Introduction Rapid industrialisation and urbanisation can worsen air quality and increase the financial pressure on health systems. However, city-level evidence on how fine particulate matter (PM2.5) and urban environmental characteristics relate to healthcare expenditures remains limited in middle-income settings. Methods We conducted an ecological panel study of 10 industrial cities in Iran (2011–2024). We assembled city-year data on per-capita healthcare expenditures and key urban characteristics from municipal statistical yearbooks and linked them to annual PM2.5 estimates. We fitted log–log panel models with city random effects and year fixed effects using robust inference. Sensitivity analyses included leave-one-city-out re-estimation and an alternative specification replacing income with the household-income Gini coefficient. Results Per-capita healthcare expenditures were positively associated with PM2.5 (elasticity=0.37; p=0.057), per-capita income (=0.18; p=0.020), population density (=0.28; p=0.010), and the share aged ≥60 years (=1.05; p=0.008). The association for green space was small and sensitive to specification (=0.05; p=0.034 in the baseline model and not statistically significant when lagged), while per-capita healthcare facilities were not statistically significant. In the inequality model, the Gini coefficient was positively associated with healthcare expenditures (p=0.002). Conclusions Higher ambient PM2.5, urban density, population ageing and income inequality were associated with higher healthcare expenditures in this city-level panel analysis. These findings suggest that coordinated policies combining emission control, health-system strengthening (particularly preventive and primary care), and improved quality and equitable access to urban green infrastructure may help curb growth in healthcare spending in rapidly industrialising and urbanising settings.
Rahmatian et al. (Fri,) studied this question.