Impacts of coal mine fire-related PM_2.5 on the utilisation of ambulance and hospital services for mental health conditions

Climate change and an increase in the number of major fire events occurring around the world have drawn attention to the importance of understanding the association between air pollution events and mental health. In 2014, the Morwell open-cut brown coal mine adjacent to the Hazelwood power station in the Latrobe Valley region of Victoria, Australia, caught fire as a result of nearby wildfires, and exposed the local community to a prolonged period of deteriorated air quality. The aim of this study was to examine how exposure to coal mine fire-related fine particulate matter (PM_2.5) during the event affected the utilisation of local health services (ambulance attendances; emergency department (ED) presentations; hospital admissions) for mental health conditions. A time-series analysis indicated that mine fire-related PM_2.5 exposure was associated with short-term increases in ambulance attendances and ED presentations but not hospital admissions. To allow for delays between exposure and changes in service utilisation, different lag periods were assessed. The most prominent effects were observed over a 5-day lag period where, for each 10 μg/m³ increase in daily mean mine fire-related PM_2.5, the risk of an ambulance attendance for anxiety increased by 38% (95%CI: 13%–69%) and the risk of an ED presentation for depression increased by 36% (95%CI: 3%–79%). Accordingly, ambulance and hospital services should expect to encounter an increase in the number of people seeking assistance for mental health conditions during extreme air pollution events and mechanisms need to be in place to ensure that surges in demand for mental health care during these circumstances can be accommodated.