Nice "Shock - Horror!" wind-up and we only have to pay fifteen quid to see it too!
Here's a link to a more reasonable review of cabin air systems - and its free too!
Cabin Air - download the Adobe PDF files from the top link button for technical details and figures including measurements of air quality.
I know its from Boeing and they may have a vested interest, but the technical details are an accurate overview of the equipment and its functioning. You may expect the rest of the article to be to the same level of objectivity.
There are differences between aircraft types, obviously; but in general the air in an aircraft cabin is similar in quality to that found in a hospital operating theatre or intensive care unit. Certainly much better than that of the average office or home.
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Through difficulties to the cinema