Explosions and Blast Injuries

1. Explosions and Blast Injuries

2. Acknowledgements South Carolina Area Health Education Consortium (AHEC) Funded by the Health Resources and Services Administration. Grant number: 1T01HP01418-01-00 P.I. : David Garr, MD, Executive Director AHEC BT Project Director: Beth Kennedy, Associate Program Director AHEC Core Team: BT Co-director: Ralph Shealy, MD BT Project Manager: Deborah Stier Carson, PharmD BT CME Director: William Simpson, MD IT Coordinator: Liz Riccardone, MHS Web Master: Mary Mauldin, PhD P.R Coordinator: Nicole Brundage, MHA Evaluation Specialist: Yvonne Michel, PhD Financial Director: Donald Tyner, MBA

3. Acknowledgment This material has been prepared for SC AHEC Bioterrorism Training Networkby Ralph M. Shealy, M.D., FACEPCo-Director of SC AHEC Bioterrorism Training Network Medical Director for Operations, Charleston County EMS Medical Director, Charleston County Rescue Squad

4. Objectives Outline what terrorist attacks are most common and most likely to occur again. Describe the different types of injuries that occur in an explosion. Describe the mechanism of blast injury. Describe physical findings used to triage multiple victims of an explosion. Describe the attributes of an explosive device. Describe what to do if you encounter a suspicious object.

5. Explosions A primary cause of wartime morbidity and mortality. Occur in mining, grain storage, and many other industrial settings. A common cause of fire-related injury. A high risk in the manufacture of illicit drugs. A vehicle of social protest. Most United States healthcare professionals have had little experience with victims of explosions outside of military service. Explosions due to bombs and munitions are a primary cause of wartime morbidity and mortality. Explosions also occur in industrial settings. On June 17, 1991, the Albright and Wilson chemical plant in Charleston exploded, killing two and injuring 33, six critically. Many fire related injuries and deaths occur when flammable or explosive materials detonate in the fire. The solvents used in clandestine methamphetamine laboratories are a serious explosion risk. These labs have been found in residential areas all over America and are most commonly detected when they catch fire or explode. Letter bombs and packages bombs have been instruments of criminal activity. Increasingly, bombs have been used world-wide as a weapon of terror. Recently, suicide bombs have been devastatingly effective.Most United States healthcare professionals have had little experience with victims of explosions outside of military service. Explosions due to bombs and munitions are a primary cause of wartime morbidity and mortality. Explosions also occur in industrial settings. On June 17, 1991, the Albright and Wilson chemical plant in Charleston exploded, killing two and injuring 33, six critically. Many fire related injuries and deaths occur when flammable or explosive materials detonate in the fire. The solvents used in clandestine methamphetamine laboratories are a serious explosion risk. These labs have been found in residential areas all over America and are most commonly detected when they catch fire or explode. Letter bombs and packages bombs have been instruments of criminal activity. Increasingly, bombs have been used world-wide as a weapon of terror. Recently, suicide bombs have been devastatingly effective.

6. Explosion as Weapon of Terror Marine Barracks, Beirut October 23, 1983 Pan Am 103, December 21, 1988 World Trade CenterFebruary 26, 1993 Oklahoma CityApril 19, 1995 On October 23, 1983, a truck loaded with explosives crashed through the perimeter of the US Marine Barracks in Beirut and exploded, killing 241 Americans. Two Libyan nationals were convicted of murder for placing explosives on Pan Am Flight 103, which exploded over Lockerbie, Scotland, on December 21,1988, killing 259 passengers and crew, and 11 people on the ground. On February 26, 1993, terrorists exploded a bomb in the garage of the World Trade Center. Six were killed and over 1,000 were injured. On April 19, 1995, the Alfred P. Murrah Federal Office Building in Oklahoma City was destroyed by Timothy McVeigh using a truck bomb made with fertilizer and diesel fuel. 169 people died and 600 were injured. On October 23, 1983, a truck loaded with explosives crashed through the perimeter of the US Marine Barracks in Beirut and exploded, killing 241 Americans. Two Libyan nationals were convicted of murder for placing explosives on Pan Am Flight 103, which exploded over Lockerbie, Scotland, on December 21,1988, killing 259 passengers and crew, and 11 people on the ground. On February 26, 1993, terrorists exploded a bomb in the garage of the World Trade Center. Six were killed and over 1,000 were injured. On April 19, 1995, the Alfred P. Murrah Federal Office Building in Oklahoma City was destroyed by Timothy McVeigh using a truck bomb made with fertilizer and diesel fuel. 169 people died and 600 were injured.

7. Prevalence of the Bomb Half of all terrorist attacks worldwide have been bombings. 86% of all terrorist incidents in the U.S. have been bombings. In fact, half of all terrorist attacks worldwide have employed bombs. Eighty-six percent of all terrorist incidents in the United States have been bombingsIn fact, half of all terrorist attacks worldwide have employed bombs. Eighty-six percent of all terrorist incidents in the United States have been bombings

8. A Terrorism Attack is a Community Disaster A terrorist attack is a community disaster.A terrorist attack is a community disaster.

9. Disaster Imminently threatens public health and safety. Cannot be handled using routine measures. Disrupts essential services. A community health emergency! From a medical perspective, a disaster is a calamity which imminently threatens public health and safety, (2) produces more casualties than can be managed using routine measures, or (3) disrupts essential medical services. For example, the derailment of a freight train carrying tank cars loaded with hazardous materials would be an imminent threat to public safety. The collapse of the stands during a major collegiate football game would produce casualties in greater numbers than could be managed using routine measures. An earthquake which damaged hospitals and destroyed clinics and private offices would disrupt essential medical services. A smallpox epidemic would qualify on all three counts. From a medical perspective, a disaster is a calamity which imminently threatens public health and safety, (2) produces more casualties than can be managed using routine measures, or (3) disrupts essential medical services. For example, the derailment of a freight train carrying tank cars loaded with hazardous materials would be an imminent threat to public safety. The collapse of the stands during a major collegiate football game would produce casualties in greater numbers than could be managed using routine measures. An earthquake which damaged hospitals and destroyed clinics and private offices would disrupt essential medical services. A smallpox epidemic would qualify on all three counts.

