The large number of casualties during major or mega-disasters are a global problem.

The role of medicine against mega-disasters is analyzed from a worldwide perspective.

Chernobyl incident, the Tokyo Subway Sarin Attack, the 9-11 attack, the Indian Ocean earthquake/tsunami, Hurricane Katrina, the Flu pandemic, the Higashi Nihon Earthquake followed by the Fukushima nuclear plant incident, etc. are critically analyzed, based on the actual medical experiences.

These mega-disasters often have a wide, severe negative influence. Linked catastrophes often form catastrophic circulus vitiosus (CCV) or malignant cycles on a global scale. The typical example is the Chernobyl incident which caused not only many deaths by radiation exposure/thyroid cancer and world anxiety, but also is considered to have contributed to the end of the Eastern European Communism system in 1989 (East Germany) and 1991 (ESSR).

Many roles of medical doctors and staff were requested, including creating preventive life-saving systems, in addition to the prevention of mega-disaster measurement to minimize the unhappiness. Moreover, medical ethics and philosophy are important, which were often overlooked. It is necessary for medical care and support to have a broad perspective. Although the classical philosophy of utilitarianism is often accepted without suspicion, it comes with the risk of disregarding vulnerable/weak people. The concept of justice according to John Rawls (USA) and the Minimal Unhappiness Theory by Naoto Kan (Japanese politician) should be considered, too. From such viewpoints, it is our conclusion to urge the establishment of systematic disaster medicine or to compile a disaster medicine compendium. Although the tentative first version was compiled with 22 volumes in 2005, only one-fourth was available in English. The English part increased up to nearly three-fourths by adding several new versions in which the nuclear/biological/chemical hazard version, tsunami measurement, and psychological care version are included at the moment.