injury prevention in natural disasters. a theoretical framework

290 INJURY PREVENTION IN NATURAL DISASTERS

injury prevention in natural - - disasters. A theoretical framework

Eric K. Noji and Keith T. Sivertson

Department of Emergency Medicine The Johns Hopkins Hospital

and School of Medicine 600 North Wolfe Street Baltimore, MD 21205 U.S.A.

~ _ _ _ _ _ ~

A theoretical framework for conceptualizing injury patterns in natural disasters is described. In this conceptual framework, natural disasters are divided chronologically into predisaster, disaster and postdisaster phases. Within each phase, four factors (human, engineering/technological, physical environmental and socioeconomic) are identified that play an important role in the causation of injury. By combining these phases and factors into a three by four matrix, one may begin to identify points in the natural history or evolution of a disaster that may be amenable to therapeutic or preventive intervention. The application of this proposed three-phase matrix model to a disaster will permit researchers to reduce a large, complex problem into more manageable, conceptually simpler parts. It may also be of value to disaster planners by suggesting preventive and mitigation measures, as well as aiding in the setting of priorities so that scarce resources can be allocated to achieve maximum reduction of injuries.

Key words: Natural disasters; Injuries; Injury prevention; Counter measures; Disaster chronology.

INTRODUCTION

Knowledge of the causes of injuries in natural disasters is essential to our effort to minimize morbidity and mortality. for it is only through this information that we can target interventions to prevent specific injuries and measure the effectiveness of injury prevention programs. We must know for certain how and where injuries occur in disasters, along

with a profile of who is injured, the type of injuries and a description of severity.

In this discussion, a theoretical framework for conceptualizing injury patterns in disasters, and how knowledge of the various chronologic stages of a natural disaster can lead to strategies for preventing or mitigating the severity of a disaster, will be described. Haddon’s chronology of injury patterns in motor vehicle accidents can be applied in a very useful way to the study of morbidity and mortality in natural disasters (Haddon, 1980). By dividing a natural disaster into predisaster, disaster and postdisaster phases, one may begin to identify points in the natural history or evolution of a disaster that may be amenable to therapeutic or preventive intervention.

Within each phase, one may identify factors that play an important role. These are the human, engineering/ technological (e.g. buildings, communications), physical environmental, and socioeconomic factors. In a sense, these factors can be likened to the classic epidemiologic model of host, agent and environment. By combining these phases and factors one may produce a useful matrix, which in the words of Haddon (19801, “can be used to pinpoint the many things that need to be found and done to make sure that the resources are being used in the most intelligent and efficient ways”, from the standpoint of reducing disaster-related injuries and their social costs (Fig. 1).

What follows is a discussion of the components of each cell in this matrix, and of some of the scientific evidence we have to date on the extent to which we can use this theoretical framework as part of an overall strategy to accomplish our objective of injury reduction.

PRE-DISASTER/HUMAN CELL

This concerns the way people themselves contribute to the development of natural disasters and the extent to which disasters can be prevented by modifying humans or their behavior. An example of human contributions to the development of natural disasters can be found in the explosive population growth that has taken place in many less developed countries, as well as increased urbanization in the industrialized world - both of which have led to a greater concentration of people exposed to new hazards.

In order for natural events such as earthquakes and tsunamis to be considered “disasters” they must have an impact on human populations. Although the incidence of major natural disasters has not increased, their effects are becoming more severe in developing world countries because of the growing numbers of people and structures located in vulnerable areas. Natural events of the same magnitude as those of the past will probably lead to greater numbers of dead and injured. For example, in 1876, a massive typhoon struck the Bay of Bengal resulting in 100.000 deaths. In 1970, a typhoon of similar strength caused nearly half a million deaths - a five-fold increase from a century before (Lechat, 1976).

Preventive measures in this cell include discouraging migration to urban centers, by creating an attractive

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INJURY PREVENTION IN NATURAL DISASTERS 291

Pre -Gisaster

Disaster

Post -D isaster

Fig. I . Matrix of phases and factors involved in natural disasters.

infrastructure in rural areas as an incentive for people to stay out of the cities. As long as such rapid population growth continues to occur in disaster-prone countries, and as long as people are forced by socioeconomic pressures to live on vulnerable land, such as hazardous flood plains, ravines and steep slopes, major loss of life will continue to result from natural disasters for some time to come.