10. Whether a building collapses as the result of an explosion or as the result of an earthquake, its consequences and management are much the same. Whether a building collapses as the result of an explosion or as the result of an earthquake, its consequences and management are much the same. Whether a building collapses as the result of an explosion or as the result of an earthquake, its consequences and management are much the same.

11. Types of Terrorism Small arms Explosive Incendiary Chemical Biological Radiation These six forms of terrorism are listed in order of frequency. Attacks with conventional small arms and bombs are still the most common forms of terrorism. The murder of 11 Israeli athletes during the Munich Olympics in 1972 and the murder of 70 West European tourists in Luxor, Egypt, in 1997,illustrates the simplicity and effectiveness of small arms as instruments of terror. The Federal Building in Oklahoma City was brought down in 1995 with a homemade explosive consisting of fertilizer and diesel oil. The 2001 attack on the World Trade Center used the commercial aircraft as an incendiary device. The 1995 Saran gas attack in the Tokyo subway is an example of a chemical weapon. The Rajneesh cult in Oregon used Salmonella in the first biological attack in modern US history by contaminating a salad bar in 1984, sickening 750 people in hopes of influencing a local election. I am not aware of a terrorist attack using radiation as yet, but the most likely event will by the dispersion of radioactive wastes with high explosives, the so-called “dirty bomb”.These six forms of terrorism are listed in order of frequency. Attacks with conventional small arms and bombs are still the most common forms of terrorism. The murder of 11 Israeli athletes during the Munich Olympics in 1972 and the murder of 70 West European tourists in Luxor, Egypt, in 1997,illustrates the simplicity and effectiveness of small arms as instruments of terror. The Federal Building in Oklahoma City was brought down in 1995 with a homemade explosive consisting of fertilizer and diesel oil. The 2001 attack on the World Trade Center used the commercial aircraft as an incendiary device. The 1995 Saran gas attack in the Tokyo subway is an example of a chemical weapon. The Rajneesh cult in Oregon used Salmonella in the first biological attack in modern US history by contaminating a salad bar in 1984, sickening 750 people in hopes of influencing a local election. I am not aware of a terrorist attack using radiation as yet, but the most likely event will by the dispersion of radioactive wastes with high explosives, the so-called “dirty bomb”.

12. Disasters Natural Weather Flood Hurricane Tornado Winter storm Geophysical Earthquake Tidal wave Volcanic Eruptions Man-made Unintentional Structural Collapse Transportation Accident Hazardous Material Spill Industrial Accident Explosion Intentional Crime Civil disturbance War Terrorism Small arms Explosive Incendiary Chemical Biological Radiation Where does terrorism fit into the overall scheme of adverse community events? Terrorist bombing is a relatively minor threat in the long list of bad things that can happen to a community in which health professionals must play a role. Still, the PROCESSES that help us deal with bioterrorism are equally applicable to all other community health emergencies as well.Where does terrorism fit into the overall scheme of adverse community events? Terrorist bombing is a relatively minor threat in the long list of bad things that can happen to a community in which health professionals must play a role. Still, the PROCESSES that help us deal with bioterrorism are equally applicable to all other community health emergencies as well.

13. Brief Primer on Explosives Energetic materials: Can undergo an exothermal chemical reaction, rapidly releasing a large amount of energy Can occur in fractions of a second Solids and liquids transformed into superheated gases almost instantaneously. Energetic materials are substances that can undergo an exothermal chemical reaction, rapidly releasing a large amount of energy. An exothermal reaction releases heat. Rapid decomposition can occur in fractions of a second. These reactions cause solids and liquids to transform into superheated gases almost instantaneously.Energetic materials are substances that can undergo an exothermal chemical reaction, rapidly releasing a large amount of energy. An exothermal reaction releases heat. Rapid decomposition can occur in fractions of a second. These reactions cause solids and liquids to transform into superheated gases almost instantaneously.

14. Energetic Materials Pyrotechnics Propellants Explosives Energetic materials are divided into three classes depending on their intended use. Pyrotechnics produce smoke, light, heat, and sound. Fireworks fall into this class, along with road flares, smoke grenades, and airbag inflators. Propellants are designed to provide controlled release of gas that can be harnessed to perform useful work. Propellants are used to push a bullet from a gun or to launch a rocket into space. Explosives are designed to yield a near instantaneous release of energy. It is normally used for destructive purposes, such as in mining, road construction, and weapons of war.Energetic materials are divided into three classes depending on their intended use. Pyrotechnics produce smoke, light, heat, and sound. Fireworks fall into this class, along with road flares, smoke grenades, and airbag inflators. Propellants are designed to provide controlled release of gas that can be harnessed to perform useful work. Propellants are used to push a bullet from a gun or to launch a rocket into space. Explosives are designed to yield a near instantaneous release of energy. It is normally used for destructive purposes, such as in mining, road construction, and weapons of war.

15. Classification of Explosives Classified by: The stimuli to which they respond The degree of response once initiated. Explosives are define by the stimuli to which they response and by the degree of their response once initiated.Explosives are define by the stimuli to which they response and by the degree of their response once initiated.

16. “Insults” Initiate Explosions Heat Friction Impact Electrostatic discharge Shock The technical term for energy put into an energetic material is “insult”. There are five forms of insults. They are heat, friction, impact, electrostatic discharge, and shock. They all cause initiation of explosions by imparting energy to the system in the form of heat. Shock is the most powerful form of energy input. Shock can be generated by putting two explosives into contact and by detonating one to initiate the other. Friction, impact and electrostatic discharge often cause accidental detonation during routine handling of explosives.The technical term for energy put into an energetic material is “insult”. There are five forms of insults. They are heat, friction, impact, electrostatic discharge, and shock. They all cause initiation of explosions by imparting energy to the system in the form of heat. Shock is the most powerful form of energy input. Shock can be generated by putting two explosives into contact and by detonating one to initiate the other. Friction, impact and electrostatic discharge often cause accidental detonation during routine handling of explosives.

