The short‐term effects of air pollution on daily mortality in four Australian cities

Objective: To examine the short‐term health effects of air pollution on daily mortality in four Australian cities (Brisbane, Melbourne, Perth and Sydney), where more than 50% of Australians reside. Methods: The study used a similar protocol to APHEA2 (Air Pollution and Health: A European Approach) study and derived single‐city and pooled estimates. Results: The results derived from the different approaches for the 1996‐99 period showed consistent results for different statistical models used. There were significant effects on total mortality, (RR=1.0284 per 1 unit increase in nephelometry [10‐4. m‐1], RR=1.0011 per 1ppb increase in NO2), and on respiratory mortality (RR=1.0022 per 1ppb increase in O3). No significant differences between cities were found, but the NO2 and particle effects may refer to the same impacts. Meta‐analyses carried out for three cities yielded estimates for the increase in the daily total number of deaths of 0.2% (‐0.8% to 1.2%) for a 10 μg/m3 increase in PM10 concentration, and 0.9% (‐0.7% to 2.5%) for a 10 μg/m3 increase in PM2.5 concentration. Conclusions: Air pollutants in Australian cities have significant effects on mortality.