DISASTER IMPACT/HUMAN CELL

The contribution of human characteristics to injury during the disaster itself, and the extent to which total injuries can be reduced by measures designed to change human characteristics and behaviors are included in this cell. Research has shown that certain population subgroups are more vulnerable or have greater exposure to hazards, while others have decreased ability to avoid hazards, lower injury thresholds, and/or decreased ability to survive the injury once it has occurred (Withers and Baker, 1984). These sub groups include the very young, the elderly and the i l l or debilitated. Other problems in this particular cell relate, for example, to the ways injuries occur in disasters; what kinds of injuries occur in different types of buildings, and what sorts of dangerous behaviors lead to increased number and severity of injuries (e.g. jumping from high tloors). After the 1979 tornado in Wichita Falls, Texas, a retrospective study of morbidity and mortality from this event has yielded interesting insights into the comparative risks of various escape behaviors, among others driving away (Glass et d., 1980). For example, the risk of severe

injuries was significantly higher among people trying to escape by car, than among people staying at home.

The inability of a community to deal effectively with a catastrophic event may also result from poor organization and lack of effective disaster planning. Much of the morbidity and mortality from natural disasters could be avoided or reduced by developing a plan which includes provisions for shelter, alternative methods of communications, escape-routes and evacuation, and arrangements for outside assistance. Sociological research, however, has suggested that familiarity with actual disasters, that is, "disaster experience" is of greater value than the best designed and rehearsed disaster plans in preparing for an event the community has never experienced (Western, 1976).

Other disaster impact/human factors amenable to intervention include, improving public education regarding potential hazards, and learning appropriate behavior under conditions of natural disasters (e.g. bringing children indoors during storm-warnings, listening to the local radio. buying provisions).

This will require enhanced risk-perception and appropriate action on the part of the populace. Unfortunately. research assessing the efficacy of behavioral nioditicaticn programs demonstrates that the best ways to reduce damage to people from hazards i n the environment are those that do not require the people to always be expert, alert and to take evasive action (Haddon, 1974). For this reason, it is probably more effective to adopt approaches that protect people automatically ("passively") rather than those that require them to act for their own protection.

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Research directions for this cell should focus on (1 1 documentation of information on deaths and hospital- izations, to evaluate selected factors that may influence w h y some people die from their injuries, while others do not and ( 2 ) determination of time trends for morbidity and mortality.

POST-DISASTER/HUMAN CELL

Here we deal with the characteristics and behavior of injured people immediately after the conclusion of the acute destructive effects of the disaster itself and the significance of those characteristics for limiting and repairing those injuries. For example, how many people who die in earthquakes were still alive the moment after the earthquake struck and at specific intervals later, i.e. how many, at least theoretically, could be saved? Just what kind of medical problems do they present with (e.g. asphyxiation, hypotherniia while trapped under rubble, muscle necrosis and subsequent kidney failure), what is the frequency and severity of such injuries, and how fast and what kind of medical care must reach them?

One major post-disaster problem concerns the conver- gence of well-intentioned but unskilled and unsolicited volunteers to the disaster scene, as well as useless goods and irrelevant supplies - all of which add to the chaos, and most importantly, may impede the effective care of the injured. It has been said that, at times, indiscriminate arrival of relief workers and supplies may constitute a second disaster on top of the first (WHO, 1984). Looting, vandalism and interpersonal violence in the post-disaster period may also contribute to increased morbidity and mortality. Finally, many health effects of a disaster do not occur immediately, but may be increased months or years afterwards (Logue et al., 1981). An example of the latter can be found by observing the mental health consequences among disaster survivors and relief workers (Lima, 1986).

Post-disaster impact/human factors amenable to intervention include improving public education regarding basic first aid and cardiopulmonary resuscitation, and survival training (e.g. life-saving instruction in the event of being washed out to sea).

Research efforts in this cell should focus on the following areas:

1. Determination of the relationship between time of

2. Assessment of injury outcome characteristics.

3. Development of quantitative severity of injury and illness scales, to determine resuscitation potentials for mass casualties, as well as to serve as a rational basis of triage.

extrication from debris and survival.

