Does air pollution in Sofia seriously impact life quality?

Hey, I got a work opportunity in Sofia for a few months which I'm quite excited about. I should be be there from Sep through January.

I learned today that Sofia in the winter is supposed to be quite polluted. So my question is, how bad is it really. Are we talking Beijing levels of bad where you can barely see more than 20m ahead for most of the winter. Or is it only a few really bad days here and there?

I'm probably being overly paranoid given that I'm only coming for a few months and you guys actually have to live with it, but I'm still a bit worried about health effects.

Anyhow, thank you to anyone answering.