I often drive between Chęstochowa and Łódź in winter. I have no direct proof that it's from this exact plant, but the smell and smog is horrendous there.

What amazes me the most is how far it goes. From my anecdotal experience the smell goes 50-100km in radius depending on the weather.

If weather is "right" you can smell burning coal out of Katowice, though maybe smell comes from residential buildings as well, I am not sure. Maybe a local could provide better info.