
Patient A as delayed.
Patient C is by far the worse off he most likely has
already had a seizure and now has flaccid paralysis, which is compromising his
respiratory muscles. In addition, his ability to oxygenate is compromised
because of the heavy secretions in his tracheobronchial tree. He needs the most
urgent treatment. If your protocols allow, he should receive three
administrations of the Mark I autoinjector set, followed by administration of
Patient B also has had a significant exposure and is
actively convulsing. He should be treated next with ventilatory support, three
administrations of the Mark I autoinjector set, and diazepam.
Patient A has the mildest symptoms but still has complaints
attributable to exposure to nerve agents. At this point, he can be provided
supplemental oxygen and should receive one administration of the Mark I
autoinjector set. He should be reassessed for a change in status after a few
Although these patients have been decontaminated, the
possibility of some residual contamination may be present. The use of air
transport vehicles (e.g., helicopters) is inadvisable except under very rare
Thus, it is prudent for transport personnel to ensure
adherence to contact precautions during transport. There is still a slight
possibility of evaporative contamination and exposure of the cab. Therefore,
open all ventilation systems in your emergency medical transport vehicle, and
proceed as directed.
If your EMS agency has procured chemical protective masks,
their use may be advisable as an additional level of safety, especially if full
decontamination has not been confirmed at the scene.
A chemical is a substance with a distinct molecular
composition. A chemical is composed of two or more atoms, which are considered
the smallest unit of matter. When two or more atoms form a bond whether
strong or weak between themselves, a chemical is formed.
Most discussions of chemical agents follow military
classification schemes. While a number of different chemicals have been
weaponized for use during combat, only a few of these are exclusively
"combat" chemical agents. Many are dual-use chemicals, with legitimate
industry or law enforcement use. There are many other chemicals that could be
encountered in a civilian setting, released accidentally or through a terrorist
Principles of Medical Response
Regardless of the agent involved, certain general
principles apply in all cases of exposure to chemical agents. These principles
Principles: Personal Protection
All responders involved with managing victims of chemical
agents must first and foremost be protected, lest they fall victim themselves.
In general, patients with significant exposures will most
likely require extrication and scene decontamination, prior to on-scene
emergency therapy and transport to treatment facilities. However, people exposed
to lesser doses, or those exposed and contaminated with delayed onset chemicals,
may attempt to leave the scene and may approach responders or bystanders for
Principles: Rapid Decontamination
Anyone suspected of being exposed to a chemical contaminant
should be considered contaminated until proved otherwise.
More than 90% of contamination may be eliminated simply by
clothing removal, and in a mass-casualty setting, a copious amount of water,
with or without soap, is probably sufficient to remove the remaining
Decontamination should be accomplished only in designated
areas by response personnel specifically trained and appropriately equipped to
perform this function. Decontamination personnel require a higher level of
personal protection than responders near the scene not involved in this process.
Once decontaminated, exposed patients pose essentially no risk to providers. Much discussion concerning possible off-gassing has appeared in medical literature, but dilution with ambient air in a live patient exhaling residual gases probably reduces concentrations of chemicals to minimal levels. No scientific research has indicated a major threat from off-gassing from an externally decontaminated patient. Still, there are anecdotal cases of providers' being affected by residual contamination on victims; thus, response personnel should monitor themselves and their colleagues for early signs and symptoms indicating such secondary exposure.
The very concept of triage implies that demand exceeds
resources. In a mass-casualty setting involving victims exposed to chemical
agents, a prioritization process must take place at every step to ensure the
maximum good for the maximum number of victims.
Some prioritization of victims actually occurs first in the
hot zone: Ambulatory victims are directed toward the decontamination corridor,
and those who are alive but require assistance are removed before entrapped
victims and those who are obviously deceased. Expedient triage occurs subsequent
to decontamination, and victims are re-evaluated after on-scene treatment and
while awaiting transport in staging or holding areas.
Triage of chemically affected victims in general follows
standard triage protocols, such as the START algorithm. START was designed
primarily for victims of trauma, however, and many victims of chemical agents
will not have classic trauma injuries. Subtle changes in the START protocols may
therefore be in order and are discussed later in this course.
Responders should follow standard trauma protocols,
modified by the addition of early administration of specific antidotes if the
chemical is known.
The cornerstone of further out-of-hospital treatment is
emergency stabilization of the patient by establishing a patent airway and
supporting tissue oxygenation and ventilation (mechanically if necessary).
Further treatment will be dictated by specific anatomical
or physiological derangements and response to antidotes or other field
Transport may also pose a risk to providers.
Current technology to determine full decontamination
that "clean" is in fact clean is limited. Failure to fully
decontaminate a patient, certainly possible under the chaotic conditions at the
scene, may inadvertently put providers in emergency medical transportation
vehicles in jeopardy, either through accidental contact or through inhalation of
vapors released in a closed compartment.
Although this risk is minimal, prudence dictates maximum
compartment ventilation during transport and, if feasible, use of patient
protective wraps, burn sheets, or linens during transport to receiving
Two types of chemical agents with no legitimate industrial
purpose have been studied and used in combat. They are classified as nerve
agents (because of their primary physiological effects) and blistering agents
These two classifications are discussed in the next few
Nerve agents are in general colorless, odorless, oily
liquids. They likely would be released as aerosols or sprays, which could
contaminate skin, eyes, clothing, or other materials. Under usual ambient
conditions, they will evaporate (some rapidly, some slowly) and either the
aerosols or the vapors could be inhaled, producing respiratory effects as well.
And although unlikely, they could be ingested. Depending on the type, amount,
and route of exposure, effects of nerve agent exposure can occur in minutes or
Five different nerve agents are recognized: GA (soman), GB
(sarin), GD (tabun), GF, and VX. Of these, VX is the most toxic on an
ounce-to-ounce basis and also has the slowest evaporative properties, allowing
it to remain longer as an environmental contaminant.
Agents: Mechanism of Action
Nerve agents produce their effects by allowing the body to
poison itself. Nerve agents interfere with the action of an enzyme called
acetylcholine esterase (AchE). AchE breaks down acetylcholine (Ach), a natural
neurotransmitter in the body. Neurotransmitters are used to send signals between
nerves or between nerves and muscles, glands, and other organs.
The interference with AchE allows Ach to build up in the
body and results in a massive over-stimulation of nerves, muscles, and glands.
Eventually, this over-stimulation leads to a depletion of the body's natural
energy packets (ATP, adenosine triphosphate), and the affected cells will stop
Agents: Signs and Symptoms
The end result of this over-stimulation can be identified
Left untreated, eventually all organ systems will fatigue
and fail. Victims of nerve agents usually die as a result of respiratory
depression or arrest.
A helpful tool to remember many of the
signs and symptoms of nerve agent or organophosphate intoxication is the SLUDGE
Lacrimation (excessive tearing)
Agents: Scene Response and Treatment
The hallmark of scene medical response is rapid removal
from the contaminated area, expeditious decontamination, airway and ventilatory
support, and the administration of antidotes and seizure-control medications.
Atropine is a drug that attaches to the same receptor sites
on some nerves and other organs on which Ach has its effects. However, atropine
does not produce the same effects at these sites as Ach does, and by
"blocking" these sites, will reduce the relative effect of excesses in
Ach on these organs. The most important therapeutic endpoints are drying of
respiratory secretions, reversal of bronchoconstriction, and reversal of
bradycardia. Pupillary response and changes in heart rate are not useful
measures of adequate atropinization. The usual adult dose is 2 mg IM, and this
may be repeated if necessary up to the limits as determined by local protocols.
Military doctrine, on which many civilian treatments are based, indicates that a
maximum of 6 mg should be used in the prehospital setting.
Pralidoxime chloride, also referred to as 2 PAM chloride,
frees up AchE from its binding to nerve agents, allowing AchE to break down Ach.
The usual adult dose is 600 mg IM and may be repeated twice.
Diazepam, Valium, or other benzodiazepines are used to
prevent or control seizure activity. Atropine, even in sufficient dose, will not
prevent seizures, since different receptor sites are involved. The usual adult
dose is 10 mg IM.
The military issues atropine and 2 PAM chloride in
autoinjectors, and many communities have issued these to first responders for
their personal use or for use in the event of a casualty from these agents.
The military autoinjectors are issued in tandem and are
referred to as Mark I kits. Each autoinjector is color coded and clearly marked.
The military is fielding a newer version of autoinjector, called the Antidote
Treatment Nerve Agent Auto-injector (ATNAA), which contains both medications in
Characteristics and Mechanism of Action
Vesicants, or blistering agents, include the mustard
agents, lewisite, and phosgene oxime. These are all liquids that can be
vaporized or turned into aerosols. Phosgene oxime is classified as a vesicant
but actually produces different effects.
The exact mechanism of action of vesicants is unknown.
However, they appear to congeal intracellular structures, causing cell death. If
absorbed, they also suppress production of blood cells, causing anemia,
increased susceptibility to infection, and an increase in long-term cancer risk.
Signs and Symptoms
Vesicants kill cells with which they have contact. The
clinical effects depend on the cells involved. Even if aerosolized, based on
historical battlefield use, their primary effects are on the skin and eyes.
However, most signs and symptoms of mustard agents are delayed. Depending on the
amount, this may be from several hours to more than a day.
Exceptions to this pattern occur with lewisite and phosgene
oxime. Lewisite causes immediate burning of the eyes and the skin. Phosgene
oxime, classified as a vesicant, actually produces a relatively rapid onset of a
severe reaction similar to anaphylaxis blotching, red, painful, and itchy
"wheals" will appear within minutes to hours of exposure.
Historically, most victims recover, although recuperation may be prolonged. With large enough exposures, however, victims will die either from chemical burn effects, secondary infections, airway obstruction, or respiratory arrest.
Scene Response and Treatment
Although an antidote called British antilewisite, or BAL,
exists to counter the effects of lewisite, this drug is not available in the
pre-hospital setting. There are no antidotes to mustard agents or phosgene oxime.
Treatment is therefore supportive. The two most critical actions are to remove
the victim from the contaminated scene and rapid decontamination to prevent
Further treatment will depend on the victim's condition.
Obviously, respiratory status must be assessed first. If the victim is having
trouble breathing, supplemental oxygen with assisted ventilation, if resources
are sufficient, may be required. Careful observation for stridor, wheezing, or
excessive secretions is necessary these victims may develop a pulmonary
edema picture as a result of "burns" of the tracheobronchial tree or
may develop airway obstruction from the formation of bullae in the hypopharnyx.
Cool compresses to affected skin or over closed eyes will provide some relief
from severe pain caused by the vesicant exposure. Although intravenous hydration
eventually may be necessary to counteract fluid loss through the skin and into
bullae (large blisters), this will not be necessary unless transport time is
prolonged or anticipated treatment will be delayed.
There are several chemicals that have legitimate industrial
uses, but which have been weaponized by the military or sought by terrorist
organizations as weapons of mass destruction. These generally are classified as
choking (pulmonary) agents or so-called blood agents.
These dual-use chemical agents are discussed in the next
Choking agents are named because their primary target organ
is the lung. There are two choking agents of principal concern phosgene (CG)
and chlorine (CL). Both were developed or used during World War I as chemical
Chlorine is widely used in industry. Phosgene is used in
chemical synthesis. It may be prepared by the reaction of carbon monoxide with
chlorine in the presence of a catalyst or by the oxidation of chloroform or
Two toxic byproducts of combustion of certain material also
produce primarily choking agent symptoms: perfluoroisobutylene, referred to as
PFIB, and oxides of nitrogen. PFIBs are created by the combustion of such
materials as polytetrafluoroethylene (Teflonฎ), while oxides of nitrogen are
toxic decomposition byproducts.
Chlorine is a greenish-yellow gas with a
pungent, irritating odor. It is heavier than air and highly corrosive.
Phosgene is a colorless, extremely volatile gas with an odor of fresh-cut hay, corn, or grass.
PFIBs are colorless and odorless gases.
Oxides of nitrogen may be liquids or gases under ambient conditions. They also have variable odors and colors. Nitrogen dioxide, for example, is commonly found on farms near silos and can be identified by its bleach-like odor and yellow to reddish-brown color.
Agents: Mechanism of Action
Choking agents produce their effects by causing tissue
damage to mucus membranes and other tissues.
The intact skin is remarkably resistant to the effects of
these agents; conversely, the lung is extremely sensitive. Most damage is due to
derangement of intracellular processes, which may lead to cell death.
Agents: Signs and Symptoms
The principal medical effects of choking agents are all
similar. Most will have some effect on the eyes, resulting in copious tearing
and some visual blurring and eye pain. Higher levels will produce some nausea,
and vomiting may be present.
Their primary effect, and most dangerous, is on the lung
tissue. They first will produce upper airway and tracheal burning and irritation
and induce violent coughing, usually after a latent period of several hours,
depending on the dose. As symptoms progress, a sense of choking, chest
tightness, and air hunger will develop, and with a full exposure, fluid will
build up in the lungs and hypoxia will ensue. Compounding this, most of these
agents are heavier than air and thus will displace oxygen, further exacerbating
Agents: Scene Triage and Treatment
Initial treatment is to remove the patient from the
irritant. If the agent is known to be only in gaseous form, minimal
decontamination (most likely clothing removal) will suffice otherwise full
decontamination is recommended.
The principal field treatment is rest, with supplemental
oxygen as available. Patients prone to bronchospasm may have an exacerbation as
the result of exposure, and inhalant bronchodilators may be of some benefit.
Victims who develop severe symptoms shortly after exposure and whose symptoms
are prominent while at rest are at the greatest risk of further deterioration,
which can include massive pulmonary edema and respiratory arrest.
Thus, patients with symptoms at rest
who do not rapidly respond to field treatment should be triaged for hospital
care first. Those who have minimal or no symptoms at rest probably can receive
delayed hospital evaluation. In a mass-casualty setting with numerous
symptomatic, immediate patients, any victim in respiratory arrest on the arrival
of response personnel may have to be triaged as expectant/deceased.
Agents: Characteristics and Mechanism of Action
Blood agents are misnamed, in that their effect is
primarily at the cellular level, not in the blood.
Blood agents include any substance that contains or
releases cyanide. These include the compounds hydrogen cyanide (AC) and cyanogen
chloride (CK). Cyanide has an odor of bitter almonds (11% of the population
cannot recognize this odor, however), and cyanide compounds usually are
colorless and are found as highly volatile liquids or solid crystals.
Cyanide exerts its effects by blocking the use of oxygen by
enzyme systems within cells. Even with adequate levels of oxygen delivered to
the cells by the blood, these cells cannot use the oxygen. Initially, cells
switch to anaerobic (oxygen-less) metabolism, but eventually, the cells die.
Agents: Signs and Symptoms
There is a very narrow margin of safety between
the development of symptoms from cyanide exposure and the amount of exposure
necessary to produce death.
Initial symptoms include
Agents: Signs and Symptoms
The most important treatment option is removal from
Immediate treatment includes standard protocols for airway,
breathing, and circulation. In unconscious victims, 100% oxygen with assisted
ventilation may be of benefit. Amyl nitrate ampoules may be used in the field in
a breathing patient to begin detoxification. Rapid transport to a receiving
facility for the administration of hospital-based antidotes (sodium nitrite and
sodium thiosulfate) may be lifesaving.
and Riot-Control Agents
Incapacitants are chemicals that are in general not
life-threatening but are used to temporarily prevent someone from functioning
properly. Riot-control agents (RCA) are used by law enforcement agencies
throughout the world and generally produce their desired effects through
interference with vision or through producing undesirable, but not
life-threatening temporary physical effects, such as coughing or vomiting. RCA
include pepper spray and Maceฎ.
Characteristics and Mechanism of Action
In practice, incapacitants have been hallucinogens. The
primary hallucinogen studied for this effect is termed BZ, which is closely
related to scopolamine. There is evidence that foreign governments have
developed a similar incapacitant, termed Compound 15. These compounds are
odorless, tasteless liquids with low evaporative properties.
BZ affects neuromuscular junctions and synapses, both
within and outside the central nervous system. It blocks the effects of
acetylcholine (which is the opposite effect of nerve agents) and thus produces
effects opposite of nerve agents.
Signs and Symptoms
Clinical effects tend to occur after a one- to 24-hour
latent period. Incapacitants have both central nervous system and peripheral
Scene Triage and Treatment
Protected individuals should remove victims from exposure
as soon as possible. Decontamination may be necessary in the event of high known
exposures or release within confined spaces, or evidence of clothing or skin
Treatment in the field primarily is supportive, directed at
ensuring that the victim does not do something that would cause himself harm.
The victim's behavior may be similar to that of an intoxicated person or someone
suffering from head trauma, and these possibilities must enter into the
Transport to a hospital with a protective escort for
further evaluation and possible administration of an antidote is warranted. In
most cases, effects will subside gradually without treatment over one to three
These agents, in and of themselves, rarely are life-threatening. A greater risk results from personal harm because of central nervous system effects.
