I would not deny that there is or at times may be contamination in public transport cabins. A thread was started last year which seemed to have a bit of an axe to grind, together with some very unlikely contamination suggestions. Because one type has a bad reputation amongst crewmembers does not mean that all aircraft are affected.
I'm probably guilty of doing the old 'when I were lad' re air contamination in industry, plating shops, diesel engine rooms and industrial towns and comparing those conditions with modern elfin safety rules.
p.s. Sorry for being a bossyboots.