Well korrol ... my last post was because you mentioned the 787 and I put forward what I thought was a more realistic reason for the 6,000ft cabin NOT that they think there is a prob with flight deck air.
Since we used to have cigarette smoke and, I think, worse recirculation rates until it reached public discussion - we are already better than we were. When did they ban smoking on the flight deck? In the cabins?
If I had to list the things that make me anxious about commercial flight these days, flight deck air quality would not be in the top five.