Characteristics and Mechanism of Action
The principal riot-control agents are pepper spray, tear
gas, and Maceฎ. These usually are dry powders that are released as small
particles. Their primary purpose is to render someone incapable of continuing
the activities he was doing as a result of irritation of the eyes.
Tear gas (CS) and chloroacetophenone (CN) are also
pulmonary irritants. CS gas is the familiar tear gas most often used by police
for crowd control. CN is available as Mace over the counter for personal
protection. Capsaicin, or pepper spray, has to some extent replaced CN as a
personal protective agent, with less dangerous effects.
Signs and Symptoms
The eyes are most sensitive and most often affected. Eye
tearing and severe blepharospasm are common. More severe injuries can occur from
the injection of these high-velocity particles into the eye.
Other symptoms include rhinorrhea, sneezing, and
salivation. Patients also may report cough, chest tightness, and shortness of
breath, and these agents can exacerbate a chronic condition such as asthma.
Redness, itching, and burning of the skin can occur but is
Rarely, death can occur but usually is due to allergic
reactions or severe exacerbation of underlying pulmonary conditions.
Scene Triage and Treatment
Most people exposed to pulmonary irritants do not seek
medical care, and the effects are self-limited. If they do seek treatment,
removal from the source of exposure and decontamination with water is indicated.
Symptoms normally will resolve spontaneously without
treatment over one to four hours, but symptomatic treatment of eye irritation
with compresses or mild reactive airway disease and coughing with humidified air
(supplemental oxygen if indicated, or even bronchodilators) may facilitate
Patients with severe symptoms or underlying diseases made
worse through the exposure may require transportation to facilities for further
evaluation and treatment.
Industrial Chemicals (TIC): Introduction
Chemicals are ubiquitous. Although there are more than 6
million known chemicals, a first responder might encounter any of 1.5 million
chemicals in an emergency. More than 63,000 of these chemicals are considered
hazardous. The Environmental Protection Agency (EPA) and the U.S. Department of
Transportation (DOT) list 2,700 chemicals deemed hazardous during commercial
The EPA maintains a list of nearly 400 extremely lethal air
toxins that could produce fatalities in less than 30 minutes. In addition, at
least that many chemicals pose a long-term health risk, be it chronic pulmonary
problems, birth defects, or an increased risk of cancer.
Some characteristics of TIC make exposure especially
Examples of chemicals that qualify as
TIC and their common usages:
Fortunately, the majority of TIC are known, and procedures
have been established at the federal and state levels to provide responders with
assistance should a chemical spill or other event be encountered.
Storage sites and vehicles involved with the transportation
of these agents are required to prominently display placards that identify the
types of the agents or materials being stored. Job aids, such as the Emergency
Response Guide 2000, published by the U.S. DOT, provide immediate action
checklists based on data contained in these markings, so that appropriate
lifesaving actions might be taken without knowing the exact substance
An abundance of detection equipment also exists.
Traditional basic hazardous materials teams carry a minimum equipment set that
includes a combustible gas indicator, an oxygen-level indicator, some
colorimetric tubes for detection of a specific chemical or family of chemicals,
pH paper to assess the potential corrosiveness of a substance, and an electronic
detector to detect the presence of additional hazardous materials.
Unfortunately, hazardous materials units cannot respond to
all incidents, and a determination that TIC may be involved may rely on human
senses specifically, sight and smell. Indicators that a chemical incident
may have occurred include:
Should any of these be present in conjunction with a
mass-casualty event, release of a chemical agent should be suspected.
Mechanism of Action
The exact mechanisms by which TIC produce illness or death
vary with the materials involved. In general, however, the most toxic of these
chemicals are very corrosive in nature and burn, irritate, or even dissolve
human tissues. Acidic or alkaline chemicals produce effects in proportion to
their pH, with those at extremes of pH producing effects most rapidly. Also,
alkalis are more easily absorbed into tissues, where their effects will
Some chemicals exert their primary effects systemically and
damage liver (carbon tetrachloride), kidneys (mercury) or other organ systems.
However, these effects either are delayed or the consequences of organ damage
may take some time before it reaches a severity in which symptoms are produced.
Signs and Symptoms
Whereas the specific mechanisms of action of these various
chemicals may be different, exposure symptoms tend to be similar and affect
specific organ systems in nearly identical fashion, varying in degree of
severity based on the amount of exposure.
Organ systems most often affected and symptoms produced
Scene Triage and Treatment
Victim triage and treatment depend on the severity of
symptoms, the capabilities of the EMS responders, and the amount of resources
available at the scene.
Presuming that victim demands exceed resources, victim
triage is required. The START algorithm is a reasonable model for an approach to
triage in a multiple casualty situation involving toxic industrial chemicals.
The two most important steps in triage and treatment are
removal from continued environmental exposure and decontamination. One primary
cause of injury or death in TIC incidents is anoxia resulting from ambient
oxygen displacement. Continued exposure or inhalation of TIC further exacerbates
symptoms and morbidity and mortality. Decontamination is discussed elsewhere in
Triage and Treatment: Continued
Obviously, victims who are able to egress from the hot zone
on their own volition and disrobe or otherwise decontaminate themselves with
minimal or no assistance have already self-triaged into a category below those
who are unable to do so.
Victims with no sign of life no respiratory effort, no
detectable pulse normally will be triaged as expectant, since significant,
limited resources would be consumed in ministering to these people.
The START algorithm should in general be followed, but with
the addition of antidotes for known TIC. For practical purposes, this would only
include such agents as organophosphate insecticides (atropine and 2 PAM CL work
for organophosphates just as they do for nerve agents). Most treatment is
Many of the more corrosive chemicals will lead to
laryngospasm or upper airway obstruction from blister formation or oropharyngeal
edema. Any sign of stridor or upper airway compromise should be treated
immediately with endotracheal intubation, event if assisted ventilation is not
possible because of manpower constraints.
Humidified oxygen, with or without the addition of
nebulized bronchodilators, may provide some symptomatic relief for those
suffering from bronchospasm or mild pulmonary edema as the result of exposures.
Certainly, rest in a comfortable, nonthreatening environment is appropriate, as
is rapid transport to receiving facilities.
C-spine control is not necessary unless traumatic injuries
also are present. However, during a mass-casualty incident, a responder may not
be able to remain in attendance to a victim because of other triage and
treatment responsibilities, and under these circumstances, a well-placed rigid
cervical collar may help maintain a patent airway in an obtunded or comatose
patient. A nasopharyngeal or oropharyngeal airway in such patients also should
be considered as an adjunct.
Victims who have minimal or few symptoms at rest may be
triaged to the delayed category, presuming no other symptoms are prevalent from
Victims with caustic burns of the skin also should be
treated symptomatically. Alkali burns may require copious amounts of fluids to
decontaminate and may require repeated decontamination as a result of leeching
of the agent from exposed tissues. This also is true in the case of ocular
injuries. Denuded skin should be covered with saline-moistened gauzes. Chemical
burns usually do not result in the degree of fluid shifts (edema) that accompany
traditional burns, but there are still losses from weeping of tissues and
thermal losses through damaged skin. Cool compresses on closed eyes after
decontamination will reduce discomfort.
Chemical warfare agents and toxic industrial materials may
pose a significant threat to unprotected citizens and responders alike. The
immediate threat from a release of the more dangerous chemicals results from
their effects on the respiratory, neurological, or dermatological systems. The
cornerstones of medical management of victims exposed to chemical agents are:
Biological weapons are defined as any living organisms or
material derived from them used, for military, criminal, or terrorist purposes,
with the intent of causing death or incapacitation to humans, animals, or
Biological agents have been used to inflict death or injury
in man for thousands of years.
There are literally thousands of microorganisms and toxins
that could be considered for use as biological agents. Fortunately, most of
these do not have the characteristics and attributes suitable for production,
weaponization, and release in large quantities. An ideal biological weapon would
need to meet certain requirements.
The agent must be available. Many are available worldwide,
but some have not been isolated in the wild even by highly trained researchers
backed by the most sophisticated equipment available.
of mass production
It must be capable of mass production. Most biological
organisms do not survive for long periods of time in the environment and may be
fragile in the laboratory, making production difficult.
Depending on the purpose of its use, an agent must be
either incapacitating or lethal in a high percentage of those affected.
To be effective against large numbers of victims, an agent
also should be easily aerosolized.
It must maintain its viability or potency throughout
production and storage. The fragility of these agents in the environment and
outside living tissues may reduce their effectiveness once produced and stored.
The population against which it is to be used must be
susceptible to the agent. An attack with poliovirus would be devastating, were
it not for the widespread use of vaccination against this microorganism.
Conventional wisdom has dictated that a would-be attacker would desire to be protected against his agent of choice. The action of suicide attackers indicates that this may no longer hold true.
a Biological Weapon
Once an ideal biological weapon is identified, it must be
produced, stored, and weaponized. These tasks can be extremely difficult to
First, the agent has to be recovered. For some agents, this
might be relatively simple. The causative agents of anthrax and plague still
exist in the United States. For others, it is practically impossible no one
has yet isolated the Ebola virus in the wild.
a virulent specimen
A virulent specimen must be collected. For most pathogens,
there is a range of virulence, or strength. A weak specimen would produce little
or no disease.
The agent must be mass-produced. For some, this can be done
relatively easily in a fermenter. Viruses require living tissue. Even with mass
production, maintaining viability of the organisms requires very strict
Processing can be difficult. It involves stabilizing the
agent while it's in storage. If the agent is to be released in a powdered form,
it must be ground to a size (1-5 microns) such that it penetrates the lungs and
remains there. Most substances harbor an electrostatic charge, which must be
eliminated or reduced to prevent the individual particles from sticking. The
toxin responsible for botulism is very fragile, and any misstep in processing
will result in an impotent mixture of denatured toxin.
the release weapon
A release weapon must be obtained. All spray nozzles do not
produce the same effect and may be clogged easily.
All these processes must be done in secret. And the developers must be protected lest they contract the disease themselves
There are numerous ways a bioterrorism attack could be
of Entry Into the Body
Nearly all biological agents have their effect inside the
body. There are several different routes of entry: inhalation, ingestion,
injection, and percutaneous absorption.
The preferred route of entry likely would be through
inhalation of an aerosolized agent. This has the greatest potential for mass
Ingestion is a possible route and has been used by
criminals and terrorists. It is, however, more difficult to affect a large
population by this route. More agent is required, and many agents are destroyed
by the heat of cooking. This method would require either contamination of
foodstuffs immediately prior to ingestion or of water either bottled or
contaminated near the source of use.
The skin is a remarkable barrier against biological agents.
With only a very few exceptions, pathogens otherwise suited for bioterrorism are
ineffective against intact skin. Injection of an agent is possible and has been
used, primarily in criminal activities or assassinations. This method could
target individuals but not masses of people.
of Biological Weapons
There are three classes of existing biological warfare
agents: bacteria, viruses, and toxins.
There also are concerns about the development of
next-generation biological weapons, such as bioregulators, genetically
engineered pathogens, and fusion toxins.
The next few pages in this course deal with the three
classes of existing biological weapons.
Bacteria are single-celled organisms. They require
substrates, such as proteins, glucose, and oxygen, to thrive. They all have some
sort of cell wall, a cytoplasm, and genetic material (DNA and RNA). They
reproduce through division. Bacteria cause disease by one or more mechanisms: by
direct tissue invasion or by the release of toxins or other substances, referred
to as "factors," which derange physiological functions or cause
further tissue damage. Most bacteria can survive outside living tissues for
variable lengths of time. A unique form of bacteria, referred to as rickettsia,
also can survive outside cells, but require materials within living cells to
Bacteria are susceptible to antibiotics and can be killed
or inhibited by extremes of temperature, ultraviolet light, or other harsh
environments. Some bacteria can convert to a dormant, spore form, which makes
them more resistant to the environment. Vaccines have been developed for certain
bacteria, such as that which causes one form of pneumonia.
Bacteria of concern include:
Viruses, like bacteria, are single celled. They are
composed of a cell wall, called a capsid, and either DNA or RNA. They do not
have the metabolic machinery that bacteria do and require living cells to
survive and reproduce. They can live for variable lengths of time outside living
Viruses cause disease by two mechanisms. They either damage
the cells in which they reside, with subsequent death or genetic alteration of
those cells, or, in an attempt to eliminate the virus, the body's immune system
causes damage to the host.
Some viruses are species-specific; polio only occurs in
humans, for example. Others may produce different disease manifestations in
different species. Cowpox, a cousin of smallpox, produces only a mild disease in
humans. Still others cause no apparent disease in their natural
"hosts" but may jump species and cause overwhelming illness or death
in other species. This is thought to be one of the mechanisms that created the
Spanish influenza epidemic of 1918 that killed 10 million to 20 million people
worldwide over a 10-month period.
Unlike bacteria, there are few chemotherapeutic medicines
that work against viruses. Vaccines can be developed against some viruses, such
as the vaccines for influenza or certain viruses that cause hepatitis. Other
viruses mutate with such frequency that vaccines are in general ineffective
Viruses of concern include those that
cause the diseases of:
Toxins are biological chemicals. They may be produced by
animals, bacteria, or fungi.
Toxins are not living and thus are not susceptible to
antibiotics. Killing the organism that produces these toxins will not eliminate
the diseases caused by them. But that generally may prevent the disease from
worsening if the toxin is produced by the organism while inside the body.
Unlike bacteria or viruses, environmental factors do not
cause a decrease in potency, and in fact, some toxins are more dangerous on an
ounce-per-ounce basis than any synthesized chemical ever manufactured.
Toxins of concern as biological agents
of Bioterrorism Agents
The Centers for Disease Control (CDC) has categorized into
three groups the agents most likely to be used in a terrorist attack:
The CDC Category A agents are discussed in this chapter.
These agents have the greatest potential to affect the first responder
community. Additionally, the necessary protections for these agents will
effectively protect against those in Categories B and C.
There are several different bacillus bacteria, but the one
that causes greatest concern is the spore-forming Bacillus anthracis, the
causative organism of anthrax. Bacillus species are ubiquitous, and in certain
parts of the world anthrax is endemic.
Anthrax is primarily a disease of herbivores (goats,
cattle, sheep, etc.). It causes disease by entering the body human or
otherwise converting from its spore phase, invading the lymph nodes, and, in
addition to tissue invasion, releasing substances (referred to as factors) that
cause direct tissue damage or interfere with the body's defense mechanisms.
Humans contract anthrax through ingestion of tainted meats,
accidental inoculation of abraded skin or cuts, or through inhalation of spores.
When acquired accidentally, inhalation anthrax is called Woolsorter's disease,
because the few who contract anthrax this way normally inhale the spores while
handling hides of infected animals.
Course of the Disease
Untreated, the mortality from anthrax is quite high
over 80%. Victims of the inhalation route normally present two to three days
later with nonspecific, influenza-like symptoms. Over the next several days, the
patient will rapidly deteriorate and eventually die from septic shock if
It is important to note that patients do not develop
pneumonia from exposure; rather, the organism gains entry by being inhaled.
Mortality from ingestion is equally high because of difficulties in early
diagnosis. However, even untreated, the majority (80%) of cutaneous anthrax
Anthrax is susceptible to antibiotic treatment if provided
early in the course of the disease. There is an FDA-approved vaccine that is
effective against B. anthracis. Close tracking of people receiving this
vaccine by the military indicates that it is as safe as, or safer than, other
vaccines given routinely throughout the United States. The vaccination schedule
requires six shots over 18 months, with annual boosters to remain effective.
Penicillin or other widely available antibiotics can be
used to treat anthrax, but to affect mortality it must be given before
significant symptoms appear. The same medications used to treat anthrax can be
used as an empiric prophylaxis if a community were to be attacked with
aerosolized B. anthracis.
Anthrax is not contagious, and standard precautions are
sufficient. Decontamination of equipment with 0.5% hypochlorite (bleach) is
acceptable. Out-of-hospital treatment is supportive based on symptoms.
causes plague. Epidemics of plague killed millions of Europeans during the Dark
Ages. Y. pestis lives symbiotically in particular species of fleas that
tend to infest rats and other rodents. Plague outbreaks still occur periodically
in developing countries but have been nearly eradicated from the United States,
although there are a few cases each year in the Southwest part of the country.
There are several clinical presentations of plague. The
most common naturally acquired presentation is bubonic plague, so named after
the large lymph nodes, called bubos, which are seen in a patient so affected.
Route of exposure in these cases usually is due to bites by infected fleas, most
often to the lower extremities. Two to five days after exposure, patients will
develop fever, malaise, and other nonspecific complaints. Bubos will form
rapidly after the patient becomes symptomatic. Left untreated, bubonic plague
may progress to septicemic, gastrointestinal, or pneumonic plague or a
combination of these.
