Black sheep look at this...
For Blackshhep to say air quality is like an operating theatre is misleading, the issue is cabin air contamination in abnormal circumstances and not volume of air in the operatig theatre.
Also if it is as good as an operating theatre all the time, why the following...
Australian Senate Inquiry 2000
Hundreds of sick crews and passengers worldwide
Regulators failing pilots medicals due to exposure
Ansett paying out compensation to crews
TCP found in ducting
Numerous ASR reports
Numerous SB and SILs such as..BAe Service Bulletin - ISB.21-150 and BAe SIL - 21-45
CAA FODCOM 2002
CAA Safety Initiative - Cabin air Contamination 2003
ETC....
I will conclude you are industry faithful, why dont you look at the documentary and see the long term effects on crews who have been exposed to contaminated air.