TERRORISM RESPONSE / HAZ-MAT

Shifting 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.

Terrorist Attacks

Although American citizens have been targeted in the past, the 1990s also heralded an increase in the frequency and lethality of these attacks.

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 representatives.

The Threat of Terrorism

Terrorists also have sought to use nonconventional and highly lethal weapons to inflict damage on society.

Chemical agents

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.

Biological agents

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.

Radioactive materials

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.

Weapons of mass destruction

More 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.

Chemical Incidents

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.

Bhopal, India

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.

Mississauga, Canada

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.

Infectious Diseases

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.

Nuclear Incidents

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

Explosions at munitions and fireworks plants and other industrial sites containing highly combustible or explosive materials are practically a daily phenomenon worldwide.

Key Definitions

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

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 objectives.

CBRNE

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

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.

CBRNE Events

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:

• Most CBRNE events involve many more casualties than are seen in traditional multiple casualty incidents.
• Victims of events involving these hazardous materials may pose a threat to responders.
• The scene itself may pose a continued threat, either from the hazardous materials themselves or, in the case of intentional releases, from secondary devices placed by perpetrators specifically targeting response personnel.
• Specialized, rarely used equipment, supplies, and medications may be required.
• Because the possibility of criminal intent may not be determined until after response operations are well underway or even completed, these incidents must be treated as potential crime scenes. Operational and clinical management at the scene may require new and unique interactions with law enforcement personnel.

Course Goal

This course will not create an expert in CBRNE medical response.

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, and aptitudes.

Dispatch

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.

Initial Assessment

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:

• There does not appear to be a fire burning in or around the automobile.
• Two adult males are lying right beside the vehicle.
• At least 10 more people — men, women, and children — are lying in the area around the automobile.
• Between 15-20 people are sitting on the ground. Many appear to be short of breath and are holding their upper chests and gasping for air. Several of them are vomiting, and one person begins convulsing.
• Several hundred sports fans are standing at a distance observing the unfolding events.

The Big Questions

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.

What is your initial assessment?

Your assessment is that noxious chemicals may have been released from or near the automobile.

Is 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.

What 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 dispatcher.

Fire 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 the scene.

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:

• What is a prudent exclusion zone?
• What advice can you provide hazmat specialists and technicians about to enter the hot zone concerning hot zone triage and treatment?

Assessment and Decontamination

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 pesticide.

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 Patients

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:

• How would you prioritize these three patients?
• If you were the only EMT, what order would you treat these patients?
• If your EMS service is equipped with antidote autoinjectors, which victims would you use these devices on, and how many would you use?

Triage

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

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 diazepam (Valium®).

Patient B

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

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 minutes.

Transport

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 circumstances.

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.

4

Chemical Agents

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 action.

General Principles of Medical Response

Regardless of the agent involved, certain general principles apply in all cases of exposure to chemical agents. These principles involve:

• Personal protection.
• Rapid decontamination.
• Triage.
• Treatment.
• Transport.

General 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 assistance.

General 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 contamination.

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.

General Principles: Triage

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.

General Principles: Treatment

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 interventions.

General Principles: Transport

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 facilities.

Military-Use Chemical Agents

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 (vesicants).

These two classifications are discussed in the next few screens.

Nerve Agents: Characteristics

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 hours.

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.

Nerve 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 functioning.

Nerve Agents: Signs and Symptoms

The end result of this over-stimulation can be identified clinically.

• Eyes: Miosis (pinpoint pupils) and blurred vision
• Skin: Fasciculation (fine twitching) and sweating
• Respiration: Excessive secretions, bronchospasm, shortness of breath, chest tightness
• Heart: Tachycardia or bradycardia
• GI: Nausea, vomiting, diarrhea, diffuse crampy abdominal pain
• CNS: Confusion, disorientation, obtundation, seizures, coma

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 syndrome:

Salivation
Lacrimation (excessive tearing)
Urination (incontinence)
Defecation
Gastrointestinal distress
Emesis

Nerve 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

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

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

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.

Autoinjectors

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 one autoinjector.

