Transcript Public Health Consequences of Earthquakes. Part II. Eric K. Noji , M.D., M.P.H.

Public Health Consequences of
Earthquakes. Part II.
Eric K. Noji, M.D., M.P.H.
Centers for Disease Control and
Prevention
Washington, D.C.
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).
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.
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).
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.
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.
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 roomby-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.
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.
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.
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).
On the basis of the earthquake
scenario that they develop,
public health officials should
devise a response plan.
This plan should include the
following:
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.
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.
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.
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.
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).
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).
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.
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.
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.
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).
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.
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.
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 earthquakeresponse 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 (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.
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.
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-devastated
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.
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).
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.
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.
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.
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 landuse planning and in the design and construction of
safer buildings.