The public health consequences of disasters.

Although disasters have exacted a heavy toll of death and suffering, the future seems more frightening. Good disaster management must link data collection and analysis to the decision-making process. The overall objectives of disaster management from the viewpoint of public health are: 1) needs assessments; 2) matching available resources with defined needs; 3) prevention of further adverse health effects; 4) implementation of disease-control strategies; 5) evaluation of the effectiveness of the application of these strategies; and 6) improvement in contingency planning for future disasters. The effects of sudden-onset, natural disasters on humans are quantifiable. Knowledge of the epidemiology of deaths, injuries, and illnesses is essential to determine effective responses; provide public education; establish priorities, planning, and training. In addition, the temporal patterns for the medical care required must be established so that the needs in future disasters can be anticipated. This article discusses: 1) the nature of disasters due to sudden-onset, natural events; 2) the medical and health needs associated with such events and disasters; 3) practical issues of disaster responses; and 4) the advance organization and management of disasters. The discussion also includes: 1) discussions of past problems in disaster management including non-congruence between available supplies and the actual needs of the affected population; 2) information management; 3) needs assessments; 4) public health surveillance; and 5) linking information with decision-making. This discussion is followed by an analysis of what currently is known about the health-care needs during some specific types of sudden-onset, natural disasters: 1) floods; 2) tropical cyclones; 3) tornadoes; 4) volcanic eruptions; and 5) earthquakes. The article concludes with descriptions of some specific public-health problems associated with disasters including epidemics and disposition of corpses. All natural disasters are unique in that the regions affected have different social, economic, and health backgrounds. But, many similarities exist, and knowledge about these can ensure that the health and emergency medical relief and limited resources are well-managed.

Deaths and injuries due to the earthquake in Armenia: a cohort approach.

BACKGROUND: This is the first population-based study of earthquake injuries and deaths that uses a cohort approach to identify factors of high risk. As part of a special project that collected data about the population in the aftermath of the earthquake that hit Northern Armenia on 7 December 1988, employees of the Ministry of Health working in the earthquake zone on 7 December 1988, and their families, were studied as a cohort to assess the short and long term impact of the disaster. The current analysis assesses short term outcomes of injuries and deaths as a direct result of the earthquake. METHODS: From an unduplicated list of 9017 employees, it was possible to contact and interview 7016 employees or their families over a period extending from April 1990 to December 1992. The current analysis presents the determinants of 831 deaths and 1454 injuries that resulted directly from the earthquake in our study population of 32,743 people (employees and their families). RESULTS: Geographical location, being inside a building during the earthquake, height of the building, and location within the upper floors of the building were risk factors for injury and death in the univariate analyses. However, multivariate analyses, using different models, revealed that being in the Spitak region (odds ratio [OR] = 80.9, 95% confidence interval [CI]: 55.5-118.1) and in the city of Gumri (OR = 30.7, 95% CI: 21.4-44.2) and inside a building at the moment of the earthquake (OR = 10.1, 95% CI: 6.5-15.9) were the strongest predictors for death. Although of smaller magnitude, the same factors had significant OR for injuries. Building height was more important as a factor in predicting death than the location of the individual on various floors of the building except for being on the ground floor of the building which was protective. CONCLUSIONS: Considering that most of the high rise buildings destroyed in this earthquake were built using standard techniques, the most effective preventive effort for this disaster would have been appropriate structural approaches prior to the earthquake.

The historical development of public health responses to disaster.

The first of a of series state-of-the-art reviews commissioned to mark Disasters' 21st anniversary, this paper considers key publications on public health aspects of natural disasters, refugee emergencies and complex humanitarian disasters over the past twenty-odd years. The literature is reviewed and important signposts highlighted showing how the field has developed. This expanding body of epidemiological research has provided a basis for increasingly effective prevention and intervention strategies.

Public health surveillance after a volcanic eruption: lessons from Cerro Negro, Nicaragua, 1992.