Vesicants: 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.

Vesicants: 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.

• Eyes: Chemosis (blisters of the cornea and sclera), excessive tearing, visual difficulties
• Skin: Blister formation, redness, pain
• Respiratory: Blister formation, airway obstruction, pulmonary edema, shortness of breath

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.

Vesicants: 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 damage.

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.

Dual-Use Chemical Agents

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 few screens.

Choking Agents: Characteristics

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 warfare agents.

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 carbon tetrachloride.

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 (Teflon®), 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.

Choking 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.

Choking 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 hypoxia.

Choking 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.

Blood 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.

Blood 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

• CNS: headache, confusion, seizures within one minute, coma.
• Heart: initial tachycardia, but cardiac arrest within four to eight minutes.
• Respiratory: tachypnea, followed by respiratory arrest within minutes.
• Gastrointestinal: nausea, vomiting.

Blood Agents: Signs and Symptoms

The most important treatment option is removal from exposure:

• Victims in arrest at the scene most likely cannot be resuscitated.
• Unless the blood agent is ingested, victims who survive to removal from exposure most likely will survive if their airways are maintained.
• Unless there is contact contamination (liquid), decontamination is not necessary.

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.

Incapacitants 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 Mace®.

Incapacitants: 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.

Incapacitants: Signs and Symptoms

Clinical effects tend to occur after a one- to 24-hour latent period. Incapacitants have both central nervous system and peripheral effects.

Central effects:

• Confusion, distractibility
• Ataxia (balance and walking difficulties), slurred speech
• Hallucinations, errors in judgment

Peripheral effects:

• Eyes: Mydriasis (dilated pupils), blurred vision
• Gastrointestinal: Dry mouth
• Heart: Variable heart rates, initially rapid
• Skin: Dry, possibly reddened flush

Incapacitants: 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 contamination.

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 differential diagnosis.

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 days.

These agents, in and of themselves, rarely are life-threatening. A greater risk results from personal harm because of central nervous system effects.

RCAs: Characteristics and Mechanism of Action

The principal riot-control agents are pepper spray, tear gas, and Mace®. 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.

RCAs: 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 usually self-limited.

Rarely, death can occur but usually is due to allergic reactions or severe exacerbation of underlying pulmonary conditions.

RCAs: 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 improvement.

Patients with severe symptoms or underlying diseases made worse through the exposure may require transportation to facilities for further evaluation and treatment.

Toxic 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 transport.

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.

TIC: Characteristics

Some characteristics of TIC make exposure especially onerous:

• High vapor pressures under ambient conditions
• High volatility
• Heavier than air
• Primary effects on mucus membranes or intact skin
• Acidic or alkali properties
• Narrow margin between the threshold of detection and lethality

Examples of chemicals that qualify as TIC and their common usages:

• Acrolein — herbicides
• Arsine — electronics
• Diborane — chemical manufacturing
• Formaldehyde — plastics
• Hydrogen selenide — semiconductor industry
• Nitric acid — industrial manufacturing
• Parathion — insecticides
• Sulfuric acid — batteries
• Toluene diisocyanate — foam, plastics, artificial, or composite woods

TIC: Identification

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 encountered.

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:

• Casualties outside the anticipated range of effects from a traditional event.
• All casualties experiencing identical or similar symptoms.
• Victims farther or upwind from the incident site having few symptoms.
• A predominance of symptoms involving the respiratory or neurological systems.
• Less severely affected victims complaining of burning skin or eyes or visual difficulties.
• A pungent, metallic, or other sharp odor (such as garlic, rotten vegetables or fish).

Should any of these be present in conjunction with a mass-casualty event, release of a chemical agent should be suspected.

TIC: 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 continue.

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.