Septicemic and Pneumonic
Septicemic plague is hallmarked by septic shock and
clotting of the smaller arteries, with necrosis of distal appendages such as the
fingers, toes, ears, and nose.
Pneumonic plague can be acquired either through internal
spread of the disease or through inhalation of aerosolized particles. And
although naturally acquired pneumonic plague has occurred, even in natural
outbreaks in such countries as India and Madagascar, this is exceptionally rare.
In pneumonic plague, the patient develops the same
nonspecific symptoms two to five days after exposure. Over the next several
days, he would rapidly develop an overwhelming pneumonia, with a severe cough,
shortness of breath, and bloody sputum or frank hemoptysis. He eventually would
die of that pneumonia and hypoxemia or overwhelming sepsis.
Treatment for plague includes vigorous supportive care,
which may include assisted ventilation and intravenous antibiotics. Antibiotics
may abort the disease process if given early during the course of the disease.
Patients with pneumonic plague are highly contagious, and
all in close proximity should use respiratory droplet precautions in addition to
standard infection-control procedures. The bacteria also live for a variable
amount of time in excrement, sputum, and other body fluids, and care must be
taken when handling soiled clothing and linens.
A vaccine existed at one time, which only worked against
the bubonic form of plague and has been discontinued. Disinfection with 0.5%
hypochlorite will kill the bacteria. Prehospital treatment is supportive only.
The eradication of smallpox is one of the great
achievements of public health. Following a worldwide campaign that extended over
a decade, the last recorded case of naturally occurring smallpox occurred in
Somalia in 1979. Two laboratory-acquired cases occurred in Great Britain in
All laboratory specimens of smallpox were either destroyed
or reportedly delivered to one of two high-level biosecurity laboratories, one
at the CDC in Atlanta and the other at the State Research Center of Virology and
Biotechnology, Koltsovo, Russia. Routine vaccination in the United States ceased
shortly thereafter, and vaccination of military personnel was discontinued in
The fear that the smallpox virus, variola, could have fallen into the hands of terrorists or that certain countries may have maintained a clandestine cache, has caused a rethinking of the proposed destruction. Indeed, the U.S. government has contracted for enough vaccine to immunize the entire population and increased supplies of other necessary medications. There also are ongoing deliberations concerning the benefits of vaccination for certain "at risk" populations.
Smallpox is caused by the DNA virus variola. Patients are
asymptomatic during the first two weeks (seven to 17 days), during which time
the virus is incubating. Following incubation, the disease progresses rapidly,
and the patient develops a rash, which starts on the face and arms and
progresses over the next two days to the legs and trunk.
Each eruption progresses through stages, beginning as a red
spot (macule), then forming a papule (pimple), then a vesicle (small
fluid-filled blister), and then a pustule (blister filled with white blood
cells). The eruption then ruptures and scabs over, the scab separates, and the
lesion heals with a pitted scar. Characteristically, eruptions in any one part
of the body are in the same stage, which is a key difference between smallpox
and the rash of chickenpox.
In addition to the rash, patients develop high fevers,
dehydration, and shock and are very prone to superimposed infections.
Incidence and Mortality
Approximately 30% of those exposed to smallpox contract the
disease and 30% of those with the disease die, usually of sepsis.
There are several forms of smallpox. The more benign forms
may not even have a rash and cause almost no deaths. In contrast, the
hemorrhagic form, in which there are bleeding abnormalities, is nearly always
fatal, as is the so-called flat type, in which the rash forms almost a solid
sheet on the body. Fortunately, less than 10% of a population afflicted with
smallpox will develop these malignant forms of the disease.
Although inoculation with live variola (referred to as
variolation) occurred in ancient China, this produced lethal disease in an
unacceptable percent of the population. Dr. Edward Jenner is cited as the
discoverer of the vaccinia vaccination (although he used cowpox virus, not the
related vaccinia virus) in 1796.
Vaccination is successful in more than 95% of attempts and
is "documented" by the presence of a pitted scar at the inoculation
site. Vaccination is not, however, without risk: Approximately 1 in a million
dies from complications either overwhelming vaccinia or encephalitis.
Numerous more develop various degrees of complications. Those with a history of
eczema, psoriasis, or other skin maladies seem most prone.
A major concern at present is the high percentage of the
population that is immunosuppressed, either from cancer or its treatment, AIDS,
or other chronic diseases. The immunoglobulin VIG (variola immune globulin)
partially protects these vaccine-adverse reactions, but there is currently only
enough VIG for about 700 adults. Plans are in place to develop more than 30,000
doses of VIG over the next several years.
Supportive care is the only treatment now available for a
patient with smallpox, although several antiviral medications are being
investigated for possible use. If given within four days of exposure, the
vaccinia virus may prevent or attenuate the development of the disease. Those
who survive an infection with smallpox have near-lifetime immunity (>99%).
Smallpox is highly contagious. People in close contact with
a patient known to have smallpox should be vaccinated. Health care workers
treating such patients also should be vaccinated and should use, in addition to
standard infection-control procedures, contact precautions (face shields, other
splash protectors) and airborne precautions (HEPA N-95 filters at a minimum). If
possible, patients with smallpox should be isolated in negative-pressure rooms
with no air recirculation.
CDC has developed plans in the event of a smallpox release, including sequestering patients with known disease to predesignated hospitals and those with suspected disease or probable contact to secondary hospitals.
Tularemia, or rabbit fever, is endemic in the United States
and causes periodic outbreaks. It is caused by the bacteria Francisella
tularensis. Typically, disease is caused by human contact with body fluids
from infected animals or bites from arthropod vectors, such as ticks.
Depending on where infection occurs glands, eyes, or
systemically (referred to as typhoidal tularemia), the patient may demonstrate a
variety of nonspecific symptoms a few days to weeks after exposure: fever,
chills, malaise, headache, weight loss, and nonproductive cough. Physical
findings also are nonspecific, but a chest X-ray may be abnormal.
Most patients survive, but the typhoidal form has a
mortality rate of up to 35%. No FDA-licensed vaccine exists, but the disease
does respond to antibiotics. Responders need to use standard infection-control
procedures and treat the patient's symptoms. Standard disinfection is sufficient
Hemorrhagic Fevers: Introduction
No fewer than 19 different viruses are known to cause the
syndrome referred to as viral hemorrhagic fever (VHF). These diseases tend to be
named for the region in which they were first discovered, thus Marburg
hemorrhagic fever, Congo-Crimean hemorrhagic fever, or Rift Valley fever. In
these locations, the disease is endemic, with periodic outbreaks of disease
among larger populations.
The particular viruses involved may affect only one species
of animal or may cross species. In some cases (Ebola, for example), the natural
host and/or vector are unknown.
Signs and Symptoms
These viruses cause an overwhelming viremia, but in
addition, a common denominator in VHFs is a disruption of the vascular lining,
or endothelium, with the release of factors in the blood stream that cause
capillary leakage, third spacing of fluids to the tissues, hypotension, and
To one degree or another, the body's normal clotting
mechanism is disrupted, with the result that patients may present with obvious
signs of tissue hemorrhage, such as petecchiae, ecchymoses, and easy
Certain viruses may target specific organs, such as the
lung, kidney, or liver, and in these cases, derangements from organ dysfunction
also will predominate, with hepatitis, renal failure, or pulmonary edema.
With the exception of yellow fever, there are no licensed
vaccines available to fight VHFs. Additionally, the only treatment available is
vigorous supportive care, although testing of an antiviral (ribovirin) has shown
some effects in certain forms of the disease and is being evaluated in others.
Vaccine development is ongoing.
VHFs may be contagious person to person. In addition to
standard precautions, droplet precautions are warranted because patients
frequently have respiratory symptoms, and respiratory droplets harbor the virus.
In the case of Ebola virus, needle sticks have proved uniformly fatal despite
treatment. There is no evidence, however, that casual contact can spread the
disease. Because of capillary fragility and the potential for worsening
bleeding, these patients should be handled with great care in the prehospital
setting and during transport.
Botulinum toxin is produced by the bacteria Clostridia
botulinum, a cousin of the bacteria that causes gas gangrene. The bacteria
tend to grow in nutrient-rich environments with low levels of oxygen, such as
damaged cans of food. There are seven different toxins referred to as botulinum
toxins some cause disease only in nonhuman species. Botulinum toxin causes
the disease botulism.
Botulism normally is contracted by ingesting foods
contaminated with the toxin, which is very heat-stable and is not destroyed by
standard cooking. It also can be contracted through inoculation of tissues with
the bacteria or, in the case of neonates, through ingestion of the live bacteria
with subsequent production of the toxin inside the body.
The toxin attacks neurons and prevents the release of
acetylcholine, which is necessary for impulse signal transmission to nerves.
This results in a paralysis of the muscles, including the muscles of
Because the muscles involved with fine motor skills are
rich with neuromuscular junctions, these are affected first. This translates to
a clinical picture of an initial flaccid paralysis of the cranial nerves,
especially of the eyes, followed by a bilateral descending paralysis. Level of
consciousness, however, is not affected, and there are no sensory losses.
Symptoms present between one and several days after exposure, depending on the
dose and route of exposure.
Death usually is due to respiratory depression or pulmonary
infection in those treated. Patients with severe botulism require mechanical
ventilation until all nerves affected regenerate. The only specific therapy is
antitoxin, which may arrest or retard progression if given soon enough. This
antitoxin has been used under experimental conditions as a prophylaxis as well.
Prehospital treatment is supportive, and intubation and assisted ventilation may
be required. Decontamination of equipment can be accomplished with standard
of a Bioterrorism (BT) Attack
In all probability, a terrorist using a biological weapon
would seek to do so covertly. Unlike the vast majority of unfolding disasters,
there would not be a "defined scene." However, there would be
indications of an attack, such as:
Record fatality rates would be expected for many agents,
since a large number of victims would receive doses of organisms far beyond what
could possibly occur in nature. This is especially true of an aerosol attack.
Additionally, you might see increased numbers of dead
animals of all species, especially among smaller animals.
However, in all likelihood, a covert attack will not
be detected by traditional first response organizations, unless public safety
access points identify increased call volumes for similar complaints. More
probably, initial cases will be identified from sentinel events, such as
unexpected deaths among previously healthy people, through fortuitous laboratory
discoveries, or through early suspicion of abnormal trends picked up by newer
"syndromic surveillance" systems.
Once a BT event has been identified, several actions will
be instituted almost simultaneously:
Issues of a BT Attack
The affected community will have to deal with several major
Although not all pathogens are amenable to prophylaxis
intervention, for those that are, treatment of the population at risk which
may be very difficult to identify early in the course of the outbreak will
be lifesaving. The smallpox vaccine, for example, has been shown to prevent or
significantly attenuate the disease if given within four days of exposure. Mass
prophylaxis will be very labor intensive, requiring many trained personnel
working around the clock to provide this within the necessary time.
Even with mass prophylaxis, depending on the amount of
agent released, the incubation period, the demographics of the affected
population, and other factors, there will be an increase in the health care
demands of the community above the baseline level. This will affect all
health care delivery sectors as they attempt to increase their resources and
capacities to deal with this surge.
Depending on the agent used, one would anticipate a surge
in fatalities. Temporary interment of these potentially contagious remains may
prove problematic in a community that has not developed prospective plans to
deal with this.
The community will require immediate and long-term mental
health counseling. Based on previous terrorism events, one can anticipate that
the community incidence of depression, abnormal coping behaviors (such as drug
and alcohol abuse), and acute anxiety disorders will increase significantly in
the days, weeks, and months following the event.
Responder organizations will suffer the same effects as the
community at large. However, certain organizations, particularly fire, EMS, and
law enforcement, will have additional challenges.
Adequate and timely personal protection including
physical, immunological, and pharmaceutical protection will be required at
the outset of operations. Depending on the terrorism agents, responders may be
required to wear additional equipment not normally used.
decontamination or restriction
Ambulances and other equipment or supplies that may come in
contact with infected and potentially contagious people or materials will need
to be either thoroughly decontaminated after every potential contact or
restricted for use only with known contagious or infected individuals. This will
place additional workloads on a system already stressed by the increased demand
Resource allocation may be problematic. Most systems
purchase and stockpile based on best estimates of requirements between resupply
times. The patient surge will require time-phased plus-ups in supplies
different equipment and supplies will be needed at different times in the
response and recovery phases. Additional personnel also will most likely be
required to manage the surge.
This increase in personnel requirements may be compounded
by worker absenteeism caused by fear on the part of some people, actual illness
of workers, or home requirements should family members become ill.
The potential exists that personnel may be requested to
perform functions that they have not been trained for, such as EMTs augmenting
hospitals or clinics, fire service personnel being requested to drive
ambulances, etc. The goal of the emergency management community will be to match
available resources with the demand for those resources in a time-sequenced
Stress among first responders will be immense. In addition to the physical increase in workload, ministering to high numbers of seriously ill victims, dealing with the deaths of friends and colleagues, and addressing community needs over self will take its toll on responders. Although Critical Incident Stress Debriefing has been shown to be of marginal effect in recent controlled studies, there can be no doubt that some form of crisis counseling and responder stress monitoring will be required beginning early in the event.
Emerging/re-emerging infectious diseases (EID) are those
that have been discovered recently, are increasing in prevalence, or have a
strong potential to do so in the future.
Emerging infectious diseases are relatively new diseases
(Legionnaire's disease and Ebola, for example), whereas re-emerging infectious
diseases are those whose incidence has increased after a period of control
(cholera and tuberculosis).
Since 1973, several new pathogenic microbes have been
identified worldwide as being a threat to humans. (Many of these microbes were
identified years ago, yet their impact on humans has only recently been
exhibited.) Among them are rotavirus, Ebola virus, E. coli O157:h7, H. Pylori,
Add to this list numerous other emerging or re-emerging
threats both to the United States and abroad, and one can see cause for concern.
A prime example of a re-emerging infectious disease in the
United States is tuberculosis. It is estimated that up to 15 million Americans
have latent TB.
TB may be even more important than
what these statistics reflect. A 1999 study indicates that at least one reason
for the high mortality of the Spanish influenza epidemic of 1918, which killed
between 600,000-750,000 people in the United States and between 10 million-20
million worldwide in four months was the high prevalence of
concurrent TB at the time.
Severe Acute Respiratory Syndrome
Severe acute respiratory syndrome (SARS) is caused by a
newly discovered virus called coronavirus. The worldwide outbreak, which began
in China in spring 2003, has spread through international travel routes.
It may take one to three years to develop an effective
vaccine. Meantime, several countries have instituted rather draconian methods to
contain the disease. As of summer 2003, more than 5,000 had been affected, and
the mortality rate was nearly 20%.
History reveals many examples of the threat of EID on
individual well-being. The emergence of HIV/AIDS in 1981, increases in dengue
and diphtheria cases in Latin America, and increases in cholera cases all serve
to illustrate the problematic nature of infectious disease.
It is now quite common to read in the newspaper or hear on
the radio about new, pathogenic organisms such as E. coli, resistant strains of
bacteria, or West Nile encephalitis. Just ten years ago, such stories would have
been relegated to the science-fiction novel or late-night "B" movies.
Why is this happening? Why is there a resurgence of these
The Institute of Medicine provides a list of potential
Others have subdivided etiology into
Future of EID
EID may become increasingly important in the decades to
A bioterrorism event will unfold as a rapidly progressive
community outbreak marked by severe illness and high morbidity and mortality
rates. Unlike most disasters, the fixed-site health care community will bear the
brunt of responsibility for containing and responding to this community
Traditional first response organizations will be
significantly affected by such an event. Primary areas of concern will include
worker safety and protection, handling the increased demands for services in
organizations that most likely will suffer material resource, and personnel
All members of the community, and especially those involved
with responding to such an event, will suffer acute and chronic mental health
issues that will require significant support and treatment.
Radiological materials are substances that produce ionizing
radiation. Nuclear materials are a subset of radiological materials that produce
very high levels of radiation. Nuclear materials also can be made to
spontaneously detonate, producing other effects besides the release of ionizing
This chapter discusses radiation and radiological materials
in general and the medical effects and treatment of ionizing radiation injuries.
Nuclear materials and the medical effects of nuclear detonations are addressed
in the next chapter.
Radioactivity exists throughout the world. Materials that
produce ionizing radiation are used in industry, health care, and even in our
homes. In fact, we are all exposed to radiation every day, totaling about 360
millirems/year. However, this amount is innocuous.
