Smoke of fires: assessing focal points for risk communications

In January 2011, a major fire erupted at a chemical storage and packing company in The Netherlands. In the aftermath, the risk communication to the public was heavily criticised. In the present study, we employed a mental... [ view full abstract ]

In January 2011, a major fire erupted at a chemical storage and packing company in The Netherlands. In the aftermath, the risk communication to the public was heavily criticised. In the present study, we employed a mental models approach to improve risk communication in case of a fire involving hazardous materials. This approach integrates descriptive assessment and comparison of the science that is relevant for lay risk decisions with lay knowledge and beliefs of the underlying hazardous processes. Key discrepancies between these two perspectives are candidate focal points for improving communication materials.
First, we constructed an expert model based on the scientific literature and interviews with experts (n=17). Next, non-expert members of the general public were interviewed (n=15) to assess key aspects of the lay mental model. To quantify these aspects in the general population, a confirmatory online survey was developed and conducted (n= 437).
We found several important knowledge gaps and typical non-expert beliefs contrary to opinions of experts. Whereas experts considered the chance of getting cancer from inhaling smoke from a chemical fire extremely small, and the impact on health at a great distance from the fire as very limited, most lay-people thought that ‘chemical fire smoke’ affects health adversely even at a great distance. In addition, lay people overrated the possibilities of environmental monitoring and the feasibility of risk assessment during the acute phase of a fire. Based on our findings we recommend to include a clarification of cancer risk, of the exposure to hazardous materials, and of the limitations of risk measurements in risk communications during the acute phase of a fire.