17. “High” and “Low” Explosives High explosives detonate at speeds greater than 3,000 feet per second. Low explosives detonate at speeds less than 3,000 feet per second. The category of the explosive dictates safety precautions Explosives are divided into two categories. High explosives detonate at speeds greater than 3,000 feet per second. Low explosives detonate at speeds less than 3,000 feet per second. The category of the explosive dictates safety precautions required for that material. Explosives are divided into two categories. High explosives detonate at speeds greater than 3,000 feet per second. Low explosives detonate at speeds less than 3,000 feet per second. The category of the explosive dictates safety precautions required for that material.

18. Low Explosives Designed to burn or “deflagrate”. Black powder. Smokeless powder. Low explosives are designed to burn, or “deflagrate”. Black powder is used as a propellant in vintage firearms, in fuses, and in fireworks. It does not deteriorate with age. It will not deteriorate when wet, and when dried out, its potency is restored. Black powder munitions submerged in Charleston waters since the Civil War are dangerous when removed from the water and dried out. It is very sensitive to friction, heat, impact, and spark or flame, making it one of the most dangerous explosives to handle. It is a favorite for use in pipe bombs. Smokeless powder is now the world standard for propellant in small arms. It is also sensitive to friction, heat, impact, sparks, and flame, and must be handled with the same caution as black powder.Low explosives are designed to burn, or “deflagrate”. Black powder is used as a propellant in vintage firearms, in fuses, and in fireworks. It does not deteriorate with age. It will not deteriorate when wet, and when dried out, its potency is restored. Black powder munitions submerged in Charleston waters since the Civil War are dangerous when removed from the water and dried out. It is very sensitive to friction, heat, impact, and spark or flame, making it one of the most dangerous explosives to handle. It is a favorite for use in pipe bombs. Smokeless powder is now the world standard for propellant in small arms. It is also sensitive to friction, heat, impact, sparks, and flame, and must be handled with the same caution as black powder.

19. High Explosives Detonate rather than deflagrate. Initiated by the shock of a detonator. Typically will not detonate by spark or flame. TNT, dynamite, nitroglycerine, and C-4 are high explosives. High explosives shatter and destroy rather than burn. They do not need to be confined to cause damage. They must be initiated by the shock of a detonator such as a blasting cap and typically will not detonate by spark or flame. TNT is the standard against which all high explosives are measured. Dynamite is bullet and impact sensitive, and safety is a major concern. Nitroglycerine is extremely sensitive and dangerous to handle. C-4 is a military plastic explosive.High explosives shatter and destroy rather than burn. They do not need to be confined to cause damage. They must be initiated by the shock of a detonator such as a blasting cap and typically will not detonate by spark or flame. TNT is the standard against which all high explosives are measured. Dynamite is bullet and impact sensitive, and safety is a major concern. Nitroglycerine is extremely sensitive and dangerous to handle. C-4 is a military plastic explosive.

20. High Explosives Ammonium Nitrate and Fuel Oil (ANFO) Favored homemade explosive Used in Oklahoma City Common in car and truck bombs Has legitimate uses is a favorite homemade explosive. It was used to destroy the Murrah Building in Oklahoma City. It is very insensitive and usually require a large detonation of another high explosive to initiate itis a favorite homemade explosive. It was used to destroy the Murrah Building in Oklahoma City. It is very insensitive and usually require a large detonation of another high explosive to initiate it

22. The Improvised Explosive Device Are made in an improvised manner incorporating explosives or destructive, lethal, noxious, pyrotechnic or incendiary chemicals. Intended to destroy, disfigure, distract, or harass. Placed or delivered to a target. An improvised explosive device can assume many shapes and sizes limited only by the resources and imagination of the designer. It need not be sophisticated to be lethal. The most common improvised explosive device is still a pipe bomb filled with black or smokeless powder an a powder train time fuse. An improvised explosive device can be categorized by its container, such as a car bomb or a letter bomb, or by other characteristics of the device.An improvised explosive device can assume many shapes and sizes limited only by the resources and imagination of the designer. It need not be sophisticated to be lethal. The most common improvised explosive device is still a pipe bomb filled with black or smokeless powder an a powder train time fuse. An improvised explosive device can be categorized by its container, such as a car bomb or a letter bomb, or by other characteristics of the device.

23. Components of an IED Power Supply Initiator Explosive Switch Packaging An improvised explosive device requires only five components: (1) a power supply, such as a battery, (2) an initiator to start the chemical chain reaction leading to detonation, such as a flash bulb, a percussion primer, or a blasting cap, (3) an explosive, and (4) a switch, which can be either electrical or mechanical, and allows the bomber to move to a safe distance before detonation. Packaging can be used to enhance the bomb’s effectiveness, such as a metal pipe to produce fragmentation injuries, or to disguise its true purpose. The following items have been used to package bombs: metal and plastic pipes and tubes, suitcases, handbags, purses, soap dishes, postal mail, trash bins, toys, cellular phones, pagers, computers, lights, furniture, cigarette boxes, rubber hoses, CO2 gas cartridges, fire extinguishers, flashlights, bottles and jars, automobiles, trucks, tankers, buses, electric and electronic appliances, fruit baskets, gifts, wrapped packages, wax containers, plaster figures, shell casings and cartridges, butane, gasoline and propane tanks. Pee Wee Gaskins, a notorious murderer serving a life sentence at South Carolina’s old Central Correctional Institution, was subsequently executed for murdering a fellow inmate with a bomb concealed in a transistor radio offered to the victim as a gift. The victim held the radio to his ear and turned on the switch.An improvised explosive device requires only five components: (1) a power supply, such as a battery, (2) an initiator to start the chemical chain reaction leading to detonation, such as a flash bulb, a percussion primer, or a blasting cap, (3) an explosive, and (4) a switch, which can be either electrical or mechanical, and allows the bomber to move to a safe distance before detonation. Packaging can be used to enhance the bomb’s effectiveness, such as a metal pipe to produce fragmentation injuries, or to disguise its true purpose. The following items have been used to package bombs: metal and plastic pipes and tubes, suitcases, handbags, purses, soap dishes, postal mail, trash bins, toys, cellular phones, pagers, computers, lights, furniture, cigarette boxes, rubber hoses, CO2 gas cartridges, fire extinguishers, flashlights, bottles and jars, automobiles, trucks, tankers, buses, electric and electronic appliances, fruit baskets, gifts, wrapped packages, wax containers, plaster figures, shell casings and cartridges, butane, gasoline and propane tanks. Pee Wee Gaskins, a notorious murderer serving a life sentence at South Carolina’s old Central Correctional Institution, was subsequently executed for murdering a fellow inmate with a bomb concealed in a transistor radio offered to the victim as a gift. The victim held the radio to his ear and turned on the switch.