PRE-DISASTER/ENGINEERING-TECHNOLOGY CELL

This cell involves the contribution of the failures and shortcomings of human-engineered structures and technol-

ogy to the initiation of disasters. Classic examples are floods, often disastrous, caused by defects in dam construction or improper construction of a dam on a fault line. Other examples include the construction of cheap, low-quality steel-reinforced concrete buildings erected on unreliable, shallow foundations (Beinin, 1985).

It is important that improved early-warning systems be developed to foster early evacuation of communities threatened by hurricanes, tornados, and floods (e.g. radar- tracking systems, satellite technology) and that accurate climate monitoring be performed to forecast drought. The timing of the warning is all important, whether to be on the safe side and run the risk of giving a false alarm, or to wait for definite signs of a disaster and risk giving the alarm too late.

DISASTER IMPACT/STRUCTURE-TECHNOLOGY CELL

The concern of this cell is the contribution of human- engineered structures and technology to the injuries that occur in disasters and how their modification can reduce the frequency and severity of such injuries. The classic examples in this cell concern the proper construction of earthquake-resistant buildings and the application of wind- engineering technology, as in the addition of storm shelters to homes in tornado country and encouraging the use of lighter housing material instead of adobe in earthquake- prone areas. The relatively new habit of using concrete slabs as a roof laid on a wall of insufficiently reinforced adobe walls, resulted in extremely high death and injury rates during the 1976 Guatemalan earthquakes (Glass et af., 1977).

In Turkey, a linear relationship has been found between the number of houses destroyed and the number of deaths -approximately 8.5 persons killed for 100 houses destroyed or badly damaged (Lechat, 1976). Not surprisingly, getting trapped under the rubble gives the victim about five times more chance of being injured (De Bruycker, 1985).

Construction of elevated shelters in flood and cyclone- prone areas illustrates ways that engineering and architect- ural innovations can reduce injury. This proved to be very effective during the 1985 Bangladesh flooding for those able to reach these shelters. Other preventive measures in this cell include the development of more stable types of furniture (e.g. built-in cabinets, desks) and other indoor fixtures since many people are injured by these objects when they are thrown from their positions during an earthquake or hurricane. Finally, the habitation of mobile homes in tornado country should be discouraged (Glass et al., 1980).

For this particular cell, engineers and geotechnical experts will probably play the dominant role in developing measures to prevent or reduce injuries. Research should therefore be directed toward the use of technology to reduce certain hazards and risks. This should include vulnerability analyses (calculation of disaster risk multiplied by damage probability) of all risks in a given area before undertaking

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construction projects. Once these risks have been identified, proper antiseismic design and construction of public buildings will allow them to withstand major structural damage from earthquakes, and hopefully result in decreased morbidity and mortality. Such mitigation measures should be enforced by better building regulations and land use codes, particularly in high-risk areas.

POST-DISASTER/STRUCTURE-TECHNOLOGY CELL

This cell includes the contribution of human-engineered structures and technology to the worsening of human damage after the disaster impact, and how their modification can reduce the frequency and severity of such damage. Long extrication times from debris following an earthquake may lead to increased morbidity as we learned in Mexico City. For this reason, there is an urgent need for better detection of trapped individuals (e.g. remote sensing equipment, sonic/seismic detectors, infrared imaging equipment, heat and sound-sensitive detectors, bore-hole cameras and dogs) and availability of heavy rescue equipment (e.g. hydraulic spreaders, cutting tools, and winches) which can be air-lifted to the earthquake site or better yet, safely stored and rescue personnel trained in their use.

Poorly designed and constructed water systems may be contaminated by floodwaters leading to the outbreak of communicable diseases in the post-disaster period. Inter- estingly, earthquakes may result in increased numbers of motor vehicle accidents in the post-disaster period with accompanying increased morbidity and mortality. It is important that straight streets be planned for rapid evacuation, particularly in regions vulnerable to hurricanes or tsunamis. Destruction of power sources in hospitals without satisfactory secondary sources of electricity may seriously affect care of the injured (Beinin, 1985). Thus, the rapidity of restoration of communications, building of shelters, and restoration of other technology is critical to the lessening of human damage after disaster impact.

