Disasters and their Effects ​on the Population: Key Concepts

Introduction

Recent advances in technology and the ease with which news and information travel around the world have made learning about disasters in distant countries an almost weekly occurrence. From the recent conflicts in Syria, Iraq, South Sudan, and the Central African Republic to the typhoon in the Philippines and flooding in the Zambezi region, these disasters have led to unimaginable levels of destruction and death.

Although most of these disasters occur in underserved areas of the world without adequate resources and technology, they can also occur in societies with advanced medical systems such as the United States, Europe, and Japan. It is impossible to predict when and where the next disaster will take place. However, we can strive to be prepared to handle both the acute and longer-term effects of a variety of disasters in different populations.

While the timing and the actual disaster event are difficult to predict, several consequences of disasters are predictable. Therefore, we can prepare to deal with these consequences. As pediatricians, we must ensure that disaster preparedness includes the unique needs of children. Children are a vulnerable population with physiologic, psychological, and developmental needs that differ from those of adults.

What Makes an Event a Disaster?

What makes an event a disaster? Why is one hurricane or tornado a disaster and the next one, even with stronger winds, is just a bad storm? The answer lies with how the population is eventually affected: both the direct effects on the people as well as the indirect effects or damage to infrastructure. The United Nations International Strategy for Disaster Reduction defines disaster as a serious disruption of the functioning of a community or a society involving widespread human, material, economic or environmental losses and impacts, which exceeds the ability of the affected community or society to cope using its own resources.

Disasters are often described as a result of the combination of: exposure to a hazard; the conditions of vulnerability that are present; and insufficient capacity or measures to reduce or cope with the potential negative consequences. Disaster impacts may include loss of life, injury, disease and other negative effects on human physical, mental and social well-being, together with damage to property, destruction of assets, loss of services, social and economic disruption and environmental degradation.

A disaster disrupts the normal pattern of life, causing both physical and emotional suffering and an overwhelming sense of helplessness and hopelessness. The impact on the socioeconomic structure of a region and environment often requires outside assistance and intervention. Although there are many definitions for disaster, there are three common factors.

Common Factors

First, there is an event or phenomenon that impacts a population or an environment. Second, a vulnerable condition or characteristic allows the event to have a more serious impact.

For example, a hurricane will cause much greater damage to life and structures if it directly strikes an area with poorly constructed dwellings compared to striking a community of well-built homes with greater structural support. Identifying these factors has practical implications for communities’ preparedness and provides a basis for prevention.

Third, local resources are often inadequate to cope with the problems created by the phenomenon or event. Disasters affect communities in multiple ways. Their impact on the health care infrastructure is also multifactorial. The disaster event can cause an unexpected number of deaths. In addition, the large numbers of wounded and sick often exceed the local community’s health care delivery capacity.

Health Care Infrastructure Impact

The community’s capacity to care for those affected is often reduced because professionals, clinics and hospitals have been affected or destroyed. This will have long-term consequences leading to increased morbidity and mortality. An example of this can be seen in the 2010 Haiti earthquake disaster.

Environmental, Psychological, and Social Effects

Disasters can also have adverse effects on the environment that increase the risk for infectious diseases and environmental hazards. The loss of clean drinking water and proper sewage treatment can have devastating effects on affected populations. Food shortages can lead to severe nutritional consequences.

All these conditions may create a sense of hopelessness, vulnerability and an inability to envision a better future. People may stop planning their future such as finishing school, getting married or working. This “foreshortened future” affects the psychological and social behavior of the community. (Figure 1)

Types of Disasters

Disasters can be divided into 2 large categories (Box 2):

• Those caused by natural forces.
• Those caused by man.

Natural disasters

Natural disasters are caused by natural forces such as earthquakes, volcanic eruptions, hurricanes, fires, tornadoes, and extreme temperatures.

They can be classified as rapid-onset disasters, such as earthquakes or tsunamis, and those with progressive onset, such as droughts that may lead to famine.

