| The Effects of Air Pollution on Hospitalizations for Cardiovascular Disease in Elderly People in Australian and New Zealand Cities Adrian G. Barnett,1 Gail M. Williams,1 Joel Schwartz,2 Trudi
L. Best,3 Anne H. Neller,3 Anna L. Petroeschevsky,3 and
Rod W. Simpson3 1School of Population Health, University of Queensland, Herston,
Australia; 2Exposure, Epidemiology, and Risk Program, Harvard School
of Public Health, Harvard University, Boston, Massachusetts, USA; 3Faculty
of Science, Health and Education, University of the Sunshine Coast, Maroochydore,
Australia Abstract
Objective: The goal of this study was to estimate the associations between outdoor air pollution and cardiovascular hospital admissions for the elderly. Design: Associations were assessed using the case–crossover method for seven cities: Auckland and Christchurch, New Zealand ; and Brisbane, Canberra, Melbourne, Perth, and Sydney Australia. Results were combined across cities using a random-effects meta-analysis and stratified for two adult age groups: 15–64 years and ≥ 65 years of age (elderly) . Pollutants considered were nitrogen dioxide, carbon monoxide, daily measures of particulate matter (PM) and ozone. Where multiple pollutant associations were found, a matched case–control analysis was used to identify the most consistent association. Results: In the elderly, all pollutants except O3 were significantly associated with five categories of cardiovascular disease admissions. No associations were found for arrhythmia and stroke. For a 0.9-ppm increase in CO, there were significant increases in elderly hospital admissions for total cardiovascular disease (2.2%) , all cardiac disease (2.8%) , cardiac failure (6.0%) , ischemic heart disease (2.3%) , and myocardial infarction (2.9%) . There was some heterogeneity between cities, possibly due to differences in humidity and the percentage of elderly people. In matched analyses, CO had the most consistent association. Conclusions: The results suggest that air pollution arising from common emission sources for CO, NO2, and PM (e.g., motor vehicle exhausts) has significant associations with adult cardiovascular hospital admissions, especially in the elderly, at air pollution concentrations below normal health guidelines. Relevance to clinical and professional practice: Elderly populations in Australia need to be protected from air pollution arising from outdoor sources to reduce cardiovascular disease. Key words: air pollution, Australia, cardiovascular disease, meta-analysis, New Zealand. Environ Health Perspect 114:1018–1023 (2006) . doi:10.1289/ehp.8674 available via http://dx.doi.org/ [Online 13 March 2006]
Address correspondence to R. Simpson, Faculty of Science, Health and Education, University of the Sunshine Coast, Maroochydore DC Queensland, Australia 4558. Telephone: 61-7-5430 2888. Fax: 61-7-5430 2889. E-mail: rsimpson@usc.edu.au We acknowledge the contributions made to this project by Queensland Health, New South Wales Health, Environmental Protection Authority Victoria, Western Australian Department of Environmental Protection, Environment Australian Capital Territory, New Zealand Ministry for the Environment, Auckland Regional Council, Environment Canterbury, and the Expansion of the Multi-City Mortality and Morbidity Study project steering committee. Daily weather data were provided by the Australian Bureau of Meteorology and the New Zealand National Climate Database. This work was funded by the Environment Protection and Heritage Council and by the National Health and Medical Research Council of Australia (grant 252834) . The authors declare they have no competing financial interests. Received 22 September 2005 ; accepted 13 March 2006. The full version of this article is available for free in HTML or PDF formats. |