Types and sources of radioactive material include:
Fortunately, as the potential severity of an exposure
increases, the probability of such an exposure decreases. The most common acute
exposures by far are those caused by industrial or medical spills, which produce
only mild exposures. No injuries or deaths have been documented from these
encounters. There are, however, more worrisome threats:
Radiation Physics: The Nucleus
An atom consists of an extremely small, positively charged
nucleus surrounded by a cloud of negatively charged electrons. The nucleus
contains more than 99.9% of the mass of the atom. Nuclei consist of positively
charged protons and electrically neutral neutrons held together by the strong
nuclear force and a weaker gravitational force.
The number of protons in the nucleus is called the atomic
number. This determines which chemical element the atom is. The normal number of
neutrons in a stable nucleus is fixed, and that number, added to the number of
protons, equals the atomic mass of the element. However, a given element can
have different numbers of neutrons. An isotope of an element is an atom with a
different number of neutrons than protons.
Radiation Physics: Electrons
In a neutral atom, the number of electrons orbiting the
nucleus equals the number of protons in the nucleus. Because the electric
charges of the proton and the electron are +1 and -1, respectively, the net
charge of the atom is zero. Electrons possess finite energy charges, and those
charges are related to the distance they orbit the nucleus. Think of each
orbital layer as a shell. There are limits to how many electrons may exist in a
shell, but the atom seeks to fill all shells to this maximum.
As an example, carbon has 12 electrons and 12 protons, but
in its outermost shell it could carry four more electrons to be "full"
at that level or lose four to be full in its outermost level. Oxygen, on the
other hand, lacks two electrons from being full in its outermost level. Thus,
when carbon and oxygen get in close proximity, they tend to combine and
"share" their electrons. Because two oxygen atoms require four more
electrons, two oxygen atoms can combine with one carbon atom and form a stable
molecule. That molecule, by the way, is CO2,
or carbon dioxide.
Most atoms are stable, meaning that they remain with the same numbers of
protons, neutrons, and electrons over time. It takes a tremendous amount of
energy for a particle to break free from an atom. Some, however, are not stable,
and given sufficient time, they will lose one or more of these particles.
Radioactivity is the spontaneous transformation of an
unstable atom and often results in the emission of radiation.
Radiation is simply energy in the form of high-speed
particles and/or electromagnetic waves.
Ionizing radiation is radiation with enough energy so that
during an interaction with an atom, it can remove tightly bound electrons from
their orbits or dislodge neutrons, causing the atom to become charged or
process by which an unstable atom gets rid of excess energy (in the form of
radiation) and becomes less unstable is referred to as radioactive decay, and it
may occur rapidly as in microseconds or over a long period of time
(years). The time that it takes for half of a quantity of radioactive material
to decay is referred to as its half-life. The longer the half-life, the more
stable the compound and the less dangerous.
of Ionizing Radiation
Ionizing radiation can be either particulate (having
matter) or electromagnetic. The predominant form of electromagnetic ionizing
radiation of concern is the X-ray. There are three primary forms of particulate
There is another form of ionizing radiation of great
concern, and that is gamma radiation. The energy packets that we call light are
referred to as photons. Photons that produce visible light are harmless. A gamma
ray is a high-energy photon. The only thing that distinguishes a gamma ray from
the visible light photon emitted by a light bulb is its much shorter wavelength.
Gamma rays may be produced during release of high-energy neutrons or alpha
particles but may also be released spontaneously without these other actions.
Radioactive materials act to a great extent like their
stable relatives. This is equally true in the human body.
For example, iodine is taken up by the body and used in the
thyroid gland. Stable iodine in appropriate amounts is not only innocuous, but
also necessary for normal metabolic functioning. Radioactive iodine also can be
taken up by the thyroid gland and will serve the same function as stable iodine.
However, it also will be a continual source of ionizing radiation to the body,
and it is this ionizing radiation that is dangerous.
Radiation has its effects at the cellular level by directly
or indirectly damaging DNA, which is the essential matter of life. At very high
levels, the energy of radiation can vaporize cells or entire beings. This is
briefly discussed later under nuclear radiation.
The rad (radiation-absorbed dose) measures absorbed energy
in a given mass. One rad is 100 ergs deposited in 1 gram of material, whether
that material is wood, metal, water, or human tissue. An erg is a very small
amount of energy. The equivalent SI unit is the Gray, equal to 100 rads.
Because different substances absorb radiation at different
rates, in order to compare radiation exposure between substances, a weighting
factor is used to produce an equivalent dose. In humans, the term used is the
rem (roentgen equivalent in man), which is the rad times the weighting factor
for human tissue.
When ionizing radiation strikes DNA, it can cause breaks in
the DNA structure. Once this happens, one of two things occurs: either the cell
is able to repair its DNA, or it can't. If enough damage is done to the DNA and
is not repairable, the cell will die. If the cell does manage to repair the DNA,
it may make errors in the repair process.
These errors may be totally innocent, and there will be no
long-term effects. However, those errors may express themselves through the
production of abnormal RNA, which produces enzymes within the cell or more
often, through a continuous reproduction of these now abnormal cells. Depending
on several variables, not all understood, these damaged cells eventually could
degenerate into cancer cells.
Damage and Repair
Cells that replicate rapidly are most affected by ionizing
radiation. These include those of the reproductive system, GI tract, and bone
marrow. Those that replicate slowly, such as neurons and muscle and bone cells,
tend to be relatively resistant to ionizing radiation. Red blood cells that do
not have a nucleus or DNA also are very resistant.
The ability of cells, and thus the body, to repair
themselves is dose-dependent:
Radiation Syndrome (ARS)
The constellation of clinical signs and symptoms that a
victim of exposure to radiation exhibits is referred to as acute radiation
Because different cell types are affected by different
levels of acute radiation exposure, the symptoms exhibited will be
dose-dependent and actually will be a combination of syndromes manifesting the
cell types affected most.
The four syndromes are:
The various symptoms making up the prodromal syndrome vary
in time of onset, maximum severity, and duration, depending on the size of the
radiation dose. A severe prodromal response to radiation exposure usually
portends a poor clinical prognosis.
The signs and symptoms of the prodromal syndrome can be
divided into two main groups: gastrointestinal and neuromuscular.
Prodromal syndrome is rarely seen at doses of radiation
below 70 rem.
The hematopoietic syndrome is identified by its effects on
the bone marrow and blood. It is composed of three components:
Following the prodromal symptoms, there is a symptom-free
period. About three weeks later, there are onset of chills, fatigue, hemorrhages
in the skin, ulceration of the mouth, and hair loss.
These symptoms are all related to damage of blood elements,
with lesser effects from damage to the GI tract.
A total body exposure of more than 1,000 rem of gamma rays
commonly leads to a gastrointestinal syndrome, culminating in death between
three and ten days later. The characteristic symptoms are nausea, vomiting,
and prolonged diarrhea. Victims lose their appetites and appear sluggish and
lethargic. After a few days, they show signs of dehydration, weight loss,
emaciation, and complete exhaustion. There is no record of a human's having
survived a dose in excess of 1,000 rem.
The symptoms that appear and the death that follows are
attributable principally to the depopulation of the epithelial lining of the
gastrointestinal tract by the radiation.
People who have received a dose large enough for the GI
syndrome to result in death already have received far more than enough radiation
to result in hematopoietic death. Death from a denuding of the gut occurs before
the full effect of the radiation on the blood-forming organs has been expressed.
Neurovascular or Central Nervous System Syndrome
A total-body dose on the order of 10,000 rem of gamma rays
results in death in a matter of hours. At these doses all organ systems also are
seriously damaged and the gastrointestinal and hematopoietic systems will fail,
resulting in both these syndromes, if the victim lived long enough. However,
damage to the central nervous system or the vascular bed brings death so quickly
that the damage to other organ systems does not have time to express itself.
Severe nausea and vomiting develop usually within minutes.
This is followed by disorientation, loss of coordination of muscular movement,
respiratory distress, diarrhea, convulsive seizures, coma, and finally, death.
The exact and immediate cause of death is not fully
understood, but it is thought to be due to an increase in the fluid content of
the brain from leakage from small vessels, resulting in a buildup of pressure
within the bony confines of the skull.
Response to Radiological Emergencies
The basic premises that guide the emergency response to
radiological emergencies are based on the fact that most incidents are minor.
Most immediate deaths from radiological incidents are due
to injuries other than the radiation exposure. In fact, except in very high
doses, medical complications and deaths caused by radiation are not seen until
some time later.
as Hazardous Material
Radiation is a hazardous material. However, there are
significant differences between a typical chemical hazardous materials incident
and one caused by radiation:
The most important step in responding to a radiological
emergency is to protect the public. An emergency alert must be sounded, and the
public must be advised on specific actions to take. These can range from
sheltering in place to evacuating the area, depending on timing and detection of
the release, meteorological conditions, and plans for rapid mass evacuation.
Detecting radiation and calculating or estimating the plume
size and geographic spread will assist in identifying the populations at risk
from radiation fallout. Several computer simulations allow field calculation of
probable geographic spread of fallout.
A variety of products are available to measure radiation.
Some measure only specific types of radiation, such as alpha particles; others
are nonspecific. There are the larger survey meters based on the old Geiger
Mueller tube counters and some newer, individual dosimeters no larger than an
Once public alert and evacuation decisions are made,
containment becomes the first priority, and hot, warm, and cold zones need to be
established. Response personnel not entering the hot zone should be positioned
upwind from the site.
All emergency responders must be adequately protected prior
to entering the hot zone. With the exception of gamma or neutron radioemitters
in the area, the greatest risk is from inhaling or ingesting radioactive
particulate matter. Intact skin is an effective barrier of alpha particles, and
simple clothing protects against beta particles. Appropriate respiratory
protection to prevent inhalation of particulate matter would include certified
filtering masks. There has never been a case of a rescuer being injured or
developing long-term complications as the result of rescue operations.
Nonetheless, only immediately lifesaving treatment such as airway and gross
hemorrhage control should be performed in the hot zone.
Distance, and Shielding
The concepts of time, distance, and shielding are useful in
considering personal protection.
The less time on scene, or in proximity, the less exposure.
Radiation concentration diminishes at the rate of the
square of the distance from the emitter. Thus, a person is exposed to only
one-fourth the amount of radiation as is someone closer by half the distance.
Anything that reduces the ability of radiation to penetrate
the skin will reduce the effects. This may be as simple as clothing or may
require lead, water, or concrete protection, depending on the radiation.
Triage should be based on both physical injuries and
resultant physiological state and exposure to radiation, estimated by either
physical finds or history or calculated by actual radiation exposure readings.
Decisions cannot be made on conventional injury factors alone. When significant
radiation exposure is combined with conventional injuries, there may be a change
in how patients are sorted. Synergistic effects also are seen when radiation is
associated with other bodily insults. Patients exposed simultaneously to
radiological and biological agents have increased morbidity and mortality. Even
minimally symptomatic doses of radiation depress the immune response and will
dramatically increase the infectivity and apparent virulence of biological
Certain parameters will help to determine the amount of
radiation to which a casualty has been exposed. These parameters include
clinical signs and symptoms demonstrated by the patient, laboratory evidence
obtained on the patient, and field and personal dosimetry.
Triage of victims of radiation exposure is different from that performed on trauma patients in a mass-casualty setting. Those without injuries or minimally injured should be expeditiously decontaminated. Those with injuries who are deemed survivable should be stabilized, grossly decontaminated, and expeditiously transferred to hospitals capable of receiving radiation-contaminated victims, for concurrent definitive treatment and decontamination.
Nonspecific clinical symptoms can be used to estimate the
degree of radiation injury. These include nausea, vomiting, diarrhea,
hyperthermia, skin erythema, hypotension not explained by other injuries, or CNS
Dosimetry can help determine that an exposure has occurred
but will not give an adequate picture that can be used to determine either the
extent of radiation injury or the prognosis. Dosimetry does not account for
partial shielding and does not reflect the delivery rate of a radiation dose,
and so it makes only a small contribution to the diagnostic picture. Dosimetry
data must be interpreted in light of the observed clinical findings. However, an
effort should be made to retrieve this data because in a mass-casualty
situation, decisions based only on dosimetric data may be all that is
practicable. It is important to emphasize that it is the clinical
presentation that is the best tool to guide initial triage in a mass-casualty
In general, the more or greater severity of signs and symptoms, the higher the probability of significant radiation exposure. Those suspected of severe radiation injury or exposure probably would be placed in the expectant category, with attention and resources focused on those less likely to have severe radiation exposure.
Decontamination of radiation victims often may be a
two-step process. The purpose of decontamination is to reduce further damage to
the patient and reduce risk of contamination and resultant injury to unaffected
personnel. In general, decontamination is not considered a medical
Decontamination does not have to be a complex process.
Discarding contaminated clothing (outer clothing and shoes) will remove up to
85% of external contaminants. Following this with showering or washing will
remove more than 95% of surface contamination.
During transportation to receiving facilities, rescue
personnel should use personal monitoring devices for radiation exposure.
Patients who have not been totally decontaminated should be placed in patient
wraps to minimize vehicle contamination, and ventilation systems should be
It should be stressed that victims of radiation exposure
are not radioactive themselves. The only exception to this would be if there
were significant internalization of the radiation source, such as through
penetrating wounds or ingestion, and this would only apply to alpha, beta, or
neutron particles. Mere exposure to gamma radiation does not make a person
radioactive. Gamma rays are consumed during the irradiation process.
Standard communications with receiving facilities as soon
as possible is mandatory so that those facilities may set up their
decontamination sites and radiation protection equipment in the emergency
Keep in mind these priorities for response to radiation
Evacuation of the population in the threatened area
Personal protection: time, distance, and shielding
Containment of radiation spread through such actions as
Stabilization before decontamination of unstable patients
Thorough decontamination of stable patients prior to transport
Nuclear materials essentially are radioactive materials
that produce large amounts of radiation. In general, the Nuclear Regulatory
Commission (NRC) monitors and regulates these materials in the United States.
The International Atomic Energy Agency (IAEA) serves as the international
inspector for the application of nuclear safeguards and verification measures
covering civilian nuclear programs.
The NRC, or in certain circumstances, individual states,
regulates three categories of nuclear materials.
Uranium-233 or uranium-235, enriched uranium, or plutonium
Natural uranium or thorium, or depleted uranium that is not
suitable for use as reactor fuel
Byproduct materials generally are nuclear materials (other
than special nuclear materials) that are produced or made radioactive in a
nuclear reactor. They also include the tailings and waste produced by extraction
or concentration of uranium or thorium from an ore processed primarily for its
source material content. Examples of byproduct materials are tritium
(hydrogen-3), krypton-85, and carbon-14. Such materials include certain isotopes
of uranium and plutonium.
of Nuclear Materials
Even though radiological materials can be used in so-called
"dirty bombs" to spread large amounts of radioactive materials for
large geographic areas, they cannot be made to produce the extreme amounts of
energy produced through nuclear fission or fusion reactions. The materials
required for nuclear weapons or reactors are isotopes of particular elements.
Some of these isotopes exist in nature but are highly diluted by other isotopes
of the same element and must be enriched (concentrated). Others exist only in
small quantities and must be manufactured through nuclear reactions.
There are currently more than 23,000 nuclear warheads in
the world. Although the majority of these are owned by the United States or
Russia, there are several other countries, including Pakistan, India, the United
Kingdom, and North Korea, that either have or are seeking to possess such
Nuclear materials also are contained in nuclear power
reactors. There are nearly 450 nuclear reactors in the world 110 in the
United States. The United States has an additional 138 nuclear-powered ships and
There have been more than 300 nuclear reactor accidents
since 1944, with well over 100,000 people exposed. Surprisingly, fewer than 200
have died from this exposure. Of note, it would be practically impossible to
produce a nuclear explosion at a nuclear reactor site because of the design and
configuration of the nuclear materials in these reactors.
Nuclear-smuggling incidents also have
been reported. Security at some installations is being upgraded, but unsettled
economic and political conditions leave much to be desired. It is important to
note that not all of these incidents involve critical nuclear material such as
uranium or plutonium. Many involve other materials not used in nuclear weapons,
such as cesium-137 and cobalt-60. This may also demonstrate that many smugglers
don't really understand what they're stealing. Since 1992, more Terrorists
and Nuclear Weapons
The possibility that a terrorist organization could develop
a nuclear weapon on its own is considered virtually nil. This is because it
takes sophisticated equipment and detailed knowledge to safely and covertly
produce such a device.
It is not beyond the realm of possibility that a terrorist
organization could, however, steal a nuclear warhead or that state actors could
participate in the development or retrieval of such devices.
than 50 kg of nuclear weapons-grade materials have been
lost or stolen.
The amount of energy released by a nuclear explosion
generally is calculated relative to the amount of energy released by the
detonation of TNT. Thus, a 1-kiloton nuclear reaction would release the same
amount of energy as 1 kiloton, or 2 million pounds, of TNT. It is difficult to
envision the amount of damage such an explosion might produce merely by these
numbers, but one example should suffice.
