Urban Air Quality Under Local Emissions and Long-Range Transport: A Dual City European Analysis

This study compares air quality in two European cities with contrasting characteristics during July–October 2024: Leon (Spain) and Gliwice (Poland). Concentrations of PM10, PM2.5, particulate matter chemical composition, and trace gases were analysed alongside meteorological data. The results show that both cities were influenced by local emissions, primarily from traffic, as well as by Saharan dust transport events. Leon, located closer to North Africa, experienced an intense dust intrusion episode with a PM10 peak of 116 µg m−3, whereas Gliwice reached 62 µg m−3. The comparison revealed differences in aerosol intensity and composition, which are determined by geographic location and atmospheric conditions. This analysis highlights the importance of integrating local and regional data to understand urban aerosol dynamics in Europe.