Risk Evaluation and Communication

Abstract

Virtually all human activities involve some associated risk. In going about their daily life individuals continuously evaluate situations and make decisions on whether the risk associated to a particular action is justified. Such decisions are mostly made involving value judgments which normally cannot be explicitly expressed in terms of quantitative criteria. This is frequently the case when the risk is of a voluntary nature, i. e. it is taken as a free choice (e. g. smoking, downhill skiing). On the other hand when the individual cannot fully choose to avoid exposure to risk, it is termed involuntary (e. g. natural disasters) and the decision making process needs to be more explicit using quantitative data. Moreover, people are generally willing to expose themselves to quite different levels of risk depending on whether they feel it was their own decision or they feel that the exposure is beyond their control. Decisions involving involuntary risks are often dominated by emotional arguments, as has been amply demonstrated in the controversy about electricity producing technologies, and here especially about nuclear power (Chiosila 1996; Scholz 1996; Ansel 1997; Stoll 1997; Tanguy 1997). In most of these controversies, the potential negative consequences rather than the related low probabilities play the dominant role, as can be expected in a discussion related to risk. This applies not only to the nuclear issue but also to other areas such as the environment, public health, etc.