Usually, a great number of persons die when a complex humanitarian emergency occurs

Since it is still extremely difficult to precisely predict the climatic and geological changes capable of causing a disaster, preparing for these types of events remains a major challenge.

Great natural disasters have also occurred recently throughout the world. (Box 3).

The inability to accurately predict these types of events underscores the need for countries to have disaster response plans to mobilize appropriate resources rapidly and efficiently. A well-defined organizational structure must also be created to coordinate both national and international assistance.

Although significant progress in sanitation and disaster response has been achieved in certain regions of the world, developing countries continue to be highly vulnerable because of their fragile economies and limited healthcare and transportation infrastructure.

Man-made disasters

Disasters caused by humans are those in which the major direct causes are identifiable as intentional or unintentional human actions. They can be subdivided into three main categories:

There has been a global increase in civil war fueled by ethnic confrontations since the mid-1990s (Figure 2). In modern conflicts, the greatest loss of life (90%) occurs among civilian non-combatants because of direct physical injury and the public health impact of war (Figure 3).

Complex humanitarian emergencies often result in a staggering loss of life. Table 1 shows the estimated excess deaths among civilians in several recent and ongoing crises.

Displaced Populations

Natural disasters and complex emergencies can force many people to leave their homes. The primary purpose of the United Nations High Commissioner for Refugees (UNHCR) is to safeguard the rights and well-being of people who have been forced to flee, including the right to seek asylum and find safe refuge in another country. Refugees and internally displaced persons (IDPs) are among the categories of people that UNHCR assists.

Refugees flee their countries because of war, violence, famine, or a well-founded fear of persecution for political, ethnic, religious, or nationality-related reasons. According to 2015 UNHCR estimates, there are 21.3 million refugees and 10 million stateless people (Figure 5). A person recognized as a refugee is entitled to certain protections under the terms of international humanitarian law.

Internally displaced persons (IDPs) leave their homes for similar reasons but do not cross the boundaries of their countries. These individuals do not receive the same kind of legal protection, which can make assisting them more difficult. According to the 2015 Internal Displacement Monitoring Centre, there are 65.3 million displaced people.

Phases of Disaster Intervention

Since interventions in emergencies evolve as a continuum, identifying the following four phases is useful for establishing priorities, guiding response activities, and systematizing previous experiences:

Effects of Disasters

Disasters affect communities in multiple ways. They represent a public health hazard for various reasons (Table 2):

Table 2. Frequent effects of disasters by type

Select each disaster type to review its frequent effects. For printing, expand all sections before printing.

Adapted from Humanitarian Assistance in Disaster Situations. A Guide for Effective Aid. Pan-American Health Organization (PAHO). Washington D.C., 1999.

Severity of a disaster

As was demonstrated in Haiti, the more fragile the pre-event health status of the affected population and the more inadequate the pre-disaster infrastructure, the more severe the disaster. Disaster severity therefore varies according to its magnitude and the vulnerability of the population.

Most diseases associated with the event can be prevented by adequate interventions, especially ensuring basic life saving needs of the population are met. This includes shelter, food, water, sanitation, health care services and security measures.

Crude mortality rate

When assessing the outcome of a disaster, public health officers describe its severity by the number of human lives lost using the crude mortality rate (CMR). CMR is usually defined as the number of deaths per 10,000 inhabitants per day.

In developing countries, the reference CMR value varies from 0.4 to 0.7 deaths per 10,000 people per day. A CMR above 1 death per 10,000 people per day, or an under-5 mortality rate above 2 deaths per 10,000 children under 5 per day, is considered a humanitarian emergency.

While both conflicts and natural disasters can result in immediate deaths due to trauma or drowning, there are many preventable deaths that occur in later phases of a disaster over a longer time period.

To assess the progression of a disaster and the effectiveness of relief interventions, the CMR should be measured over several appropriate time intervals. For example, during the month following the massive movement of Rwandan refugees to eastern Zaire (present-day Democratic Republic of the Congo), the CMR in that region was 40 to 60 times above the corresponding reference value.

