Australian study estimates transport-related air pollution responsible for 1,800 premature deaths per year
22 August 2025
New research published in the journal Environmental Research estimates particulate and nitrogen dioxide pollution from transport-related air pollution (TRAP) leads to more than 1,800 earlier than expected deaths a year in Australia. This is more than the Australian road toll of 1,300 fatalities.
The study found cars were responsible for about half of the estimated total annual premature deaths from air pollution.
Fay Johnston, director of the Centre for Clean Air at the University of Tasmania and a co-author of the study, said the new research showed "traffic pollution is the single-most important source of air pollution."
Vehicles mostly contribute to air pollution through the emission of particulate matter and nitrogen dioxide in tailpipe exhaust, or by tyre and brake wear. These pollutants cause inflammation, contribute to heart and lung disease, and are linked to other health problems such as diabetes and asthma.
Methods
The authors of the latest study used previously published predictions for all source particulate and nitrogen dioxide and chemical transport model outputs to estimate TRAP-related concentrations. The attributable number of deaths were estimated by applying a life tables approach. Publicly available population and mortality data, together with effect estimates obtained from global meta-analyses for particulate (Chen and Hoek, 2020) and nitrogen dioxide (COMEAP, 2018), were then used to estimate health impacts.
Of note, the study then undertook a series of sensitivity analyses, including the adoption of New Zealand air pollution epidemiological risk estimates (Hales et al., 2021), which yielded higher mortality estimates suggesting the results may be conservative.
Results
In 2015, an estimated 3,684 (95 % CI, 3051–4350) premature deaths were attributable to air pollution from all sources, with 51 % (95 % CI, 19 %–86 %) linked to TRAP. Using mutually adjusted coefficients from two pollutant models and summing results did not appreciably change estimates derived from a single pollutant marker.
Estimated deaths attributable to traffic-related air pollution in Australia in new study by University of Tasmania
[Source: ABC]
Context
This is the first peer-reviewed study attributing health effects to transport at the national level in Australia. However, the new study’s results are significantly lower than modelling undertaken by the University of Melbourne research hub Melbourne Climate Futures (MCF) in 2023, which estimated 11,000 premature deaths in Australia each year due to TRAP.
Clare Walter, a health and policy researcher at the University of Melbourne who co-authored MCF's 2023 position statement, told the ABC the estimate of premature deaths in the recent Centre for Safe Air study was too conservative.
"And that worries me because it will feed into cost-benefit analyses that guide policy decisions," she said.
Simon Hales, an environmental epidemiologist at the University of Otago and co-author of the NZ research from 2016, said the use of a minimum-exposure threshold in the new study affected its premature deaths estimate. "We didn't assume any [minimum] threshold. We assumed air pollution had a health effect right down to zero exposure," Dr Hales said.
"If they had done that, they would have found air pollution had a much greater effect."
World Health Organization air quality guidelines state there is no safe level of exposure to air pollution.
Dr Hales said Australia needed more intensive research into the health impact of air pollution.
The Centre for Safe Air study relied upon epidemiological studies from other countries, including NZ, to estimate the health impact of exposure to air pollution.
"What's missing in Australia is local evidence of the sensitivity of the population [to air pollution]," Dr Hales said.
Dr Walter agreed that Australia need a long-term epidemiological study focusing on air pollution.
"Instead of debating whose estimate is 'more accurate', I think the best path forward is to follow New Zealand’s example and carry out a thorough long-term study here in Australia that produces risk estimates informed by the Australian population."
(We here at EIL agree!)
[Source: ABC]
