General effects of Disasters on
Health
2011.11.07
International health and health management
Prof. Naoki NAKAZONO
Term
Disaster refers to the natural event (,,,)
in combination with its damaging
effects (loss of life, destruction of ,,,).
Hazard refers to the natural event.
Vulnerability refers to the susceptibility
of population or system to the effects of
the hazard.
Risk is
The probability that a particular system
or population will be affected by hazard.
Risk is a function, expressed as
Risk=Vulnerability x Hazard
Disasters affect areas
with different levels of vulnerability
with distinct social, health, and
economic conditions.
However, there are still similarities
between disasters.
Lesson learned from Disasterｓ
Our goal is to optimize the management
of health humanitarian assistance and
use of resources,
to make strategic decisions to relieve
the victims and to reconstruct the
health system (response, mitigation)
to make disaster preparedness.
Lesson learned from Disasters
There is a relationship between the type of disaster
and its effect on health.
Some effects are potential, rather than inevitable,
threat to health.
The actual and potential health risks after disaster do
not occur at the same time.
Disaster-created needs for food, shelter, and primary
care are usually not total.
Civil wars and conflicts are also public health
problems.
Health problems common to all natural
Disasters
Social Reactions
Communicable Diseases
Population Displacements
Food and Nutrition
Water Supply and Sanitation
Mental Health
Damage to the Health Infrastructure
Social Reactions
After a major disaster, behavior rarely reaches
generalized panic or stunned waiting.
Spontaneous individual action accrues as survivors
rapidly recover from their initial shock.
Survivors begin search and rescue activities.
Antisocial behavior, widespread looting occurs only in
exceptional circumstances.
Rumors abound, particularly of epidemics.
People are reluctant to evacuate, even if their homes
are to be or have been destroyed.
Communicable Diseases(CD)
In certain circumstances, natural disasters increase
the potential for disease transmission.
Enteric disease caused by fecal contamination of water/food
Risk of epidemic outbreaks of CD is proportional to
population density and displacement.
Unsafe delivery of water supplies and food supplies
Disruption of preexisting sanitation services such as piped
water and sewage increases the risk of CD.
In the longer term, an increase in vector-borne disease
occurs because of disruption of vector control efforts.
Malnutrition, overcrowding, lack of basic sanitation
Population Displacements
When large, spontaneous or organized
population movements occur, an urgent need
to provide humanitarian assistance is created.
Public services to large number of population,
such as shelters, water, foods, fuel, toilets
Food and Nutrition
Food shortages in immediate aftermath may
arise in 2 ways. (extended droughts)
1:Food stock destruction within the disaster area→reduce the
amount of food available
2:Disruption of distribution system→hardly access to food
Food shortages cause nutritional problems.
Nutritional condition depends on the
populations, especially of vulnerable groups.
Water Supply and Sanitation
Drinking water supply and sewerage systems
are particularly vulnerable to natural disaster.
Disruptions in them pose to a serious health
risk.
Deficiencies in established amounts and quality of
portable water and difficulties in the disposal of
excreta and other wastes results in the
deterioration of sanitation.
That impact contributes to the conditions
favorable to spread of enteric and other diseases.
Mental Health
Anxiety, neuroses, and depression are not major.
Family and neighbors in rural/traditional societies can
deal with them temporarily.
Wherever possible, efforts should be made to
preserve family and community social structures.
In industrialized/metropolitan areas in developing
countries, mental health problems are reported to be
significant during long-term rehabilitation and
reconstruction during the reestablishing phase.
Damage to the Health
Infrastructures
Natural disasters can cause serious
damage to health facilities and water
supply and sewage systems, which
have a direct impact on the health of
the population dependent on these
services.
WHO defines Disaster
Act of nature (natural disaster)
earthquake, Tsunami, epidemic of infectious diseases
volcanic eruption, landslide, high winds, flash floods,
destructive winds, drought
Act of man made(man made disaster)
Explosion of nuclear power, manufacturing industries
Fire, transport accidents,
War, bombs
Displacement
Complex emergencies(armed conflict)
Preparedness of Disasters
Predictable Hazard
Unpredictable Hazard
Disaster
may mean a threaten serious
or great enough to justify emergency
aid,
in which extensive material damage is
followed by
tragic losses of human life, and large
number of victims whose injuries are
invariable serious.
Health problems related to the
type of Disaster
Immediate health problems are related
to the type of Disasters.
Short-term effects (deaths, severe
injuries, risk of communicable diseases,
damages to health facilities and water
systems, foods storage) depend on the
type of Disaster and their severities.
Earthquakes (Eq)
The toll depends mostly on 3 factors.
1:housing type
Built of adobe / of wood-frame
2:time of day at which Eq occurs
Night time / day time (in urban areas)
3:population density
Large variations within disaster-affected areas
Distance from the epicenter
Lethality: fit adults
Floods
Slow-onset flooding causes limited immediate
morbidity and mortality.
Traumatic injuries caused by flood are few,
require limited medical attention.
However, they have the potential to spark
communicable disease outbreaks because of
the interruption of basic public health services.
Volcanoes
Volcanic eruptions affect the population and
infrastructure in many ways.
Burns:super-heated ash, gases, magmas
Crush-type injuries:falling rocks
Respiratory distress:breathing the gases and
fumes
Contamination of the environment (air, water,
food) with volcanic ash disrupts environ-
mental health conditions.
Landslides
Landslides have become an increasingly common
disaster,
because of Intense deforestation, soil erosion,
construction of human settlements in landslide-prone
area (in both urban and rural area).
