Careful with your logic!
If I took up smoking now, then it will be some time before I have serious adverse effects. Likewise, the onset of this air pollution at current levels has only been with us for a few years. Lets see what happens to the longevity of HK locals once they breathe this air for 20-30 years.
Smoking didn't kill straight away - it took time and regularity. Thats what we have going on here;-/