TIC: 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 include

• Eyes: blurring, burning or pain in eyes, photophobia (extreme sensitivity to light), excessive tearing, blepharospasm (inability to open or keep open eyes).
• Nose: complaints of foul or pungent smells, rhinorrhea (excessive fluid discharge from the nares).
• Respiratory: irritative cough, wheezing, shortness of breath.
• Cardiovascular: chest pain or chest tightness, rapid heart beat.
• Gastrointestinal: excessive salivation, bitter or metallic taste in mouth, nausea, vomiting.
• Skin: sense of burning or itching of skin, redness of skin, blistering.
• Neurological: balance difficulties, dizziness, confusion, coordination problems, unconsciousness.

TIC: 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 this course.

Scene 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 supportive.

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.

TIC Treatment: Conclusion

Victims who have minimal or few symptoms at rest may be triaged to the delayed category, presuming no other symptoms are prevalent from trauma.

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.

Chapter Summary

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:

• Self-protection. Don't become a victim yourself — at the scene and during transport.
• Rapid extrication and expedient decontamination. Separate the victim from the chemical.
• Determination of the agent or class of agents. Look for symptom complexes. Are victims experiencing respiratory difficulties? Do they complain of burning eyes or skin?
• Administration of antidotes if indicated, based on the syndromic diagnosis.
• Rapid triage based on physiological parameters.
• Provision of field supportive care. For most agents, rest, supplemental oxygen, and further environmental protection measures to prevent hypothermia will suffice.
• Transportation based on triage category to designated facilities capable of further treating such victims.

5

Introduction

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 plants.

History

Biological agents have been used to inflict death or injury in man for thousands of years.

• In combat: In ancient days, plague-infected bodies were catapulted over fortress walls to cause illness among enemy troops. During WWI, German spies in the United States attempted to infect horses being shipped to France with the bacteria that cause the disease Glanders in hoofed animals.
• In suicides and homicides: Socrates was forced to drink hemlock; so was Rommel.
• In assassinations: In 1979, the Bulgarian spy Georgi Markov was injected surreptitiously with a pellet containing the toxin ricin and died several days later.
• In criminal activity: The religious cult led by Bhagwan Shri Rashneesh poisoned salad bars in The Dalles, Ore., in 1984 in an attempt to influence a local election.
• In terrorism: Even prior to the mailings of letters laden with anthrax spores in the fall of 2001, hoaxes involving anthrax and other biological pathogens had increased dramatically since 1995.

Ideal Biological Weapons

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.

Available

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.

Capable 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.

Effective

Depending on the purpose of its use, an agent must be either incapacitating or lethal in a high percentage of those affected.

Aerosolizable

To be effective against large numbers of victims, an agent also should be easily aerosolized.

Viable

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.

Susceptible target

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.

Protectable delivery

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.

"Building" a Biological Weapon

Once an ideal biological weapon is identified, it must be produced, stored, and weaponized. These tasks can be extremely difficult to accomplish.

Recovery

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.

Collecting 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.

Mass production

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 environmental controls.

Processing

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.

Obtaining the release weapon

A release weapon must be obtained. All spray nozzles do not produce the same effect and may be clogged easily.

Secrecy

All these processes must be done in secret. And the developers must be protected lest they contract the disease themselves

Methods of Release

There are numerous ways a bioterrorism attack could be conducted:

• Bomblets or bombs could be used, but this might eliminate the advantages of covert operations and would destroy large quantities of the agent or microorganism.
• Bursting charges would cause less destruction but still eliminate surprise.
• Sprayer assemblies are by far the most efficient, using either dried powder or a liquid slurry. Releases may take place from a point source for high concentration in the proximity or through a line source. A line source release occurs when the release takes place from a vehicle moving perpendicular to the wind direction.
• Foodstuffs or water supplies could be contaminated, but doing so would be difficult to cause large numbers of casualties. Most biological agents would be killed through standard water treatments or diluted to the degree as to make them ineffectual.

Routes 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 population effect.

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.

Classes 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.

• Bioregulators affect human physiological functions, such as metabolism.
• Genetically engineered pathogens could target specific DNA sequences, for example, and only affect those with specific sequences, such as those that code for race, eye color, or other specific attributes.
• Fusion toxins are toxins that, by themselves, are innocuous, but when combined with other substances found normally in the body become lethal.

