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4th Annual Disaster Medicine Symposium


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Title: 4th Annual Disaster Medicine Symposium

4th Annual Disaster Medicine Symposium
Public Health Consequences of Earthquakes
  • Charles E. Stewart MD EMDM MPH

  • A major earthquake affecting a large United
    States city has the potential to be the most
    catastrophic natural disaster ever seen in the

Frequency of Occurrence of Earthquakes
Descriptor Magnitude Average Annually
Great 8 and higher 1 ¹
Major 7 - 7.9 17 ²
Strong 6 - 6.9 134 ²
Moderate 5 - 5.9 1319 ²
Light 4 - 4.9 13,000(estimated)
Minor 3 - 3.9 130,000(estimated)
Very Minor 2 - 2.9 1,300,000(estimated)
¹ Based on observations since 1900. ² Based on observations since 1990. ¹ Based on observations since 1900. ² Based on observations since 1990. ¹ Based on observations since 1900. ² Based on observations since 1990.
Scope/Relative Importance of Earthquake
  • During the past 20 years, earthquakes alone have
    caused more than a million deaths worldwide.
  • Nine countries account for more than 80 of all
    fatalities this century, and almost half of the
    total number of earthquake deaths in the world
    during this period have occurred in just one
  • The United States has been lucky so far.
  • Only an estimated 1,600 deaths have been
    attributed to earthquakes since colonial times,
    with over 60 of these having been recorded in

Growing Risks
  • Population growth in areas of high seismic risk
    in the United States has greatly increased the
    number of people at risk since the last
    earthquake of great magnitude struck (1906 in San
  • There are a LOT more people in Memphis than in
  • Researchers estimate that a repetition of the
    1906 San Francisco earthquake, which measured 8.3
    on the Richter scale, could cause 2,000 to 6,000
    deaths, 6,000 to 20,000 serious injuries, and
    total economic losses exceeding 120 billion

Growing Risks
  • Earthquakes have even occurred on the east coast.
  • Charleston, South Carolina, experienced a
    magnitude 6.8 (Intensity X) earthquake in 1886
    that killed 83 people and was felt over most of
    the United States east of the Mississippi River
  • Washington DC earthquake (5.9 Richter) 23 August
    2011 had significant damage to many monuments
    including the Washington Monument.

Factors that Contribute to Earthquake Disasters
  • Depending on magnitude, proximity to an urban
    center, and the degree of earthquake disaster
    preparedness and mitigation measures implemented
    in the urban center, an earthquake can cause
    large numbers of casualties.
  • The risk of catastrophic earthquakes in the
    western part of the United States is widely
  • Few people realize the high probability that a
    major earthquake will hit the eastern United
    States in the next several decades.
  • Three great earthquakes (estimated magnitudes
    8.6, 8.4, and 8.7) all of intensity XII occurred
    during a 3-month period in the winter of
    1811-1812 near the town of New Madrid, Missouri.

Trauma in an Earthquake
  • Trauma caused by the collapse of buildings or
    falling pieces of the building is the cause of
    most deaths and injuries in most earthquake.
  • Deaths resulting from major earthquakes can be
    instantaneous, rapid, or delayed.

Injuries Causing Death
Minor Injuries Following Earthquakes
  • The majority of people requiring medical
    assistance following earthquakes have minor
    lacerations and contusions caused by falling
    elements like pieces of masonry, roof tiles, and
    timber beams.
  • The next most frequent reason for seeking medical
    attention is simple fractures not requiring
    operative intervention.
  • Such minor injuries usually require only
    outpatient-level treatment and tend to be much
    more common than severe injuries requiring

Major Injuries Following Earthquakes
  • Major injuries requiring hospitalization
  • Skull fractures with intracranial hemorrhage
    (e.g., subdural hematoma)
  • Cervical spine injuries with neurologic
  • Damage to intrathoracic, intra-abdominal, and
    intrapelvic organs such as pneumothorax, liver
    lacerations, and ruptured spleen
  • Most seriously injured people will sustain
    combination injuries, such as pneumothorax in
    addition to an extremity fracture.

