Environmental Geochemistry and Health

, Volume 34, Issue 6, pp 697–709 | Cite as

Risk of respiratory and cardiovascular hospitalisation with exposure to bushfire particulates: new evidence from Darwin, Australia

  • Helen Crabbe
Original Paper


The risk of hospitalisation from bushfire exposure events in Darwin, Australia, is examined. Several local studies have found evidence for the effects of exposure to bushfire particulates on respiratory and cardiovascular hospital admissions. They have characterised the risk of admission from seasonal exposures to biomass air pollution. A new, unanalysed data set presented an additional chance to examine unique exposure effects, as there are no anthropogenic sources of particulates in the vicinity of the exposure monitor. The incidence of daily counts of hospital admissions for respiratory and cardiovascular diagnoses was calculated with respect to exposures of particulate matter (PM10), course particulate matter, fine particulate matter (FPM) and black carbon composition. A Poisson model was used to calculate unadjusted (crude) measures of effect and then adjusted for known risk factors and confounders. The final model adjusted for the effects of minimum temperature, relative humidity, a smoothed spline for seasonal effects, ‘date’ for a linear effect over time, day of the week and public and school holidays. A subset analysis adjusted for an influenza epidemic in a particular year. The main findings suggest that respiratory admissions were associated with exposure to PM10 with a lag of 1 day when adjusted for flu and other confounders (RR = 1.025, 95 % CI 1.000–1.051, p < 0.05). This effect is strongest for exposure to FPM concentrations (RR = 1.091, 95 % CI 1.023–1.163, p < 0.01) when adjusted for flu. Respiratory admissions were also associated with black carbon concentrations recorded the previous day (RR = 1.0004, 95 % CI 1.000–1.0008, p < 0.05), which did not change strength when adjusted for flu. Cardiovascular admissions had the strongest association with exposure to same-day PM and highest RR for exposure to FPM when adjusted for confounders (RR = 1.044, 95 % CI 0.989–1.102). Consistent risks were also found with exposure to black carbon with lags of 0–3 days.


Particulates Bush fires Cardiovascular and respiratory hospital admissions Health risk 



The study was conducted for a MSc thesis by H. Crabbe at the London School of Hygiene and Tropical Medicine (LSHTM) in Public Health (Environment and Health). Particular thanks go to Dr Fay Johnston for supervisory advice and providing access to the data sets. Acknowledgements are also due to staff at CDU and CSIRO for providing data files. Support and supervisory advice on the analysis were provided by the Public and Environmental Health Research Unit at LSHTM. The views presented in this paper are representative of the author and are not necessarily reflective of any associated institutions.

Conflict of interest

The author declares that they have no conflict of interest. The guest editors/author declares that they have no conflict of interest with the conference sponsors.

Ethics approval

As hospital admission count data are not publicly available, ethics approval was sought and gained from the London School of Hygiene and Tropical Medicine (LSHTM) Ethics Committee for the MSc thesis. Ethics approval was also gained from Charles Darwin University and the Royal Darwin Hospital Ethics Committees.


