I think that over here in Czechia and other Visegrad countries it might partially be due to the fact that some people, especially in villages, still heat their houses with coal and other rubbish.
Yes, especially Silesia and around
Great way to visualize this! Draws your attention to the areas with most people, not necessarily the areas of worse pollution.
Northern Italy, wtf are you doing?
The Po Valley, surrounded by the Alps to the north and the Apennines to the south, acts as a natural basin, creating a microclimate that often traps pollutants.
https://www.esa.int/Applications/Observing_the_Earth/Air_pollution_fluctuations_over_the_Po_Valley
I know, a city nearby my place has a similar problem. However, it is not in deep red, so the problem is on a smaller scale.
Pretty crazy considering I don’t even feel like Norwegian cities have all that great air during winter.
