Combined effects of atomic radiation and other agents in Hiroshima and Nagasaki and possible application of fuzzy theory

Abstract

The survivors of atomic bombings and those who visited Hiroshima and Nagasaki immediately after the atomic bombing could have been subjected to many other possible noxious effects in addition to atomic radiation. Various toxic substances must have been released from destroyed hospitals, laboratories, drugstores, storehouses of chemicals and so on. Among the destroyed facilities, a large storage of gasoline for the army transportation and containers of mustard gas for chemical weapons are possibly included. There was no food and the drinking water was contaminated. There would have been various possibilities of infection. It is confusing which factor played a dominant role, but, the authors emphasize that, in addition to ionizing radiation, various other direct and indirect factors such as the noxious factors must be considered instead of ascribing all the effects solely to ionizing radiation.In addition, it is important to consider the uncertainties involved in the above various factors and their combined effects. Under emergency conditions of wartime or accidents, much fuzziness may be added to the randomness. The authors propose a method to analyze the total cause-effect relationships. The method uses a simple model to visualize how the total effect is intuitively derived from various factors with uncertainties.