You know what I don't get? Hong Kong does have these health care issues - but regardless, it has one of the longest life expectancies in the world. I believe the life expectancy rate here is higher than that of the USA, Canada or Great Britain!!
http://en.wikipedia.org/wiki/List_of_countries_by_life_expectancy
So it can't be TOOOOO bad - people still live on average 3-4 years longer than people in the USA...
The bad pollution here, according to those who have been here for a long time, is relatively recent. It would be shockingly bad if a build up of pollution over the course of say 10 years was adversely impacting life expectancy already.
It isn't so bad that it is going to kill you tomorrow or even next year, it's going to be 30 or 40 years from now. Life expectancies would need to be compared around 2050.