The CMR is usually highest during the initial phase of a disaster. Figure 6 displays the differences between baseline and peak disaster CMR experienced by displaced populations in different countries. Additional information regarding these epidemiologic measurements may be found in Module 2, “Preventive Medicine in Humanitarian Emergencies.”

Vulnerable Populations During Disasters

Most diseases associated with disasters can be prevented by adequate interventions, especially by ensuring that the basic life-saving needs of the population are met. These include shelter, food, water, sanitation, healthcare services, and security measures.

The most vulnerable groups include children, especially those separated from their families; pregnant or lactating women; women living without their spouses; individuals in female-headed households; people with disabilities; and the elderly.

In addition to disproportionately high mortality rates, children separated from their families are at high risk of adverse consequences such as violence, exploitation, and abuse, including child labor, trafficking, and recruitment as child soldiers. Furthermore, infants and children are more vulnerable to toxic exposures and overcrowding associated with large population displacements (Table 3).

Consequently, it is critical to reunite children with their families as soon as possible and to prioritize reducing their vulnerability in all disaster response planning (Box 4).

Mortality in Humanitarian Emergencies

The immediate goal of any intervention in humanitarian emergencies is to reduce the number of deaths. While both conflict and natural disasters can result in immediate deaths, many preventable deaths occur during later phases over a longer period.

Five leading medical problems have consistently been identified as the major causes of mortality in post-conflict or post-natural disaster settings among vulnerable populations (Box 5).

Unique features in each disaster, such as climate, topography, pre-existing social structure, and physical conditions, affect the proportion of deaths associated with each of these causes, as well as other causes. Figure 7 shows mortality in various displaced populations following natural disasters and armed conflicts.

In the context of a disaster, each of the leading causes of death relates to one or more predisposing environmental conditions that increase the incidence of disease and the mortality rate per case (Box 6). For interventions to be effective, resources should be targeted to prevent and correct these predisposing environmental factors, in addition to treating affected individuals.

Emergency Relief Measures

Each disaster or humanitarian emergency is a unique situation determined by the event that caused it, as well as climate, geography, culture, social structure, and the pre-existing conditions of the affected population. Therefore, national and international organizations should begin with a rapid assessment and avoid the impulse to respond immediately before critical information is available.

Unanticipated effects may require urgent attention. For example, a safe water supply may not be directly affected by a strong storm or mudslide. However, if the regional system for water pumping or purification is damaged, access to safe water becomes a critical issue that must be addressed to prevent disease and excessive mortality.

Essential Emergency Relief Measures

Organizations capable of providing assistance during humanitarian emergencies

When local resources are insufficient, assistance from multiple national or perhaps multinational organizations will be needed. Each involved organization has its own institutional structure and culture, in addition to other features, such as capacity for response, technical and logistic resources, and thematic or regional approach.

Several international agencies may have activities in the country prior to the event. In response to the disaster these agencies may retarget their resources in the country to emergency relief. Effective coordination and cooperation among involved organizations are essential but very difficult to achieve in the chaotic situation of a massive emergency. There are two major types of organizations that can get involved in assistance when a disaster

Foreign organizations that provide help in case of disaster

Foreign organizations that provide help in case of disaster - Box 8 identifies some of the governmental agencies of developed countries that provide funding and technical help to countries affected by humanitarian emergencies. PAHO and WHO have developed guidelines to assist disaster-affected countries in managing donor offers from various agencies. According to the 1999 PAHO publication Humanitarian Assistance in Disaster Situations: A Guide for Effective Aid, “In the most advanced developing countries, in particular in Latin America, national health services, voluntary organizations and the affected communities mobilize their own resources to meet the most compelling medical needs in the early phase after a disaster. Requirements for external assistance are generally limited to highly skilled expertise or equipment in a few specialized areas.”

Military help

Military help - Both local and foreign military can be mobilized to assist in the response to natural disasters or complex emergencies. Certain unique features make military organizations useful in a disaster.

