This document discusses explosives, improvised explosive devices (IEDs), and blast injuries. It begins by providing historical examples of bombings and notes that 70% of terrorist incidents involve conventional explosives. It then explains the explosion process and describes the shock wave and different phases. Primary blast injuries involve gas-containing organs and can include ruptured eardrums, lung injuries, and bowel injuries. Secondary injuries involve penetrating shrapnel and tertiary injuries include blunt trauma from being thrown. The document concludes by noting the massive destruction caused by suicide bombers and importance of understanding explosives and blast-related injuries.

1. Explosives, IED’s and
Blast Injuries
Dale Carrison, DO, MS, FACEP, FACOEP
Professor/Chairman Emergency Medicine
University Medical Center
University of Nevada School of Medicine

2. Bombings
 First terrorist bombing in Belgium
1585
 6,000Kg gunpowder used to destroy
a bridge.
 > 1,000 fatalities, many with no
external evidence of injury.

3. Bombings
 70% of all terrorists incidents are
conventional.
 10,000 terrorists explosions from
1990-1995.
 Goal is to induce panic and
apprehension.

4. Explosion
 Rapid chemical conversion of a solid
or liquid into a gas with resultant
energy release.

5. Explosives
 Propellants (e.g., gunpowder) release
energy relatively slowly.
 High explosives (e.g., TNT, PETN, C-4)
almost instantaneous transformation of
the physical space occupied by the
original material within a few
microseconds. Therefore, under extremely
high pressure.

6. 5 Billion Pounds
Produced Each Year in U.S.
Explosive matter
Explosives
Chemicals for non-
explosive purpose
High explosives(HE) Propellants(LE) Pyrotechnic (LE)
°1 °2
Military-
grade
Industrial-
grade
Gun
Rocket
Lead azide
Hg fulminate
Tetrazene
Singles = TNT;
RDX; PETN;
Mixes = CB;
RDX-based
plastics; Torpex
Gelatins;
powders;
permitted;
ANFO; slurries,
emulsions
Black
powder
Double base;
composites;
liquid fuels;
oxidizers
Flashes, Flares
Fume generators
Optical/acoustic
signals, fireworks
Fertilizer grade
ammonium nitrate
Chlorates as weed
killers
Gas generating for
foam plastics
Organic peroxides as
catalysts
NTG and PETN-soln
for pharmaceuticals
Salts of nitrated
organic acids for pest-
control
From Explosives, R. Meyer – 5th Edition

7. Explosion
 Virtual instantaneous increase in
pressure can be so abrupt that high-
explosive blast waves (blast wind)
are also “shock waves.”
 Shock waves possess a
characteristic called “brisance”
(shattering effect).

8. Explosion
 The gas expands with an exponential
increase in pressure.
 It forms a sphere.
 The sphere of this compressed air is
called a shock wave, blast pressure
head, blast wind, or blast wave.
 Leading edge is called the “blast
front.”

9. POLICE
POLICE
EFFECTS OF AN EXPLOSION

11. Explosion

12. PROCESS OF DETONATION

13. Blast Front

14. Explosion
 This wave of compressed air can be
measured as overpressure or direct
impulse.
 The magnitude of the overpressure is
proportional to the amount and type
of explosive used.

15. Overpressure
 Overpressure is measured in pounds
per square inch.
 Relative power is calculated by
multiplying PSI X duration in
milliseconds of the impulse.

16. Overpressure
 Overpressure of 58 – 80psi is 95%
lethal.
 7 – 8psi can shear brick walls or
overturn rail cars.
 5psi can rupture tympanic
membranes.
 0.5 – 1psi can break windows and
knock people down.

17. Shock Wave
 The shock wave has 3 components:
– Positive phase
– Negative phase
– Mass air movement.

18. POLICE
POLICE
Dynamite
Positive Phase
Negative Phase
After an Explosion
EFFECTS OF AN EXPLOSION

19. Shock Wave
 Positive phase.
– Velocity and duration of the blast head.
 Dependant upon:
– Size/type of the explosive
– Surrounding media
– Distance from the detonation.

20. Shock Wave
 Closed spaces magnify the effects of
the direct impulse.
 “Shock Wave” “bounces” off hard
surfaces and is referred to as a
“Reflected Impulse.”

21. Shock Wave
 Shock waves all create similar rates
of rise in pressures at the blast front.
 The magnitude of this “positive-
phase impulse” becomes the
important property in the generation
of the Primary Blast Injury (PBI).

22. Shock Wave
 Negative phase.
– Partial vacuum is created near the
epicenter after outward movement of air
– Consumption of oxygen by the burning
process.

23. Shock Wave
 The “reflected impulse” may
combine with the “direct impulse”
and increase injuries at a greater
distance from the blast site than
expected.

