Ambient air pollution and hospital admissions for cardiovascular and respiratory disease in Melbourne, Australia

Background: This paper presents the findings of a time-series analysis of the health effects of air pollution in Melboume, Australia. Objectives: To examine the effects of 03, N02, fine particles and CO on daily emergency hospital admissions for cardiovascular and respiratory disease and asthma between 1994 and 1997. Methods: The methodological approach utilises GAM with Poisson regression. Meteorological conditions, influenza epidemics and temporal factors such as day of the week, public holidays and school holidays were controlled for in the analysis. Results: Significant positive associations were observed for N02, particles, CO and 03 in the 0-14 age group for admissions for total respiratory disease and asthma. In the 15-64 year age group, positive associations were observed for all pollutants for all health out- comes. In the 65+ age group significant associations were observed for all pollutants for admissions for respiratory and cardiovascular disease. Admissions for asthma in the 0-14 age group showed a 14.8% increase in risk of admission per unit increase in bsp (equiva- lent to 20 ug/m3 PM2.5). Controlling for N02 in a multi-pollutant analysis reduced the size and significance of the particle effect. Effects for particles were stronger in the cool sea- son while associations with N02 were strongest during the warm months. Ozone effects were strongest during the warm months. The most consistent effects with CO were asso- ciated with admissions for cardiovascular disease and ischemic heart disease. Conclusions: Current levels of ambient pollution in Melboume are making a significant contribution to daily variations in emergency hospital admissions for respiratory and car- diovascular disease