Rain brought by typhoon triggers landslides.
IN general, landslide causes high mortality, although
injuries are few.
Severely damaged or destroyed health structures
including water systems are limited.
Many mistaken assumptions are
associated with the impact of Disaster.
Please keep them (the realities of natural
disasters) in your mind,.
Should be familiar with the following realities.
Foreign medical volunteers with any kind of
medical background are needed. True/False?
The local population almost always covers
immediate lifesaving needs.
Only medical personnel with skills that are
not available in the affected country may
needed.
Epidemics and plagues are inevitable after
every disaster. True/False ?
Epidemics do not spontaneously occur after
disaster.
Dead bodies will not lead to the catastrophic
outbreaks of exotic diseases.
The key to preventing disease is to improve
sanitary conditions and educate the public.
Disasters bring out the worst in human behavior
(looting, rioting). True/False ?
Although isolated cases of antisocial
behavior exist, most people respond
spontaneously and generously.
海外のメディアが今回の日本人を
patient（辛抱強い）
tolerant（寛容な）
restrain（抑制的） と絶賛
no looting（略奪） no rioting（暴動）なし
The affected population is too shocked and
hopeless to take responsibility for their survival.
True/False ?
On the contrary,
During an emergency, the thousands of
volunteers who spontaneously united to
sift through the rubble in search of
victims after the disaster.
Disasters are random killers. True/False ?
Disaster strike hardest at the most
vulnerable groups.
The poor, especially women, children,
and the elderly.
Things are back to normal within a few weeks.
True/False ?
The effects of a disaster last a long time.
Disaster-affected areas deplete much of their
financial and material resources in the
immediate post-impact phase.
Successful relief programs gear their
operations to the fact that
international interest wanes as needs and
shortages become more pressing.
Technical Health Programs
In Disaster, the health sector is responsible for
treatment of casualties
epidemiologic surveillance
disease control
basic sanitation and sanitary engineering
oversight of health care in camps or temporary
settlements for displaced persons (refugees)
training
logistic resources and support
simulation exercises
Treatment of Casualties
Prehospital and hospital plans for treating
casualties are essential in health services.
Prehospital:focused on search and rescue of victim
The injured are identified/tagged at the disaster site,
classified according to the priority for treatment(Triage)
→transfer to hospital
Hospital:focused on emergency treatment, skill
training,information
Backup systems for communication, power, water supply,
transportation
Identification of Bodies
Identification of bodies requires careful
coordination with forensic medicine
departments.
The health sector should develop protocols
for the identification and conservation of
cadavers, death certification, local and
international transport.
Mass casualty management
Prehospital emergency care
Search, Rescue(SAR) and First Aid
Most immediate help will come from uninjured survivors.
Field care
Triage (Red, Yellow, Green, Black)
Triage consists of rapidly classifying the injured on the basis of severity
of their injuries, the likelihood of their survival with prompt medical
intervention.
Tagging
Diagnosis, initial treatment
Risk of outbreaks following Disaster
Disasters may increase the risk of preventable
diseases due to adverse changes.
1:Population density
2:Population displacement
3:Disruption and contamination of water supply and
sanitation services
4:Disruption of public health programs
5:Ecological changes that favor breeding of vectors
6:Displacement of domestic and wild animals
7:Provision of emergency food, water, and shelter in disaster
situations
Principles of prevention,
controlling Communicable Dis
Implement as soon as possible, public health
measures to reduce the risk of disease transmission
Organize a reliable disease reporting system to
identify outbreaks and promptly initiate control
measures
Investigate all reports of disease outbreaks rapidly
Early clarification of the situation
Environmental Health Management
Priority areas for intervention
Temporary settlements often create areas
of extremely high population density where
suitable services may be absent.
Lack of water and basic sanitation facilities
lowers the existing level of hygiene
and that increases the risk of
communicable diseases.
Priority environmental health services
Ensuring that there are adequate amounts of
Safe drinking water
Basic sanitation facilities
Disposal of excreta (emergency latrines,toilets, )
Wastewater
Solid wastes
Shelter
Providing food protection measures
Mass distribution of Disinfectants
Environmental Health Management
Water supply
The first priority for ensuring water quality in emergency
situation is chlorination (A minimum free residual chlorine
level of 0.7mg/dl)
Alternative water sources
Deep groundwater, spring water, rain water, surface
water
Food safety and food supplies
Environmental Health Management
Basic sanitation and personal hygiene
Ensuring the sanitary disposal of excreta
Latrines, toilets (water), lime should be used
People should bury their excreta
Water supplies
Basic hand washing, cleaning, bathing
Avoid overcrowding in sleeping quarters
Launch education campaign on hygiene
Environmental Health Management
Vector Control
Vector control measures should be associated with
other health measures, such as .......….
Burial of the dead
Dead bodies represent a delicate social problem.
Burial is simplest and best method, if acceptable.
Mass cremation requires large amounts of fuel.
Public information and the media
Exercise
Prepare the post-disaster “disease
surveillance daily report” (syndrome-based
surveillance system)
Imagine the situation as follows:
Flash floods occurred at the rural area in Cambodia in rainy
season.
Over 3,000 farmers and their families have to move to the
temporary evacuation center.
You are the chief in charge of the health post (Nurse section).
Overcrowded, not enough sufficient safe water and foods, 2 doctor from UK, 8 nurses and
20 health personnel (speak both local language and English) in the this center.