The next few pages in this course deal with the three classes of existing biological weapons.

Bacteria

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 reproduce.

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:

• Bacillus anthracis, the agent of anthrax.
• Yersinia pestis, which causes plague.
• Francisella tularensis, the causative pathogen of tularemia or rabbit fever.
• Coxiella Burnetii, which produces Q fever.
• Brucella, which produces brucellosis.

Viruses

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 cells.

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 (e.g., HTLV-III).

Viruses of concern include those that cause the diseases of:

• Smallpox.
• Certain viral encephalidities.
• Viral hemorrhagic fevers.

Toxins

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 include:

• Botulinum toxin.
• Staphylococcus enterotoxin B (SEB).
• Ricin.

Categories 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:

• Category A agents are of greatest concern because they have high lethality or incapacitation, are more readily available in general, and have the greatest potential to disrupt society should they be released.
• Category B agents are moderately easy to disseminate, cause moderate morbidity and low mortality, and require specific enhancements of CDC's diagnostic capacity and enhanced disease surveillance.
• Category C agents are available, easy to produce, and have a high potential for future development.

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.

Anthrax: Introduction

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.

Anthrax: 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 untreated.

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 victims recover.

Anthrax: Treatment

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.

Plague: Introduction

Yersinia pestis 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.

Plague: 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.

Plague: Treatment

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.

Smallpox

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 1980.

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 1990.

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: Disease Process

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.

Smallpox: 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.

Smallpox: Inoculation

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.

Smallpox: Treatment

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

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 for equipment.

Viral 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.

VHFs: 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 septic shock.

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 bruisability.

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.

VHFs: Treatment

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.

Botulism: Introduction

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.

Botulism: Disease Process

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 respiration.

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 solutions.

Indications 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:

• A high number of sick and dying patients presenting within a short period of time, i.e., 12-48 hours.
• Very high attack rates, i.e., 60%-90% of personnel in a given area are affected/symptomatic.
• A high incidence of pulmonary involvement signaling an aerosol route of infection.
• "Impossible epidemiology." If Congo-Crimean hemorrhagic fever occurred in Alaska or pneumonic plague in Baltimore, a man-made epidemic would be extremely likely.
• Localized areas of disease epidemics might occur in a sector downwind from the point of attack.
• Multiple infections caused by unusual pathogens at a single location.
• The near simultaneous outbreak of similar or different epidemics at different locations.
• Direct evidence of an attack, e.g., finding unexploded munitions or contaminated exploded munitions.

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:

• Public health officials will promulgate specific protective actions for those at high risk. They will notify private physicians, hospitals, and other health organizations, including EMS agencies, of "case definitions" — signs and symptoms most associated with the disease — and will provide information on rapid reporting. The objectives of these initiatives will be to track and contain the spread of contagious diseases while treating affected victims, and reassuring the public concerning environmental surety.
• Law enforcement and public health officials will begin their respective forensic and outbreak investigations.

Major Issues of a BT Attack

The affected community will have to deal with several major issues.

Mass prophylaxis

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.

Mass care

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.

Temporary interment

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.

Mental health counseling

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 Challenges

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.

Personal protection

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.

Equipment 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 for services.

Resource allocation

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.

Worker absenteeism

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.

Extraordinary duties

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 manner.

First responder stress

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 Infectious Diseases

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, and hantavirus.

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.

Tuberculosis

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.

• Minorities are disproportionately affected, with 54% of the active cases diagnosed in 1995 falling to African-Americans and another 17% among Asian-Americans.
• In some localities in the United States, the mortality from TB exceeds that in underdeveloped countries.
• It is believed that several factors, such as HIV infection, IV drug abuse, and poverty, are causally related to this resurgence.

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.

EID: 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%.

Resurgence of EID

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.

Resurgence of EID

Why is this happening? Why is there a resurgence of these diseases?

The Institute of Medicine provides a list of potential reasons:

• Demographic shifts
• Technological advances
• Economic development
• Land-use pattern shifts
• Travel/migration
• Microbial adaptation
• Breakdown in public health infrastructures
• Social policies

Others have subdivided etiology into factors of:

• Environment.
• Demographics.
• Social policy.
• Zooinosis.
• Changes in human behavior.
• Pathogenic mutation.