Military Help

Limitations of Military Assistance

Despite all the advantages mentioned above, the use of the military can have significant shortcomings and limitations in some situations.

Non-Governmental Organizations

NGOs are nonprofit organizations working on a full-time basis in assistance for appropriate development. Thousands of NGOs, both international and national, are functioning throughout the world. Most NGOs are small agencies focusing on very specific development projects (e.g., providing education, working tools, or training in sustainable development). Only a few of them have the resources required for supporting activities targeted to promote development and to respond to disasters in multiple countries or regions. Each NGO is specialized in specific aspects of assistance in emergencies (Box 9). Although NGOs may receive contributions from individuals, most of their funds come from the governments of industrialized countries. These governments distribute their money for assisting projects through contracts with NGOs. Unlike the International Committee of the Red Cross (ICRC), some NGOs maintain a “right to interfere.” This means they can operate across borders without written approval of their hosts.

Although usually looking for the neutrality of the ICRC, some NGOs may be more willing to report any perceived injustice. They perform well in emergencies within their area of specialty (e.g., water provision, food distribution), but most cannot achieve self-sufficiency in an emergency setting and rely on UN, military, or other agencies for security, transportation to remote sites, communication, support of logistics, or medical care for their own personnel. NGOs have enhanced ability to provide person-to-person assistance because they are likely to have a pre-disaster relationship with the affected communities and understand the local culture and public health issues. They can also shift easily from disaster relief to development, and are willing to make a long-term commitment to community development and rebuilding.

International Committee of the Red Cross (ICRC)

The ICRC provides a complete account of its activities to all the parties involved in the conflict. It will refuse to participate in any activity that can be seen as showing favoritism. This may include transportation in vehicles belonging to one of the parties or joining efforts with groups that have their own interests. The ICRC is usually self-sufficient and can use its own resources for air lifts, communication, and logistics. It will participate only if all parties involved in the conflict sign an agreement recognizing and showing respect for its neutrality and mission. The ICRC is related to but independent from the Red Cross and the Red Crescent Societies national agencies. These organizations provide assistance primarily to victims of disasters or wars within their own nations. They have a similar commitment with neutrality, provision of assistance based only on the need, and independence from national governments.

Coordinating Disaster Response Activities

Coordinating the activities of all these organizations poses a tremendous challenge. Following a natural disaster the host nation’s government/agencies and military are likely to have operational command. Most nations now have defined governmental authorities responsible for global disaster planning and response, as well as coordinators for individual sectors such as health. External agencies or governments play a supportive role in providing technical assistance and resources. PAHO has developed a number of technical manuals and training activities to assist nations in the planning of coordinated disaster responses at the regional and national level.

Medical Volunteering

Following a disaster many pediatricians and other health professionals volunteer for a limited time. During the initial response phase, the greatest pediatric needs include air transport teams, surgical teams (a surgeon, OR nurse, anesthesiologist, and critical care pediatrician), as well as pediatricians with training and experience in emergency medicine and critical care. Volunteers may have to be self sufficient for a period of time in terms of food, water, and shelter. Volunteers should work through an established NGO or governmental agency rather than simply “show up” to help. Volunteers should be prepared to respond quickly, as the quicker the response teams can provide appropriate care, the more effective they can be at saving lives and limiting morbidity.

Part of preparation is anticipating the types of injuries that will be seen with different types of disasters. When sending a response team into a disaster during the acute response phase, it is important to have the personnel with the ability to treat the most likely injuries seen with the specific type of disaster. In a major earthquake like the one in Haiti in January 2010, one would expect the majority of the casualties to be secondary to traumatic injuries related to collapsed buildings.

Therefore, a team should be prepared to have personnel and supplies that can be used to treat crush injuries, a large number of open wounds, along with a variety of orthopedic injuries. In a disaster involving an explosion (large industrial accident or terrorist attack), the pattern of injuries would include many of the same traumatic injuries as seen in an earthquake, but would also include a large number of burns and blast injuries such as blast lung. Personnel required in this type of disaster should include those with training in caring for burns as well as experience with other traumatic injuries.