PRE-DISASTER/PHY SICAL ENVIRONMENT CELL

This cell deals with the contribution of physical environment characteristics to the occurrence of disasters, and how their niodification can reduce the frequency of natural disasters. For example, destruction of ground-cover vegetation and deforestation lead to increased flooding. Such destructive annual flooding could be reduced by better management o f tvater resources, and the development of hydrotechnical projects to regulate the seasonal flow of water and the drainage of precipitation (e.g. properly located systems of dams and locks, construction of break\vater piers and reinforced banks and programmed tree planting). Other ways in which modification o f the physical environment can prevent the marshalling of potentially injurious agents, include seeding of hurricanes and triggering ot avalanches before people are in the area.

Improved efficiency of agricultural output, and better use of water resources in countries affected by drought will decrease the magnitude and future occurrences of famine. Prognostic maps specifying potential natural disasters in any given region can be compiled for virtually all types of natural disasters (e.g. zones of tectonic instability, annual flooding, location of volcanic, cyclone and tsunami activity). Unfortunately, at present there are no current composite natural hazard risk maps on a global scale with detailed local information. Such a composite risk map would be of value by showing where - at any time of the year - cyclones, tsunamis, and flooding may endanger a given community, while during another season earthquakes, sea surges or volcanic eruptions may do similar damage (Havlick. 1986).

DISASTER IMPACT/PHYSICAL ENVJRONMENT CELL

The substance of this cell is the contribution of physical environment characteristics to injury in disasters, and the ways their modification can reduce the frequency and severity of injury. Much of the variation in injury patterns may be explained to a certain extent by such physical environment factors as wind-speed, seismic force, volume of water displaced and time of day and year. Particularly in areas prone to annual flooding an efficient system to allow runoff of water (flood-discharge canals) would decrease flooding of residential areas, and planting of ground cover vegetation would lessen the physical impact of a flood.

Urban planners may not be able to reduce immigration into crowded cities, but improved policies for providing long-term protection can be implemented. Such preventive measures involving the populations' physical environment include ( 1 ) Providing land on sites away from the highest risk of avalanches, flood, earthquake and tsunami; ( 2 ) Building settlements on elevated land in regions subject to regular flooding.

POST-DISASTER/PHYSICAL ENVIRONMENT CELL

The contribution of physical environment characteristics to the worsening of injury once the disaster impact has taken place, and ways their modification can reduce injury are the topics of the post-disaster/physical environment cell. Unfavorable geographical and climatic conditions may delay the arrival of outside medical aid. and the reestablishment of transportation and communications. Also, there is a greater frequency of fires and explosions i n urban areas following earthquakes. I n floods, saltwater contamination of soil may result not only in t h e loss of the present crop. but also several future harvests. In Jakarta. floods frequently cause the canals and latrines to overtlou into the living quarters of slum dwcllers. reculting in skin and gastrointestinal diseases and increased infant and childhood mortality in the post-disaster period (Guha-Sapir. 1986). Interestingly, there is also a regular and predictable

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risk of animal bites in the post-disaster period, particularly froin stray dogs in cities and from snakes in flooded areas. However, while widely believed in, this hazard is not well documented.

Although it would be very difficult to modify unfavorable geographical and climatic conditions that delay the arrival of outside medical aid, we can at least insure that search and rescue teams be self-sufficient in terms of food and supplies, and trained to operate in adverse weather conditions and difficult geographic terrain.

PRE-DISASTER/SOCIOECONOMIC ENVIRONMENT CELL

This cell deals with the contribution of society, culture and economics to the initiation of disasters and how their modification can reduce the severity of injuries. The impact of a disaster, particularly in the developing world (where most major natural disasters occur), is largely determined by preexisting socioeconomic factors, characterized by a range of variables from health, nutrition, education, and quality of housing to earning power. All of these simply reflect the individual’s ability to withstand life’s major crises.

Shantytowns and slum areas in the burgeoning metropolises of several high-risk, less developed countries are especially susceptible to all types of disasters. The unprecedented increase in these slum populations has contributed to the intlation of the number of disaster victims in recent years. Sound economic development with accompanying reduction of poverty will help as much as any other intervention to reduce the deaths and injuries resulting from disasters. Most injuries from natural disasters in the less developed world occur among the poor and lower socioeconomic classes. For example, in many parts of Latin America and the Middle East, it is the poor who live in earthquake-vulnerable adobe structures.

