Abstract
In the Environmental risk evaluation, the most important problem are: to attempt to anticipate the risks, to assess the relationships between causes and effects and to balance the benefits with the costs associated to the control of risks. Risk assessment is mixed with risk management, which is in effect a different area of human behavior. According to mainstream economics refer risk to individual behavior, the Expected utility function (EUF) incorporates risk: risk aversion is strictly individual, it’s necessary a good knowledge of probability occurrence and risk is managed through decision. But, when we use multidimensional data to describe the risk, EUF seems inadequate: environmental risks are complex, and so individual can not manage them. The main consequence is that environmental risk is to be considered exogenous with respect to individual behavior. Environmental economics assesses risks on the basis of the relationship: causes lead to effects. Effects have to be evaluated as physical/technical ones, afterwards it is possible to assess their economic value.