In the 1950s, the United States successfully tested a
51-pound, mortar-fired nuclear warhead called the Davey Crockett. The Davey
Crockett produced 0.1 kT of energy (equivalent to 200,000 pounds of TNT) with a
ground burst and ten times that amount with an airburst. By comparison, the 1995
explosion that nearly leveled the Murrah Federal Building in Oklahoma City had
an equivalency of roughly 2,000 pounds of TNT or 1/100th that of the Davey
The destructive action of conventional explosions is due
almost entirely to the blast wave and shrapnel. A nuclear explosion has three
zones of effect: blast, thermal radiation, and nuclear radiation. The energy
distribution from a nuclear detonation is distributed as follows:
The radii of these zones will depend on the size and type
of the explosion (airburst, ground burst, or underground detonation). Using the
Davey Crockett as a model, one would expect the following zone sizes from an
Note that the ionizing radiation zone is the immediate detonation zone and does not take into account the spread of radioactive fallout caused by prevailing meteorological conditions.
A nuclear explosion above ground produces a shock wave
accompanied by a gale wind, referred to as a blast wave. The blast wave is
responsible for most of the material damage caused by a nuclear explosion.
Objects are subjected to rapid increases in atmospheric pressure and severe
winds. Most buildings, with the exception of reinforced or blast-resistant
structures, will suffer moderate to severe damage. The velocity of the blast
wind may exceed several hundred miles per hour.
The primary blast wind velocities may reach 400 mph. When a
blast wave contacts the ground, part is reflected and part will penetrate some
distance into the ground and may damage underground structures.
At some point on the Earth's surface, the reflected wave
and primary wave fronts merge. This is known as the Mach effect, and the
combined front is known as the Mach stem. Mach effect essentially
amplifies the blast forces at the Mach stem, resulting in even more
Effect: Air Pressure
Two phenomena are associated with the blast wave in air:
static overpressure and dynamic pressures. Static overpressure is the increase
in pressure caused by compression of the atmosphere. Dynamic pressures are
sudden changes in pressure (both positive and negative) that result in drag
forces exerted by the strong transient blast winds.
A static overpressure of only 5 psi over atmospheric
pressure is sufficient to destroy brick structures. Dynamic pressures cause the
violent displacement of structures and occur in two phases, a compression phase
and a negative (reverse) phase.
Blast injuries are caused by the overpressure wave. A
1-megaton (MT) weapon creates a static overpressure of 6 pounds per square inch
(psi) and winds of 400 mph at a distance of 5 miles from ground zero. Biologic
systems also are subject to injuries from flying objects, being impaled on
stationary objects, or blunt force trauma.
Thermal radiation (infrared, visible, and ultraviolet) is
emitted from the fireball within the first minute or less after detonation.
Thermal radiation primarily is responsible for the majority of burns and fires
associated with a nuclear detonation.
The resultant burns can be classified as flash burns and
flame burns. Thermal radiation is released in two pulses. The first pulse lasts
only about one-tenth of a second and represents 1% of the total thermal
radiation release. However, it is capable of producing permanent or temporary
effects on the eyes. The second pulse lasts for several seconds and carries 99%
of the total thermal radiation energy. It is the main cause of various degrees
of skin burns suffered by exposed individuals.
When thermal radiation strikes an object, part will be
reflected, part will be transmitted, and the rest will be absorbed. Thermal
damage is due to the absorption of large amounts of thermal energy within
relatively short time periods, raising the temperature of the absorbing surface
and resulting in scorching, charring, and possible ignition of combustible
materials. The probability of significant fires, particularly firestorms,
depends on a variety of factors. Secondary fires can compound incendiary
A person who looks directly at the flash will suffer burns
of the retina, at distances up to 10 miles from ground zero. Someone who looks
in another direction will be temporarily flash-blinded. Because dark colors
absorb heat and then ignite, burns will exhibit the patterns of the dark
clothing worn at the time of detonation.
About 15% of the energy released in a nuclear airburst is
transmitted in the form of initial neutron and gamma radiation. This radiation
decreases rapidly with distance from the point of burst.
The range for significant levels of initial radiation does
not increase markedly with weapon yield. Therefore, paradoxically, the initial
radiation becomes less of a hazard with increasing yield, since people close
enough to be significantly irradiated would be killed by the blast and thermal
The residual radiation hazard from a nuclear explosion is
in the form of neutron-induced activity and radioactive fallout. Residual
ionizing radiation arises from more than 300 different fission products produced
during detonation, some of which remain in the environment for years.
Radioactive fallout is small-particle radioactive material, carried aloft by the
blast winds and carried even farther by meteorological conditions.
of Nuclear Materials Incidents
Responders to the scene of even a small nuclear explosion
face numerous hazards not seen in conventional explosions or will encounter
similar hazards to much greater degrees. These hazards include:
Note these aspects of casualties that
you might encounter after a nuclear incident:
Response and Detection
Any explosive event of large magnitude should be viewed as
containing hazardous materials unless proved otherwise. One of these materials
may be nuclear residues or fallout.
Demolition and hazardous materials units will determine the
area of exclusion and establish hot, warm, and cold zones.
There are numerous devices that can detect specific
radiation threats, but standard instruments, based on the old Geiger counter,
can identify the presence of a radioactive substance and should be available for
first-pass screening of any explosion.
Safety and Protection
OSHA Level C protection is most likely adequate for
rescuers in open environments. Neutron and gamma emissions will penetrate all
standard OSHA levels of protection. However, stay times in hot zones should be
kept to a minimum to reduce overall responder radiation exposure.
Any particulate filter mask should prevent inhalation of
radiation fallout. Closed-circuit breathing apparatuses may be required if there
are fires in the immediate area, for several reasons: toxic fumes from burning
materials unrelated to the actual nuclear explosion; heavy metal fumes, which
may not be filtered by conventional particulate filter masks; and the potential
oxygen-deprived environment, especially if enclosed spaces are entered.
Responders to reactor and other types of nuclear incidents
also should receive potassium iodide. Potassium iodide, taken prior to exposure
to radiation, blocks the thyroid gland's uptake of radioactive iodine. Thus, it
could help prevent thyroid cancers and other diseases that might otherwise be
caused by exposure to airborne radioactive iodine that could be dispersed in a
Finally, rescuers should not smoke, eat, or drink in the
areas immediately surrounding the hot zone. Because of variable winds, some
spillover of radiation outside the predicted perimeter of exclusion may occur
prior to discovery. Smoking potentiates the inhaled dose of radiation, and
particulate matter may settle on food or in potable water. Any water ingested
should come from sealed containers that are protected from these particles.
First aid for nuclear casualties should focus on treating
conventional blast and thermal injuries. This consists of performing the
standard lifesaving measures and then treating conventional injuries such as
head wounds, fractures, and burns.
There are no direct first aid measures for suspected
radiological casualties. Therefore, personnel exposed to low-level radiation
without any conventional injuries should be transported to the nearest treatment
facility after decontamination.
Triage of victims of nuclear explosions initially should
follow those protocols used for multicasualty incidents.
In general, those with life-terminating injuries, such as
decapitation, evisceration, or blunt trauma without pulses or blood pressure in
the field or lack of spontaneous respirations after reposition of the head,
either will not survive even with aggressive prehospital and hospital therapies
or will consume so many resources in a resource-constrained environment that
they should be triaged to the expectant category. So should those victims who
present with the signs and symptoms of severe radiation exposure but without
significant traumatic injuries.
These findings, discussed in detail in the chapter on
radiological incidents, include mental status or neurological changes, skin
erythema, evidence of shock without blunt or penetrating trauma, or
People with traumatic injuries who otherwise would be
triaged into an immediate category most likely should be placed in this category
even if exposed to significant radiation, since the actual dose of radiation
most likely will be impossible to determine in the field. Partial exposure may
significantly alter eventual outcome, but unless obvious radiation injuries are
present, these people may be salvageable, and their demise from radiation
exposure will be delayed.
Victims with obvious signs of radiation injury but without
evidence of life-terminating exposure and who have conventional injuries that
would categorize them as delayed triage patients, should continue with that
classification. But these patients should be transported prior to conventional
triage patients. This is primarily because if they require operative
interventions, these procedures should be performed as soon as possible. If
undue delay occurs in surgery, it will have to be postponed beyond the acute
phase, since radiation retards hemostasis and healing of wounds.
of Exposed Victims
Decontamination is covered in greater detail in the last
chapter of this course.
Most radioactive contamination of victims will be surface
particles containing radioactive isotopes. As previously stated, clothing is a
sufficient barrier to the majority of these particles. It is only those
particles that have been internalized through inhalation or ingestion or those
carrying a sufficient mass to cause shrapnel penetration, that pose risks after
Simple removal of clothing will eliminate 90%-95% of
radioactive contaminants. Water washdown after clothing removal will eliminate
the balance, except internalized contamination.
Beyond first aid measures, follow standard prehospital
trauma life support measures under multicasualty incident conditions. This may
include placing oral or nasopharyngeal airways, protecting potential cervical
spinal injuries, controlling external hemorrhage, and splinting long bone
Patients with significant burns should be wrapped with
sterile sheets or burn wraps. Unless a significant delay in transport is
anticipated, or the patient has significant blood loss (internal or external),
intravenous hydration probably should be delayed until after arrival at
Blunt and penetrating trauma as a consequence of a nuclear
explosion should be treated as for a conventional injury. Bear in mind, however,
that the penetrating shrapnel may be radioactive, posing a continued risk to the
Victims with delayed injuries should be decontaminated
prior to transport. Those with immediate injuries should be grossly
decontaminated concurrent with lifesaving or limb-saving treatments. Because
this gross decontamination will not remove all contaminants, take additional
precautions during transport.
Use dedicated transport vehicles for these victims to
reduce cross-exposure among victims. Victims should be wrapped in protective
sheeting to reduce vehicular or responder exposure. Wear particulate filtering
masks while attending these victims, and fully ventilate the patient
Finally, these contaminated victims should be transported
only to facilities with the capabilities to perform thorough decontamination and
further stabilize, if not fully treat, the conventional injuries sustained by
Nuclear explosions or major accidents combine the worst
effects of conventional explosive and incendiary incidents with those of
radiological events. The scene may pose fire, hazardous materials, structural
collapse, and of course, radiation threats to responders and surviving victims.
In general, triage and field treatment of survivors of
nuclear accidents or incidents should follow standard triage and treatment
algorithms for conventional injuries under multicasualty incident scenarios.
Severely injured and contaminated victims should be treated first and
potentially transported while still contaminated to appropriate
receiving facilities. Those with lesser injuries should be decontaminated prior
YIELD EXPLOSIVES: Introduction
Explosions are very common. From 1992 to 1996 there were
more than 14,000 actual or attempted bombings in the United States, resulting in
over 3,000 injuries and 300 deaths. Most explosives are low-level detonations,
done as the result of pranks.
A terrorist's explosive arsenal is huge. Although
terrorists still primarily use small bombs and guns, car and truck bombs have
become very powerful weapons, especially in suicide attacks. They also make use
of letter bombs, parcel bombs, and grenades. The use of missiles is rare, but a
few groups have surface-to-air shoulder-fired missiles that can bring down
helicopters, fighter aircraft, and civilian airliners. U.S. property and its
citizens have been the targets of terrorist bombings, both overseas and in the
United States. The list of targets is long and well known, including the Marine
barracks in Beirut, embassies in Africa, the USS Cole, the military barracks (Khobar
Towers) in Saudi Arabia, the World Trade Center in New York, and the Murrah
Federal Building in Oklahoma City.
An explosive is an unstable chemical compound or mixture
ignited by heat, shock, impact, friction, or a combination of these conditions.
Upon ignition it decomposes rapidly in a detonation (as opposed to a
deflagration, which is a slower decomposition as with ignition of gunpowder).
Upon detonation there is a rapid release of heat and
high-pressure gases, which expand rapidly with sufficient force to overcome
Use of Explosive Devices
Terrorists have used virtually every type of explosive.
These range from the more commonly used TNT, dynamite, and nitroglycerin, to
those normally found primarily in military operations, such as RDX and C4.
Terrorists also are great innovators and frequently use weapons termed
improvised explosive devices, or IED.
Pipe bombs are the most common type of terrorist bomb,
being easily made using gunpowder, iron, steel, aluminum, or copper pipes. They
are sometimes wrapped with nails.
Incendiary bombs (Molotov cocktails) are simple devices
usually made from materials such as gasoline, kerosene, ethyl or methyl alcohol,
or turpentine. The explosive material is placed in a glass bottle. A piece of
cotton serves as a fuse.
Fertilizer bombs are made from ammonium nitrate. Hundreds
of kilograms may be required to cause major damage.
A barometric bomb is not a device per se, but a form of
detonation activation. The detonator of the bomb is linked to an altitude meter,
causing the explosion to occur in midair.
Explosives frequently are classified as either low yield or
Nitroglycerin, first prepared in 1847, is still one of the
most widely produced nitrate ester explosives. It usually is soaked into fine
wood meal or other powdered absorbent and then thickened with nitrocellulose to
prevent "weeping" (exuding). Nitroglycerin is one of the most
important and most frequently used components of explosive materials. Together
with nitroglycol, it is the major component of gelatinous industrial explosives.
In combination with nitrocellulose and stabilizers, it is the principal
component of powders and solid rocket propellants.
Nitroglycerin is a pungent-smelling, clear, oily liquid in
its natural form. Its vapors cause a severe and persistent headache if inhaled.
It is unstable, sensitive to shock, and flammable if heated, it will
Dynamite actually is a composite mixture. Patented by Nobel
in 1863, it contains such substances as nitroglycerine (NG), ethylene glycol
dinitrate (EGDN), ammonium nitrate (AN), nitrocellulose (NC), sodium nitrate (SN),
carbonaceous fuel (wood pulp and ground shells), and sulfur.
The dynamite industry flourished during the first half of
the 20th century. But when modern blasting agents came into wide usage and began
to replace packaged high explosives in the 1950s, many dynamite plants closed.
As of 1996, only one dynamite plant remained in operation in North America.
Invented in 1867, ammonium nitrate is the most important
raw material in the manufacture of industrial explosives. It also serves as the
constituent in rocket propellants.
Very soluble in water, this substance tends to congeal or
cake up. It normally is sold as colorless crystals or compacted into dense or
Ammonium nitrate/fuel-oil bombs are mixtures of ammonium
nitrate with carbon carriers (such as wood meal, oils, or coal) and sensitizers
(such as nitroglycol or TNT and dintroluene). They also may contain aluminum to
improve strength. Such mixtures can be detonated with blasting caps. Mixtures of
porous ammonium nitrate with liquid hydrocarbons, loaded by free pouring, are
extensively used under the name ANFO blasting agents.
These mixtures frequently are used in road construction and
Binary or two-component explosives are blasting explosives
formed by mixing or combining two commercially manufactured, prepackaged
chemical ingredients. These consist of oxidizers, flammable liquids or solids,
or similar ingredients that individually are not classified as explosives but
when mixed or combined form a detonable mixture.
Boosters generally are mixtures of various high explosives
and are used to initiate larger explosions. Boosters tend to be very sensitive.
TNT was first prepared in 1863. Its stability, which
permits melt-pour loading into munitions and storage over wide temperature
conditions, and its ability to be used in other explosive mixtures, has made it
the most widely used military explosive. It is used in all types of military
ammunition, including aircraft bombs, artillery projectiles, mines, grenades,
TNT is a light yellow or gray substance. It is so stable
that even in the form of demolition blocks, it is virtually bullet safe. It is
not affected by moisture or seawater. TNT burns, but does not detonate, when
heated with fire. It normally will not detonate unless large quantities are
burned in one pile at one time.
RDX (cyclotrimethylenetrinitramine, cyclonite) is probably
the most important high-yield explosive. It has a very high density and high
RDX is used as a medicine, under the name of methenamine,
which is used to treat urinary tract infections. It also is used in the
manufacture of plastics and as an accelerator for the vulcanization of rubber.
As an explosive, it is incorporated in the manufacture of boosters, detonating
cord, and detonators.
RDX is a white or red crystalline solid, depending on use.
In detonating cord it is red to pink.
During World War II, the British used an explosive that
could be shaped by hand and had great shattering power. Designated as
Composition C, it contained RDX and a nonexplosive oily plasticizer. Composition
C was replaced by C-2, then C-3, and now C-4.
C-4 is an odorless, white to light brown, putty-like
material. It contains RDX, polyisobutylene, motor oil, and di (2-ethylhexyl)
sebacate. It primarily is used as a block demolition charge.