Table 4 provides a list of pediatric equipment that, if possible, should be brought in if not available on site.

Among the recommended equipment, elements for proper airway management in children are crucial. A major challenge of any disaster response is gathering, organizing, and moving supplies to the affected area. Resource management within the hospital and other facilities or agencies may prove to be a decisive factor in whether a mass casualty event can be handled.

Communication

Communication in a disaster situation is essential between disaster relief team members as well as with coordinating groups and logistical support personnel in home countries. Modern technology has provided many different types of communication devices, which have different advantages and disadvantages. Communication networks and contingency plans are an essential part of the disaster preparedness phase. Radios are useful for short range communications when a disaster relief team is separated. However, they are limited by range and will not allow communication with the other teams or organizations that are a long distance away.

Mental health considerations

Disaster response providers are often thrust in to a high stress situation with exposure to situations they may have never experienced before. The degree of destruction and death will likely be much greater than what the health care providers are accustomed to dealing with in their daily lives. Local first responders and medical providers thrust in to the role of the initial emergency response phase may be faced with the additional stress of personally knowing many of the victims (or their family members) that they are caring for.

The emotional impact of large scale destruction, suffering, and death will elicit different responses in different people, but all volunteer providers should recognize how their experiences can affect their wellbeing both emotionally and physically. The emotional stress experienced by disaster response providers has been well documented after events such as 9/11 and Hurricane Katrina. The effect of stress is amplified by the long hours of intense work experienced during the response to a disaster. Environmental conditions (such as extreme heat/cold/rain/flooding), lack of sleep, and inadequate nutrition impair a provider’s ability to deal with the stressful situation.

Crisis response workers and managers, including first responders, public health workers, construction workers, transportation workers, utilities workers and other volunteers, are repeatedly exposed to extraordinarily stressful events. This places them at higher than normal risk for developing stress reactions (Pan American Health Organization [PAHO], 2001). It is important for all disaster response providers to recognize the potential emotional stress they will be entering before arriving on scene. Stress prevention and management needs to be considered and addressed from the start of the deployment in order to prevent problems. By anticipating stressors and individual's responses to these stressors, the response team and individuals can potentially prevent a crisis within the team of care providers.

The US Department of Health and Human Service, Substance Abuse and Mental Health Services Administration (SAMHSA), and Center for Mental Health Services (CMHS) have published a guide focusing on general principles of stress management and offers simple, practical strategies that can be incorporated into the daily routine of managers and workers. It also provides a concise orientation to the signs and symptoms of stress. 

Conclusion

References

Case Discussion

Disasters can be due to natural causes, such as hurricanes and earthquakes, to alterations or to technological causes; i.e., related to events triggered by man’s intervention (e.g., the release of toxic or radioactive agents). In addition, civil or international wars cause complex emergencies that affect civilians and result in their displacement.

Vulnerable Populations

Children, as well as old people and pregnant women are the most vulnerable populations when a disaster occurs. For children, the risk of being separated from their families determines their vulnerability. In addition, their physical, physiological and mental features render them more susceptible to environmental, sanitary and social changes resulting from disasters.

All affected children should be identified and their identity should be properly documented. They should also receive preferential attention during the distribution of sanitary and feeding resources, as well as effective preventive interventions.

Initial Assessment and Response

The initial and highly critical step is the immediate assessment of the situation and the affected population. This will define the actual needs and the interventions that are most appropriate in the current circumstances. It is important to establish clearly defined priorities and the effective coordination of rescue activities, in both the early and the subsequent phases.

The capacity for response of local and regional services will determine whether or not external assistance is needed. Immediate external help is unlikely to be necessary in this case, but there will probably be a need for resources to provide the affected population with shelter and clothing.

Myths and realities of disasters

The Pan American Health Organization has identified many myths and erroneous beliefs that are widely associated with the public health impact of disasters; all disaster planners and managers should be familiar with them.