The anthracite is used to heat oven bricks, the flue gas itself doesn't come near the product as far as I know. All the ovens in this area would have been anthracite fired for bakeries at the turn of the century. Wasn't too long ago they found some old forgotten ones that were walled up on one building across the river. Was actually quite interesting, kinda "Indiana Jones" like...
Ironic but there isn't many coal fired oven pizzerias in the area considering there popularity elsewhere, I'm not aware of one in the Wyoming Valley. I know there is a few south of here.
As far as the smell goes I've probably smelled ours a hand full of times in the 25 years it's been installed and I would know exactly what it smelled like unlike my neighbors. As I'm typing this I'm in my office on the second floor of my home not more than 15 or 20 feet from the top of the chimney. I've never smelled flue gas in this room in the summer/spring/fall when the windows were open that I can recall. The few times I have smelled it is on very humid mornings. We live right next to the river so the fog can get very dense.
I'm not saying there isn't a smell but unless you're power venting it ground level or even have a very low chimney you shouldn't smell anything for the most part.