The Future of EID

EID may become increasingly important in the decades to follow:

• Our populations are in general immuno-naïve to these diseases. This will result in higher morbidity and mortality among those who might contract these diseases.
• The increase in complications will be especially high among those with concurrent chronic diseases, such as hepatitis or HIV.
• Diseases that affect the immune system may adversely affect treatment. A case in point is the smallpox vaccine, which cannot be given to immunodeficient people.
• Drug resistance also will compound treatment.
• These diseases, because of these factors, would be expected to produce outbreaks and epidemics.

Bioterrorism Summary

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 disaster.

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 shortages.

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.

6

Introduction

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 radiation.

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.

Radiation Sources

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:

• Americium-241 (used in smoke detectors).
• Cesium-137 (used in radiation therapy).
• Iodine-131 (used to diagnose and treat thyroid cancers).
• Iridium-192 (used in industrial radiography).
• Phosphorus-32 (used in molecular biology).
• Plutonium-238 (used to generate electric power for satellites).
• Technetium-99m (used in nuclear medicine).
• Thorium-232 (used in gas lantern mantles).

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:

• In Brazil, in September 1987, an abandoned nuclear medicine machine was vandalized for the "glowing substance" in it. The cesium-137 killed four and contaminated another 244.
• A nuclear reactor accident in Japan Sept. 30, 1999, claimed two lives, exposed nearly 700, and affected the lives of more than 300,000.
• Nov. 21, 1995, Chechen terrorist Shamil Bassaev put a container with radioactive cesium-137 in Izmailovo Park, Moscow. The only practical, but very effective, purpose of putting that source of low radiation in Moscow was to alarm the Russian public.

Basic 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.

Basic 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.

Definitions of Terms

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

Radioactivity is the spontaneous transformation of an unstable atom and often results in the emission of radiation.

Radiation

Radiation is simply energy in the form of high-speed particles and/or electromagnetic waves.

Ionizing radiation

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 ionized.

Radioactive decay

The 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.

Types 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 ionizing radiation:

• Alpha particles — equivalent to hydrogen atoms with the electrons torn away
• Beta particles — high-energy electrons
• Neutrons — high-energy, free neutrons

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.

Similar Characteristics

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.

Measurement of Radiation

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.

Rad

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.

Rem

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.

Radiation and DNA

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.

Cellular 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:

• At 25 rem single-dose whole-body irradiation, lymphocytes temporarily disappear from the circulating blood.
• At 100 rem single-dose whole-body irradiation, mild radiation sickness occurs, and one can see a depressed white blood cell count.
• At approximately 450 rem single-dose whole-body irradiation, approximately 50% of a given human population will die.

Acute Radiation Syndrome (ARS)

The constellation of clinical signs and symptoms that a victim of exposure to radiation exhibits is referred to as acute radiation syndrome (ARS).

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:

• Prodromal.
• Hematopoietic.
• Gastrointestinal.
• Neurovascular (or central nervous system).

ARS: Prodromal Syndrome

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.

• Gastrointestinal symptoms: anorexia, nausea, vomiting, diarrhea, intestinal cramps, salivation, dehydration, and fluid loss
• Neuromuscular symptoms: easy fatigability, apathy or listlessness, sweating, fever, headache, and hypotension

Prodromal syndrome is rarely seen at doses of radiation below 70 rem.

ARS: Hematopoietic Syndrome

The hematopoietic syndrome is identified by its effects on the bone marrow and blood. It is composed of three components:

• Prodromal syndrome
• A latent period
• Clinical illness

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.

ARS: Gastrointestinal Syndrome

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.

ARS: 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.

Emergency 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.

