Air pollution events from forest fires and emergency department attendances in Sydney, Australia 1996-2007: a case-crossover analysis
Document Type: Journal Article
Author(s): Fay H. Johnston; Stuart Purdie; Bin Jalaludin; Kara L. Martin; Sarah B. Henderson; Geoffrey G. Morgan
Publication Year: 2014

Cataloging Information

  • air pollution
  • air quality
  • Australia
  • Cardiovascular
  • case crossover
  • emergency departments attendances
  • fire management
  • forest fires
  • health factors
  • New South Wales
  • pollution
  • respiratory
  • smoke effects
  • smoke management
  • wildfires
  • International
Record Maintained By:
Record Last Modified: May 28, 2019
FRAMES Record Number: 53700
Tall Timbers Record Number: 31175
TTRS Location Status: Not in file
TTRS Call Number: Available
TTRS Abstract Status: Fair use, Okay, Reproduced by permission

This bibliographic record was either created or modified by the Tall Timbers Research Station and Land Conservancy and is provided without charge to promote research and education in Fire Ecology. The E.V. Komarek Fire Ecology Database is the intellectual property of the Tall Timbers Research Station and Land Conservancy.


Background: Severe air pollution generated by forest fires is becoming an increasingly frequent public health management problem. We measured the association between forest fire smoke events and hospital emergency department (ED) attendances in Sydney from 1996-2007. Methods: A smoke event occurred when forest fires caused the daily citywide average concentration of particulate matter (PM10 or PM2.5) to exceed the 99th percentile of the entire study period. We used a time-stratified case-crossover design and conditional logistic regression models adjusted for meteorology, influenza epidemics, and holidays to estimate odds ratios (OR) and 95% confidence intervals (CI) for ED attendances on event days compared with non-event days for all non-trauma ED attendances and selected cardiorespiratory conditions. Results: The 46 validated fire smoke event days during the study period were associated with same day increases in ED attendances for all non-trauma conditions (1.03, 95% CI 1.02, 1.04), respiratory conditions (OR 1.07, 95% CI 1.04, 1.10), asthma (OR 1.23, 95% CI 1.15, 1.30), and chronic obstructive pulmonary disease (OR 1.12, 95% CI 1.02, 1.24). Positive associations persisted for one to three days after the event. Ischaemic heart disease ED attendances were increased at a lag of two days (OR 1.07, 95% CI 1.01, 1.15) while arrhythmias had an inverse association at a lag of two days (OR 0.91, 95% CI 0.83, 0.99). In age-specific analyses, no associations present in children less than 15 years of age for any outcome, although a non-significant trend towards a positive association was seen with childhood asthma. A further association between smoke event and heart failure attendances was present for the 15-65 year age group, but not older adults at a lag of two days (OR 1.37 95% CI 1.05, 1.78). Conclusion: Smoke events were associated with an immediate increase in presentations for respiratory conditions and a lagged increase in attendances for ischaemic heart disease and heart failure. Respiratory impacts were either absent or considerably attenuated in those < 15 years. Similar to previous studies we found inconsistent associations between fire smoke and cardiovascular diseases. Better characterisation of the spectrum of population health risks is needed to guide public heath responses to severe smoke events as this exposure becomes increasingly common with global climate change. © 2014 Johnston et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the oreginal work is properly credited. The Creative commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.

Online Link(s):
Johnston, F. H., S. Purdie, B. Jalaludin, K. L. Martin, S. B. Henderson, and G. G. Morgan. 2014. Air pollution events from forest fires and emergency department attendances in Sydney, Australia 1996-2007: a case-crossover analysis. Environmental Health, v. 13, p. 105 [article no. online].