Understanding of the concept of ‘uncertain risk’. A qualitative study among different societal groups

In environmental health science, the concept ‘uncertain risk’ refers to situations in which epistemic uncertainties prevent definitive statements about the presence or existence of risk. The concept is difficult for risk communication and may easily lead to miscommunications and misunderstanding. This research investigated how the concept of uncertain risk is understood by different societal groups. We conducted in-depth interviews with the general public (N = 40), and online open-ended questionnaires and online focus groups with scientists, policy makers and communication experts (N = 49). Results show that the understanding of ‘uncertain risk’ varied within and between groups. While at least some representatives of all groups described epistemic uncertainties, groups focused on different aspects of risk. That is, scientists based their descriptions only on uncertainties in risk assessment. Policy makers commonly indicated that these uncertainties caused uncertainty in risk management. Communication experts mainly gave general descriptions, but recognized aspects that were important for other groups. Representatives of the general public often described aspects that deviate from the scientific understanding, such as a lack of personal control. In risk communication, stating that ‘a risk cannot be excluded’ is not clear. Different associations and understanding have to be taken into account in risk communication. Explicating uncertainties may improve consistent understanding and foster a more balanced dialogue between different societal groups. Further (empirical) research is needed to demonstrate if and how explicating evidence and uncertainties in specific cases of uncertain risks improves understanding within and between groups.