The eruption of the Cerro Negro volcano near León, Nicaragua, on 9 April 1992 distributed an estimated 1.7 million tons of ash over a 200 square kilometer area. An assessment was conducted to evaluate the health effects on approximately 300,000 residents, using routine data obtained by the national epidemiologic surveillance system. It was found that rates of visits to health care facilities for acute diarrheal and respiratory illnesses increased in two study communities, one within and one near the disaster zone. Specifically, visits for acute diarrhea were nearly 6 times more numerous than before the eruption in both communities, while visits for acute respiratory diseases were 3.6 times more frequent in Malpaisillo (the community near the disaster zone) and 6.0 times more frequent in Telica (the community within it). Most of the visits were for infants and children less than 5 years old. Increased diarrheal disease morbidity, which commonly occurs after volcanic eruptions, demands detailed investigation of the type and quality of water supplies following heavy ashfall. Ash-related respiratory problems should be further examined to determine the spectrum of such diseases and the timing of illness onsets among infants and other special population subgroups. Data collected on health conditions before and after an eruption by passive surveillance can be used to detect eruption-related morbidity. Systems already in place, such as Nicaragua's national epidemiologic surveillance system, can be modified or extended so as to increase their sensitivity to new cases and hence their ability to provide appropriate notification to medical relief agencies.

The World Trade Center bombing: injury prevention strategies for high-rise building fires.

The WTC disaster provided an opportunity to look for ways to prevent morbidity among occupants of high-rise buildings during fires. This paper first describes the overall morbidity resulting from the explosion and fire, and second, presents the results of a case-control study carried out to identify risk factors for smoke-related morbidity. The main ones include: increased age, presence of a pre-existing cardio-pulmonary condition, entrapment in a lift and prolonged evacuation time. Study results point to the importance of the following safety systems during high-rise building fires: smoke-control systems with separate emergency power sources; lift-cars, lift-car position-monitoring systems, and lift-car communication systems with separate emergency power sources; two-way emergency communication systems on all floors and in stairwells; stairwells with emergency lighting and designed for the rapid egress of crowds; evacuation systems/equipment to assist in the evacuation of vulnerable people (elderly, infirm). Also important are evacuation plans that include regularly scheduled safety training and evacuation drills.

Disaster epidemiology.

Sound epidemiologic knowledge of the morbidity and mortality caused by disasters is essential when determining what relief supplies, equipment, and personnel are needed to respond effectively in emergency situations. All disasters are unique because each affected region of the world has different social, economic, and baseline health conditions. Some similarities exist, however, among the health effects of different types of disasters, that if recognized, can ensure that the limited health and medical resources of the affected community are well managed.

Assessment of a severe-weather warning system and disaster preparedness, Calhoun County, Alabama, 1994.

Tornado preparedness warning system effectiveness, and shelter-seeking behavior were examined in two Alabama areas after tornado warnings. In the area without sirens, only 28.9% of 194 respondents heard a tornado warning of these, 73.2% first received the warning from radios or television. In the area with sirens, 88.1% of 193 respondents heard a warning, and 61.8% first received the warning from a siren. Knowledge of warnings, access to shelter, and education were key predictors for seeking shelter. Our findings indicate that installing sirens, providing access to shelter, and teaching appropriate responses to warnings are important elements of an effective disaster prevention system.

Evaluation of long-term community recovery from Hurricane Andrew: sources of assistance received by population sub-groups.

Two three-stage cluster surveys were conducted in South Dade County, Florida, 14 months apart, to assess recovery following Hurricane Andrew. Response rates were 75 per cent and 84 per cent. Sources of assistance used in recovery from Hurricane Andrew differed according to race, per capita income, ethnicity, and education. Reports of improved living situation post-hurricane were not associated with receiving relief assistance, but reports of a worse situation were associated with loss of income, being exploited, or job loss. The number of households reporting problems with crime and community violence doubled between the two surveys. Disaster relief efforts had less impact on subjective long-term recovery than did job or income loss or housing repair difficulties. Existing sources of assistance were used more often than specific post-hurricane relief resources. The demographic make-up of a community may determine which are the most effective means to inform them after a disaster and what sources of assistance may be useful.

Long-term effects of Hurricane Andrew: revisiting mental health indicators.

Two population-based surveys of South Dade County, Florida, were conducted after Hurricane Andrew to compare hurricane-related symptoms of mental distress and describe the impact of mental health outreach teams. Households were selected by three-stage cluster sampling and findings from the two surveys, 13 months apart, were compared. Response rates were 75 per cent and 84 per cent. The prevalence of symptoms of mental distress decreased over time. However, in the households contacted by the teams (25 per cent of sample), the prevalence of symptoms (50 per cent) did not differ from households not contacted (43 per cent). Households contacted by teams that reported symptoms were just as likely to have been referred for help by the teams (72 per cent) as those without symptoms (68 per cent). Households reporting symptoms were equally likely to get counselling regardless of whether the teams visited. Mental health teams had no significant impact on mental health symptoms or the use of mental health services. Alternative approaches to mental health outreach teams need to be explored.

