Asthma presentations to emergency departments in western Sydney during the January 1994 Bushfires

From 5 to 12 January 1994, the state of New South Wales suffered from the worst bushfires seen this century. High levels of particulate air pollution were recorded in western Sydney from 7 to 14 January 1994, with nephelometry readings reaching 10.24 beta scat (10(-4)/m) and particulate matter < 10 mu readings peaking at 250.00 micrograms/m3. The aim of this study was to determine whether there was an increase in the proportion of asthma presentations to emergency departments (ED) in western Sydney as a result of the bushfire-generated particulate air pollution.

We retrospectively analysed the emergency room attendance books for asthma presentations from seven public hospitals serving the Western Sydney and Wentworth Health Areas over two 6-7 week periods, 17 December 1992 to 31 January 1993, and 17 December 1993 to 31 January 1994. Air pollution and meteorological data were obtained from local monitoring stations.

The difference in the proportion of all ED presentations that were due to asthma during the week of the bushfire-generated air pollution, compared with the same week 12 months before, after adjusting for baseline changes over the 12-month period, was 0.0067 (95% CI: -0.0007, 0.0141). The maximum daily nephelometry reading was not a significant predictor of the daily number of asthma presentations to ED in any of the Poisson regression models.

The bushfire-generated particulate air pollution in January 1994 did not result in an increase in asthma presentations to ED in western Sydney.