How old were the planes that this happened on? There has definitely been a dramatic improvement over the years. I remember flying in the 90's and pretty unifor

How old were the planes that this happened on? There has definitely been a dramatic improvement over the years. I remember flying in the 90's and pretty uniformly feeling like I needed at least a good face wash, if not a shower after any flight longer than a half hour. Now this only happens when I am unlucky enough to get stuck on an old aircraft (i.e. the original westjet 737's still get me with this). I swear I saw a paper on this being tested showing particle diffusion on some newer crafter being really impressive for how it kept your particles around you until they were removed and replaced with fresh ones fairly quickly but I can't remember enough to find a link to the study to back this statement up.