Trajectories of posttraumatic distress after smoke exposure during a coalmine fire: An analysis of risk and protective factors

In 2014, the coalmine adjacent to the Hazelwood power station in the Latrobe Valley, Australia caught fire and distributed a large volume of toxic smoke into the surrounding community over 45 days. This study investigated risk and protective factors associated with four trajectories of posttraumatic distress (resilience; in-recovery; delayed-onset; chronic) in the affected community. A sample comprising 709 adults participated in two survey rounds, conducted in 2016-2017 and 2019-2020. Participants’ exposure to mine fire-related particulate matter (PM2.5) during the event, sociodemographic circumstances, physical and mental health histories, prior trauma, and exposure to recent stressful events were assessed. Mine fire-related posttraumatic distress was measured using the Impact of Events Scale – Revised and trajectories determined by categorising scores at each survey according to a threshold prescribed for identifying symptoms warranting clinical concern. Responses were analysed with univariate and multivariate multinomial regressions. Socioeconomic advantage and social support were associated with the resilient trajectory, which was the most common posttraumatic distress trajectory among participants. Prior trauma and recent stressful life-events, physical and mental health diagnoses, and loneliness were associated with chronic and delayed-onset trajectories. PM2.5 exposure during the mine fire was not a strong determinant of posttraumatic distress trajectory. Socioeconomic status, social connection, health and life experiences are among the most important factors shaping posttraumatic distress trajectories. These findings contribute to better understanding longer-term psychological resilience and vulnerability following disasters and can inform mental health initiatives within at-risk communities.