I don't know you, but in every lecture in college that was done in a room with no air flow, I got distracted every five minutes or so. If the proportion of C02 had a cognitive effect that I could feel, then I wouldn't be surprised if other kinds of contaminants do the same.
Can’t find a source, but there’s a similar thing with long meetings — after two hours in a conference room, you’ve added enough CO2 to affect cognitive function.