24. Shock Wave

25. Shock Wave
 Effects are cumulative.
 Example:
– A blast that causes a 1% mortality when
experienced once, causes a 20%
mortality when experienced twice, and
100% mortality if experienced three
times.

26. 1. Safety Fuse
2. Electric
Blasting Cap
3. Dynamite
Primary ExplosiveElectric Wires
Secondary Explosive
EXPLOSIVE DANGEROUS
EXPLOSIVE TRAIN
ELECTRIC BLASTING CAPS

27. EXPLOSIVE DANGEROUS
1. Shock Tube
2. Non-Electric
Blasting Cap
3. Dynamite
Primary Explosive
Secondary Explosive
HMX/Aluminum Powder
EXPLOSIVE TRAIN
Shock Wave
SHOCK TUBE

28. 1. Safety Fuse
2. Non-Electric
Blasting Cap
Low Explosive Primary Explosive
(Black Powder)
EXPLOSIVE TRAIN
TIME/SAFETY FUSE
EXPLOSIVE DANGEROUS Shock Wave
4. ANFO
Blasting Agent
3. Booster
Secondary Explosive

29. 1. Safety Fuse
2. Non-Electric
Blasting Cap
Low Explosive Primary Explosive
(Black Powder)
EXPLOSIVE TRAIN
TIME/SAFETY FUSE
EXPLOSIVE DANGEROUS Shock Wave
4. ANFO
Blasting Agent
3. Booster
Secondary Explosive

30. Tactical Uses

35. Det Cord Injury

36. POLICE
POLICE
INJURIES
Blasting Cap
M-80
I.E.D.
M-116
Pipe Bomb
Fireworks
CO2

37. Injuries
 Primary blast injuries (overpressure)
occur in gas-containing organ
systems.
– Middle ear,
– Lungs,
– Bowels.

38. Physical Findings

39. PBI
 New research indicates that most
pathophysiologic effects on the body
result from the consequences of
extreme pressure differentials
developed at body surfaces.

40. PBI
 “Blast loading”
 Force results in rapid acceleration of
the surface, creating a relatively
high-frequency “stress wave”
propagated into the underlying
tissues.

41. PBI – Tympanic Membrane
 Tympanic membrane ruptured from
overpressure of 1 – 8 psi.
 Less common is dislocation of the joints
in the inner ear.
 Temporary hearing loss very common.
 Structural damage to the organ of Corti
can cause permanent hearing loss.

42. PBI – Tympanic Membrane
 Studies show no correlation between
ruptured TM and Blast Lung.
 TM’s generally heal without
complications

43. PBI - Lung
 Pulmonary contusion
– Worse on side of approach of blast
waves in open air.
– Bilateral and diffuse when victim is
located in confined space.
 Degree of pulmonary pathology is
proportional to the velocity of chest
wall displacement.

44. Blast Lung
 PBI to lung is referred to as blast
lung.
 Greater incidence in confined spaces
 Major cause of death in PBI’s
 Alveolar membranes torn
 Minimal to massive hemorrhage with
hemothorax or air emboli

45. Blast Lung
 Diagnosis made clinically
 Confirmed by CXR showing a
butterfly appearance with or without
pneumothorax
 Similar to Pulmonary Contusion or
ARDS
 Respiratory distress with hypoxemia
greatest in the first 72 hours.

46. Blast Lung
 Treatment similar to Pulmonary
Contusion.
 Studies have shown no long term
effects
 Generally normal after 1 year

47. Degree of Injuries - Pulmonary

48. PBI - Hypotension
 Bradycardia and hypotension
without hemorrhage.
– Blast loads directly at the chest cause a
unique vagal nerve-mediated form of
cardiogenic shock without
compensatory vasoconstriction.
– Occurs within seconds and resolves
over 1 – 2 hours.

49. PBI – Arterial Air Embolus (AAE)
 Hemopneumothoraces, traumatic
emphysema, and alveolovenous
fistulas from stress-induced tears of
air-tissue interfaces.
 Lead directly to bronchopleural
fistulas or Arterial Air Embolus
(AAE).

50. PBI - AAE
 AAE to the brain or head may be the
most common cause of rapid death
caused solely by PBI in immediate
survivors.
 May be precipitated by positive-
pressure ventilation (PPV).
 Often occurs at the moment of PPV.

51. PBI - Abdomen
 Injuries occur in similar manner and
at similar overpressures to the lungs.
 Hemorrhages, from petechiae to
large hematomas are the dominant
form of pathology.
 Colon most common site of
hemorrhage and/or perforation.

52. PBI - Abdomen
 Tension
pneumoperitonem
 Mesenteric, retrop
eritoneal, and
scrotal
hemorrhages.
 Usually no
significant
compression of
solid organs.

