Public Health Consequences of Earthquakes. Part II.

1
Public Health Consequences of Earthquakes. Part
II.

• Eric K. Noji, M.D., M.P.H.
• Centers for Disease Control and Prevention
• Washington, D.C.

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PREVENTION AND CONTROL MEASURES

• Until earthquake prevention and control measures
  are adopted and mitigation actions implemented
  throughout the United States, a single severe
  earthquake could cause tens of thousands of
  deaths and serious injuries and economic losses
  exceeding one hundred billion dollars (5).

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Primary Prevention of Earthquakes
Although we can neither prevent earthquakes nor
set off small ones to prevent big ones, we should
take earthquakes into consideration before
undertaking activities known to precipitate
earthquakes, such as making deep well injections,
filling water impoundments, and discharging
nuclear explosives underground.
4
Safer Construction
Recent research findings support the view that
preventing structural collapse is the most
effective approach to reducing earthquake-related
fatalities and serious injuries (5). Engineering
interventions have largely been directed to
increasing the ability of new buildings to
withstand ground shaking or to retrofitting
existing hazardous buildings. The most stringent
level of seismic security will allow buildings to
withstand earthquakes with little or no damage
(94).
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Safer Construction (cont.)
Anecdotal evidence from earthquakes in Guatemala
(1976), Mexico City (1985), and Armenia (1988)
suggests that suffocation from dust inhalation
may be a significant factor in the deaths of many
people who die without apparent severe external
trauma (15,46,97). However, the use of certain
building materials and finishes may reduce dust
production--for example, plasterboard may produce
less dust on collapse than wet applied plaster.
Developing and using methods of reducing dust
release during a building collapse could perhaps
prevent many deaths.
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Development and Enforcement of Seismic Safety
Codes
Because of improved building construction codes,
land use planning, and preparedness, the losses
in the San Francisco Bay area from the 1989 Loma
Prieta earthquake and in the Los Angeles area
from the 1994 Northridge earthquake were kept
much lower than would have occurred in a less
well-prepared region.
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Nonstructural Measures
Many injuries and much of the cost and disruption
from earthquakes are caused by the contents of
buildings, including equipment, machinery, and
other nonstructural elements. Therefore, the
structural stability and robustness to violent
shaking of all of these elements should be
reviewed. A room-by-room review is likely to
reveal many items that could cause injury to the
room's occupants in the event of violent shaking.
Although often beyond the purview of building
codes (or any reasonable hope of enforcement for
that matter), heavy furniture, glass cabinets,
appliances, and objects placed where they could
fall or be thrown about should be firmly secured
to prevent them from striking people in the event
of an earthquake. Special precautions must be
taken with sources of flame or electric filaments
in boilers, heaters, space heaters, pilot
lights,cookers,etc.because violent shaking could
cause fires.
8
Drills for Evasive Actions During Earthquakes
Earthquake drills are important. Earthquakes,
although sudden, are usually not instantaneous.
Building occupants usually have a few seconds to
react before the shaking reaches maximum
intensity, raising the possibility of taking
evasive action to escape injury (50,87,102).
Despite the relative lack of data on the efficacy
of various evasive actions, it seems worthwhile
for people to practice taking some evasive
actions particularly since they will have just a
few seconds to act when an earthquake strikes.
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Drills for Evasive Actions During Earthquakes
(cont.)
However, anecdotal stories should not be the
basis for responding to an earthquake there is a
distinct need to reassess all such widely
accepted citizen safety actions to ensure that
they are indeed the best responses (31,79,106).
Only by conducting epidemiologic studies of the
location of injured and noninjured people can we
determine which behaviors are truly most likely
to reduce the risk for injury.
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Planning Scenarios for Earthquakes

• Relative chaos is likely to
  prevail immediately after a major earthquake.
  Area residents, cut off from the outside, will
  initially have to help themselves and their
  neighbors (16,17). They can best do this if they
  have already planned their responses to the most
  likely earthquake scenarios and practiced the
  necessary skills (107).

