Lesson 8.
Effects of Hazard, Exposure, and Vulnerability to Disaster Risks
Hazard
A harmful condition, substance, human behavior, or condition that can cause loss of life, injury, or
other health effects, harm to property, loss of livelihood and services, social and economic disruption,
or damage to the environment.
Any imminent risk is a threat.
Exposure
The presence of elements at risk or chance of being harmed from a natural or man-made hazard
event.
Elements include the individuals, households or communities, properties, buildings and structures,
agricultural commodities, livelihoods, public facilities, infrastructures, and environmental assets
present in an area that are subject to potential damage or even losses.
The more a community is exposed to hazard factors, the higher the disaster risk or the higher the
chance of disaster occurrence.
Vulnerability
The characteristics and circumstances of a community, system, or asset, that make it susceptible to the
damaging effects of a hazard and inability of a community to prevent, mitigate, prepare for, and
respond to hazardous events.
Risk
It implies the probability of possible adverse effects.
This results from the interaction of social and environmental systems, from the combination of
physical danger, and exposed item vulnerabilities.
Disaster
A serious disruption to the functioning of a community or society causes widespread human, material,
economic, or environmental losses that exceed the capacity of the community or society concerned to
cope with the use of their own resources.
It results from the mix of hazards, risk conditions, and inadequate capability or measures.
Exposure and vulnerability, on the other hand, are distinct. A certain community can be exposed but it
does not mean that it is vulnerable. Buildings and structures in Japan are exposed to earthquakes, but they
are not vulnerable since their architectural and engineering designs are earthquake-proof or resistant.
However, to become vulnerable, it must be exposed to hazards first.
Exposure to hazards can make a community vulnerable. However not all communities that are exposed to
hazards can be considered vulnerable. Vulnerability depends on the preparedness and readiness for a
hazard in the community. It depends mostly on how they mitigate, respond, and recover. If a certain
community can reduce the vulnerability by reducing the risk, the said community is already considered less
vulnerable or resilient
Lesson 9 Hazard and Its Types
Hazards can be categorized into different types:
1. Natural hazards - arise from natural processes in the environment.
e.g. earthquakes, tsunamis, landslides, volcanic eruptions, and floods
2. Quasi-natural hazards- arise through the interaction of natural processes and
human activities
e.g. pollution or desertification, smog, and fog
3. Technological (or man-made) hazards- These arise directly as a result of
human activities.
e.g. accidental release of chemicals, toxic and pesticides to floral and fauna
Hazards Signs and Symbols
These signs and symbols with corresponding meanings below help people to be extra cautious, aware, and
observant in their surroundings. Each picture is designed to become recognizable to anyone as a signal
word like “danger” or “warning”.
Lesson 10. Hazard: Its Impact, Identification, and Risk Assessment
What are the Different Impacts of Hazards?
A hazard can bring about many impacts which can come in different types. Facilities and infrastructures are
commonly the target of natural hazards. Specifically, these impacts can trigger accidents and the release of
toxic substances, fires, and explosions, potentially resulting in health effects, environmental pollution, and
economic losses.
One way to classify hazard impacts is by using general impact themes namely:
Danger to life which includes physical and psychological harm and diseases
Denial of access to energy, water, communication, and transport access
Damage to the physical environment like buildings and land
The six (6) specific types of hazard impacts.
1. Physical impact
Physical injuries (bone fracture, wounds, bruises)
Destruction and loss of vital infrastructure like transportation systems, roads, bridges, power lines, and
communication lines.
Widespread destruction of housing and buildings
2. Psychological impact
Grief and psychological illness
Marital conflict
Depression due to the loss of loved ones and properties
Chronic anxiety
3. Socio- cultural impact
Displacement of population
Loss of cultural identity
Forced to adopt new sets of culture
Ethnic conflicts
4. Economic impact
Loss of job due to displacement
Loss of harvest and livestock
Loss of farms, fish cages and other source of food
Loss of money and other valuables
5. Environmental impact
Loss of forest due to forest fires
Loss of freshwater due to salination
Disturbance of biodiversity
Loss of natural rivers
6. Biological impact
Epidemic to people, flora, and fauna
Chronic and permanent illness caused by biological agents
Proliferation of different viral diseases
Identification of Hazards and Risk Assessment
Hazard identification -is the process of determining all physical and nonphysical agents in the workplace or
specific environment.
*Most occupational health and safety problems are caused by hazards that are not eliminated or managed.
*To prevent untoward incidents in a workplace or community, elimination or controlling of hazards is
crucial.
*In some workplaces where hazards cannot be eliminated, they must be monitored and properly managed
at the least.
Risk assessment
A way to determine which hazards and risks should be prioritized is by taking into consideration the
probability and severity of impact.
Below are the steps in hazard identification and risk assessment.
1. Identify the hazards.
Use the following methods:
a. Observation - use your senses of sight, hearing, smell, and touch - combined with knowledge and
experience.
b. Material Safety Data Sheets (MSDSs) - obtain them from manufacturers and suppliers. It gives
information on possible harm from hazardous substances and precautions that need to be taken.
c. Hazard and risk surveys - interview other people about their safety concerns as far as the workplace is
concerned. Utmost consideration should be given to children or visitors who could be at risk.
d. Discussion groups - are useful for identifying hazards and recommending solutions.
e. Safety audits – a committee must be assigned to periodically check safety in the area.
2. Assess the Risk.
Once a hazard has been identified, the likelihood and possible severity of injury or harm will need to be
assessed before determining the best way to minimize the risk. High-risk hazards need to be addressed
more urgently than low-risk ones.
3. Make the changes.
Once risks are assessed, the next step is to make decision for some necessary changes. These changes
include removing the hazard and replacing it with something less hazardous, engineering modifications like
installation of exhausts, safety barriers and safety exits, modification of procedures, etc. Combination of
the risk control measures mentioned above to effectively reduce exposure to hazards can also be done.
4. Checking the changes made.
To make sure risk has been minimized, and a further hazard has not been created, the new safety
measures may need to be carefully tested before work begins again. Risk assessment doesn’t end with
making changes. It is essential that these changes made are monitored and checked. It must be monitored
if the changes done are being followed consistently and if these changes contribute to the improvement of
safety management in the workplace. This last step has to be done periodically to accurately assess the
effectiveness of the entire process.
