Unprecedented health costs of smoke-related PM2.5 from the 2019–20 Australian megafires

In flammable landscapes around the globe, longer fire seasons with larger, more severely burnt areas are causing social and economicimpacts that are unsustainable. The Australian 2019–20 fire season is emblematic of this trend, burning over 8 million haof predominately Eucalyptus forests over a six-month period. We calculated the wildfire-smoke-related health burden and costsin Australia for the most recent 20 fire seasons and found that the 2019–20 season was a major anomaly in the recent record,with smoke-related health costs of AU$1.95 billion. These were driven largely by an estimated 429 smoke-related prematuredeaths in addition to 3,230 hospital admissions for cardiovascular and respiratory disorders and 1,523 emergency attendancesfor asthma. The total cost was well above the next highest estimate of AU$566 million in 2002–03 and more than nine timesthe median annual wildfire associated costs for the previous 19 years of AU$211 million. There are substantial economic costsattributable to wildfire smoke and the potential for dramatic increases in this burden as the frequency and intensity of wildfiresincrease with a hotter climate.