24. Fusing of Improvised Explosive Devices Electronic Mechanical Sensors which respond to a myriad of stimuli: Light Sound Motion Pressure Vibration Temperature The fusing of IEDs is limited only by the resources, skill, and imagination of the bomber. Anything that can be used to turn something on or off can be used to activate a device. Bombers now commonly used integrated circuits to activate bombs. This can be done remotely utilizing TV remote controls or garage door openers. Command wires can be used to activate the bomb remotely when the time is right. Other devices use radio controls for toys, pull or tension release strikers, and devices sensitive to temperature, light, sound and proximity. A barometric bomb detonates with changes in atmospheric pressure, and is useful on an aircraft. Time fuses may utilize a mechanical or electric clock, a burning time fuse, or a chemical delay. Some switches are sensitive to vibration or change in position of the device. Motion detectors can detonate a device when it is approached.The fusing of IEDs is limited only by the resources, skill, and imagination of the bomber. Anything that can be used to turn something on or off can be used to activate a device. Bombers now commonly used integrated circuits to activate bombs. This can be done remotely utilizing TV remote controls or garage door openers. Command wires can be used to activate the bomb remotely when the time is right. Other devices use radio controls for toys, pull or tension release strikers, and devices sensitive to temperature, light, sound and proximity. A barometric bomb detonates with changes in atmospheric pressure, and is useful on an aircraft. Time fuses may utilize a mechanical or electric clock, a burning time fuse, or a chemical delay. Some switches are sensitive to vibration or change in position of the device. Motion detectors can detonate a device when it is approached.

25. Letter Bombs Marked “Personal” Mailed from a foreign country Excess postage Addressed to a person by title only Badly typed or written Misspelled words Rigid or bulky No return address. Letter bombs are typically activate by the victim during the process of opening the letter. The musical greeting card is a ready made letter bomb. It contains a power source, speaker, and some mechanism designed to activate the system when the card is opened. With the addition of some explosives and replacement of the speaker with a blasting cap, a letter bomb is made that will explode when the card is opened. Experience with letter bombs has led to the identification of some characteristic features. These include restrictive markings, such as “Personal”, addressed to a title only, mailed from a foreign country, excess postage, badly typed or written with misspelled words, rigid or bulky, and no return address. These indicators suggest that the letter or parcel should be examine by a bomb technician before opening.Letter bombs are typically activate by the victim during the process of opening the letter. The musical greeting card is a ready made letter bomb. It contains a power source, speaker, and some mechanism designed to activate the system when the card is opened. With the addition of some explosives and replacement of the speaker with a blasting cap, a letter bomb is made that will explode when the card is opened. Experience with letter bombs has led to the identification of some characteristic features. These include restrictive markings, such as “Personal”, addressed to a title only, mailed from a foreign country, excess postage, badly typed or written with misspelled words, rigid or bulky, and no return address. These indicators suggest that the letter or parcel should be examine by a bomb technician before opening.

26. Vehicle Bombs Vehicles make excellent delivery system for homemade explosives. A small pick-up will hold more than 2.5 times the explosives that were used to bomb the World Trade Center in 1993. A standard pick-up will hold the amount of explosives used to bomb the Federal Building in Oklahoma City. Vehicles make a good delivery system for a bomb. The World Trade Center and the Oklahoma City bombings utilized vehicle bombs. The bomb that inflicted extensive damage on the World Trade Center contained approximately 1200 pounds of Ammonium Nitrate and Fuel Oil explosive. A small bed pickup such as the Chevy S-10 can carry approximately 3,000 pounds of ANFO if the bed is filled flush to the top and covered with a tarp. A Chevy Silverado pick-up will hold the amount of explosives used to bomb the Federal Building in Oklahoma City if the bed is filled flush to the top and covered with a tarp. Such vehicles would be unlikely to attract attention anywhere in America.Vehicles make a good delivery system for a bomb. The World Trade Center and the Oklahoma City bombings utilized vehicle bombs. The bomb that inflicted extensive damage on the World Trade Center contained approximately 1200 pounds of Ammonium Nitrate and Fuel Oil explosive. A small bed pickup such as the Chevy S-10 can carry approximately 3,000 pounds of ANFO if the bed is filled flush to the top and covered with a tarp. A Chevy Silverado pick-up will hold the amount of explosives used to bomb the Federal Building in Oklahoma City if the bed is filled flush to the top and covered with a tarp. Such vehicles would be unlikely to attract attention anywhere in America.

27. Brief Case Bomb currently used by suicide bombers in Israel Note that this device contains ten pipe bombs and pieces from a hardware store, which are intended as antipersonnel fragmentation devices. The device is detonated by an incoming call to the cellular telephone, which generates an electrical impulse that initiates detonation.Note that this device contains ten pipe bombs and pieces from a hardware store, which are intended as antipersonnel fragmentation devices. The device is detonated by an incoming call to the cellular telephone, which generates an electrical impulse that initiates detonation.

28. Concealed Bomb currently used by suicide bombers in Israel Here, a device is worn by a bomber, who detonates the device by pushing a button on the control in his right hand. Multiple pipe bombs are on the front and back of the concealment vest. The device is armed by a switch seen as the grey box in the center of this vest.Here, a device is worn by a bomber, who detonates the device by pushing a button on the control in his right hand. Multiple pipe bombs are on the front and back of the concealment vest. The device is armed by a switch seen as the grey box in the center of this vest.

29. Concealed Bomb This close up view demonstrates how the various components are worn on the concealment vest.This close up view demonstrates how the various components are worn on the concealment vest.