An incendiary bomb contains flammable matter. Usually
dropped by aircraft, incendiary bombs were used in World War I, and incendiary
shells were used against aircraft. Incendiary bombs were a major weapon in
attacks on cities in World War II, causing widespread destruction. To hinder
firefighters, delayed-action high-explosive bombs usually were dropped with the
In the Vietnam War, U.S. forces used napalm in incendiary
bombs. Napalm consists of powdered aluminum soap or similar compounds used to
gelatinize oil or gasoline. Incendiary bombs have been found as booby traps in
clandestine drug labs and have been used by terrorists, especially in South
Nuclear detonations produce significant primary thermal
effects. Other explosives tend to not cause primary fires because of oxygen
consumption during the explosion. A full discussion on nuclear devices appears
in an earlier chapter of this course.
Explosives produce three primary effects on the surrounding
Secondary effects also occur, as a result of reverberations
through or reflection off solid structures.
When an explosion occurs, there is an initial gross
overpressurization in the immediate area of the event. This overpressurization
causes barotrauma and can rupture eardrums and other hollow organs. The pressure
gradient also produces a wind radiating from the center of the blast. Initially
very high, the wind effect dissipates at the cube of the distance from the
detonation. These two effects frequently are referred to as the blast effect.
As energy further dissipates, a drop in the pressure below
pre-explosion levels actually occurs, and a reverse blast effect is transiently
seen, with underpressurization and a reverse wind back toward the blast.
Underpressurization effects usually are less pronounced than overpressurization.
Both wind and pressure effects can be affected by enclosed
spaces not breached by the blast
Shrapnel originally was a type of antipersonnel munitions,
named after its inventor, Henry Shrapnel. Today, it refers to a fragmented piece
of material traveling at very high speeds.
Shrapnel damage may be minimal or extensive. The effects of
shrapnel are proportional to the blast strength and the size and density of the
shrapnel material. Shrapnel also may produce other hazards through severing
electrical lines, rupturing tanks or gas lines, and further weakening
As stated previously, nuclear detonations primarily produce
electromagnetic thermal effects. Incendiary devices also result in high
temperatures and resultant fires.
Although fires often are the result of explosions of more
conventional devices, these usually are secondary to the ignition of other
materials in the immediate area of the blast.
The primary response challenges with explosions relate to
collapsed structures, with attendant entrapment of victims.
In densely populated areas, other challenges arise from the
high probability of hazardous materials leakage and fires generating toxic fumes
and smoke. These conditions obscure vision and require the use of closed
breathing devices, which increase the stress on rescue workers.
Secondary explosive devices may exist if the explosion was
intentional. Ruptured gas lines and fuel leaks also could be sources of
accidental explosions. All of these situations can be hazardous to responders.
The important components of emergency response to explosive events include:
of the scene/incident
The size of the incident will dictate the level of response
and required additional resources. Look for signs of fire and explosions.
The deceased are best left alone until the event is totally
stabilized. Live victims most likely will require extrication and immediate
triage and treatment. Remember that if the event is intentional, victims and
deceased play an important role in forensic investigations there may be
valuable evidence contained on the clothing or around the body.
A primary role for law enforcement is identifying suspects.
An injured person trying to leave the scene with rescuers on hand is considered
The initial assessment will dictate whether additional resources are needed to manage fires. Seek bomb disposal squads if an intentional act is suspected, because the perpetrator may have planted secondary devices. This happened in several bombings in the South in the late 1990s.
Invariably, some hazardous materials will be present,
either from the explosion and subsequent release or from combustion effects.
During emergency operations, ensure the integrity of
remaining structures and contain hazardous materials. If there are victims,
rescuers should be cautious of exposure to blood, body parts, or blood products.
Also, secure all utilities water, light, gas, and other
fuels to prevent secondary explosions or fires.
Scene safety is paramount. More firefighters are lost in
structural collapses and fires than are victims. Operational challenges facing
medical first responders are the same as for other responders: collapsed
structures, fire, smoke, and other hazardous materials.
The most important aspect of safety is to gain control of
the scene contain the disaster and control the perimeter. If a terrorist
event is suspected, an exclusion zone should be set sufficiently large so that a
closely placed secondary device will not harm responders.
Mortality from explosions is highly variable and is
dependent on such factors as the amount of explosive used, location of the
detonation, and whether the explosive material was intended to produce shrapnel.
Of survivors, roughly 50% usually require some sort of
surgery; however, only about one-third require hospitalization. Orthopedic cases
predominate, with soft tissue and head and neck injuries following.
Penetrating injuries are common, resulting from falling or
thrown objects, especially close to the scene. A victim being hurled as the
result of wind blast may become impaled on stationary objects as well. Impaled
objects should not be removed from the victim in the field, since these
objects frequently provide a tamponade effect, reducing massive hemorrhage.
Generally, victims with severe head or chest trauma most
likely will be beyond recovery by the time rescuers arrive. Blunt abdominal
trauma may result in significant intra-abdominal hemorrhage. Blunt trauma to the
pelvis or long bones of the lower extremities may result in sequestration of
large quantities of blood and hypovolemic shock without evidence of significant
hemorrhage. The incidence of bilateral long-bone fractures or pelvic disruptions
is particularly high.
Most commonly seen in explosions causing structural
collapse, extremity amputations can result in large amounts of blood loss,
especially in jagged-edged amputations. Control of hemorrhage is paramount. If
possible, the amputated limb should be recovered, placed in a sterile wrap (with
sterile saline-soaked gauze over the avulsed end), and taken with the victim.
Re-implantation may be possible without significant ischemic injury if response
and recovery are performed in a timely fashion.
Amputation in the field may need to be performed. Entrapped
victims may require field amputations because of dangerous structural integrity
or continued hemorrhage during extrication attempts. (Secure agreements with
surgeons in advance of such treatment.) Those who are successfully extricated
without amputation suffer a high incidence of compartment syndrome or crush
Burns often are most significant on exposed skin, although
flammable materials in clothing may increase the burning process. However,
because many burns are due to the flash effect, any protective clothing may be
beneficial. Burns around the face are especially ominous, since they may
represent further injury to the upper airway. Any evidence of respiratory
stridor in conjunction with facial burns warrants consideration of pre-emptive
endotracheal intubation, prior to the onset of significant edema.
A great deal of dust, particulate debris, smoke, and other
pollutants may be released as a result of the explosion. All of these may cause
inhalation injuries or exacerbate pre-existing pulmonary conditions, such as
asthma or chronic obstructive pulmonary disease. These are especially pronounced
in the case of prolonged extrication. The delay in removal from the scene
exposes these patients to the possibility of toxic gas or smoke inhalation and
other environmental stressors from heat or cold.
and imbedded foreign objects
Lacerations and imbedded foreign objects are by far the most common survivable injuries in the area around the blast zone. Most lacerations can be treated initially in the field with hemorrhage control and protective dressings. Disposition of victims with minor lacerations and imbedded foreign objects should be based on either prospectively determined MCI protocols or as the result of consultation with online medical control. In the case of a large multicasualty incident, it may be prudent to release these victims on their own recognizance to seek treatment at receiving facilities. Again, imbedded foreign objects should not be removed in the field.
Standard triage procedures used in emergency departments
are totally inappropriate for mass-casualty events. Probably the most widely
adopted triage algorithm for field use is the simple triage and rapid treatment
(START) system, developed by the Newport Beach (Calif.) Fire and Marine
Department and Hoag Hospital.
The START system employs three variables: mental status,
respiratory effort, and evidence of perfusion, and can be performed in less than
one minute per patient:
Recently, some modifications to the
basic START algorithm have been recommended to account for the wide
physiological disparities between children and adults. Called the JUMP-START, it
has been incorporated into the National Disaster Medical System's core
curriculum for DMAT personnel, the "Pediatric Disaster Life Support"
course and the National Association of School Nurses' "Managing School
Explosive incidents are most closely related to naturally
occurring, high-intensity traumatic events.
Additional problems frequently encountered during response
operations include fires, exposure to toxic materials, and extreme structural
Most victims who survive the initial blast are salvageable,
suffering only from minor lacerations, contusions, and imbedded small foreign
objects. Significant injuries can occur either from the primary blast or thermal
effects or secondary effects from impalement, blunt or penetrating trauma,
inhalation injuries, or entrapment.
Nonconventional weapons produce nonconventional disasters.
The ingenuity of a terrorist in creating a situation ripe for mass casualties
and community terror cannot be underestimated.
This chapter discusses types of weapons of mass destruction
(WMD) events, release methods, and indications of these events. Prompt and
appropriate response to early indicators of a WMD event is paramount to reduce
lives lost and property destruction, and may make the difference in survival and
safety of response personnel.
the Disaster Scene
Traditional disasters usually occur at a specific location
and produce what might be termed a "sudden impact, defined scene"
disaster. Whether the scene is large, as might occur from a hurricane, or
discrete and well circumscribed, as would be produced by a structural collapse,
the perimeter and thus the exclusionary zone usually is relatively
easily discerned, as is the actual timing of the event.
Many WMD events may produce similar "sudden impact,
defined scene" disasters. Examples include the attacks against the World
Trade Center, the Pentagon, and the Murrah Federal Building in Oklahoma City. In
each case, the event was readily recognized, and the extent of the damage was
identified almost immediately.
Other weapons may not create disasters with such clarity.
Take, for example, a chemical release involving an unknown substance of an
unknown quantity and potency.
First, the release may be covert and depending on the
agent used, there may be a time delay between the release and the onset of
victim symptoms. This will allow the exposed crowd to disperse from the actual
release site. Mustard agents may not produce any symptoms for several hours
after exposure more than ample time for an exposed crowd to travel long
distances from the scene. When these victims do develop symptoms and response
organizations are notified, how are responders to determine the exact extent of
Victims exposed to nonexplosive radiological dispersal
devices may not develop symptoms for even longer, and, should the terrorist use
a biological weapon, several days to weeks may pass before initial symptoms
develop among the victims.
Covert releases may take multiple forms. A terrorist most
likely would seek to affect the maximum number of victims. Therefore, the method
of choice most likely would be through an aerosol release. However, other
methods of terrorism have been used quite effectively.
The Rashneesh religious cult chose to spray the pathogen
Salmonella on vegetables at restaurant salad bars in The Dalles, Ore., in the
1980s. This resulted in 751 people developing food poisoning. So successful was
this method of employment that the subsequent outbreaks were judged as
accidental for over a year after the incident, and it was only serendipity that
allowed the perpetrators to be caught.
Although the actual purpose has never been determined, in
the 1970s the antipyretic Tylenolฎ was contaminated with cyanide in several
drug stores in the Midwest, and numerous copycat incidents occurred after the
One of the alleged atrocities committed as the result of
experiments with WMD at the infamous Japanese Unit 731 was the aerial release of
plague-infected fleas over China's Hunan province in 1941.
When Chechen rebels left a trunk in a park in Moscow in 1995, they likely were unaware that the amount of radioactive cesium-137 contained therein was insufficient to cause illness. As was seen in incidents involving orphan radioemitters in Brazil and other locations, this did not have to be the case. Had the trunk contained sufficient amounts of enriched uranium, for example, and had the rebels chosen to remain silent, the potential for many illnesses would have existed. Further, because of the delay in symptoms, outbreak investigation might have been difficult.
vs. Line-Source Releases
Aerosol releases usually are classified as point-source or
In a point-source release, a pressurized container is
placed at a location and timed to release its contents. All contents are carried
by winds, but in general, because of the fragility of the contents and the
effects of turbulent air at higher velocities, the majority of those severely
affected will be down range but in close proximity to the release point.
A line-source release can be conducted from a ground,
maritime, or airborne conveyance. The optimal release occurs over a several-mile
distance, during which the vehicle moves perpendicular to the prevailing winds.
Under these circumstances, a larger geographic area may be covered with the
agent, although the absolute concentration per unit area covered would be less
than that covered through a point-source release.
There are a variety of indicators of a terrorist attack
using unconventional, nonexplosive weapons. Some of these require information
analysis usually only available through epidemiological data collection, and
that, though valuable, would not be available routinely to first responder
Depending on the agent selected, however, these
organizations and their members may serve as part of the human detection system
for early identification of such covert attacks.
Agent Attack Indicators
A chemical agent attack may be thought of simplistically as
an intentionally produced hazardous materials mass-casualty event. Therefore,
such attacks will have several similarities with industrial chemical accidents.
These events usually occur at well-known and
well-publicized mass-gathering events, such as football games, other sporting
venues, arenas, movie theaters, or large office buildings.
A terrorist seeking an ideal release time would seek events
occurring in the early evening, when meteorological conditions would be ideal
(inversion layers and low or no wind conditions), since light inactivates some
chemical agents, and high wind velocities dissipate the chemicals.
In general, chemical agents produce symptoms immediately on
contact or within several hours, to all victims affected.
Chemical agents would produce similar symptoms in all
victims and most frequently would affect the respiratory system, nervous system,
or the skin. Victims closest to the release point would exhibit more severe
symptoms or develop symptoms first.
bystanders or even initial responders who have attempted to assist victims may
themselves succumb to the effects of residual agent.
Notification of a Chemical Event
Anyone who approaches a scene in which there are mass
casualties exhibiting similar symptoms but without an obvious cause should not
continue his approach. Instead, he should immediately notify a dispatch center
or public safety answering point to report a suspicion of a hazardous materials
This information alone should be sufficient to ensure that
arriving responders take initial appropriate actions to establish a safe
perimeter, define an exclusionary zone, and protect themselves and other
responders from harm.
Unfortunately, a radiological event, even one caused by a
radiation dispersal device (RDD), may not be readily apparent. Unless enriched
uranium is used, even large amounts of released radiological materials will not
produce initial symptoms from the radiation. Rather, symptoms will be due to
either the releasing detonation (blast, thermal, projectile, or structural
collapse-induced symptoms) or inhalation of the subsequent particulate matter.
Initial victims, therefore, will present with either
traumatic injuries expected from any explosion or with respiratory difficulties
from inhaling the particles. Indications that an RDD has been used would be
sparse but could include the list below.
of particulate matter
Inordinate amount of particulate matter in the air for the
and timing of the event
Similar to those for a chemical agent attack
Similar to those for a chemical agent attack
of the event
terrorist desiring to contaminate a large area with radioactive materials would
not do so using a vest bomb or pipe bomb. To be successful, a larger device such
as a vehicle bomb would be required to carry enough radioactive material to have
a significant environmental or toxic effect
Notification of a Radiological Event
Those witnessing an explosion of any type should therefore
consider the possibility of the use of an RDD. Public safety dispatchers should
specifically elicit information from callers, which may help responders rate the
probability of such an event.
However, the only way to ensure that a radiological event
has not occurred is through the use of radiation survey instruments to record
area radiation levels. These should be carried on first-arriving vehicles.
of the Biological Agent Event
Biological agent releases are especially difficult to
identify. With the exception of dermally active toxins, there is a time delay of
hours to weeks from exposure to initial symptoms. This delay would result in the
dispersal of the affected crowd, and thus the scene could be very large,
covering an entire city, region, state, or even the nation.
Another difficulty in recognizing a biological release
early in its course is that initial symptoms caused by many of these agents
mimic common daily maladies, such as colds, flu, and allergies. Symptom
complexes of the majority of biological agents of concern fall into four
categories: respiratory, neurological, dermatological, and general systemic.
Agent Event Indicators: Continued
Within the responder systems (fire, police, EMS) the likely
initial indicators of a biological terrorist attack would be those listed below.
A dramatic increase in call volume as a result of
nontraumatic complaints of one, and only one, of the four categories listed on
the previous screen
distribution of calls
A possible geographic skewing of this increase to one
quadrant of the municipality
of those affected
Symptoms affecting either all ages equivalently or skewed
toward those least likely to have such problems normally the young and
previously healthy adult population
An apparent outbreak of community-acquired pneumonia or
rash resembling chickenpox in the adult population
case of nontraumatic, gradual paralysis in the community. Any death not caused
by trauma of a seemingly previously healthy adult or child
Notification of a Biological Event
Although any of the indicators may represent naturally
occurring phenomena, their presence, together or singularly, should raise the
responder's index of suspicion.
And these suspicions should be reported through the
appropriate shift supervisor so that an appropriate investigation may be
commenced in a timely fashion. The public health community needs to be brought
in early for such cases.
of Scene Response
Because biological agent attacks most likely will not be
identified as a defined scene, the following discussion applies most
appropriately to the response of a mass-casualty event of unknown cause or as
the result of a suspicious release of a known toxic industrial material. These
same principles of scene response would apply, however, to an overt release of a
Emergency response is defined as those actions taken
immediately prior to or after a disaster occurs to limit damage, save lives,
protect property, and re-establish continuity of essential community operations.
of Emergency Response
FEMA identifies five specific phases of emergency response:
Warning the public and notifying response organizations
Ensuring immediate public safety
Securing property from damage, looting, and further loss
Establishing public welfare programs to maintain immediate
Restoring critical functions within the community
Although these actions usually are not completed
simultaneously, emergency response is considered to have ended once the
preponderance of these actions has been completed, the disaster has been
contained, and the situation is no longer worsening. This point is referred to
in much of the literature as "stabilization."
