Bulgaria Pollution?

I spent several days in Sofia, enjoyed it very much, and at least at that time, never sensed that it was particularly polluted. Air seemed fine. I loved Bulgaria!

I've been to Sofia in September, never felt that it was any different to any other major city.

I've been to Sofia a couple of times and didnt notice it being any worse than Rome. Of course that's not a complement. Very interesting city, do some research before you go and you will find it fascinating. I dont think tourists spend enough time in Sofia. But after a couple of nights get out and see the rest of the country. Fascinating and beautiful country.

The Balkan capitals are generally polluted cities.Belgrade, Skopje and Sofia are known to be the worse.

Actually Belgrade and Sofia are pretty far down on the list. https://www.google.com/amp/s/www.dailymail.co.uk/news/article-6773899/amp/Worlds-polluted-capital-cities-revealed-Delhi-ranked-worst.html

Then again this one puts Sofia up higher on the list https://www.airvisual.com/

I've been to most of the Eastern European capitals and they aren't bad at all. That list compares capitals. I suspect there are worse cities in the West.