  1. Artaxo, P., Parry, D., Gillett, R., Selleck, P, & Ayres, G. (1995). Black carbon, elemental and ionic composition of atmospheric aerosols in Northern Australia. Unpublished research report, Charles Darwin University.Google Scholar
  2. Bowman, D. M. J. S., Dingle, J. K., Johnston, F. H., Parry, D., & Foley, M. (2007). Seasonal patterns in biomass smoke pollution and the mid-20th century transition from Aboriginal to European fire management in northern Australia. Global Ecology and Biogeography, 16(2), 246–256.CrossRefGoogle Scholar
  3. Bowman, D. M. J. S., & Johnston, F. H. (2005). Wildfire smoke, fire management and human health. In Ecohealth, 2(1), 76–80.CrossRefGoogle Scholar
  4. Delfino, R. J., Brummel, S., Wu, J., Stern, H., Ostro, B., Lipsett, M., et al. (2009). The relationship of respiratory and cardiovascular hospital admissions to the southern California wildfires of 2003. Occupational Environmental Medicine, 66, 189–197.CrossRefGoogle Scholar
  5. EPA Victoria (Environment Protection Authority). (2001). Ambient air pollution and daily hospital admissions in Melbourne 1994–1997. EPA Publication 789, Melbourne, Australia, November 2001.Google Scholar
  6. Hanigan, I.C., Johnston, F. H., & Morgan, G. G. (2008) Vegetation fire smoke, indigenous status and cardio-respiratory hospital admissions in Darwin, Australia, 1996–2005: a time series. BMC Environmental Health 7(42).Google Scholar
  7. Hanninen, O. O., Salonen, R. O., Koistinen, K., Lanki, T., Barregard, L., & Jantunen, M. (2009). Population exposure to fine particles and estimated excess mortality in Finland from an East European wildfire episode. Journal of Exposure Science & Environmental Epidemiology, 19, 414–422.CrossRefGoogle Scholar
  8. Jalaludin, B., Marks, G., & Morgan, G. (2002). Serial correlation and confounders in time series air pollution studies. Medical Journal of Australia, 177, 397.Google Scholar
  9. Johnston, F. H., Baile, R. S., Pilotto, L. S., & Hanigan, I. C. (2007). Ambient biomass smoke and cardio-respiratory hospital admissions in Darwin, Australia. BMC Public Health, 7, 240.CrossRefGoogle Scholar
  10. Johnston, F. H., Kavanagh, A. M., Bowman, M. J. S., & Scott, R. K. (2002a). Exposure to bushfire smoke and asthma: an ecological study. Medical Journal of Australia, 176, 535–538.Google Scholar
  11. Johnston, F. H., Kavanagh, A. M., Bowman, M. J. S., & Scott, R. K. (2002b). Serial correlation and confounders in time series air pollution studies: In reply. Medical Journal of Australia, 177, 397.Google Scholar
  12. Lewis, P. R., & Corbett, S. J. (2002). Bushfires, air pollution and asthma. We need more research on the health effects of air pollution caused by bushfires. Medical Journal of Australia, 176, 517.Google Scholar
  13. Morgan, G., Sheppeard, V., Khalaj, B., Ayyar, A., Lincoln, D., Jalaludin, B., et al. (2010). Effects of bushfire smoke on daily mortality and hospital admissions in Sydney, Australia. Epidemiology, 21(1), 47–55.CrossRefGoogle Scholar
  14. Naeher, L. P., Brauer, M., Lipsett, M., Zelikoff, J. T., Simpson, C. D., Koenig, J. Q., et al. (2007). Woodsmoke health effects: A review. Inhalation Toxicology, 19(part 1), 67–106.CrossRefGoogle Scholar
  15. Schwartz, J., Spix, C., Touloumi, G., Bacharova, L., Barumamdzadeh, T., le Terte, W., et al. (1996). Methodological issues in studies of air pollution and daily counts of deaths or hospital admissions. Journal of Epidemiology and Community Health, 50(Suppl 1), S3–S11.CrossRefGoogle Scholar
  16. Tham, R., Erbas, B., Akram, M., Dennekamp, M., & Abramson, M. J. (2009). The impact of smoke on respiratory hospital outcomes during the 2002–2003 bushfire season, Victoria, Australia. Respirology, 14, 69–75.CrossRefGoogle Scholar
  17. United States Environment Protection Agency (USEPA) (2004) Air quality criteria for Particulate Matter (October 2004) Vol I of II. Available at Last accessed 31/01/12.
  18. World Health Organisation (WHO). (2000). Air quality guidelines for Europe. 2nd Ed., European Series, Vol. 91. Copenhagen: WHO Regional Publications.Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2012

Authors and Affiliations

  1. 1.Geography DepartmentQueen Mary UniversityLondonUK

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