Injuries Causing Death
  • Instantaneous death
  • Severe crushing injuries to the head or chest
  • External or internal hemorrhage
  • Drowning from earthquake-induced tidal waves
  • Rapid death occurs within minutes or hours
  • Asphyxia from dust inhalation or chest
  • hypovolemic shock
  • environmental exposure (e.g., hypothermia)

Injuries Causing Death
  • Delayed death occurs within days
  • Dehydration
  • Hypothermia
  • Hyperthermia
  • Crush syndrome
  • Wound infections
  • Postoperative sepsis

Injuries Causing Death
  • Identified major medical complications causing
    frequent deaths in past earthquakes
  • Crush syndrome
  • Hypothermia
  • Secondary wound infections
  • Gangrene requiring amputation
  • Sepsis
  • Adult respiratory distress syndrome (ARDS)
  • Multiple organ failure

Other Problems
  • A large number of patients require acute care for
    nonsurgical problems
  • Acute myocardial infarction
  • Exacerbation of chronic diseases
  • diabetes or hypertension
  • Anxiety and other mental health problems
  • Respiratory disease caused by exposure to dust
    and asbestos fibers from rubble
  • Near drowning caused by flooding from broken dams
    or tsunami

More Problems
  • Substantial morbidity following earthquakes can
    be caused by
  • Building contents (e.g., glass, furniture,
    fixtures, appliances, chemical substances)
  • Nonstructural elements (e.g., facade cladding,
    partition walls, roof parapets, external
    architectural ornaments)

  • Submarine earthquakes can generate damaging
  • A tsunami can be created directly by underwater
    ground motion during earthquakes or by
    landslides, including underwater landslides.
  • Can travel thousands of miles at speeds of 300
    600 mph bringing destruction to low-lying coastal
    areas, bays and harbors.

  • Most earthquakes are followed by many aftershocks
  • May be as strong as the main shock itself
  • Many fatalities and serious injuries occurred
    from a strong aftershock
  • 2 days after the September 19, 1985, Mexico City
    earthquake that killed an estimated 10,000
  • Landslides may be triggered by an aftershock
  • Some major debris flows start slowly with a minor
    trickle and then are triggered in waves.
  • Sufficient warning allows a community to evacuate
    in time

Time of Day
  • Time of day is an important determinant of a
    population's risk for death or injury
  • For example, the 1988 Armenia earthquake occurred
    at 1141 AM, and thus many people were trapped in
    schools, office buildings, or factories.

Human-Generated Factors
  • Fires and dam ruptures following an earthquake
    are examples of major human-caused complications
    that aggravate the destructive effects of the
    earthquake itself.
  • Transportation may become difficult as roads and
    bridges are destroyed.

Human-Generated Factors
  • In industrialized countries, an earthquake may
    also be the cause of a major technological
  • Damaging or destroying
  • nuclear power stations
  • research centers
  • hydrocarbon storage areas and complexes making
    chemical and toxic products
  • can lead to many more deaths than those caused
    directly by the earthquake
  • Note that in the recent Japanese earthquake,
    there was much more news about the reactors than
    the tsunami or the earthquake

Fire Risks
  • One of the most severe follow-on or secondary
    disasters that can follow earthquakes is fire.
  • Fire caused by
  • Overturned stoves
  • Heating appliances
  • Lights
  • Other items that can ignite materials

Fire Risks
  • Historically, earthquakes in Japan that trigger
    urban fires cause 10 times as many deaths as
    those that do not. The Tokyo earthquake of 1923,
    which killed more than 140,000 people, is a
    classic example of the potential that fires have
    to produce enormous numbers of casualties
    following earthquakes.
  • Fire was also a major cause of damage in the 1906
    San Francisco Earthquake.