Radiation 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:

• There usually are no initial signs or symptoms of exposure to radiation as there would be to a significant chemical exposure.
• Radiation detection equipment is easier to operate than many of the tools used to detect hazardous chemicals, and, depending on the location of the incident, it may be possible to measure the actual human exposure at the scene.
• Personal safety in responding to chemical hazards may require the use of expensive personal protective equipment. For the most part, simple coverings such as coveralls, long-sleeve shirts, and particulate filter masks will provide adequate protection against fallout for short durations.

Radiological Emergency Management

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 ink pen.

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.

Time, Distance, and Shielding

The concepts of time, distance, and shielding are useful in considering personal protection.

Time

The less time on scene, or in proximity, the less exposure.

Distance

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.

Shielding

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.

Radiological Triage

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 agents.

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 dysfunction.

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 situation.

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

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 function.

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.

Transportation

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 operated.

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 department.

Priorities for Response

Keep in mind these priorities for response to radiation incidents:

1.     Evacuation of the population in the threatened area

2.     Personal protection: time, distance, and shielding

3.     Containment of radiation spread through such actions as extinguishing fires

4.     Stabilization before decontamination of unstable patients

5.     Thorough decontamination of stable patients prior to transport

7 

Nuclear Materials

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.

Special nuclear materials

Uranium-233 or uranium-235, enriched uranium, or plutonium

Source materials

Natural uranium or thorium, or depleted uranium that is not suitable for use as reactor fuel

Byproduct materials

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.

Sources 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 weapons.

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 submarines.

Accidents and Smuggling

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.

Energy Release

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 Crockett.

Nuclear Destruction

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:

• Blast: 50%
• Thermal radiation: 35%
• Ionizing radiation: 15%

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 airburst:

• Blast zone: 500 feet
• Thermal zone: 1,500 feet
• Ionizing radiation zone: 3,000 feet

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.

Blast Effect

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 damage.

Blast 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 Effect

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 effects.

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.

Ionizing Radiation Effect

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 effects.

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.

Hazards 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:

• A variety of different types of radiation.
• Secondary explosions from combustion and subsequent detonation of contained volatile hazardous materials.
• A large amount of radioactive material in the smoke, if there is a fire. Inhaled radioactive metals are a dual hazard — one from the radioactivity and one from heavy metal poisoning.
• Contamination of the area around the scene and the injured with hazardous materials.
• Contamination of facilities, equipment, and response personnel.

Note these aspects of casualties that you might encounter after a nuclear incident:

• A potentially large number of casualties, depending on the circumstances
• Victims with serious injuries (frequently multiple), requiring early, skilled treatment. These include burns, fractures, and head injuries.
• Absence of significant, obvious radiation injuries. Contamination of the injured may be present but should not be a serious, immediate hazard to either the injured or to personnel caring for them.

Scene 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.

Responder 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 nuclear accident.

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

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

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 exsanguinating injuries

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.

Decontamination 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 decontamination.

Simple removal of clothing will eliminate 90%-95% of radioactive contaminants. Water washdown after clothing removal will eliminate the balance, except internalized contamination.

Field Treatment

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 fractures.

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 treatment facilities.

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 victim.

Transportation

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 compartment.

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 these victims.

Summary

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 to transport.

8

HIGH 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.

Explosives

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 confining forces.

Terrorist 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

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

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

Fertilizer bombs are made from ammonium nitrate. Hundreds of kilograms may be required to cause major damage.

Barometric bombs

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.

Classification of Explosives

Explosives frequently are classified as either low yield or high yield.

• Low-yield explosives burn rather than detonate, and the reaction is subsonic.
• High-yield explosives detonate. They have a fast rate of reaction and range in sensitivity from sensitive (primary) to insensitive (secondary or blasting agents).
• Primary high-yield explosives require a very small quantity of energy to be initiated. They are extremely sensitive to heat, shock, and friction and require less power than secondary explosives to detonate. Although classified as high-yield explosives, they primarily are used in detonators and initiation systems.
• Secondary high-yield explosives are less sensitive and more powerful than primary explosives.

Nitroglycerin

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 detonate.

Dynamite

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.

Ammonium Nitrate

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 porous pills.

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 quarry operations.

Binary Compounds

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

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, etc.

