Air pollution in the context of building structure and density in selected Polish cities

The aim of the study was to determine the differentiation of mean annual concentrations of particulate matter PM2.5 and PM10, benzo(a)pyrene (BaP), nitrogen dioxide (NO₂), and benzene (C₆H₆) in 2018-2024 in the context of the structure and intensity of development in Gdańsk, Kraków, and Łódź.The analysis also accounted for reported pollutant emissions and mean annual wind speed.Data from GIOŚ, KOBiZE, and IMGW-PIB, as well as building data from BDOT10k were used.The highest mean annual concentrations of all analysed pollutants were recorded in Kraków, where the share of built-up area was 49%, and the lowest in Gdańsk, where this share was 30%.After accounting for differences between cities, significant positive correlations between reported emissions and concentration were found for BaP (ρ = 0.90), NO₂ (ρ = 0.60), and PM10 (ρ = 0.55).However, in the models accounting for the city effect, reported emissions were not significantly associated with the concentration of any of the analysed pollutants.The mean annual wind speed was highest in Gdańsk (3.98 m/s) and lowest in Kraków (3.08 m/s).The height structure of buildings differed between cities, but did not directly correspond to the observed differences in concentrations.The results indicate that the differentiation of mean annual air pollutant concentrations between cities co-occurs with differences in building intensity and wind speed.Due to the limited number of cities analysed, these relationships should not be interpreted as causal.