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On the basis of the earthquake scenario that they
develop, public health officials should devise a
response plan. This plan should include the
following
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Disaster Response to Earthquakes
Disaster response to earthquakes is more akin to
medical treatment than to prevention, but some
aspects of the response may be likened to
tertiary prevention in that those responding seek
to limit further injury and to control the
secondary effects of the earthquake (92). Prompt
rescue should improve the outcome of victims, and
early medical treatment should lessen the
sequelae of the primary injuries (e.g., wound
complications, chronic neurological
disabilities). Provision of adequate food,
water, and shelter should especially 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.
13
Search and Rescue
People trapped in the rubble will die if they are
not rescued and given medical treatment. To
maximize trapped victims' chances of survival,
search-and-rescue teams must respond rapidly
after a building collapses.
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Search and Rescue (cont.)
With the exception of personnel from countries in
close geographical proximity, foreign assistance
usually arrives after the local community has
already engaged in much of the rescue activity.
15
Surveillance of Search and Rescue Activities
The 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
itself. Knowledge of collapse conditions helps
set rescue priorities.
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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 hours
(33). 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 (26).
17
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 (117).
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 (118).
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Surveillance of Injuries at Medical Treatment
Sites
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.
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Dissemination of Public Health Information
Public health organizations 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. Furthermore, radio and television
news crews often arrive at the scene of a
disaster with sophisticated communications
equipment.
20
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. However, the 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. If large areas of
buildings are destroyed, the population made
homeless will have an urgent need for shelter and
food (121). They will also need drinking water,
clothing, sanitation, hygiene education, and
basic comfort provision. Effective environmental
control measures should prevent secondary
environmental health problems.
21
Detailed Follow-Up Epidemiology
Few earthquakes have been adequately studied
epidemiologically, with the exceptions previously
noted (122). It is vital that plans for
follow-up epidemiology be developed before an
earthquake occurs so that the initial
surveillance data collected will allow proper
follow-up (123).
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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
  (126). The more we know about the manner in
  which injuries and deaths occur, 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 earthquakes.

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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 difficult.
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CRITICAL KNOWLEDGE GAPS (cont.)
! Incorporate postearthquake 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 communicated to key decision-makers and
citizens at national, state, and local levels so
that they can incorporate such findings into
community earthquake-preparedness and
earthquake-response programs.
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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 (131). The
study of earthquake injuries is difficult to
approach from any narrow background, as it
requires the active collaboration of workers
having a number of areas of expertise (122).
First, one must understand the mechanisms of
physical failure in earthquakes. This requires
structural engineering and architectural
competence.
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METHODOLOGIC PROBLEMS (cont.)
The difficulty of collecting information on
entrapped people is compounded by the fact that
traditional, institutionalized sources of injury
data (e.g., hospital medical records) do not
usually document information such as where in a
building the injury occurred, which attributes of
the building contributed to the injury, the
injured person's initial behavior when ground
shaking began, and the circumstances of
entrapment. Unfortunately, this lack of data on
the circumstances of entrapment tends to hinder
the development of effective search-and-rescue
techniques and effective injury-prevention
strategies.
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METHODOLOGIC PROBLEMS (cont.)
Analytic studies that establish and quantify the
magnitude of the relationship between significant
risk factors and injuries are also very difficult
to organize and conduct in an earthquake-devastate
d region where most dwellings have been destroyed
and populations relocated--factors that make
locating injured people extremely difficult.
Furthermore, in most areas of the world where
major earthquakes have occurred, official census
records are poor.
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RESEARCH RECOMMENDATIONS
! Seek to understand the mechanism by which
people are killed or injured in earthquakes
(e.g., what components of the building have
directly caused trauma). Such knowledge is
essential to developing effective prevention
strategies (134).
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RESEARCH RECOMMENDATIONS (cont.)
! Establish detailed autopsy data on a sample of
earthquake victims to determine the exact cause
of death. Such information could provide the
basis upon which to suggest modifications to
buildings to prevent death. Similar autopsy
information has been valuable in analyzing
automobile crashes and making appropriate
modifications to automobile interiors.
30
RESEARCH RECOMMENDATIONS (cont.)
! Analyze previous building failures in the
context of injury studies. The results could
lead to the development of simple but effective
retrofit prevention strategies designed to
mitigate injury or death.
31
RESEARCH RECOMMENDATIONS (cont.)
! Examine the manner in which buildings collapse
during other kinds of disasters. For example,
structural collapses caused by tornadoes,
hurricanes, single-building construction
failures, mine disasters, terrorist bombings,
aircraft or train crashes, wartime experiences,
and so on could provide valuable insights into
the manner in which buildings collapse during
earthquakes.
32
SUMMARY

• A major earthquake in one of our urban areas
  ranks as the largest potential natural disaster
  for the United States. Most of what can be done
  to mitigate injuries must be done before an
  earthquake occurs. Researchers have identified a
  number of potentially important risk factors for
  injuries associated (either directly or
  indirectly) with earthquakes. Because structural
  collapse is the single greatest risk factor,
  priority should be given to seismic safety in
  land-use planning and in the design and
  construction of safer buildings.