Chemical Disasters

Ancient Greek myths spoke of the effectiveness of chemical warfare, and various agents have been used throughout the ages, culminating with the widespread use in World War I. Many of the chemical agent–related disasters in modern times are related to industrial accidents. One of the most famous chemical disasters was the December 3, 1984, Bhopal disaster in India that killed between 4000 and 20,000 people from exposure to methyl isocyanate.

Disasters from chemical exposures create numerous casualties very quickly and place first responders in danger of also being contaminated. Proper decontamination of patients at the scene by trained civilian or military personnel takes priority before rendering medical care. Contamination of medical personnel and facilities risks not only the provider’s health but may also place the ability of the hospital to receive casualties in jeopardy. First responders will usually be able to communicate the type of chemical agent involved to the receiving hospital, and treatment of patients should be focused on that contaminant. The injuries associated with chemical disasters depend on the class of agent involved. Some of the more common agents that may be encountered include

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  Choking agents that target the pulmonary system such as chlorine and phosgene. These agents are lung irritants that cause injury to the lung–blood barrier, resulting in asphyxia.

  
  
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  Blood agents, such as hydrogen cyanide, are rapidly lethal via halting cellular respiration. Treatment is the rapid removal of the victim from the environment, application of oxygen, and administration sodium nitrite.

  
  
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  Blister agents or vesicants, such as mustard gas, are some of the most common chemical warfare agents. These oily substances act via inhalation and contact with skin. Blister agents affect the eyes, respiratory tract, and skin, first as an irritant and then by affecting cell metabolism. Blister agents cause large and often life-threatening skin blisters that resemble severe burns. The effects of mustard agents are typically delayed: Exposure to vapors becomes evident in 4 to 6 hours, and skin exposure is seen in 2 hours to 48 hours. Treatment is decontamination and supportive care targeted to address life-threatening respiratory compromise.

  
  
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  Nerve agents are perhaps the most rapidly lethal chemical agents and result in respiratory paralysis and death in a matter of minutes. Nerve agents, such as sarin and VX, enter the body through inhalation or through the skin. The degree of symptom severity depends on the level of exposure. Classic symptoms of moderate to high doses of nerve agent result in pronounced secretion of mucus, bronchoconstriction, abdominal cramping, vomiting, involuntary urination and defecation, muscle weakness, convulsions, and death by suffocation. Treatment must be rapid to prevent death and include decontamination and administration of high doses of atropine and 2-PAM (2-pyridine aldoxime methyl) chloride. Supportive care must be aggressive because the physiological effects can continue long after nerve agent is reversed.

  
  
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  Riot control agents (tear gas) are chemical compounds that temporarily make people unable to function by causing irritation to the eyes, mouth, throat, lungs, and skin. The effects of exposure to a riot control agent last about 15 to 30 minutes after the patient has been decontaminated. Immediate signs and symptoms of exposure to a riot control agent include excessive tearing, eye burning, blurred vision, a runny nose, difficulty swallowing, chest tightness, coughing, and nausea and vomiting. Long-lasting exposure or exposure to a large dose of a riot control agent can result in blindness, glaucoma, and sometimes death from respiratory compromise. Treatment includes the removal of the patient from the environment, copious irrigation, and symptomatic treatment.

  
  
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  Toxins are poisons produced by living organisms. One of the most well-known toxins is botulinum toxin. Botulinum toxin is produced by the bacteria Clostridium botulinum and is extremely lethal. The lethal dose has been estimated to be about 1 microgram if ingested and even less if inhaled. The incubation period is between 1 and 3 days at which time the patient presents with abdominal pain, diarrhea, visual changes, and muscular weakness. Paralysis ensues, compromising respiratory function, and asphyxia ensues. No specific treatment is available for botulinum toxin. Treatment is directed at supporting the cardiopulmonary system.

