'Breathing Fire': Impact of Prolonged Bushfire Smoke Exposure in People with Severe Asthma

Int J Environ Res Public Health. 2022 Jun 16;19(12):7419. doi: 10.3390/ijerph19127419.


Wildfires are increasing and cause health effects. The immediate and ongoing health impacts of prolonged wildfire smoke exposure in severe asthma are unknown. This longitudinal study examined the experiences and health impacts of prolonged wildfire (bushfire) smoke exposure in adults with severe asthma during the 2019/2020 Australian bushfire period. Participants from Eastern/Southern Australia who had previously enrolled in an asthma registry completed a questionnaire survey regarding symptoms, asthma attacks, quality of life and smoke exposure mitigation during the bushfires and in the months following exposure. Daily individualized exposure to bushfire particulate matter (PM2.5) was estimated by geolocation and validated modelling. Respondents (n = 240) had a median age of 63 years, 60% were female and 92% had severe asthma. They experienced prolonged intense PM2.5 exposure (mean PM2.5 32.5 μg/m3 on 55 bushfire days). Most (83%) of the participants experienced symptoms during the bushfire period, including: breathlessness (57%); wheeze/whistling chest (53%); and cough (50%). A total of 44% required oral corticosteroid treatment for an asthma attack and 65% reported reduced capacity to participate in usual activities. About half of the participants received information/advice regarding asthma management (45%) and smoke exposure minimization strategies (52%). Most of the participants stayed indoors (88%) and kept the windows/doors shut when inside (93%), but this did not clearly mitigate the symptoms. Following the bushfire period, 65% of the participants reported persistent asthma symptoms. Monoclonal antibody use for asthma was associated with a reduced risk of persistent symptoms. Intense and prolonged PM2.5 exposure during the 2019/2020 bushfires was associated with acute and persistent symptoms among people with severe asthma. There are opportunities to improve the exposure mitigation strategies and communicate these to people with severe asthma.

Keywords: bushfire smoke; particulate matter; severe asthma; wildfire smoke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Air Pollutants* / analysis
  • Asthma* / epidemiology
  • Australia / epidemiology
  • Environmental Exposure
  • Female
  • Fires*
  • Humans
  • Longitudinal Studies
  • Male
  • Middle Aged
  • Particulate Matter / analysis
  • Quality of Life
  • Smoke / adverse effects
  • Smoke / analysis


  • Air Pollutants
  • Particulate Matter
  • Smoke

Grant support

Funding support for this research study was provided by the Medical Research Future Fund’s Emerging Priorities and Consumer Driven Research Initiative 2020 Bushfire Impact Research Grant (APP1201288) and a Hunter Medical Research Institute Research Grant (G2000105). Both grants supported data collection, data analysis and some research staff. The development of the validated bushfire smoke data was supported by funds from grants from the Australian Research Council (LP0882048) and the National Health and Medical Research Council (490057) and the Australian National Data Service (ANDS) SWISH Climate Impacts project (project code AP07). Australian Mepolizumab Registry data collection was supported by funding received through the GlaxoSmithKline Investigator-Sponsored Studies program (protocol 207455) and the Australasian Severe Asthma Registry was supported by funding from AstraZeneca, GlaxoSmithKline, Novartis, Boehringer Ingelheim and Roche. The funding bodies had no role in the design of the study, collection, analysis, and interpretation of data or writing the manuscript.