  • Dams may fail
  • Threat to communities downstream
  • Inspection of all dams in the vicinity is
  • Rapid reduction of water levels behind any dam
    suspected of having structural damage

(No Transcript)
Landslides May 30, 1970 Peru disaster
Magnitude 7.9 A large mass of ice and rock
slid from a vertical face on Nevado Huascaran,
the highest peak in Peru Debris reached a
velocity of 280 km/hr traveled 11 km
horizontally in about 4 minutes at a mean
velocity of 165 km/hr. Buried the towns of
Yungay and Ranrahirca, The death toll in both
villages was 20,000.
Structural Factors
  • Type of housing construction is a major risk
    factor for injuries.
  • Third world construction is a real factor
  • Those living in newer style adobe houses are at
    highest risk for injury or death
  • Those living in the traditional mud and stick
    construction houses are at less risk
  • Traditional bamboo and paper construction used in
    Japan is quite earthquake tolerant.

Structural Factors
  • Type of housing construction is a major risk
    factor for injuries.
  • By far the greatest proportion of victims have
    died in the collapse of unreinforced masonry
    (URM) buildings (e.g., adobe, rubble stone, or
    rammed earth) or unreinforced fired-brick and
    concrete-block masonry buildings that can
    collapse even at low intensities of ground
    shaking and will collapse very rapidly at high
  • There are many homes built in this construction
    in the New Madrid area.

Structural Factors (cont.)
  • Wood-frame buildings such as suburban houses in
    California are among the safest structures one
    could be in during an earthquake.
  • Indeed, these buildings are constructed of light
    wood elements--wood studs for walls, wood beams
    and joists for floors, and wood beams and rafters
    for roofs.

Structural Factors (cont.)
  • The relative safety of wood-frame buildings has
    been shown quantitatively following the 1990
    Philippine earthquake.
  • People inside buildings constructed of concrete
    or mixed materials are three times more likely to
    sustain injuries
  • Even if the wood-frame buildings did collapse,
    their potential to cause injury is much less than
    that of old stone buildings, like those often
    used for businesses, offices, or schools.

Nonstructural factors
  • Nonstructural elements and building contents have
    been known to fail and cause significant damage
    in past
  • Facade cladding, partition walls, roof parapets,
    external architectural ornaments, unreinforced
    masonry chimneys, ceiling tiles, elevator shafts,
    roof water tanks, suspended ceilings and light
    fixtures, raised computer floors, and building
    contents such as heavy fixtures in hospitals are
    among the numerous nonstructural elements that
    can fall in an earthquake, sometimes causing
    injury or death.
  • In high rise buildings, window breakage presents
    a significant risk to the people below.

Factors Influencing Earthquake Morbidity And
  • Entrapment appears to be the single most
    significant factor associated with death or
  • In the 1988 Armenia earthquake, death rates were
    67 times higher and injury rates more than 11
    times higher for people who were trapped than for
    those who were not.
  • In the 1980 southern Italian earthquake,
    entrapment requiring assistance to escape was the
    most important risk factor the death rate was
    35 for trapped people versus 0.3 for untrapped
  • In the Philippine earthquake of 1990, people who
    died were 30 times more likely to have been
    trapped than were injured survivors.

Occupants Behavior
  • The behavior of people during an earthquake is an
    important predictor of their survival.
  • In several recent earthquakes (e.g., 1990
    Philippines and 1992 Egypt earthquakes), there
    were widespread reports of deaths and injuries
    due to stampedes, as panicked building occupants
    and students rushed for the nearest exits.
  • On the other hand, a review of the first reaction
    of people following an initial earthquake shock
    revealed that those who immediately ran out of
    buildings had a lower incidence of injury than
    did those who stayed inside.

Occupants Behavior
  • Other reports, however, suggest that running
    outside may actually increase the risk of injury.
  • During the 1976 Tangshan earthquake, many were
    struck by the collapse of outer walls after
    running out of their houses.
  • In modern high-rise buildings, falling glass can
    be lethal.

Time Until Rescue
  • Although the probability of finding live victims
    diminishes very rapidly with time, entrapped
    people have survived for many days.
  • People have been rescued alive 5, 10, and even 14
    days after an earthquake
  • These "miracle rescues" are often the result of
    exceptional circumstances--for example, someone
    with very light injuries is trapped in a void
    deep in the rubble with air and possibly water

Disaster Response to Earthquakes
  • Prompt rescue should improve the outcome of
  • Early medical treatment should lessen the
    sequellae of the primary injuries
  • Provision of adequate food, water, and shelter
    should help people in vulnerable age groups and
    those with pre-existing diseases.
  • Effective environmental control measures should
    prevent secondary environmental health problems.
  • Identification and control of long-term hazards
    (e.g., asbestos in rubble) should reduce chronic
    health effects.