Biological Disasters

Biological disasters are diseases conveyed by biological vectors, including exposure to pathogenic microorganisms, toxins, and bioactive substances that can cause injury, illness, social, and economic disruption and death. Biological disasters can be naturally occurring or can be human-made in the form of accidental release or bioterrorism. Naturally occurring biological disasters can be divided into epidemics and pandemics. An epidemic is a disease process affecting a disproportionately large number of individuals within a population, community, or region at the same time. A pandemic is an epidemic that spreads across a continent or worldwide, such as the 1917 influenza pandemic. Epidemics are common after tropical storms, floods, earthquakes, and wars when normal hygiene and sanitation services are disrupted. Examples of natural epidemics include the avian flu common in southeast Asia; the cholera outbreak in Haiti after the earthquake in 2010 as the result of improper sanitation protocols by Nepalese soldiers who were part of the United Nations forces; dengue fever and malaria outbreaks from mosquito-borne vectors; the Ebola outbreak in West Africa in 2015; and measles, which has a high mortality rate in developing countries.

Epidemics can also be the result of bioterrorism. Bioterrorism is a method that disseminates widespread panic in a population and produces a slow onset of mass casualties. Bioterrorism can be targeted to both a human population and an animal population, which can produce large-scale economic losses. Many of the common bioterror weapons such as smallpox, anthrax, and plague were weaponized by the United States and the Soviet Union after World War II. Although many of these bioweapon stocks were destroyed as the result of arms agreements, some stockpiles remain in the former Soviet Union. These stockpiles, as well as the scientific ability to produce these weapons, are sought after by terrorist groups. Recognizing bioterrorism is a critical first step in decreasing the number of casualties. Incidentally, frontline medical professionals may be the first to recognize health trends that indicate a bioterrorism attack.

Biological disasters present differently from chemical disasters. The vectors are different and can include agents dispersed into the air that may drift for miles; animals, including fleas, mice, mosquitoes, and livestock; food and water supplies; and from person to person such as smallpox. Unlike chemical agents, there is a lag time between exposure and the appearance of symptoms. This lag time gives the vector more time to expose a greater number of victims. Furthermore, it increases the time it takes before the disease is recognized, isolated, and treated. Three categories of biological agents can cause mass casualties:

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  Category A (which pose the most risk to public health): These agents are easily disseminated from person to person and have a high mortality rate. These agents include smallpox, Ebola, Lassa fever, anthrax, plague, tularemia, and botulism. Special isolation precautions of contaminated patients are required. Consequently, multiple casualties can be devastating to the medical system as patients require an inordinate amount of resources.

  
  
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  Category B: These agents are moderately easy to disseminate; have moderate morbidity and low mortality rates; and include alphaviruses, Brucella (brucellosis), Burkholderia mallei (glanders), Coxiella burnetii (Q fever), ricin, staphylococcus enterotoxin B, Salmonella, Vibrio cholera, and Escherichia coli O157:H7. Children, older adults, and immunocompromised individuals are more at risk for complications from these diseases. Early, aggressive treatment is critical in reducing the long-term morbidity of the diseases.

  
  
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  Category C: These agents include many that have insect vectors, including Nipah, yellow fever, tick-borne hemorrhagic fever viruses, tick-borne encephalitis, and bacteria such as Mycobacterium tuberculosis. Although these diseases have the potential for morbidity and mortality, they are less likely to be widespread public health threats.

