You don't need to be an aerodynamics engineer to understand this either: Take a deep breath inside a usual aircraft cabin and tell me if that air is fresh and clean. If you do, either you are fucking lying out your ass or you never tasted truly clean, fresh air in your life.
Is anything that comes in the form of an academic paper bullshit in your mind, or just the ones about plane air quality?
Practically speaking, anyone who has ever been inside an aircraft cabin can speak all day about that distinctive "aircraft smell": A cocktail of smells that reminds one of industrial petroleum products, aged metal and plastics, human sweat and other biological waste products, dust, and tired cloth, among many other unpleasant things.
Noone is ever going to convince me that air that smells like /that/ is "clean", regardless how many layers of HEPA it's been through.
And
>Noone is ever going to convince me that air that smells like /that/ is "clean"
Seem to be at odds with each other. But, for what it's worth, I agree that there is a distinctive "aircraft smell" whenever I've flown, and I'm not particularly keen on breathing it in either.
Thing is, I haven't seen anything from anyone to that effect other than the "air is cycled through HEPA" canned PR response which is hardly convincing.
If there are scientific papers which note the contents of aircraft cabin air and compares it to objective definitions of clean air, coming to the conclusion the aircraft cabin air is clean, I'm interested and maybe they can change my mind.
Life's short, I'm well past the point of caring about people's fee fees regarding something we'll all forget about tomorrow.
So I'll say my piece and bug out. Don't like it? Don't read it; don't care.
Unfortunately though, most of my friends will never meet eachother, to preserve world peace.
I would trust the science, but not an ad from an airliner (which the linked page is).