Unfortunately for these people, the most hazardous areas often present superior short-term economic opportunities than are available elsewhere (WHO, 1984). Frequently, people living in such areas would find it extremely difficult or even impossible to move. In Bangladesh, for example, poor squatters live on vulnerable coastal islands because no other accessible land offers comparable soil fertility to grow crops. Some researchers feel that in such disaster-prone areas of the world, a “disaster mentality” develops that fosters a feeling of inevitability of such events and the worthlessness of preparing for them. Not surprisingly, such culturally-bound behavior is extremely resistant to educational approaches.

DISASTER IMPACT/SOCIOECONOMIC ENVIRONMENT CELL

This cell deals with the contribution of social and cultural characteristics to the frequency and severity of injuries in natural disasters, and how their modification would reduce injury. Examples of economically-related disaster vulner-

ability can be found by examining the pattern of death rates from tornadoes, where greater protection against high- velocity winds is generally offered in housing in high-income areas, and by looking at injury rates from flooding where floodplains are often located in areas with low real estate value, and indigent populations (Baker et al., 1984). What leads people to settle knowingly on such land that regularly floods with a predictable great loss of life, and more importantly, to refuse to evacuate despite ample fore- warning? In Bangladesh, when warned of impending disaster, many families refuse to leave for two major reasons : (1) They have no other place to go and (2) If the warning was a false alarm, they risk losing their parcel of land to another landless family.

POST-DISASTER/SOCIOECONOMIC ENVIRONMENT CELL

The contribution of social (especially institutional) and cultural factors to the worsening, or limiting, of injury once the disaster impact has taken place, and ways in which these can be modified to reduce morbidity and mortality, are included in this cell. Post-disaster activities of primary health care workers, police, tire, and emergency medical services personnel, and the extent to which they, and members of the general public, have been trained in disaster triage, search and rescue techniques, CPR, and basic first aid is of particular importance. Other factors include development of designated trauma centers (e.g. specialized burn, hand, eye, and pediatric trauma facilities), and provision for immediate psychological support and crisis intervention. Unfortunately, the disruption of the societal and governmental infrastructure may lead to delays in provision of protective and rescue services leading to increased morbidity and mortality.

Permanent disruption of the social infrastructure may result from a major disaster. An example of this occurred in Nicaragua following the catastrophic 1972 Managua earthquake, in which the inability of the government to respond to the most basic needs of its people was exposed due to widespread inefficiency and corruption. This precipitated the bloody civil war which ultimately led to the toppling of the Somoza regime.

Research efforts in this cell should focus on the following areas:

1. Evaluation of the effectiveness of medical response to the disaster event (evaluation of transportation, commun- ication, hospital-based problems).

2. Improving data collection systems to increase their utility in evaluating the response of public health services during natural disasters (development of standardized guidelines for information to be recorded).

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Table 1. Basic strategies to reduce injuries and deaths in natural disasters

Strategy Example

1. Preventing the marshalling of potentially

2. Reducing their amounts

injurious agents and

3 . Preventing inappropriate release of the

4. Modifying the release of the agent

agent

5. Separating in time and space

6. With physical barrier

7. Modifying surfaces and basic structures

8. Increasing resistance to injury

9. Beginning to counter damage already done

10. Stabilizing, repairing and rehabilitating the injured

Triggering avalanches before people appear in the vicinity.

Encouraging the use of lighter housing material instead of adobe in earthquake-prone areas. Earthquake engineers will be of help here.

Decrease annual flooding by better hydrological planning (properly located system of dams and locks)

Decrease destruction of ground-cover vegetation, the destruction of which leads to increased flooding

a. Improved early warning systems to foster early evacuation of communities threatened by hurricanes, tornadoes, floods, etc. (e.g. satellite technology)

b. Building homes and communities away from high-risk areas (coastal island areas, fault lines, volcanoes).

a. Building of elevated shelters in flood and cyclone-prone areas. This proved to be very effective in Bangladesh

b. Storm cellars in tornado country.

a. Application of earthquake and wind engineering technology to structures in the appropriate areas.

b. Development of stable furnishings in buildings. For example, many people are injured by flying desks and bookcases (e.g. in Japan) in earthquakes.

a. Reduction of osteoporosis.

b. Otherwise strengthening the body.

a. Widespread education in search and rescue techniques, CPR, basic first aid, etc. among primary health care workers and the general population.

b. Development of an effective emergency medical services system.

c. Intermediate psychological support/crisis intervention.