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

RDX (cyclotrimethylenetrinitramine, cyclonite) is probably the most important high-yield explosive. It has a very high density and high detonation velocity.

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.

C-4

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.

Incendiary Devices

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 incendiary bombs.

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 America.

Nuclear Devices

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.

Explosive Effects

Explosives produce three primary effects on the surrounding environment:

• Blast effects: either from overpressurization or underpressurization
• Fragmentation effects
• Thermal effects

Secondary effects also occur, as a result of reverberations through or reflection off solid structures.

Blast Effects

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

Fragmentation Effects

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 structures.

Thermal Effects

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.

Response Challenges

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.

Incident Size-Up

The important components of emergency response to explosive events include:

• Incident size-up.
• Operations.
• Safety.

Size 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.

Victims

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.

Suspects

A primary role for law enforcement is identifying suspects. An injured person trying to leave the scene with rescuers on hand is considered suspicious.

Initial assessment

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.

Operations

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.

Safety

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.

Medical Challenges

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 trauma

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.

Blunt trauma

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.

Extremity amputations

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 injury.

Burns

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.

Inhalation injuries

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.

Lacerations 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.

Triage

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

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:

• Patients who can follow direction and ambulate on their own are separated initially, triaged, and designated as delayed.
• Patients with high or very low respiratory rates are classified as immediate. For those not breathing, the only treatment offered is head positioning and possibly insertion of a nasal trumpet or oropharyngeal airway. No CPR is performed.
• Patients with evidence of poor perfusion are likewise triaged as immediate. Patients with gross exsanguinating hemorrhage may be provided an external tamponade, if done rapidly.
• Finally, mental status is evaluated again.

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 Emergencies" course.

Summary

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 hazards.

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.

9

WMD :  Introduction

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.

Defining 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 the release?

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 Events

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.

Food poisoning

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.

Product tampering

Although the actual purpose has never been determined, in the 1970s the antipyretic Tylenol® was contaminated with cyanide in several drug stores in the Midwest, and numerous copycat incidents occurred after the initial contaminations.

Aerial release

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.

Orphan radioemitters

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.

Point-Source vs. Line-Source Releases

Aerosol releases usually are classified as point-source or line-source releases.

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.

Early Detection

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 organizations.

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.

Chemical 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.

Location

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.

Timing of event

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.

Timing of symptoms

In general, chemical agents produce symptoms immediately on contact or within several hours, to all victims affected.

Types of symptoms

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.

Secondary casualties

Unprotected bystanders or even initial responders who have attempted to assist victims may themselves succumb to the effects of residual agent.

Initial 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 incident.

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.

Radiological Event Indicators

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.

Amount of particulate matter

Inordinate amount of particulate matter in the air for the damage encountered

Location and timing of the event

Similar to those for a chemical agent attack

Meteorological conditions

Similar to those for a chemical agent attack

Magnitude of the event

A 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

Initial 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.

Indicators 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.

Biological 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.

Call volume

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

Geographic distribution of calls

A possible geographic skewing of this increase to one quadrant of the municipality

Demographics 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

"Abnormal outbreak"

An apparent outbreak of community-acquired pneumonia or rash resembling chickenpox in the adult population

Sentinel Cases

Any case of nontraumatic, gradual paralysis in the community. Any death not caused by trauma of a seemingly previously healthy adult or child

Initial 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.

Principles 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 biological agent.

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.

Phases of Emergency Response

FEMA identifies five specific phases of emergency response:

1.     Warning the public and notifying response organizations

2.     Ensuring immediate public safety

3.     Securing property from damage, looting, and further loss

4.     Establishing public welfare programs to maintain immediate community viability

5.     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."

Early Warning

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:

• Some form of sensor must identify the impending event. The "Biowatch" program initiated by the federal government has as one of its goals the placement of biological agent sensor arrays to identify a release prior to exposure.
• Sensor information must be retrieved to a central location, which would then
• Analyze this data, and, using
• Decision matrices, determine whether some appropriate
• Actions should be taken.

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.

Principles 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 action.

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 communities.