Emergencies and disasters tend to present in one of two
ways: anticipated or without warning. Under ideal circumstances, the community
would be forewarned, actions would be taken to minimize damage or injuries, and
response organizations would be alerted and standing by to respond.
Unfortunately, this rarely happens. The ability of the community to be
forewarned is dependent on a series of events and/or actions that need to occur:
Unfortunately, some covert WMD events
would not lend themselves to early detection by any form of sensor, or analysis
has not reached the point that actions may be taken appropriately. This fact is
important to note, since "false" warnings actually may desensitize the
community to further alarms and impede future community actions.
of Event Warning
To be effective, warnings should reach every person at risk
and only people at risk, no matter what they are doing or where they are.
There is a window of opportunity to capture peoples' attention and encourage
Appropriate response to a warning is most likely to occur
when people have been educated about the hazard and have developed an action
plan well before the warning. A single, consistent, easily understood
terminology should be used and may need to be conveyed multilingually in certain
The probabilistic nature of warnings is clear. This is the
reason for the various terrorist threat alerts released by the Department of
Homeland Security. If warnings repeatedly are not followed by the anticipated
event or there is a significant disparity between the alarm and the timing of
the event, people are likely to disable the warning device or ignore its alarm.
A variety of warning devices need to be used to reach
people according to what activity they are engaged in. Effective warning systems
also should be redundant.
The most immediate duty of response organizations is to
preserve life. This not only includes actions directed at victims of the
disaster, such as search and rescue, extrication, triage, scene treatment,
transportation, and definitive treatment and rehabilitation, but also involves
preventing further risks to the community through containing the disaster or
evacuating people at risk.
Command and Communications
The incident command system (ICS) or a unified incident
emergency management system should be used for scene response to a WMD incident.
The most experienced initial responder should assume incident command until
relieved by an authorized official with greater experience.
Early establishment of the ICS will allow augmentation
personnel to integrate more effectively into the response. It will further allow
those in charge to maintain better control of assets, determine additional
needs, and coordinate the overall response.
Equally critical to effective response are communications
both systems and procedures. Communications discipline is crucial. A great
deal of "radio chatter" most likely will exist. Incorrect or
misinterpreted information could result in resources being withheld or
inappropriately applied and breakdowns in coordinated prosecution of the event.
Most significantly, it also could pose a safety hazard to response personnel.
The disaster must be contained. This is relatively
easy to envision in the case of a spreading hazardous materials incident, but
the concept applies to any disaster.
Containment can be geographic or functional. Firebreaks can
contain a wild land fire, which is an example of geographic containment.
Functional containment may be exemplified by a process
recently referred to as "shielding." In the case of a progressive
infectious disease outbreak (one caused by a contagious agent measles,
influenza, or smallpox), subsets of the community may isolate themselves from
contact with others to prevent the spread of the disease. Containment of disease
spread is the principal goal of public health. Failure to contain the disaster
early on will result in significantly greater losses, whether measured in
economic terms or in lives.
All actions to rescue and treat people directly affected by
the disaster must take priority over salvage and property protection operations.
Sequentially, these actions include:
These activities are covered in the next several pages.
Search and rescue (SAR), though not normally a medical or
EMS function, involves information gathering and reconnaissance of the scene,
followed by identification of exit points for SAR teams. Only then do SAR teams
enter the scene and begin the search process. Open areas usually are searched
first because these are the easiest.
Only basic sorting is done within the hot zone. Victims are
separated into salvageable and unsalvageable, and those who can be saved are
further separated into those who may extricate themselves (alone or with
assistance), those requiring assistance, and those who are entrapped.
and Rescue: General Rules
There are several general rules involving SAR operations.
The overriding rule is team safety first, which includes use of appropriate
safety equipment for the hazards involved.
Triage of victims may have to be done at multiple stages of
the operations. Classic triage is based on trauma, and this form of triage may
not be the best for victims of chemical or biological incidents. Most first
responders and EMS personnel have been trained in the simple triage and rapid
treatment (START) algorithm. This algorithm, which assesses mental status,
respiratory effort, and peripheral perfusion, can be performed in as little as
30 seconds. It also allows only minimal treatment repositioning of the head
to decrease airway resistance and bandaging of gross hemorrhage. START is
acceptable for traumatic injuries, whether radiation related or from
Chemical injuries require a modification of START, since a
significant delay in decontamination will worsen injuries. In the case of events
involving chemicals for which antidotes exist, these may, according to
protocols, be administered during triage. Additionally, more advanced airway
techniques may be used to buy time while decontamination is performed.
Radiation injuries require a crude assessment of radiation
exposure. In general, however, loss of consciousness, severe burning, charring,
or erythema of the skin, or unstable vital signs without evidence of trauma
portends a very poor prognosis.
Biological agent triage is perhaps the most difficult, because a patient could be only mildly affected at the time of evaluation and still have a very poor prognosis. First responders will rarely be required to make these hard decisions for biological pathogens (bacteria and viruses), since even in an overt release, the agents themselves will produce no initial symptoms. Biological toxins for the most part also will produce no initial symptoms. People who do should be triaged and treated as chemical agent casualties.
Decontamination is important, especially in known hazardous
materials incidents. A study done several years ago revealed that of those
victims of hazmat incidents who were treated at hospitals, only 18% received
decontamination prior to arrival.
In the Tokyo sarin attack in 1995, nearly 600 patients
arrived at St. Luke's Hospital within the first 45 minutes after the incident.
None had been decontaminated (fortunately, most did not require this). Still,
several hospital personnel developed nerve agent exposure symptoms from treating
and evaluating these victims. Decontamination is covered more fully in the next
Most victims with minimal injuries do not stay at the scene
long enough to receive prehospital triage and treatment. Those who remain on the
scene usually are the most severely injured and unable to escape the scene.
Although this mass exodus will reduce the total patient
load, those remaining may require more extensive treatment.
Transportation of victims also is more complicated in a
disaster situation. Ambulance and vehicle control at the scene are important
considerations. All arriving vehicles should be sent to staging areas out of the
way, with at least one staff member remaining with the vehicle at all times.
Although the nearest hospital might be the best equipped, if it already has been
overwhelmed by the arrival of other critically ill victims, EMS will require the
use of "first wave" protocols, in which the most critically ill
patients are distributed among potential receiving hospitals with little regard
to proximity. Once adequate hospital capabilities are determined, the
destination will be driven by these capabilities.
Contaminated vehicles pose a risk to patients and staff.
Stable patients should receive full decontamination at the scene prior to
transportation, while unstable ones may receive gross decontamination only and
be placed in nonporous patient wraps for transport. Once used for a potentially
contaminated patient, vehicles should be considered contaminated until fully
cleaned inside and out.
Facility Triage and Treatment
Finally, victims need to be re-triaged at receiving
fixed-site medical treatment facilities. Procedures and policies must be in
place to handle this sudden surge of victims while still tending to those
already anticipated patients from other locales.
Receiving facilities must have capabilities to
decontaminate patients and should have sufficient space to maintain these
patients for a period of time, even if they are to be transferred elsewhere
eventually. Treatment facilities must be able to rapidly expand services for the
surge of patients. This entails increasing staff through recall, credentialing
volunteers expediently, canceling elective procedures, and discharging stable
patients prematurely. It also means that additional bed space be made available.
Some caches should be available to handle the disaster until outside resources
Above all, facilities must be protected. If a facility
becomes contaminated, it threatens this entire function.
Property security is primarily a responsibility of the
local police and fire departments. The public works department also may play an
important part by providing manpower and equipment to remove debris or providing
street barricades. Preserving documents hard copies or electronic is
Additionally, in many larger events, theft, looting, and
vandalism are rampant.
Environmental protection is a little more subtle but
possibly more difficult. Witness the difficulties in hazardous materials
protection for rescue and recovery operations at the World Trade Center in 2001.
In a disaster involving large geographic areas, people may
be displaced. Three significant elements of managing displaced people are
shelter, food, and health care.
The majority of evacuees on the East Coast as the result of
hurricane warnings generally stay with friends or relatives over a larger
geographic area where the impact of this surge population is not felt. Those who
have not evacuated may be forced into shelters.
After people find shelter, food and sanitary conditions are
required to maintain the population's health. This could be a logistical
This population has additional needs as a result of the
recent stressors, but people within this cohort also may have special
Public welfare programs seek to assist
the community in post-disaster stabilization. Family assistance programs become
important early in a disaster. People from outside the region want to know that
their loved ones are safe. Families get separated during the disaster, and
relocation is an important issue. Bereavement programs for survivors must be
ready to go during this period.
of Critical Services
Concurrent with other emergency response activities is the
requirement to restore critical services to a community. In the case of all WMD
events, except those involving explosives, critical infrastructure damage will
be minimal. However, the potential of contamination or the perception of
contamination will have to be addressed.
Residual chemical contamination in the environment may pose
a threat to rescuers and the citizenry, and environmental surety operations may
be time- and labor-intensive. Risk communications will be important in allaying
the public's fear of water or food contamination. Depending on the location of
the release, certain public facilities also may be affected.
Effective response to a disaster produced as the result of
the release of a chemical, biological, radiological, nuclear, or explosive agent
will depend on early recognition of the release and prompt notification of
response organizations. There are certain characteristic features of a chemical
incident that should prompt such notification. Covert radiological or biological
releases may be more insidious in their onset, thus blurring this clarity of
recognition. For most WMD incidents biological releases involving pathogens
being the exception there will be a defined scene to which to respond.
Actions taken at the scene follow a general pattern that includes establishing a
perimeter of exclusion; identifying the agent; performing search, rescue, and
extrication functions; conducting scene triage and treatment; and transporting
victims to a receiving medical treatment facility for further stabilization and
treatment. An understanding of the various elements of emergency response will
facilitate improved performance and actions by all first responders.
PROTECTION, SAFETY, & DECONTAMINATION:
Safety is an overriding concern in any response to a
disaster. This is especially true during response operations to an event caused
by a WMD agent. Response personnel who neglect scene and personal safety
considerations are apt to become victims themselves reducing their ability
to assist in operations and requiring resources that should have been used in
Along with safety considerations are issues related to
working in a contaminated environment or treating victims of agents that produce
contamination. The ideal approach to contamination is to avoid it altogether,
but this is not likely for response personnel. Protection against contamination
is the next best defense, and response personnel should understand the
principles of decontamination of self, victims, and equipment.
Safety at a WMD Event
Safety should be the first priority in all WMD responses.
Typical disaster responses in America involve known
disasters. The immediate dangers from the event usually subside or at least are
well-known to rescuers. Few organizations have participated in response
operations in which WMD agents have been involved, and although the challenges
are not necessarily unique, they bear repeating.
WMD events may involve chemical, biological, radiological,
nuclear, or explosive agents or devices, alone or in combination.
a Zone of Exclusion
The most important safety action that can be taken at the
scene of a WMD event is to establish a zone of exclusion.
A zone of exclusion typically is an area immediately
surrounding the obvious disaster scene, into which no one should enter without
proper protective equipment and clearance by the incident commander.
This zone should be large enough to ensure that those
outside the zone, whether rescuers or bystanders, are protected from hazards
contained within the zone. The zone of exclusion also should have a buffer area
in case those hazards extend further damage as a result of wind shifts or other
The North American Emergency Response Guide 2000 recommends
zones of exclusion for hazardous materials spills that range from 500 to 1,000
yards. Military explosive ordnance demolition teams typically establish zones
out to 2,000 yards from the site of the weapon.
Zones, Warm Zones, and Cold Zones
Within the zone of exclusion, three relatively concentric
and overlapping areas usually are established, referred to as hot, warm, and
cold zones. Originally designed for use in hazardous materials operations, these
zones apply to any disaster, anthrogenic or natural, regardless of the threats
or risks involved.
The hot zone is "the scene." This is the clearly
identified risk area. Within this zone, all personnel should be adequately
protected against anticipated threats and should only enter this zone once
cleared by the incident commander.
The warm zone is the transition zone. It is within the warm
zone that principal logistics personnel operate in support of those working
within the hot zone, whether they be hazardous materials or SAR units. It also
is within this zone that response personnel gain access to the hot zone, and
victims are removed from the hot zone through clearly defined corridors. Because
the risk of exposure to the threats of the hot zone is very high, personnel
within the warm zone should be adequately protected, although usually not to the
extent of hot zone operations personnel.
The cold zone extends from the warm zone to the perimeter of the exclusion area. Only emergency response personnel should be allowed within the cold zone. Depending on the type of hazards, personnel within the cold zone but outside the warm zone may or may not require protective equipment. Although theoretically the cold zone is safe from these hazards, the uncertainty of mapping the actual perimeter of the scene and the potential for the scene to extend itself either because of failure of containment, wind shifts, or unidentified hazards may result in people within the cold zone finding themselves suddenly in the midst of the threat area.
Scene response is a high tempo, high-risk operation. In
addition to obvious hazards such as smoke, fire, combustible materials, and
other toxic substances, the scene site may be structurally unstable. Leaking
gases and volatile liquids, exposed power lines, and flowing water in a
disrupted environment make for unseen but highly lethal conditions. If the
disaster is caused by a terrorist attack, the possibility exists of intentional
secondary releases or explosives. Heavy equipment and machinery may be involved,
leading to potential inadvertent risks to responders.
To assist in managing these risks, the incident commander
usually will have an incident safety officer assigned to him. The safety
officer's responsibility is to observe the scene and the evolving response
operation and advise the incident commander on safety concerns and procedures to
lessen the risk to response personnel.
Zone Operational Safety in a WMD Event
After the various zones and incident command have been
established, hot zone operations commence.
The first order of business is to ascertain immediate
threats within this zone. In the case of a disaster caused by WMD agents,
threats will fall within three categories: the agent or material used by the
perpetrators, other hazards incidentally within the area or created as a result
of the primary incident, and secondary devices placed to injure or kill
Many chemical agents and toxic industrial materials and
all radiological and biological weapons are odorless and tasteless.
Determining the extent of contamination may be very difficult under these
circumstances. Responders who enter a hot zone involving an unknown material
must be maximally protected. This usually entails the use of a fully
encapsulated suit and a self-contained breathing apparatus (SCBA). SCBAs are
used not only to protect the wearer against toxic fumes, but also to ensure the
provision of oxygen, since the event may result in the release of chemicals that
are heavier than and displace air.
The various protection levels are covered later in this
chapter. It should be noted here that the use of protective equipment is itself
risky. During fast-paced operations, this additional equipment places more
stress on the wearer both physical (from the weight of the equipment) and
thermal. Heat stress is a possibility during prolonged operations. SCBA bottles
also have a limited air supply.
Secondary hazards may be obvious (smoke, fire, damaged
structures) or may be inapparent on casual observation (natural gas leaks,
Although it is unlikely that special teams will search for
these, total situation awareness on the part of all responders who enter the hot
zone is crucial. With the exception of specially trained EMS personnel who have
been prospectively designated to accompany hazardous materials technicians into
the hot zone, these threats pose little if any danger to EMS units. However,
medical personnel should consider these threats, since hot zone responders may
fall victim to these threats and require emergent medical treatment for injuries
sustained by hazards other than the obvious.
Secondary devices pose a significant threat to responders
because they are likely to be hidden. These could include chemical,
radiological, or biological agents, but more likely are explosive devices that
may be triggered remotely or by some mishap on the part of responders.
Tactical EMS personnel and law enforcement teams responding
to clandestine drug labs probably are most familiar with the risks of booby
traps and secondary devices. Any intelligence that may have been gathered and
the judgment of the incident commander may promote this suspicion, and
specialized units or remote-controlled robotics may be deployed into the scene
to search for secondary devices.
All response personnel who are at risk of coming in contact
with WMD or hazardous materials should be adequately protected. Personal
protection falls into two categories: physical protection and chemotherapeutic
protection (this includes both pharmacological protection and immunizations).
Chemotherapeutic protection is agent- or agent-class-specific, whereas physical
protection in general will work for all agents, to some extent.
Physical protection may be either collective or personal.
Whereas collective protection, such as a hardened facility, has utility during
military operations, the difficulties and costs in maintaining such protection
in a free society coupled with the most likely unannounced release of WMD
agents make collective protection unviable. Certainly, this would not be an
option for responders to an event.
Personal protective equipment (PPE) refers to the
respiratory equipment, clothing, and other materials that protect personnel from
exposure to environmental, biological, chemical, and radioactive hazards. Hot
zone personnel, those involved with decontamination, and others responding to
the scene of an incident may require PPE. Hospital employees rarely require this
equipment unless they are providing decontamination at the facility. Hospital
workers may require protection against highly contagious diseases,
Respiratory protection may be afforded by either
closed-system or open-system devices. Closed-system devices include an SCBA and
a supplied-air respirator (SAR). Open systems refer to air-purifying systems, in
which ambient air is filtered prior to breathing.