31. Mechanics of an Explosion Explosives are converted to massive volumes of gas when detonated. Pressure wave radiates outward, producing overpressurization. Rapidly expanding gases result in blast wind. Blast wind can result in atomization of tissue. Explosives are materials that are rapidly converted into gases when detonated. Large amounts of energy are released in the forms of pressure and heat. If the explosion occurs within a rigid casing, as is the case with a bomb, pressure rises rapidly until the casing ruptures, transmitting energy to the surrounding environment in the form of a blast wave, blast winds, ground shock, and fire. The blast wave is a single pulse of very high pressure which rises over milliseconds. The pressure then rapidly falls to a minimum that is actually lower than atmospheric pressure. The atmosphere then rushes back into the low pressure area until normal atmospheric pressure is restored. The pressure wave radiates out from the explosion, forming a sphere with a sharply demarcated boundary. The blast wave pressure peak determines the extent of overpressure to which surrounding persons and structures are subjected. This overpressure phenomenon is responsible for what is referred to as primary blast injury. Rapidly expanding gases displace air, which results in “blast wind”. Blast wind accelerates objects and people through space. Blast windage can cause atomization or total disintegration of the body, as well as evisceration and traumatic amputations. A rapid over pressurization of about one hundred pounds per square inch generates blast winds of about fifteen hundred miles per hour!Explosives are materials that are rapidly converted into gases when detonated. Large amounts of energy are released in the forms of pressure and heat. If the explosion occurs within a rigid casing, as is the case with a bomb, pressure rises rapidly until the casing ruptures, transmitting energy to the surrounding environment in the form of a blast wave, blast winds, ground shock, and fire. The blast wave is a single pulse of very high pressure which rises over milliseconds. The pressure then rapidly falls to a minimum that is actually lower than atmospheric pressure. The atmosphere then rushes back into the low pressure area until normal atmospheric pressure is restored. The pressure wave radiates out from the explosion, forming a sphere with a sharply demarcated boundary. The blast wave pressure peak determines the extent of overpressure to which surrounding persons and structures are subjected. This overpressure phenomenon is responsible for what is referred to as primary blast injury. Rapidly expanding gases displace air, which results in “blast wind”. Blast wind accelerates objects and people through space. Blast windage can cause atomization or total disintegration of the body, as well as evisceration and traumatic amputations. A rapid over pressurization of about one hundred pounds per square inch generates blast winds of about fifteen hundred miles per hour!

32. The Explosion Site and Structural Considerations Fire and blast damage create structural instability. Assessment of stability is a job for structural engineers. Unstable elements must be shored up or pulled down for the safety of rescuers. No one should enter an unstable structure to recovery bodies. When an explosion results in fire and structural collapse, the resulting mechanical instability of a structure poses an immediate threat to rescuers. Some victims may be able to extricate themselves. (One New York City firefighter was in the first World Trade Center tower when it collapsed on September 11. He was able to extricate himself and sought refuge in the other tower, only to have it collapse on him as well. His luck was bad in one sense, but he had remarkable good fortune in that he was able to extricate himself from unstable structures on both occasions.) Rescuers should not enter a potentially unstable blast site until its structural integrity has been assets by engineers and until steps have been take to shore up or pull down unstable elements. This was a major issue in the Oklahoma City explosion. Rescuers should never be allowed to enter unstable structures to recover remains.When an explosion results in fire and structural collapse, the resulting mechanical instability of a structure poses an immediate threat to rescuers. Some victims may be able to extricate themselves. (One New York City firefighter was in the first World Trade Center tower when it collapsed on September 11. He was able to extricate himself and sought refuge in the other tower, only to have it collapse on him as well. His luck was bad in one sense, but he had remarkable good fortune in that he was able to extricate himself from unstable structures on both occasions.) Rescuers should not enter a potentially unstable blast site until its structural integrity has been assets by engineers and until steps have been take to shore up or pull down unstable elements. This was a major issue in the Oklahoma City explosion. Rescuers should never be allowed to enter unstable structures to recover remains.

33. Explosion Site as HazMat Incident Stored hazardous materials released. Blood and body fluids. Decomposition of remains. Personal Protective Equipment essential. Remember that an explosion may also generate a hazardous materials incident. Stored hazardous materials may escape their containers and contaminate the site. If there are victims, the scene may be contaminated with blood and body fluids. Deterioration of human remains may become an issue. Appropriate personal protective equipment should be used to avoid contamination. We are only now beginning to recognize pulmonary disease resulting from inhaled contaminants during the recovery operations and subsequent clean-up following the World Trade Center collapse in 2001. Remember that an explosion may also generate a hazardous materials incident. Stored hazardous materials may escape their containers and contaminate the site. If there are victims, the scene may be contaminated with blood and body fluids. Deterioration of human remains may become an issue. Appropriate personal protective equipment should be used to avoid contamination. We are only now beginning to recognize pulmonary disease resulting from inhaled contaminants during the recovery operations and subsequent clean-up following the World Trade Center collapse in 2001.

34. Explosion Site as Crime Scene All explosions will be investigated. Preserve evidence! Disturb site only as necessary to rescue the living. Do not disturb fatalities. Be wary of secondary devices. In many ways, the issues for health care professionals following an explosion are the same whether an explosion is an accident or whether it is a deliberate attack. The same approach will be taken with regard to rescue, triage, and treatment. And the same approach will be taken with regard to preservation of evidence. Every explosion will be investigated to determine what caused the explosion and whether it was accidental or deliberate. The investigation will be conducted by fire investigators and possibly by other law enforcement officials. The scene of an explosion should be disturbed only as required to rescue living victims, so that potential evidence can be preserved. Fatalities should not be disturbed until recovery is authorized by law enforcement officials. Remember that the scene of an explosion is a very dangerous area. Secondary devices may have been placed by a perpetrator. Criminals and terrorist will often lure first responders by detonating an explosion with the intent to kill them with a secondary device while they are focused on rescue, fire suppression, and investigation of the initial event. What better way to demoralize a community than to annihilate its public safety protectors, as was clearly demonstrated on September 11. 2001. In many ways, the issues for health care professionals following an explosion are the same whether an explosion is an accident or whether it is a deliberate attack. The same approach will be taken with regard to rescue, triage, and treatment. And the same approach will be taken with regard to preservation of evidence. Every explosion will be investigated to determine what caused the explosion and whether it was accidental or deliberate. The investigation will be conducted by fire investigators and possibly by other law enforcement officials. The scene of an explosion should be disturbed only as required to rescue living victims, so that potential evidence can be preserved. Fatalities should not be disturbed until recovery is authorized by law enforcement officials. Remember that the scene of an explosion is a very dangerous area. Secondary devices may have been placed by a perpetrator. Criminals and terrorist will often lure first responders by detonating an explosion with the intent to kill them with a secondary device while they are focused on rescue, fire suppression, and investigation of the initial event. What better way to demoralize a community than to annihilate its public safety protectors, as was clearly demonstrated on September 11. 2001.

