http://www.aerotoxic.org/download/do...don%202006.pdf
Here is a University College London paper from 2006 estimating that:
(Top of page 523.)
".......recorded a total of 72 flights experiencing
contaminated air. Given the low reporting rate of
3.66%, this could indicate that up to 1,967 flights in
the UK may have experienced contaminated air
events during 2004. If a modest passenger number
of 100 per flight is assumed, over 196,000
passengers could potentially present to general
physicians with symptoms of acute toxicity."
~ 500 a day.
The numbers game is impossible with no toxic air detection systems - remember, that's how the airlines want it....
And the doctors can't work out why their anti-depressants aren't working.