SCBAs include a high-pressure air tank, air-flow regulator,
harness straps, and a face mask. They provide air for 30-60 minutes, depending
on the tank. These devices also have a low-air warning alarm that usually
indicates when 5 minutes of air is left. SARs include a faceplate and an air
hose to a pressurized and purified air system and have two advantages over
SCBAs: They can supply nearly an unlimited supply of air, and they weigh
substantially less. The drawback is that the hose can get tangled, kinked, or
severed. SARs are never used in the hot zone.
An air-purifying respirator (APR) consists of a facepiece
worn over the mouth and nose with a filter element that filters ambient air
before inhalation. Three basic types of APRs exist: powered, disposable, and
chemical cartridge or canister. A powered air-purifying respirator (PAPR)
provides air under positive pressure and is the safest. All APRs use canisters
to filter noxious or dangerous chemicals. Unfortunately, no one canister can
filter all chemicals. Some newer devices allow "stacking" of
canisters. However, even under these circumstances, the face seals are not
sufficient to ensure that immediate danger to life and health (IDLH) values can
be prevented; therefore, these should not be worn unless the concentration of a
chemical agent is known. Further, open systems do not protect responders from
Filters and Surgical Masks
High-efficiency particulate air (HEPA) filters are masks
that cover the wearer's mouth and nose. These masks are tested against the
penetration of particles (not gases) and therefore are ineffective against
chemical agents or toxic industrial materials. HEPA masks are tested using
0.3-micron particles and are rated as 95%, 99% or 100% efficient (actually
99.97%) in preventing penetration by particles of that size. Studies have shown
that smaller-size particles do not impact and adhere to the mucosal lining
within the respiratory system
Surgical masks provide minimum protection. They are
designed primarily to prevent exposure to others from respiratory droplets from
Most protective clothing was designed to protect against
toxic industrial materials. Intact skin is an effective barrier against all
biological pathogens and toxins except T2 mycotoxins. It also is effective
against alpha particles and somewhat protective against beta particles. Chemical
protective equipment is not adequate against neutrons or gamma rays.
No single piece of protective equipment is adequate against
all known or potentially toxic industrial materials or hazards, and thus
multiple layers of garments usually are worn. The highest protection is provided
by fully encapsulated suits.
The Occupational Safety and Health Administration (OSHA), a
division of the Department of Transportation, has set in place regulatory
standards on personal protective equipment to ensure the safety of workers in
hazardous materials operations. OSHA recognizes four levels of protection. Each
level consists of protective respiratory equipment and clothing to protect
against varying degrees of inhalation, ocular, or dermal exposure.
Level A PPE consists of an SCBA and a totally encapsulating
chemical-protective suit. This combination provides the highest level of
respiratory, eye, mucous membrane, and skin protection.
Level B PPE consists of a positive-pressure respirator
(SCBA or SAR) and chemical-resistant garments, gloves, and boots, which guard
against chemical splash exposures. Level B PPE is used when the agent is known
and the concentrations are such that maximum inhalation protection is required,
but total dermal protection is not.
Level C PPE consists of an APR and chemical-resistant
clothing, gloves, and boots. Level C PPE provides the same level of skin
protection as Level B, with a lower level of respiratory protection. Level C PPE
is used when the type of airborne exposure is known to be guarded against
adequately by an APR.
Level D PPE consists of standard work clothes. In hospitals, Level D consists of surgical gown, mask, and latex gloves (universal precautions). Level D PPE provides no respiratory protection and only minimal skin protection.
Against Biological Agents
The medical community uses isolation precautions to protect
people working around contagious patients. Four levels of precautions have been
Standard precautions are designed to reduce the risk of
transmission of microorganisms from both recognized and unrecognized sources of
infection in hospitals and are used with all patients regardless of their
diagnosis or presumed infection status. Standard precautions apply to (1) blood,
(2) all body fluids, secretions, and excretions except sweat, regardless of
whether they contain visible blood, (3) nonintact skin, and (4) mucous
membranes. Standard precautions include the use of surgical masks, face shields
or eye protection, gowns, and surgical or impermeable gloves.
Airborne precautions are designed to reduce the risk of
airborne transmission of infectious agents. Airborne transmission occurs by
dissemination of either airborne droplet nuclei (small-particle residue [5 ตm
or smaller in size] of evaporated droplets that may remain suspended in the air
for long periods of time) or dust particles containing the infectious agent.
These precautions apply to patients known or suspected to be infected with
epidemiologically important pathogens that can be transmitted by the airborne
route. In addition to certain environmental controls, people with close contact
to such patients should wear N95 HEPA filtered masks that have been fit tested.
Droplet precautions are designed to reduce the risk of
droplet transmission of infectious agents by large-particle droplets (larger
than 5 ตm in size) containing microorganisms generated from a person who has a
clinical disease or who is a carrier of the microorganism. These precautions
apply to any patient known or suspected to be infected with epidemiologically
important pathogens that can be transmitted by infectious droplets. Certain
additional environmental controls also apply, but protective equipment as
described for standard precautions are suitable for use with patients requiring
precautions are designed to reduce the risk of transmission of epidemiologically
important microorganisms by direct or indirect contact. Standard precautions
also are effective against contact in the out-of-hospital setting, but if there
is a risk of significant body fluid exposure, splash-proof or impermeable gowns
and face shields are required.
Personal Protective Equipment
As previously stated, protection against high levels of
electromagnetic or nuclear radiation is best afforded using the principles of
time, distance, and shielding. It also should be noted that no emergency
responder has ever been injured as the result of short-term exposure to
radiation during rescue operations.
Filtered masks or higher will protect against particulate
radiation (alpha and beta particles) as will OSHA level D protective clothing.
Protection against gamma radiation requires lead shielding or the equivalent.
Water buffers 1 foot or more thick, concrete, and similar materials that
obviously cannot be worn are required to protect against neutrons.
Protective Equipment: Caveats
There are a few more important points to remember
Military PPE, often referred to as MOPP (military
mission-oriented posture), is not approved for civilian use. The masks used by
the military do not meet NIOSH standards and are not protective against all
chemicals. Clothing falls between level C and level B capabilities.
No civilian PPE has been tested against all chemical
terrorism agents, although evaluation continues.
Levels A through C will protect responders against all
Chemotherapeutic protection that involving either
immunizations or administration of antidotes, pretreatments, or prophylactic
antibiotics is still an evolving science. There are several options,
although limited, for protection of responders against some forms of radiation,
chemical exposure, or biological agents.
No pre-exposure antidotes exist for any of the chemical
warfare agents except nerve agents. The Food and Drug Administration recently
approved the medication pyridostigmine bromide (PB) for use as a pretreatment
against exposure to nerve agents. PB will not work if taken after exposure, and
emergency response personnel aware that a nerve agent is in an area should be in
appropriate PPE, so this medication has little use in the civilian sector as a
Several forms of topical skin protectorants exist that have
been fielded for use, but again, these should have limited utility in the
Vaccinations exist against several different agents, such
as the causative pathogens for anthrax and smallpox. Most vaccinations require
time from days to weeks to be effective and may require multiple
administrations. Research continues at various laboratories, such as the U.S.
Army Medical Research Institute of Infectious Diseases and the Centers for
Disease Control and Prevention (CDC), into new and safe vaccinations.
Antibiotics are effective against all bacterial pathogens.
Unfortunately, pathogens may develop resistance against traditional antibiotics,
and use of these in a prophylactic mode should be done only in consultation with
physicians, public health officials, and intelligence personnel based on a high
risk of exposure. A study done by the CDC in 2000 indicated that there was
little economic efficacy in indiscriminate pre-event prophylaxis, especially
since no single antibiotic works against all potential pathogens. However, once
a release has occurred, and the pathogen is known, there may be efficacy in
providing at-risk people, such as EMS personnel, with prophylaxis against the
Although research continues and shows some promise, there
are no antiviral medications approved for prophylactic use
Similarly, there is no efficacy in the indiscriminate
administration of the limited medications effective against radiation exposure.
Potassium iodide (KI) is effective in blocking the uptake of radioactive iodine
by the thyroid gland, and for those who must go into a hot zone involving
ionizing radiation, pre-exposure administration may be advised because it is for
those who cannot escape exposure should an event involving ionizing radiation
occur. There are, however, many different radioactive elements for which KI is
Since the 1960s, Prussian blue has been used to treat
people who have been internally contaminated with radioactive cesium (mainly
Cs-137) or thallium (mainly Tl-201). Prussian blue can be given at any point
after doctors have determined that a person is internally contaminated because
it will help speed up the removal of cesium and thallium from the body.
Prussian blue is in limited supply and was just recently approved by the FDA. Protocols for use are still being developed. Neither Prussian Blue nor potassium iodide work against all radioactive materials.
Decontamination serves three purposes:
Some prioritization of contamination victims should be made
in the event of mass-casualty exposure. Ambulatory victims should be directed
out of the scene in a controlled fashion toward decontamination areas and may
assist in their own decontamination, while nonambulatory victims are triaged and
transported to decontamination areas.
Victims closest to the scene of the release are most likely
to have the greatest exposure and should be decontaminated first. They should be
followed by those with obvious contamination by liquids, since continued
exposure will occur from these substances. Victims with severe clinical effects
also are a high priority, regardless of the type of exposure, since any
continued exposure may be fatal.
The decontamination site should be at the junction of the
hot and warm zones and usually will be located within an evacuation corridor. As
victims are decontaminated, they move out of the hot zone into the evacuation
corridor for further treatment and stabilization.
The diagram at right depicts a nominal, single-lane
decontamination area. Victims in the hot zone are presumed to be contaminated,
and all should pass through the decontamination area. Two-lane designs also are
possible but require more personnel.
Clothing removal should occur just prior to or during
egress from the hot zone, since the majority of the contaminants will be on
garments, and simple removal of these garments will result in 80%-90%
decontamination. Little if any treatment should occur before starting
decontamination, since it most likely will be of no benefit if the patient
continues to be exposed.
As victims are disrobed, they may move into the warm zone.
There, personnel, who should be in appropriate PPE (which mostly likely will be
at least OSHA level B), can continue decontamination. Most chemical warfare
agents and all biological agents are denatured or rendered harmless by the use
of a weak hypochlorite (bleach) solution. A 5% solution is used for equipment,
but 0.5% should be used for human decontamination.
Also note that bleach solutions are not innocuous, and in a
mass-casualty setting, high volumes of low-pressure water probably are as
effective, more environmentally friendly, and more accessible. Contaminants
should be blotted or washed off and not scrubbed, since this may result in some
denuding of the skin, allowing more systemic absorption of the contaminants.
Administering antidotes, repositioning the head to open the airway, and
tamponading gross hemorrhage can be done concurrent with decontamination.
Once decontaminated, victims are moved to the cold zone,
where emergency medical treatment is first initiated. It is also within this
area that any surety tests for full removal of contamination should occur.
While water, or preferably soap and water, is the staple of
decontamination solutions, there are several other potential decontaminants
available. Hypochlorite has already been mentioned.
Biosafe emulsions that can be used in contaminated wounds
or even ingested recently have been tested and approved for use.
Aminoethanol is a strong base that has been studied for use
in decontamination of nerve agents.
charcoal or clay
Activated charcoal or clay absorbents may have wide utility
in the absorption of a variety of chemicals.
Catalytic enzymes (specific for nerve agents only) or
enzyme polymers are now in use.
powder is a dry form of bleach.
Field decontamination procedures do not address internal
contamination, which must be dealt with in the hospital setting by inducing
vomiting or catharsis or by administering certain medications.
of Biological Casualties
Decontamination applies primarily to victims and equipment exposed to chemical
agents or toxic industrial materials. Most terrorist attacks with biological
agents will be clandestine, and it may be days or even weeks before the attack
Ultraviolet light and soap and water used in showering most
likely will have removed biological contaminants well prior to the onset of
symptoms. There are two exceptions to this rule of thumb, however.
The first exception is in the case of an overt release.
Because it may be impossible during the initial hours of the response to
ascertain exactly what agents have been used, all victims of overt releases
should be treated as though contaminated and thoroughly decontaminated, just as
for chemical agent attacks.
The second exception is if certain biological toxins have
been used. Staphylococcus enterotoxin B and T2 mycotoxins produce symptoms
within a few hours of exposure, and thus, these toxins may remain as a hazard to
the victims or rescuers at the time of discovery. Victims exhibiting signs and
symptoms consistent with either of these toxins should undergo decontamination
at the time of discovery
of Radiological Casualties
As is true for chemical and biological agents, 80%-90% of
radioemitters are successfully removed with simple clothing removal, and this is
the first line of decontamination as a result of a radiation incident.
Unlike chemical events, however, radiation events pose
little if any short-term risk to rescuers. Thus, full decontamination should not
delay emergency treatment and stabilization to prevent loss of life. In many
systems, full decontamination of the most seriously injured victims is delayed
until after arrival at hospitals that have been designated to receive, treat,
and decontaminate radiation-affected patients. Full decontamination of these
victims, regardless of the location, can be accomplished through dry or wet
decontamination, and soap and water are perfectly acceptable decontaminants.
There are additional issues that should be addressed when
planning for events involving decontamination: personal privacy,
post-decontamination environmental concerns, the collection and handling of
personal effects, and disposition of contaminated effluents (wastewater).
Cultural values vary within our society. There are many who
may be reluctant to disrobe in front of the opposite gender. Dual-lane
decontamination facilities with barriers for patient privacy may adequately
address this issue.
Environmental concerns are most significant during cold
weather operations and have the most effect on the injured and those at the
extremes of age. Organizations tasked with planning for decontamination should
ensure that some form of protective clothing is available after decontamination
(both for environmental protection and personal privacy). There are a few
elaborate decontamination trailers that allow the use of temperature-controlled
water in decontamination, but many systems still do not have access to these
of personal effects
These items may include both porous materials (wallets,
purses) and nonporous materials (glasses, watches). Personal effects probably
are of value to the victim. Strict control over personal effects and adequate
decontamination prior to their return must be addressed in planning for
decontamination events. Personal effects also may be considered evidence by law
enforcement investigators, and thus, planning concerning disposition of personal
effects should be made in conjunction with these officials.
The EPA issued a letter ruling concerning capture of contaminated wastewater at the scene of hazardous materials emergencies. In essence, the EPA ruled that it probably was not feasible to require capture of such contaminated liquids in an unannounced emergency. However, it further admonished that agencies that have reason to believe that such a situation might occur should perform reasonable steps to attempt capture. There are several decontamination stations on the market that include retrieval pumps and storage tanks.
and Logistics for Decontamination
There obviously must be sufficient personnel who are
trained in decontamination procedures. There also must be an available pool of
augmentees and replacements. PPE can induce a significant thermal stress on its
wearer, and time on station may be drastically reduced during hot temperatures.
There must be people identified as triage officers, decontamination personnel,
litter bearers, record keepers, and individuals to retrieve additional supplies
Contaminant identification equipment
Agencies should seek a method of ascertaining the success
of decontamination. There are several agent-specific testing devices, such as
the military M8 and M9 paper, that are available for commercial use. Other more
expensive and sophisticated equipment also is available for those agencies that
can afford them.
Scene safety is the responsibility of all first responders.
Responders who fail to heed safety recommendations may soon find themselves
victims. During scene operations in a hazardous materials or WMD environment,
emergency medical services is considered a supporting operation and not the
primary function of scene response.
All response personnel who may come in contact with WMD
materials should be adequately protected, including the use of PPE appropriate
for the event. At present, there are few pre-treatments available to provide
chemotherapeutic protection. Vaccines do not work immediately, and it is likely
that scene response will be required before identification of specific
biological agents. In the event of a response to a radiological incident, use of
KI may be recommended for responders within the hot zone.
Decontamination of victims reduces the effects of the
agent, protects responders, and may offer some psychological comfort. At least
80% to 90% of contaminants are removed by undressing. The balance can be removed
in a mass-casualty setting by using low-pressure, high-volume water. Rudimentary
patient prioritization should occur prior to decontamination, and most treatment
should be delayed until after the victim is decontaminated.
We live in a world under the constant threat of terrorism.
You now have a solid baseline knowledge upon which to build additional
knowledge, skills, and aptitudes to help you handle a WMD/CBRNE event, should
one arise in your area.
As you were advised earlier, expertise can be gained only
through continued and more detailed education, psychomotor skills training,
practicing individual procedures, and integrated exercises with personnel from
other agencies that would be involved with the response to these complex
You have the foundation. It is up to you to build on it.