35. Types of Injuries with Explosions Type I: Blast wave pressure injuries Type II: Flying debris strikes victim Type III: Victim thrown into stationary object Type IV: Thermal burns, radiation, inhalation, crush injuries Blast injuries are divided into four types. Type One are caused by the blast wave and overpressurization itself. Type Two are cause by debris which becomes missiles when propelled by blast wind. Type Three injuries result from the victim being propelled by the blast wind into an immovable object. Type Four injures are all other injuries resulting from the explosion, such as burn injuries, or crushing injuries inflicted by collapsing structures.Blast injuries are divided into four types. Type One are caused by the blast wave and overpressurization itself. Type Two are cause by debris which becomes missiles when propelled by blast wind. Type Three injuries result from the victim being propelled by the blast wind into an immovable object. Type Four injures are all other injuries resulting from the explosion, such as burn injuries, or crushing injuries inflicted by collapsing structures.

36. Type I Injuries Overpressure injuries are not familiar to many trauma care providers. Solid, non-compressible organs vibrate during overpressurization. Gas-filled organs are compressible. Rapid changes in pressure results in distortion and tearing. Type One injuries are cause by blast overpressurization itself. These injuries do not occur commonly in American civilian life and may be unfamiliar to trauma care providers who are not veterans of battlefield medicine. The are all to familiar in Ireland and the Middle East. Solid tissues such as the liver are noncompressible, just as a fluid cannot be compressed. A solid organ will only vibrate as a whole in response to the blast wave. Gas filled organs, such as lung and bowel, are compressible and have tissue-gas interfaces. This results in the distortion and tearing of tissue when subjected to overpressurization.Type One injuries are cause by blast overpressurization itself. These injuries do not occur commonly in American civilian life and may be unfamiliar to trauma care providers who are not veterans of battlefield medicine. The are all to familiar in Ireland and the Middle East. Solid tissues such as the liver are noncompressible, just as a fluid cannot be compressed. A solid organ will only vibrate as a whole in response to the blast wave. Gas filled organs, such as lung and bowel, are compressible and have tissue-gas interfaces. This results in the distortion and tearing of tissue when subjected to overpressurization.

37. Mechanisms of Type I Injuries Spalling Implosion Differential acceleration and deceleration. When a shock wave travels through a dense medium into a less dense medium, a negative reflection is created at the interface, creating fragmentation of the surface of the dense medium. Thus when a shock wave travels from bowel wall into the gas filled lumen, pressure is reflected back into the bowel 180 degrees out of phase, causing structural damage to the bowel wall. If one strikes the outside of a rusty bucket with a hammer, rust will flake off the interior of the bucket. This is called “spalling”. “Implosion” occurs when a high pressure is exerted onto the solid walls of an gas-filled structure. The volume of the gas-filled structure is rapidly reduced, disrupting its solid walls. Blood and fluid are forced from the walls into the lumen. This is especially important in the lungs, where pulmonary compression injury and hemorrhage occurs. Tissues of different density accelerate and decelerate at different rates, resulting in shearing forces that tear tissues. When a shock wave travels through a dense medium into a less dense medium, a negative reflection is created at the interface, creating fragmentation of the surface of the dense medium. Thus when a shock wave travels from bowel wall into the gas filled lumen, pressure is reflected back into the bowel 180 degrees out of phase, causing structural damage to the bowel wall. If one strikes the outside of a rusty bucket with a hammer, rust will flake off the interior of the bucket. This is called “spalling”. “Implosion” occurs when a high pressure is exerted onto the solid walls of an gas-filled structure. The volume of the gas-filled structure is rapidly reduced, disrupting its solid walls. Blood and fluid are forced from the walls into the lumen. This is especially important in the lungs, where pulmonary compression injury and hemorrhage occurs. Tissues of different density accelerate and decelerate at different rates, resulting in shearing forces that tear tissues.

38. Organs Commonly Injured Ears Lungs Central Nervous System Gastrointestinal Tract The organs most vulnerable to primary blast injury are the ears, lungs, central nervous system, and gastrointestinal tract. The organs most vulnerable to primary blast injury are the ears, lungs, central nervous system, and gastrointestinal tract.

39. Ear Manifestations Hearing loss Rupture of tympanic membrane Disruption of ossicles Perilymphatic fistula Hearing loss due to rupture of the tympanic membrane is the most common blast wave injury. More violent overpressurization will in turn produce disruption of the bones of the middle ear and perilymphatic fistula due to rupture of the round window in the inner ear.Hearing loss due to rupture of the tympanic membrane is the most common blast wave injury. More violent overpressurization will in turn produce disruption of the bones of the middle ear and perilymphatic fistula due to rupture of the round window in the inner ear.

40. Triage Pearl A patient with intact tympanic membranes is unlikely to have any other significant overpressure injury! Use the otoscope to triage blast victims. Rupture of the tympanic membrane occurs at a pressure differential between the external ear and the middle ear of about seven pounds per square inch. This is of great prognostic significance, since a patient without rupture of the tympanic membrane is extremely unlikely to have any other significant overpressure injury. This provides us with an important triage tool: the otoscope exam. Rupture of the tympanic membrane occurs at a pressure differential between the external ear and the middle ear of about seven pounds per square inch. This is of great prognostic significance, since a patient without rupture of the tympanic membrane is extremely unlikely to have any other significant overpressure injury. This provides us with an important triage tool: the otoscope exam.