Development of specialty trauma centers (e.g. burn, hand, eye, pediatric facilities).

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2% INJURY PREVENTION IN NATURAL DISASTERS

CONCLUSION AND COMMENTS

According to Haddon, the fundamental tasks of injury control are: (a) To prevent hazardous agents from reaching people in amounts or at rates that exceed injury thresholds, and (b) To minimize the consequences of injury. Haddon has formulated ten interrelated approaches to injury control that may be equally well applied to injuries resulting from natural disasters. These strategies provide another organ- ized approach to analysis of injury problems in natural disasters and the development of appropriate counter- measures. Table 1 lists these strategies and gives examples of their application, many of which have already been described above under a different conceptual framework (Haddon, 1973).

The division of a disaster into chronological phases is difficult because, in reality, each phase has no true endpoint but. rather, blends into the next phase. However, the application of Haddon's three-phase matrix model to a disaster permits researchers to reduce a large, complex problem into more manageable, conceptually simpler parts. It also has potential to be of value to disaster planners by suggesting preventive and mitigation measures as well as aiding in the setting of priorities so that often scarce resources can be allocated to achieve maximum reduction of injuries.

In summary, solution to the problem of injury prevention in natural disasters will require a rigorous scientific, technologic and intellectual approach, and will involve the broadest possible range of disciplines. Out of such research should come greater insight and advances, which should further our overall goal of minimizing morbidity and mortality in natural disasters.

Acknowledgements - I would like to thank Dr. Nicholas Jones, Assistant Professor of Civil Engineering at the Johns Hopkins University for his assistance in the preparation of Fig. 1 and Table 1. I also wish to express my gratitude to Professor Susan P. Baker of the Johns Hopkins School of Hygiene and Public Health for introducing me to the field of injury research and for encouraging me to submit this manuscript for publication.

REFERENCES

Baker S.P., O'Neil B. and Karpf R.S., The Injury Fact Book. D.C. Heath, Lexington, MA (1984).

Beinin L., Medical Consequences of Natural Disasters. Springer-Verlag, Berlin (1985).

De Bruycker M., Greco D. and Lechat M.F., The 1980 earthquake in Southern Italy - morbidity and mortality, International Journal of Epidemiology 14(1), 113-1 17 (1 985).

Glass R.I. et al., Earthquake injuries related to housing in a Guatemalan village, Science 197, 638-643 (1977). Glass R.I. et al., Injuries from the Wichita Falls tornado: Implications for prevention, Science 207, 734-738 (1980).

Guha-Sapir D. and Lechat M.F., Mortality and morbidity in natural disaster: A global analysis of time trends and regional differentials, Monograph, Centre for Research on the Epidemiology of Disasters, Brussels, Belgium (1986).

Haddon W., Energy damage and the ten countermeasure strategies, Journal of Trauma 13, 321 (1973).

Haddon W., Strategy in preventive medicine: Passive versus active approaches to reducing human wastage, Journal of Trauma 14, 353 (1974).

Haddon W., Options for the prevention of motor vehicle crash injury, IsraelJoumal of Medical Science 16(1), 4 5 - 6 8 (1 980).

Havlick S.W., Third world cities at risk: Building for calamity, Environment 28(9), 6 (1986). Lechat M.F., Disaster epidemiology, Annales de la Societe Belge de Medicine Tropicale 56(4-5), 193-197 (1976).

Lima B.R., Primary mental health care for disaster victims in developing countries, Disasters 10(3), 203-204 (1986).

Logue J.N. et al., Research issues and directions in the epidemiology of health effects of disasters, Epidemiologic Reviews 3, 140-172 (1981).

Western K.A., The epidemiology of natural and man-made disasters: Present State of the Art, DTPH Dissertation for the London School of Hygiene and Tropical Medicine, London (1976).

WHO, Health aspects of disaster preparedness: Report of a WHO Workshop, Trieste, Italy (15-20th October 1984).

Withers B.F. and Baker S.P., Epidemiology and prevention of injuries, Emergency Medicine Clinics of North America 2(4). 701-715 (1984).

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injury prevention in natural disasters. a theoretical framework

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