Search and Rescue
  • People trapped in the rubble will die if they are
    not rescued and given medical treatment
  • Search and rescue teams responding rapidly after
    a building collapse maximizes trapped victims
    chances of survival

Search and Rescue (cont.)
  • Foreign assistance usually arrives after the
    local community has already engaged in much of
    the rescue activity
  • Exceptions
  • Personnel from neighboring countries in close
    geographical proximity

Monitoring Our Responses
  • Conduct of future rescue operations can be
    enhanced by lessons learned from the position and
    circumstances of trapped victims and from
    specific details about the extrication process
  • Knowledge of collapse conditions helps set rescue

Medical Treatment
  • Just as speed is required for effective search
    and extrication, it is also essential for
    effective emergency medical services.
  • The greatest demand occurs within the first 24
  • Ideally, "disaster medicine" (medical care for
    victims of disaster) would include immediate
    life-supporting first aid (LSFA), advanced trauma
    life support (ATLS), resuscitative surgery, field
    analgesia and anesthesia, resuscitative
    engineering (search and rescue technology), and
    intensive care.
  • This may not be readily available when local
    hospitals and response agencies are damaged.

Medical Treatment (cont.)
  • The medical and public health impact of a severe
    earthquake may well be compounded by significant
    damage to medical facilities, hospitals, clinics
    and supply stores within the affected area.
  • In the worst-case scenario, a hospital building
    may itself be damaged by the earthquake, and the
    hospital staff may have to continue emergency
    treatment without using the buildings.

Surveillance of Injuries at Medical Treatment
  • Treatment sites, whether at hospitals or in
    temporary field clinics should designate someone
    to organize surveillance of injuries, collect
    data, and see that the data are tabulated and
    reported to disaster-response health officials.

Dissemination of Public Health Information
  • Public health should work out scenarios for
    various information-dissemination contingencies
    before an earthquake occurs.
  • This will be difficult.
  • Telephone service is likely to be disrupted in
    the impact area of an earthquake.
  • However, police, fire, and many emergency service
    organizations maintain radio networks, which
    public health officials may be able to use.
  • Amateur radio may be of immense assistance
  • Radio and television news crews often arrive at
    the scene of a disaster with sophisticated
    communications equipment.

Environmental Health
  • In the day or so immediately following an
    earthquake, the priorities are undoubtedly
    rescuing and treating victims.
  • Saving the lives of those injured or trapped far
    outweighs most other needs.
  • Other needs of a population suddenly deprived of
    homes, possessions, urban services, and other
    essentials cannot be ignored and will assume
    greater significance as soon as the
    life-threatening situation stabilizes.

Environmental Health
  • If large areas of buildings are destroyed, the
    population made homeless will have an urgent need
    for shelter and food.
  • They will need drinking water, clothing,
    sanitation, hygiene education, and basic comfort
  • This may be difficult to provide when
    infrastructure has been damaged.
  • Effective environmental control measures should
    prevent secondary environmental health problems.

Critical Knowledge Gaps
  • Because we do not know enough about the precise
    causes of deaths and nature of injuries that
    occur during earthquakes, relief services are
    often misdirected and community medical/health
    planning for earthquakes is often inadequate.
  • The more we know, the better we can prepare for
    and respond to earthquakes. The following are
    steps researchers can take to help health
    officials and individuals better prepare for
    future earthquakes.

Epidemiology Research
  • Few earthquakes have been adequately studied
  • In most cases, we simply dont know what position
    people were in when the quake struck and killed
    them. We also dont know what saves survivors.
  • Good disaster medicine research requires that
    plans for follow-up epidemiology be developed
    before an earthquake occurs so that the initial
    surveillance data collected will allow proper
    follow-up and analysis of the data.