41. Pulmonary Overpressure Syndrome Most life threatening pressure wave injury. Alveolar rupture. Interstitial and intra-alveolar hemorrhage and edema. Lacerations of lung and pleura. Alveolar-venous fistulae. The lungs are the organs most severely affected by blast injury and are most likely to pose a threat to life. The blast wave causes widespread alveolar injury because of its tissue-gas interface. There is associate interstitial and intra-alveolar hemorrhage and edema. There are lacerations of the parenchyma of the lung and pleura, with the formation of alveolar-venous fistula. Alveolar-venous fistulae are channels by which air can be introduced into the vascular tree. The lungs are the organs most severely affected by blast injury and are most likely to pose a threat to life. The blast wave causes widespread alveolar injury because of its tissue-gas interface. There is associate interstitial and intra-alveolar hemorrhage and edema. There are lacerations of the parenchyma of the lung and pleura, with the formation of alveolar-venous fistula. Alveolar-venous fistulae are channels by which air can be introduced into the vascular tree.

42. Pulmonary Overpressure Syndrome Non-cardiogenic pulmonary edema Subcutaneous and mediastinal emphysema Simple pneumothorax or tension pneumothorax Arterial air embolism. Findings secondary to lung injuries may include non-cardiogenic pulmonary edema, subcutaneous and mediastinal emphysema, simple pneumothorax or tension pneumothorax, and arterial air embolism. Glossary: Non-cardiogenic pulmonary edema: leakage of tissue fluid into the alveolar air sacs through damaged alveolar wall membranes. Subcutaneous and mediastinal emphysema: bubbles of air in the loose tissues under the skin and in the space between the lungs and surrounding the heart. Findings secondary to lung injuries may include non-cardiogenic pulmonary edema, subcutaneous and mediastinal emphysema, simple pneumothorax or tension pneumothorax, and arterial air embolism. Glossary: Non-cardiogenic pulmonary edema: leakage of tissue fluid into the alveolar air sacs through damaged alveolar wall membranes. Subcutaneous and mediastinal emphysema: bubbles of air in the loose tissues under the skin and in the space between the lungs and surrounding the heart.

43. CNS Blast Wave Injuries Blast wave concussive effects. Brain tissue injury with bleeding and swelling. Embolic stroke secondary to arterial air embolism. Central nervous system injuries are of two type. (1) Direct shock wave effects cause a concussion syndrome with transient loss of consciousness. If there is actual disruption of nerve tissue in the brain, then hemorrhage and swelling may occur, with resulting coma. (2) If air is introduced into the arterial system because of lung injury, the air bubbles may migrate into the cerebral circulation, causing embolic stroke.Central nervous system injuries are of two type. (1) Direct shock wave effects cause a concussion syndrome with transient loss of consciousness. If there is actual disruption of nerve tissue in the brain, then hemorrhage and swelling may occur, with resulting coma. (2) If air is introduced into the arterial system because of lung injury, the air bubbles may migrate into the cerebral circulation, causing embolic stroke.

44. Gastrointestinal Overpressure GI blast injury is more common in explosions on or under the water. Results in damage to bowel wall, including perforated viscus. May be detected as occult or gross blood in the stool. If perforation occurs, the typical findings or perforated viscus are expected. Barotrauma to stomach and bowel occur at the tissue-gas interface between the gut wall and the lumen. This results in tearing, hemorrhage and perforation. Clinical findings may include melena or gross blood in the stool, findings of an acute abdomen, and free air in the peritoneal cavity. Because the large bowel contains more gas, it is more vulnerable to injury. Because water is more dense than air, an underwater explosion results in faster propagation of the pressure wave and greater transfer of energy. This results in a much higher incidence of gastrointestinal barotrauma when the victim is in the water, such as might be the case following a shipboard incident.Barotrauma to stomach and bowel occur at the tissue-gas interface between the gut wall and the lumen. This results in tearing, hemorrhage and perforation. Clinical findings may include melena or gross blood in the stool, findings of an acute abdomen, and free air in the peritoneal cavity. Because the large bowel contains more gas, it is more vulnerable to injury. Because water is more dense than air, an underwater explosion results in faster propagation of the pressure wave and greater transfer of energy. This results in a much higher incidence of gastrointestinal barotrauma when the victim is in the water, such as might be the case following a shipboard incident.

45. WARNING! Potentially fatal primary blast injuries may not be initially obvious. Some blast victims are “dead men walking”. Signs and symptoms evolve over hours. Any victim with ruptured ear drums needs observation for twelve hours. Signs and symptoms of primary blast injury may not be initially obvious, even in victims whose injuries will ultimately prove fatal. Signs and symptoms of blast injury may evolve over a period of hours. The absence of ruptured tympanic membranes is a reassuring finding. All explosion victims who have ruptured tympanic membranes need to be observed for up to twelve hours to detect evolving evidence of primary blast injury. Signs and symptoms of primary blast injury may not be initially obvious, even in victims whose injuries will ultimately prove fatal. Signs and symptoms of blast injury may evolve over a period of hours. The absence of ruptured tympanic membranes is a reassuring finding. All explosion victims who have ruptured tympanic membranes need to be observed for up to twelve hours to detect evolving evidence of primary blast injury.

46. Management Blast victims should be managed as any trauma victim, with special attention to the respiratory system. Positive pressure ventilation may be necessary because of hemorrhage or fluid in the lungs, but risk or complications is high. Arterial gas emboli benefit from hyperbaric oxygen therapy. Blast victims should be managed as any trauma victim, with special attention to the respiratory system. Positive pressure ventilation may be necessary because of hemorrhage or fluid in the lungs, but risk or complications, such as tension pneumothorax and arterial air embolism, is high. Arterial gas emboli benefit from hyperbaric oxygen therapy. Blast victims should be managed as any trauma victim, with special attention to the respiratory system. Positive pressure ventilation may be necessary because of hemorrhage or fluid in the lungs, but risk or complications, such as tension pneumothorax and arterial air embolism, is high. Arterial gas emboli benefit from hyperbaric oxygen therapy.

