Perceived risk of nuclear power and other risks during the last 25 years in Japan.

The present study described the results of three "fixed-point" surveys on perceived risk related to a list of social and individual risk events during 25 years in Japan. Female clerical staff and researchers were asked to rank 30 items related to various types of technologies and human activities according to their subjective judgments on the order of perceived magnitude of risk in 1983, 1992, and 2007. A similar survey was undertaken for Japanese citizens using web-based questionnaires in 2007. In general, the risk perceptions of the Japanese people, irrespective of gender, age, and occupation, have been uniform during the last 25 years. The female clerical staffs have consistently judged nuclear power as most risky during the last 25 years, whereas researchers' judgment fluctuated with events such as the Chernobyl accident. The ranking of the risk of motor vehicles fell during the 25-y period, whereas those of health risks with food preservatives, x-rays, and antibiotics rose transiently in the 1992 survey. During the 15 years from 1992 to 2007, people tended to learn how to accommodate themselves to these technologies with low risks in exchange for high benefits, except in the case of nuclear power. Nuclear power was regarded as a high-risk item by the Japanese even before the Fukushima nuclear power plant accident in March 2011. This partly explains that the crisis inevitably provokes further high risk perception in Japan, although the overall health threat to the human population in Japan is estimated to be relatively limited so far.