Impact of the 2019/2020 Australian megafires on Air Quality and Health

The Australian 2019/2020 bushfires were unprecedented in their extent and intensity, causing a catastrophic loss of habitat, human and animal life across eastern‐Australia. We use a regional air quality model to assess the impact of the bushfires on particulate matter with a diameter less than 2.5 μm (PM2.5) concentrations and the associated health impact from short‐term population exposure to bushfire PM2.5. The mean population Air Quality Index (AQI) exposure between September and February in the fires and no fires simulations indicates an additional ∼437,000 people were exposed to “Poor” or worse AQI levels due to the fires. The AQ impact was concentrated in the cities of Sydney, Newcastle‐Maitland, Canberra‐Queanbeyan and Melbourne. Between October and February 171 (95% CI: 66–291) deaths were brought forward due to short‐term exposure to bushfire PM2.5. The health burden was largest in New South Wales (NSW) (109 (95% CI: 41–176) deaths brought forward), Queensland (15 (95% CI: 5–24)), and Victoria (35 (95% CI: 13–56)). This represents 38%, 13% and 30% of the total deaths brought forward by short‐term exposure to all PM2.5. At a city‐level 65 (95% CI: 24–105), 23 (95% CI: 9–38) and 9 (95% CI: 4–14) deaths were brought forward from short‐term exposure to bushfire PM2.5, accounting for 36%, 20%, and 64% of the total deaths brought forward from all PM2.5. Thus, the bushfires caused substantial AQ and health impacts across eastern‐Australia. Climate change is projected to increase bushfire risk, therefore future fire management policies should consider this.
Key Points The fires led to widespread exposure to “Poor” or worse Air Quality Index levels across eastern‐AustraliaThe highest all‐cause, all‐age mortality from short‐term exposure to bushfire particulate matter with a diameter less than 2.5 μm (PM2.5) was seen in the states of New South Wales, Queensland, and VictoriaAll‐cause, all‐age mortality from short‐term exposure to bushfire PM2.5 was highest in the cities of Sydney, Melbourne, and Canberra