Risks and Risk Assessment

Abstract

Specific risk assessment methods have been developed for different types of risks. Nevertheless, they present some common features. This Chapter focusses on the assessment of chemical, biological, ecological and radiation risks, the safety of food and feed derived from genetically modifies plants, and on the safety assessment of nuclear power plant. The aim is to introduce the basic methodological issues and problems of risk assessment through the example provided by the methods applied in a range of sectors which are of particular interest for the EU regulatory action. The basic paradigm of risk assessment includes the identification and characterisation of the hazards, the assessment of the exposure to the relevant stressors, the characterisation of the risk integrating the information on the two dimensions of risk: the hazard and the exposure. Risk assessment methods try to quantify the risk, but in many cases only a qualitative expression is possible. Risk assessment is often affected by uncertainty and variability. Probabilistic methods have been developed to address and represent uncertainty. Several aspects of risk assessment are characterised by a certain degree of subjectivity, notably when evidence and data are weighed, defaults are selected, assumptions are made based on professional judgment and expert opinion elicitation or subjective probabilities are assigned. Transparency on such aspects is key for the credibility of the assessment process. Close collaboration between assessors and managers is needed in order to frame the assessment within a risk assessment policy setting criteria and guidance for the value-laden or subjective aspects of the process as well as for the functioning of the interface between assessment and management.