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.

Immediate Public Safety

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.

Incident 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.

Containment

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.

People Before Property

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:

• Search and rescue.
• Triage of victims.
• Decontamination.
• On-scene treatment.
• Transportation of victims.
• Receiving facility triage and treatment.

These activities are covered in the next several pages.

Search and Rescue

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.

Search 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.

• All potential sources of electrical discharge should be secured as soon as possible.
• Routes of ingress and egress should be clearly marked, as should any potential hazards.
• All closed spaces should be cleared prior to entry, for potential fire and/or hazardous materials.
• All spaces should be checked for potential victims.
• Pulling entrapped debris may cause structures to fall.
• Throwing debris may cause injury to others.
• The buddy system should always be used.

Triage of Victims

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 conventional explosives.

Chemical incidents

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 incidents

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 incidents

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

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 chapter.

On-Scene Treatment

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

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.

Receiving 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 arrive.

Above all, facilities must be protected. If a facility becomes contaminated, it threatens this entire function.

Property Security

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 particularly important.

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.

Public Welfare

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 nightmare.

This population has additional needs as a result of the recent stressors, but people within this cohort also may have special requirements.

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.

Restoration 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.

Summary

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.

PERSONAL PROTECTION, SAFETY, & DECONTAMINATION:

Introduction

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 the response.

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.

Scene 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.

Establishing 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 events.

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.

Hot 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.

Hot zone

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.

Warm zone

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.

Cold zone

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

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.

Hot 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 responders.

Primary Threats

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 Threats

Secondary hazards may be obvious (smoke, fire, damaged structures) or may be inapparent on casual observation (natural gas leaks, electrical dangers).

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

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.

Personal Protection

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

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

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, however.

Respiratory Equipment

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.

Closed-system respirators

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.

Open-system respirators

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 low-oxygen environments.

HEPA 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 the wearer.

Protective Clothing

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.

OSHA Standards

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

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

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

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

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.

Protection Against Biological Agents

The medical community uses isolation precautions to protect people working around contagious patients. Four levels of precautions have been identified.

Standard precautions

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

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 µm 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

Droplet precautions are designed to reduce the risk of droplet transmission of infectious agents by large-particle droplets (larger than 5 µm 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 droplet precautions.

Contact precautions

Contact 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.

Radiation 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.

Personal Protective Equipment: Caveats

There are a few more important points to remember concerning PPE.

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 biological agents.

Chemotherapeutic Protection

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.

Chemical Protection

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 pretreatment.

Several forms of topical skin protectorants exist that have been fielded for use, but again, these should have limited utility in the civilian sector.

Biological Protection

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 known pathogen.

Although research continues and shows some promise, there are no antiviral medications approved for prophylactic use

Radiation Protection

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 ineffective.

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

Decontamination serves three purposes:

• Removal of a contaminant from a victim's skin, thereby reducing the harmful effects of continued exposure
• Protection of rescue and response personnel
• Providing some degree of psychological comfort to the victim

Decontamination Triage

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.

Site Selection

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.

Decontamination Procedures

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.

Decontamination Solutions

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.

Nanoemulsions

Biosafe emulsions that can be used in contaminated wounds or even ingested recently have been tested and approved for use.

Aminoethanol

Aminoethanol is a strong base that has been studied for use in decontamination of nerve agents.

Activated charcoal or clay

Activated charcoal or clay absorbents may have wide utility in the absorption of a variety of chemicals.

Enzymes

Catalytic enzymes (specific for nerve agents only) or enzyme polymers are now in use.

Dutch powder

Dutch powder is a dry form of bleach.

Internal Decontamination

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.

Decontamination 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 is discovered.

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.

Overt release

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.

Certain biological toxins

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

Decontamination 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.

Additional Decontamination Issues

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).

Victim privacy

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

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 apparatuses.

Disposition 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.

Contaminated wastewater

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.

Resources and Logistics for Decontamination

Personnel

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 as necessary.

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.

Summary

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.

Course Summary

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 emergencies.

You have the foundation. It is up to you to build on it.