47. Trauma Flying debris and violent impacts cause blunt and penetrating trauma Crush injuries and burns are similar to the same injuries caused by other mechanisms. Trauma not due to overpressure are very familiar to trauma care providers. Type two injuries secondary to flying debris and type three injuries that occur when the blast wind hurls the victim into a stationary object result in blunt and penetrating trauma which is very familiar to trauma care providers. Likewise, type three burns and crush injuries associated with explosions are no different than similar injuries resulting from other mechanisms.Type two injuries secondary to flying debris and type three injuries that occur when the blast wind hurls the victim into a stationary object result in blunt and penetrating trauma which is very familiar to trauma care providers. Likewise, type three burns and crush injuries associated with explosions are no different than similar injuries resulting from other mechanisms.

48. “Situations” Bomb threats Most made by phone Most are hoaxes Occur in clusters Often cause evacuation of workplace or school Most bomb threats are received by phone. Most are hoaxes. They tend to occur in clusters. They often serve the purpose of causing the evacuation of a workplace or a school.Most bomb threats are received by phone. Most are hoaxes. They tend to occur in clusters. They often serve the purpose of causing the evacuation of a workplace or a school.

49. Bomb Threats Information to get from caller: Location of bomb(s) Type/size of bomb(s) Time of Detonation Detonation timed, on command, or other Healthcare organizations should have policies on how to respond to bomb threats and suspicious objects. The person who receives the threat should ask the caller to identify the location of the bomb or bombs, the type and size of the bomb or bombs, the expected time of detonation, and the type of detonation device used. The more information the caller provides, the more likely that the threat is real.Healthcare organizations should have policies on how to respond to bomb threats and suspicious objects. The person who receives the threat should ask the caller to identify the location of the bomb or bombs, the type and size of the bomb or bombs, the expected time of detonation, and the type of detonation device used. The more information the caller provides, the more likely that the threat is real.

50. Bomb Threats Information from threat recipient Time and duration of call Background noises during call Attributes of caller’s voice The recipient of the threat should note the time and duration of the call, and should carefully note any background noises during the call and attributes of the callers voice. A list of possible voice attributes makes this task easier.The recipient of the threat should note the time and duration of the call, and should carefully note any background noises during the call and attributes of the callers voice. A list of possible voice attributes makes this task easier.

51. Bomb Threats Evacuation Procedures: Time until detonation Evacuation distance Shielding If the time until expected detonation is short, it may be wiser to shelter in place and rely on the structural integrity of the building than to begin evacuation and bring people into exposed positions which may be more hazardous if an actual explosion occurs The distance that people are evacuated away from the site of the reported bomb or actual suspicious object should be based on the destructive potential of the alleged bomb. The Bureau of Alcohol Tobacco, and Firearms has published recommended evacuation distances based on the size of the potential bomb. For example, evacuation distance from a small box containing less than thirty pounds of explosive is about 300 yards, while the evacuation distance from a semi-trailer would be more than 2,000 yards. Remember, if you can see the bomb, it can see you! It is better to move the people away from the bomb than to remove the bomb away from the people. Shielding can be buildings, vehicles, or terrain. The more shielding, the better. The denser the shielding, the better.If the time until expected detonation is short, it may be wiser to shelter in place and rely on the structural integrity of the building than to begin evacuation and bring people into exposed positions which may be more hazardous if an actual explosion occurs The distance that people are evacuated away from the site of the reported bomb or actual suspicious object should be based on the destructive potential of the alleged bomb. The Bureau of Alcohol Tobacco, and Firearms has published recommended evacuation distances based on the size of the potential bomb. For example, evacuation distance from a small box containing less than thirty pounds of explosive is about 300 yards, while the evacuation distance from a semi-trailer would be more than 2,000 yards. Remember, if you can see the bomb, it can see you! It is better to move the people away from the bomb than to remove the bomb away from the people. Shielding can be buildings, vehicles, or terrain. The more shielding, the better. The denser the shielding, the better.

52. “Situations” Suspicious Items Found in potential bombing target, such as an airport Often are false alarms Real threats often go unnoticed Suspicious objects are most often reported in secured areas which are potential targets, such as airports. Reporting is often stimulated by heightened aware of a threat as reported in the media. As a result, investigations of suspicious objects are often false alarms. On the other hand, the Ryder truck parked in front of the Murrah Building was apparently not perceive by security personnel and others as suspicious.Suspicious objects are most often reported in secured areas which are potential targets, such as airports. Reporting is often stimulated by heightened aware of a threat as reported in the media. As a result, investigations of suspicious objects are often false alarms. On the other hand, the Ryder truck parked in front of the Murrah Building was apparently not perceive by security personnel and others as suspicious.

53. Conclusions Health professionals may encounter both accidental and intentional explosions. Blast overpressure injuries are unfamiliar to most providers and signs and symptoms must be intentionally sought. The appearance of bombs varies widely and are best recognized as “something out of place”. Every healthcare organization needs to have plans for responding to bomb threats and suspicious objects.

54. Acknowledgements This presentations borrows heavily from “Incident Response to Terrorist Bombings”, produced by the New Mexico Institute of Mining and Technology – Energetic Materials Research and Testing Center. “Emergency Medicine, Fourth Edition, produced by the American College of Emergency Physicians and edited by Judith Tintinalli, M.D. South Carolina AHEC wishes to give credit where credit is due. This presentations borrows heavily from “Incident Response to Terrorist Bombings”, produced by the New Mexico Institute of Mining and Technology – Energetic Materials Research and Testing Center. AND Emergency Medicine, Fourth Edition, produced by the American College of Emergency Physicians and edited by Judith Tintinalli, M.D.South Carolina AHEC wishes to give credit where credit is due. This presentations borrows heavily from “Incident Response to Terrorist Bombings”, produced by the New Mexico Institute of Mining and Technology – Energetic Materials Research and Testing Center. AND Emergency Medicine, Fourth Edition, produced by the American College of Emergency Physicians and edited by Judith Tintinalli, M.D.