The rapid implementation of a statewide emergency health information system during the 1993 Iowa flood.

In the face of disastrous flooding, the Iowa Department of Public Health established the statewide Emergency Computer Communications Network to establish rapid electronic reporting of disaster-related health data, provide e-mail communications among all county health departments, monitor the long-range public health effects of the disaster, and institute a general purpose public health information system in Iowa. Based on software (CDC WONDER/PC) provided by the Centers for Disease Control and Prevention and using standard personal computers and modems, this system has resulted in a 10- to 20-fold increase in surveillance efficiency at the health department, not including time saved by county network participants. It provides a critical disaster assessment capability to the health department but also facilitates the general practice of public health.

Disaster epidemiology and disease monitoring.

Better epidemiologic knowledge of the mechanisms of death and of the types of injuries and illnesses caused by disasters is clearly essential to determining the appropriate relief medications, supplies, equipment, and personnel needed to effectively respond to such emergencies. The overall objective of disaster epidemiology is to measure scientifically and describe the health effects of disasters and the factors contributing to these effects. The results of such investigations allow disaster epidemiologists to assess the needs of disaster-affected populations, efficiently match resources to needs, prevent further adverse health effects, evaluate relief effectiveness, and plan for future disasters.

Tornado injuries related to housing in the Plainfield tornado.

BACKGROUND: On 28 August 1990, a tornado in Will County, Illinois, caused 29 deaths and more than US $200 million in damage. Risk factors for impact-related morbidity and mortality were studied. METHODS: A case-control study was conducted of 26 people hospitalized or killed, and 116 injured, randomly selected people who were in houses damaged by the tornado. To obtain information on study subjects, telephone interviews were conducted, and hospital records, coroners' reports, and American Red Cross records were abstracted. Structural details on houses were collected from tax assessor records. RESULTS: Cases were more likely than controls to have been in multistorey houses than in single-storey houses (OR = 3.9; 95% CI: 1.2-13.2). The risk associated with houses built after 1972 (OR = 7.9) and those built from 1962 to 1972 (OR = 2.2) was greater than for those built before 1962 (OR = 1.0; chi 2 for trend = 12.1; P < 0.01). Being in the basement when the tornado hit was protective (OR = 0.1; 95% CI: 0.0-0.4). CONCLUSIONS: One-storey houses were safer than multistorey houses, and basements were safer than other rooms. The association of risk with the construction date of the house is a new finding and should be examined in further studies.

Deaths due to flash floods in Puerto Rico, January 1992: implications for prevention.

BACKGROUND: In January 1992, the Commonwealth of Puerto Rico sustained unusually heavy rainfall, which caused flash floods and deaths. METHODS: We conducted a descriptive study and a case-control study to determine the circumstances of these deaths and to identify mortality-prevention strategies. We describe the time, place, and circumstances of each death, and compare this information with water-level and rainfall data and the timing of warnings. Using controls selected from the affected population, we estimated the risk of death by age, sex, and vehicle occupancy during the flood. RESULTS: Within 7 hours, 23 people died in 17 incidents; 20 of the decedents (87%) were occupants of motor vehicles. The estimated risk of mortality was significantly elevated for motorists (odds ratio = 16, 95% confidence interval: 3.5-144). Being in a vehicle to evacuate a flash flood area was protective; however, being in a vehicle during the flood for other reasons further increased the risk of mortality. Deaths occurred early during the rapid rise of water and before official warnings were issued. CONCLUSION: We recommend improving the sensitivity of the warning system and its ability to disseminate appropriate information rapidly. We also recommend educating officials and the public about the risks of driving on flooded roads and in potential flash flood conditions; and about the unique flash flood risks associated with specific topographical features in their region.

Evaluating a fluorosis hazard after a volcanic eruption.

The August, 1991 eruption of Mt. Hudson (Chile) deposited ash across southern Argentina and contributed to the deaths of thousands of grazing sheep. Early ash analysis revealed high levels of fluoride, a potential ash constituent toxic to humans and animals. In order to evaluate fluorosis as the cause of sheep deaths and to examine the possibility that similar ash and airborne toxins could also have an effect on the human population, we conducted an investigation that included health provider interviews, hospital record review, physical examination of sheep, determination of sheep urine fluoride levels, and complete constituent analysis of ash samples collected at proscribed distances from the volcano. Ash deposited farthest from the volcano had highest fluoride levels; all fluoride measurements were normal after rainfall. There were no signs or symptoms of fluorosis observed in sheep or humans. Sheep deaths resulted from physical, rather than chemical properties of the ash.