Causes and concequenses of natural disasters
Sudden-onset natural and technological disasters impose a substantial health burden, either directly on the population or indirectly on the capacity of the health services to address primary health care needs. The relationship between communicable diseases and disasters merits special attention. This chapter does not address epidemics of emerging or reemerging diseases, chronic degradation of the environment, progressive climatic change, or health problems associated with famine and temporary settlements.
In line with the definition of health adopted in the constitution of the World Health Organization (WHO), the chapter treats disasters as a health condition or risk, which, as any other "disease," should be the subject of epidemiological analysis, systematic control, and prevention, rather than merely as an emergency medicine or humanitarian matter. The chapter stresses the interdependency between long-term sustainable development and catastrophic events, leading to the conclusion that neither can be addressed in isolation.
Disasters as a Public Health Condition
According to the International Federation of Red Cross and Red Crescent Societies, internationally reported disasters in 2002 affected 608 million people worldwide and killed 24,532—well below the preceding decade's annual average mortality of 62,000 (IFRC 2003). Many more were affected by myriad local disasters that escaped international notice.
Disaster has multiple and changing definitions. The essential common element of those definitions is that disasters are unusual public health events that overwhelm the coping capacity of the affected community. This concept precludes the universal adoption of a threshold number of casualties or victims. What would be a minor incident in a large country may constitute a major disaster in a small isolated island state. Not only are "quantitative definitions of disasters unworkably simplistic" as noted by Alexander (1997, 289), but when based on the economic toll or the number of deaths, they are also misleading with regard to the immediate health needs of the survivors or their long-term impact on the affected country.
Classification of Disasters
In the early 1970s, a series of well-publicized disasters (the civil war and resulting famine in Biafra, the cyclone in Bangladesh, and the earthquake in Peru) triggered the scientific interest of the international public health community.