Interesting topic this one.
I've travelled as SLF 5 times this year on Delta's 777 MAN-ATL-MAN.
On 3 of these flights someone has passed out and there has been a PA for medical assistance.
On most of these flights, I myself have felt uncomfortable, nauseous and dry mouthed, and have always deplaned with a splitting headache......and it's not the cheap wine !
Is this a genuine aircraft problem, or is it all to do with economics and the amount of recirculated air ?