Spatial patterns of environmental injustice in social vulnerability and ambient dust levels across Australia

•Introduction: Ambient dust exposure has been associated with several adverse health outcomes. Unlike ambient air pollution, the vulnerability of subpopulations to ambient dust has not yet been explored. As the driest inhabited continent, Australia provides a natural laboratory for studying large-scale dust exposure. This study aimed to examine environmental injustice in ambient dust of ≤ 10 μm particle size and vulnerability of subpopulations in Australia, which has not been studied previously. •Methods: A nationwide cross-sectional design was employed by linking a highly spatially resolved census-derived composite measure of social vulnerability index (a wide range of factors measuring susceptibility, and a more complex capacity of individuals and society to cope with hazards and damage) to 2021 annual mean ambient dust concentrations in Australia. Local spatial autocorrelations, bivariate spatial correlations, and generalised additive logistic regression with spatial smoothing were applied to investigate geographic variation and the association between social vulnerability and ambient dust at the Australian Census’ most precise geographical unit. •Results: The results indicated geographical inequalities of social vulnerability and ambient dust exposure, with a positive association and more elevated in urban areas than in rural areas. Those with high vulnerability were 13% more likely to reside in areas with the highest dust exposure (OR 1.13, 95% CI:1.03, 1.23). High dust exposure was especially elevated in urban areas (OR 1.74, 95% CI: 1.42, 2.13) and areas with relatively high cultural and minority vulnerability (OR 3.55, 95% CI: 3.20, 3.94) and housing vulnerability (OR 2.63, 95% CI: 2.38, 2.90). •Conclusion: Social vulnerability is associated with greater exposure to ambient dust with identified hotspots, particularly in urban areas and communities with elevated cultural and housing vulnerability. These areas could be prioritised for policies and interventions to reduce the health burden of ambient dust, as initial steps to addressing environmental injustice in Australia.