1. ^aCentre for Research, Evidence Management and Surveillance, South Western Sydney Area Health Service, Liverpool Hospital, New South Wales, Australia
2. ^bSchool of Public Health and Community Medicine, University of New South Wales, Sydney, Australia
3. ^cNorthern Rivers University Department of Rural Health, University of Sydney, Lismore, Australia
4. ^dCentre for Epidemiology and Research, New South Wales Health Department, Sydney, Australia
5. ^eEnvironmental Health Branch, New South Wales Health Department, Sydney, Australia
6. ^fFaculty of Science, University of the Sunshine Coast, Maroochydore, Australia
7. ^gCentre for Public Health, Western Sydney Area Health Service, Sydney, Australia

Correspondence: Professor B. Jalaludin, Centre for Research, Evidence Management and Surveillance, South Western Sydney Area Health Service, Liverpool Hospital, Locked Bag 7017, Liverpool BC, New South Wales 1871, Australia. Tel.: +612 9828 6000; Fax: +612 9828-6012; E-mail: b.jalaludin@unsw.edu.au

Received 8 November 2004; Accepted 7 July 2005; Published online 24 August 2005.

Abstract

There are no reported studies on the effects of ambient air pollution on emergency department (ED) attendances in Sydney, Australia. This study aimed to determine associations between ambient air pollutants and ED attendances for cardiovascular disease (CVD) in those aged 65+ years. We constructed daily time series of hospital ED attendances, air pollutants and meteorological factors for the Sydney metropolitan area from 1 January 1997 to 31 December 2001. We used generalised linear models to determine associations between daily air pollution and daily ED attendances and controlled for the effects of long-term trends, seasonality, weather and other potential confounders. Increased ED attendances for all CVD, cardiac disease and ischaemic heart disease were seen with 24-h particulate pollution, 1-h NO₂, 8-h CO and 24-h SO₂. Air pollutants were associated with decreased ED attendances for stroke. The effects of air pollutants on CVD, cardiac disease and stroke attendances were generally greater in the cool period compared to the warm period. The single-pollutant effects of CO, O₃, NO₂ and SO₂ were essentially unchanged in two-pollutant models. Although air pollution levels in Sydney are relatively low compared to similar cities, we have demonstrated associations between ambient air pollutants and ED attendances for CVD in people aged 65+ years. Our study adds to the growing evidence for the effects of ambient air pollution on CVD outcomes even at relatively low ambient concentrations.