Understanding Public Responses to Domestic Threats

Abstract The overall goal of this report is to improve understanding of public responses to domestic threats. Project 1 focuses on pandemic influenza and dirty bomb threats, aiming to understand the role of emotions in anticipated behavioural responses. Project 2 examines a situation in which people are evacuated from a community to avoid exposure to radioactive fallout from an upwind nuclear explosion. The project aims to understand the factors that affect people’s decisions about how long to wait until returning to their homes, given the gradual decline in radiation levels resulting from radioactive decay. First, we present an overview of each problem, by presenting models summarizing scientific knowledge. The resulting models use the logic of influence diagrams (Clemens, 1997; Fischhoff, 2000) with nodes reflecting relevant variables affecting the risk, and mitigating it, and links showing how they are connected. The models differ from traditional risk models, because they include emotional and behavioural components that affect how a risk event unfolds. Project 1 models concern the interplay between emotional and behavioural responses to domestic threats, focusing on fear and anger. The model for project 2 concerns the health, social, and economic factors that may affect people’s decisions to return to a community with residual radiation levels that elevate cancer risk. Second, we report on surveys with Canadian and U.S. participants, based on these models. For project 1, we presented participants with scenarios describing the risks and mitigation strategies for pandemic influenza and radiological dispersion devices. We examined the independent relationship of fear and anger with different responses to these scenarios. We found that, independent of anger and trait emotions, fear was related to seeing more risk of morbidity and mortality, and predicting less resilience, more compliance with mitigation strategies, and higher likelihood of being absent from work in case of pandemic influenza. However, anger showed no significant relationship with these variables, after controlling for fear and trait emotions. For project 2, the survey examined people’s decisions about how long to stay evacuated before returning to a fallout-contaminated neighbourhood. We found that those decisions were affected by the cancer risk of radioactive fallout, as well as the availability of free housing in the evacuation zone. Although cancer risk was rated as the most important factor affecting these decisions (as was the overall health of participants and their household members),other characteristics of the household, the neighbourhood, and temporary housing were also rated as relatively important.