Biological and Chemical Terrorism
Without preplanning, the risk of injury or death to first responders is greatly increased. Each responding organization should develop standard operating procedures (SOPs) to implement personal protective equipment (PPE) use, decontamination of casualties, and technical decontamination of first responders. Individual SOPs should be part of the overall incident response plan. Frequent multiagency training is necessary to unify resources, decision-making, and information exchange.
Organizations must identify potential threats and have appropriate PPE to address these threats. Gowns, gloves, air-purifying respirators (APRs), self-contained breathing apparatus (SCBA), or supplied air respirators (SARs) are all examples of PPE. Frequent training with all required PPE is necessary to surmount real-world limitations in delivering care.
Lists the chemical agents most likely to be used in a terrorist attack.
CATEGORY AGENT
Nerve Tabun (GA), soman (GB), sarin (GD), and VX gases
Pulmonary Phosgene and chlorine gases
Riot control CS (tear gas), OC (oleoresin capsicum)
Vesicants Mustard gas, Lewisite
Blood agents Cyanide
Chemical agent release is most likely to occur using a recognized dissemination device precipitated by a fire or explosion, also known as point source dissemination. The chemical agent could also be aerosolized from a point of elevation, from an airplane or helicopter, also known as line source dissemination. Regardless of dissemination, such an event would be recognizable by a large group of casualties presenting simultaneously.
Nerve agents cause DUMBELS—defecation, urination, myosis, bronchorrhea, emesis, lacrimation, and salivation. This could be better pictured as liquids pouring from every part of the body. Neurological manifestations include muscle twitching, seizures, and coma. Treatment includes atropine, pralidoxime, decontamination, and supportive care.
Pulmonary agents cause mucosal irritation (burning eyes, throat, mouth) in small doses but choking and dyspnea can occur in higher doses related to pulmonary edema. Phosgene has a pleasant odor at low concentrations, like corn or freshly cut hay. Chlorine gas smells like bleach and is very irritating. Treatment is decontamination and supportive care.
The presenting signs and symptoms of vesicants are respiratory, dermal (partial thickness burns with blistering), gastrointestinal (vomiting), and ocular (conjunctivitis and corneal burns). Treatment is decontamination and supportive care. The presenting signs and symptoms of cyanide exposure are skin flushing, respiratory distress, and shock. Cyanide is a highly volatile toxic asphyxiant that shuts down cellular oxygen use. This can cause rapid decompensation, multisystem organ failure, and death.
Lists the biological agents most likely to be used in a terrorist attack.
CATEGORY AGENT
Bacterial Anthrax, brucellosis, cholera, plague, tularemia
Viral Viral hemorrhagic fever, smallpox
Toxin Botulinum, ricin, staphylococcal enterotoxin B
Anthrax presents in two primary varieties, cutaneous and pulmonary. Spores are inhaled, ingested, or inoculated. The spores germinate into bacilli inside macrophages releasing toxins that cause edema and cell death. Pulmonary anthrax presents with flulike symptoms (fever, cough, malaise) 2–10 days after exposure. Cutaneous anthrax presents in 1–5 days with a progression from papule, vesicle, to black eschar. Treatment includes one of the following antibiotics: doxycycline, ciprofloxacin, or amoxicillin.
Plague comes in three varieties: bubonic, pneumonic, and septicemic. Pneumonic plague is the most likely to present in a terrorist attack because it can be aerosolized and disseminated. Casualties will present with flulike symptoms and hemoptysis with pneumonic plague. Onset occurs in 2–3 days. The mortality rate is nearly 100%. The disease rapidly progresses to systemic organ failure and death. Septicemic and bubonic plague will present with terrorist attacks but will likely be secondary to primary pneumonic plague. Treatment is the same for all types of plague, which includes doxycycline or tetracycline.
Smallpox can present in many forms: variola major, variola minor, hemorrhagic, and malignant. Variola major and minor are the more common forms of smallpox, representing 90% of cases. Casualties present 8–12 days after exposure and present with fever, prostration, and headache. Pustules form around day 12–15. When making a diagnosis of smallpox, there are three major criteria and five minor criteria. If a casualty has all three major criteria, they require immediate isolation and reporting. Supportive care is the only available therapy.
Presentation of symptoms from botulism occurs anywhere from 6 hours to 10 days after exposure. Symptoms include facial paralysis, bulbar weakness, and descending muscle paralysis. The symptoms can progress to paralyze the diaphragm and lead to death. Treatment is supportive.
Red flags for biological agents include off-season flu symptoms, unexpected antibiotic resistance, large numbers of patients presenting simultaneously with similar complaints, localization of outbreaks, infected animal populations, and excessive morbidity and mortality. Biological agents are difficult to identify and require observation of signs and symptoms along with progression of disease.
Biological agents can be dispersed by unrecognized methods such as food or water tampering. Line source exposure from a mobile aerosol sprayer via boat or airplane is the most effective dissemination technique used to disperse biological agents. A less effective dissemination technique is point source exposure, which can occur with use of stationary aerosol sprayers, explosives, or missiles. The severity of presentation can depend on atmospheric conditions, agent stability, and particulate size of the agent. Airborne pathogens must be less than 5 microns in size to be effective inhalation agents.
Incendiary devices are more common than biological and chemical devices because they are easily produced, transported, and deployed. If an explosion has occurred, secondary explosions meant to injure or kill first responders should be considered. First responders must remain observant for suspicious people and activity.
Nerve and blister agents can be identified with M8 and M9 chemical detector paper, which uses an enzyme method for detection. Other methods to identify chemical agents include flame spectrophotometry, acoustic infrared spectroscopy, filter-based infrared spectroscopy, and ion mobility spectroscopy.
First responder safety and casualty care will always take priority, even over evidence collection. Evidence collection for terrorist attacks is under the authority of the FBI Hazmat Response Unit. Evidence collection includes hazard identification, evidence identification, determination of collection methods and containers, the necessary PPE, and maintaining the chain of custody.