Clinicians should be aware of the diseases that lend themselves to becoming bioweapons. Anthrax, smallpox, plague, tularemia, and brucellosis are diseases that are relatively easy to produce, inexpensive, readily spread from person to person, and can be “weaponized” for distribution over a wide area. Bioweapons are considered to be a “poor man’s nuclear bomb” and can produce widespread casualties. For example, smallpox causes a one in five mortality rate. Furthermore, there are associated widespread panic and economic chaos. Unlike chemical weapons, where casualties would occur quickly after an attack, victims of bioterrorism would present days after the exposure with initial “flulike” symptoms. Be aware that with modern air travel, a bioterrorism victim on another continent may present to an emergency department (ED) or medical office in the United States with the early stages of the disease. It cannot be emphasized enough that a thorough travel history is obtained on every ill patient. Clinicians should inquire about friends and family members with similar symptoms and maintain a high index of suspicion if multiple patients present with similar symptoms. Clinicians should also become suspicious of an epidemic curve that rises and falls during a short period of time, an endemic disease rapidly emerging at an uncharacteristic time of the year, lower attack rates of people who have been indoors, clusters of patients arriving from a single location, and large numbers of rapidly fatal cases. Isolation of the patient and those exposed to the patient should take first priority, including personal protective equipment (PPE) for all staff. Decontamination should only be considered in cases of gross contamination, and this determination needs to be made in conjunction with local and state health departments. Basic decontamination includes removal of clothing and bathing in soap and water. Clinicians should notify the hospital’s infection control personnel, public health officials, law enforcement, emergency medical services (EMS), and the Centers for Disease Control and Prevention (CDC) promptly. Postexposure immunization and prophylaxis measures depend on the biologic agent involved. Furthermore, the determination on proceeding with an intervention should be made in conjunction with the local and state health departments. Treatment of patients should be directed at addressing presenting symptoms because exposure to many of the bioterror agents presents with respiratory or gastrointestinal complaints. Additionally, clinicians should be ready to address the potential for respiratory failure, hemorrhagic shock, or septic shock.

Nuclear and Radiologic Disasters

Nuclear and radiation disasters are, fortunately, uncommon in the United States. Although the prospect for a large-scale nuclear power disaster on the scale of the Fukushima, Japan, accident is remote, incidents involving radiologic dispersal devices (i.e., dirty bombs), occupational accidents, or even an explosion from an improvised nuclear device are possible events. Clinicians should be prepared for these events and be familiar with the types of nuclear and radiologic devices, decontamination methods, and recognition of radiation sickness and should have a basic knowledge of treatment for radiation injuries.

Natural Disasters

By far, the most common type of mass casualty event seen worldwide is natural disasters. Depending on location, PAs should be prepared for natural disasters that are common to that location. The gulf coast and the eastern coast of the United States are prone to hurricanes, which can produce widespread devastation, resulting in not only mass casualties as the result of trauma (i.e., penetrating and crush injuries) but also infectious disease issues as the result of a loss of infrastructure and sanitation. The Midwest and the southern United States are prone to tornadoes. Tornadoes give very little warning and tend to cause injuries similar to those from hurricanes except in a smaller geographic area. The West Coast and Alaska are prone to earthquakes and tsunamis, which give little or no warning and generate widespread destruction. In the case of earthquakes, many of the injuries are crush injuries from collapsed structures or injuries related to resulting fires or explosions. Similar to hurricanes, earthquakes involve a wide area and can result in severe impairment of local fire departments and EMS to render care. Tsunamis result in widespread inland flooding and structure damage. Many of the deaths are the result of drowning; however, exposure to sewage, industrial chemicals, and waterborne pathogens can result in a widespread public health emergency. By knowing what types of environmental events are common to an area, proper preparation can ensure a better outcome in the event of one of these disasters.

Terrorism

Terrorism is the use of violence in the pursuit of political gains. Terrorism gained a foothold by various groups in the 1970s, culminating with the events of September 11, 2001. Terrorism can be from domestic sources, such as the Oklahoma City Federal Building bombing, or from foreign terrorist groups. PAs should be aware of potentially high-value terrorist targets in their communities and be prepared to respond to blast injuries, chemical exposures, biological exposures, radiation exposures, and penetrating injuries such as gunshot wounds. Potential targets include famous landmarks, transportation hubs, hotels, government offices, chemical factories, railcars and transfer trucks carrying sensitive materials, petroleum plants, nuclear facilities, and military installations, to name a few. Clinicians should practice situational awareness and know that in a mass casualty situation, there is the potential that an armed terrorist could present to a medical facility as a patient. Clinicians should be knowledgeable in regard to decontamination procedures and PPE in the event of a CBRNE attack. Protection of hospital staff and clinicians is of the utmost importance so as not to risk the ability of the facility to provide care.

Mass casualty incident and disaster preparedness is not a luxury in the 21st century. As threats grow from both natural and human-made sources, all PAs must be prepared to respond as frontline health care providers no matter their specialty. The threats can come from any place at any time. The best chance of mitigating suffering and death is proper training and preparation of the responding providers.