54. Pathology

55. Injuries - Penetrating
 Secondary blast
injuries
– Injuries from
devices that
contain foreign
bodies:
• Nails
• Rivets
• Ball bearings
• Nuts and bolts,
• Etc.

56. Secondary Missiles

57. Injuries – Penetrating

58. Injuries - Penetrating
 Medically, usually no
different than other
penetrating injuries
seen.
 Complicated by the
PBI’s.
 Bone and tissue from
suicide bombers may
be secondary
missiles.
– Aids, hepatitis, etc.

59. Injuries - Penetrating
 Secondary missiles created by
container fragments or added
missiles can have velocities of up to
1,500m/sec.
 Rapid deceleration seconday to poor
ballistic properties.

60. Injuries
 Tertiary injuries – Blunt trauma.
– Physically thrown through the air and
strike or impale themselves on objects.
– Collapsing structures.
– Other objects propelled through the air
striking the victim.

61. Tertiary Injuries
 Severe head injury is a leading cause
of death in victims of blasts.
 Subdural and subarachnoid
hemorrhages are the most common
findings in fatalities.

62. Injuries
 Thermal injuries
 Primary or
secondary
incendiary.
– Inhalation
– Dermal

63. Thermal Burns
– Few victims admitted to burn centers
– Little skin grafting needed

64. Thermal Burns
Flash Burns
Large body surface area
Shallow depth

65. EMS Scene
 Contact incident
commander to ensure
that the area is safe to
enter.
 Beware of #2 or
secondary explosion
directed at personnel
responding to the first
incident.

66. EMS Scene
 Recent studies suggest the PBI
victims do poorly when strenuous
physical activity follows significant
blast loading.
– Reduce activity of potential blast-
exposed individuals.
– Provide history of activity to ED
personnel receiving patient.

67.  Post Mortem Care - Mass fatality event
–Identification & notification
– Family Assistance Center needed at scene!

68. Suicide Bombs
 Explosives worn on
belt or vest
 Significant Shrapnel
 Arms raised to
maximize damage

69. Suicide Bombers
 Why Suicide?
 Prevention is difficult to impossible !
– NO SECURITY SYSTEM IS
IMPENETRABLE IF THE BOMBER HAS
A SUICIDAL INTENT
 Terrorists can change targets at the
last minute
– Crude guided missile
 Suicide Bombers = only 0.6% of all
attacks . . .
. . . but 66% of all fatalities!

70. Suicide Bombers
 With explosive
device strapped to
body they sustain
massive injuries.
 Frequently lose
their heads,
secondary to the
primary explosion.

71. Suicide Bombers
 They sustain
massive bodily
injuries because of
being at ground
zero.
Remains of first terrorist in yard
Remains of third terrorist - (probably blew up with dog)

72. Suicide Bombers
 Devices designed for maximum explosive
value and fragmentation.

73. Suicide Bombers
 Easily concealable
and maximum
secondary missile
effect.

74. Improvised Explosive Device:
IED

75. IED’s
 Explosive material
 Shrapnel
 Common package
Women’s clinic
Otherside nightclub

76. Package Bombs
Light enough to carry easily
Common enough to blend in
Centennial park

77. POWER SOURCE – 9-V
Firing switch in comparison
to similar switch

78. RESIDUE OF SUITCASE SUITCASE FRAME
RIGHT SHOE
OF THE BOMBER

79. RESIDUE OF A LEATHER OBJECT
NYLON CLOTH STRIPS

80. CARDBOARD GLUED TO
BULB HOUSE
BULB HOUSE WHICH HOUSED THE INITIATOR

81. POWER SOURCE – 9-V
FIRING
SWICH.
SIMILAR SWICH.
ELECTRIC WIRES.

82. RESIDUE OF
DETONATOR
SIMILAR
DETONATOR

83. RESIDUE OF MOBILE PHO
COMPERISSON OF PIECES FOUND AT THE SC
WITH A SIMILAR MOBILE PHONE

84. GENERAL VIEW –
INSIDE OF THE CAR
DRIVER'S SEAT
FRAME
HEAD SUPPORT

85. Suicide Bombers Massive Destruction

86. Suicide Bombers Massive Destruction

87. Suicide Bombers
 Car bombing with
early detonation.

88. PSYCHOLOGICAL TRAUMA

89. PSYCHOLOGICAL TRAUMA

90. Conclusion
 Basic Understanding of Explosive
and Explosive Devices
 Awareness of Explosive Injuries
 Awareness of Suicide Bombers and
IED’s
 Awareness of Presence of Evidence

91. Explosives and Blast Injuries
QUESTIONS