Air quality governance across developing and developed urban environments

This study examines contrasting air quality governance approaches in Isfahan, Iran, a UNESCO World Heritage site, and Birmingham, UK, representing developing and developed urban environments respectively. Analysing five years (2018-2023) of ground-based measurements and satellite observations through machine-learning-based methods, we reveal critical differences in pollution dynamics and management strategies. Satellite-derived tropospheric NO2 column measurements show a concerning upward trend in Isfahan (+30% over five years) versus a measurable decline in Birmingham (-8%), demonstrating Birmingham's successful policy implementation through Clean Air Zone regulations since 2021. Isfahan's atmospheric chemistry exhibits strong NOx-limited ozone formation, evidenced by a 50% decrease in ground-level ozone following a 20% reduction in NO2 during COVID-19 lockdowns, contrasting with Birmingham's VOC-limited photochemistry. SO2 concentrations in Isfahan consistently and significantly exceed both Birmingham levels and WHO guidelines, with seasonal peaks (increasing 20-30% from baseline) directly corresponding to Mazout fuel substitution in power plants during winter gas shortages. Furthermore, while Birmingham demonstrates stable, predictable pollution patterns amenable to long-term planning, Isfahan exhibits pronounced daily and seasonal fluctuations that complicate mitigation strategies and accelerate the formation of secondary atmospheric pollutants. The observed complexity suggests that pollution management solutions from developed nations often cannot be directly implemented in developing contexts; for instance, fleet electrification without access to clean energy infrastructure may fail to deliver intended benefits. This comprehensive analysis demonstrates how socioeconomic factors, geopolitical contexts, and regulatory frameworks produce divergent air quality outcomes in these historically significant industrial cities, offering insights for urban environments navigating complex external pressures while addressing environmental challenges.