Vehicle pollution may contribute to more deaths each year than road accidents in Australia, according to a groundbreaking study by the University of Tasmania’s Centre for Safe Air. The research estimates that particulate and nitrogen dioxide pollution from traffic leads to over 1,800 premature deaths annually, surpassing the 2024 road toll of 1,300 fatalities.
The study highlights that cars are responsible for about half of these premature deaths, making traffic-related air pollution (TRAP) the leading environmental cause of premature death and disease in the country. Published in the journal Environmental Research, the study’s estimates are lower than a previous 2023 University of Melbourne study, which suggested 11,000 annual deaths due to TRAP.
Understanding the Impact of Traffic Pollution
Fay Johnston, director of the Centre for Clean Air and a co-author of the study, emphasized the significance of traffic pollution as a major air pollution source. “If we’re wanting to reduce chronic heart disease and illness and deaths, traffic pollution is a good place to look,” she stated. The study’s conservative estimates aim to account for uncertainties in pollution exposure impacts on health.
Vehicles contribute to air pollution primarily through emissions of particulate matter (PM) and nitrogen dioxide (NO2) from exhaust, as well as from tyre and brake wear. These pollutants are known to cause inflammation, exacerbate heart and lung diseases, and are linked to diabetes and asthma. The study utilized air quality data from 2015, combined with statistical modeling, to assess TRAP concentrations across Australia, matching these with population data to estimate premature deaths.
Regional Disparities and Methodological Differences
New South Wales, Victoria, and Queensland account for over three-quarters of the premature deaths attributed to air pollution, with Sydney and Melbourne being significant contributors due to their large populations. The study’s approach, which includes a minimum threshold for pollution exposure, contrasts with the 2023 University of Melbourne estimate, which did not undergo peer review and applied findings from a New Zealand study to Australia’s larger population.
Clare Walter, a health and policy researcher at the University of Melbourne, expressed concerns that the conservative estimate might influence policy decisions. She noted that the New Zealand study, which informed the Melbourne estimate, did not assume a minimum exposure threshold, suggesting that even low levels of pollution can have significant health impacts.
The Need for Comprehensive Local Research
Simon Hales, an environmental epidemiologist and co-author of the New Zealand research, pointed out that the Centre for Safe Air’s use of a minimum-exposure threshold affected its findings. “We didn’t assume any [minimum] threshold. We assumed air pollution had a health effect right down to zero exposure,” he explained.
Dr. Hales and other experts advocate for more intensive research in Australia to better understand the local population’s sensitivity to air pollution. Such studies require detailed health records to accurately attribute mortality and morbidity to pollution exposure.
Policy Implications and Future Directions
Professor Johnston suggests a rapid transition to electric vehicles, which emit less pollution, as a key strategy to mitigate traffic pollution. Additionally, supporting public transport and active transport methods like walking and cycling could further reduce emissions and protect public health.
Dr. Vicki Kotsirilos, spokesperson for Doctors for the Environment Australia, advocates for a public information campaign to raise awareness about the harms of traffic pollution, drawing parallels to past anti-smoking campaigns. She emphasizes the importance of reducing vehicle reliance, especially in scenarios like idling cars at childcare centers, which can increase the risk of childhood asthma.
As Australia grapples with the health impacts of traffic pollution, the call for comprehensive, locally-focused research grows louder. Experts agree that a thorough long-term study would provide more accurate risk estimates and guide effective policy measures to protect public health.