Critical Knowledge Gaps (cont.)
  • Evaluate the role of occupant behavior in
    earthquake injury susceptibility.
  • Collect more extensive data concerning the
    circumstances of entrapment (e.g., location of
    victims in the collapsed structure).
  • Lack of such data has made planning search and
    rescue actions, providing proper medical care,
    and requesting the appropriate outside aid more

Critical Knowledge Gaps (cont.)
  • Incorporate post-earthquake research findings
    into specific emergency-preparedness and
    response-guidance protocols.
  • The gap between what researchers have learned and
    the knowledge base underlying the protocols of
    the "user community" (e.g., response and recovery
    organizations) can be lessened considerably if
    researchers and members of the user community
    interface more effectively.
  • Results of research should be at national, state,
    and local levels so that they can incorporate
    such findings into community earthquake-preparedne
    ss and earthquake-response programs.

Methodologic Problems
  • The data needed for comparative earthquake
    studies is often lacking, including such basic
    information as the magnitude or intensity of the
    earthquake, the number of deaths, the number of
    people injured (using standard definitions) and
    the size of the affected population.
  • The study of earthquake injuries is difficult to
    approach from any narrow background, as it
    requires the active collaboration of researchers
    with a number of areas of expertise.
  • First, one must understand the mechanisms of
    physical failure in earthquakes. This requires
    structural engineering and architectural

Methodologic Problems
  • Second, one must understand the process of human
    injury in earthquake-induced building failure.
  • Third, one must develop the analytical framework
    for the analysis of injury patterns and for the
    analysis of the relationship between specific
    causative agents and negative consequences.

Methodologic Problems
  • One must consider
  • Hazard exposure
  • Construction types and their performance during
  • Influence of nonstructural components, building
    components, and building contents
  • Building occupancy and the behavior of occupants
  • Emergency and rescue response
  • Medical treatment provided
  • These plans for research must be done in advance
    "backtracking" injuries from hospitals to
    specific building-collapse sites may be

Earthquake size two ways to measure
  • Magnitude Richter Scale
  • Measures the energy released by fault movement
  • related to the maximum amplitude of the S wave
    measured from the seismogram
  • Logarithmic-scale quantitative measure
  • For each whole number there is a 31.5 times
    increase in energy
  • eg. an increase from 5 to 7 on the Richter scale
    an increase in energy of 992 times!!

  • 2) Intensity Mercalli Scale
  • What did you feel?
  • Assigns an intensity or rating to measure an
    earthquake at a particular location (qualitative)
  • I (not felt) to XII (buildings nearly destroyed)
  • Measures the destructive effect
  • Intensity is a function of
  • Energy released by fault
  • Geology of the location
  • Surface substrate can magnify shock waves e.g.
    Mexico City (1985) and San Francisco (1989)

Earthquake Preparedness
  • Develop a home earthquake plan.
  • Conduct earthquake drills.
  • Develop a plan for reuniting family members.
  • Identify an out-of-state family contact.
  • Keep supplies on hand.

Earthquake Preparedness
  • Store heavy and breakable objects on low shelves.
  • Secure bookshelves and water heaters.
  • Install flexible pipe.
  • Move beds away from windows.
  • Move or secure hanging objects over beds, sofas,
    or chairs.
  • Keep shoes and a flashlight under the bed.

During an Earthquake
  • Drop, cover, and hold.
  • If indoors, stay there!
  • If outdoors, find a spot away from buildings,
    trees, streetlights and power lines, and
  • If in a vehicle, drive to a clear spot and stop.

After an Earthquake
  • Extinguish small fires.
  • Clean up spills.
  • Inspect home for damage.
  • Help neighbors.
  • Tune to Emergency Alert System (EAS).
  • Expect aftershocks.

Take-Away Points
  1. Earthquakes generate waves that travel through
    the earth
  2. Earthquakes occur when rocks slip along faults
  3. Faults are classified by the kinds of movement
    that occur along them
  4. Earthquakes dont kill people, buildings kill
  5. Magnitude and Intensity
  6. Seismic waves are used to map the earths
  7. Predicting earthquakes is not yet possible

Charles Stewart MD EMDM, MPHcharles-e-stewart_at_ouh
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