I've been here for 5 years and it has changed massively
Seconded!
Also, here in Wroc, it seems the pollution on even the residential streets that have through traffic is worse than when I lived in London and had to walk along busy roads near the city centre. If Krakow's air pollution is worse than Wroclaw's, then I don't know what to say. I find myself trying not to breath here until I get back to the estate's greenery. I never recall this problem in my parts of England.