A study has found that children living in outer suburbs of Perth have higher asthma rates than those in inner city areas where there is thought to be more traffic and air pollution.
Researchers from the Telethon Kids Institute used geospatial modelling and Census data to map asthma risk across Australia’s four biggest cities, Sydney, Melbourne, Brisbane and Perth.
Led by Associate Professor Ewan Cameron, from TKI and Curtin University, the team analysed health data captured for the first time when a new question was added to the last Census about long-term health conditions – and found that children aged 5-14 living in the outer suburbs of Australian cities were twice as likely to have asthma as those living in the inner city.
Their study combined the data with cutting-edge statistical modelling and satellite imagery to intricately map the distribution of childhood asthma and look for environmental or other risk factors.
Associate Professor Cameron said that while the team had expected to find the highest prevalence in inner city areas due to heavy traffic/air pollution, they were surprised to find that in fact, the further away you got from the affluent inner suburbs, the higher the asthma prevalence.
“This pattern was witnessed uniformly across all four cities, with socioeconomic status explaining at least half of the stark spatial variation, and combined climate factors and outdoor air pollution accounting for the other half,” he said.
“In many ways it was surprising just how similar all the cities were. We found that in every city there was that same trend – increasing prevalence from the wealthier inner-city suburbs to the poorer outer-city suburbs.
“For Perth and Sydney, for example, when you look at the maps you immediately see it’s much lower in the more advantaged inner, northern and beach suburbs compared to suburbs that are more inland.
“We know from earlier studies, including the Raine Study in WA, that the risk of developing asthma is strongly shaped by socio-economic factors. These factors include higher rates of chronic family stress and poor housing quality, including dampness and poorly ventilated gas stoves, as well as dietary and obesity factors.
“People in lower socio-economic areas, many of whom are renting, often lack the means to alleviate these issues and may have poorer access to health care support for asthma management.”
Associate Professor Cameron said the findings highlighted the challenges faced by government and health authorities tasked with fighting Australia’s childhood asthma epidemic.
However, they could be used to plan the locations of new asthma clinics and guide policy interventions such as providing financial assistance to convert cooktops from gas to electricity and install high-efficiency rangehoods and ventilation that could eliminate cooking gases or dampness in the home.
The study also showed the significant role played by climate and environmental factors, after the team used the satellite imagery to investigate the levels of different pollutants around each city, vegetation, and temperature and rainfall variation.
“We do find there’s a contribution from environment – places that experience large daily temperature variations tend to have higher risk of asthma. More extreme weather can be a factor in triggering asthma,” Associate Professor Cameron said.
The striking socioeconomic gap in child health witnessed within the study was also seen across other diseases – findings the team plan to reveal in future publications.
The team will also repeat their analysis following the 2026 Census.
The paper, A health inequality analysis of childhood asthma prevalence in urban Australia, was published in the Journal of Allergy and Clinical Immunology and can be read here.