Not to dismiss the other stuff you said, but this probably isn't relevant to the pollution. Up until recently, China was pretty poor and even now a large number of people moving to cities come from impoverished rural regions. A lot of it probably comes down to insufficient childhood nutrition. Look at the height difference between 20-something Koreans and the 40+ crowd. There's a huge disparity in height.
Also, Asians in general tend to be a bit shorter than Europeans.
>Shanghai has major, major negatives in terms of quality of life and especially if you don't speak Chinese (because almost no one there speaks English).
And this is always a weird thing to me. It's like saying living in Germany sucks because almost nobody speaks Chinese. It's true, yeah, but that burden is on you, not them. :)