I know i'm late for this thread but thot I would add on.
i came to HK last year and my wife and I took a flat in Tung chung, against all warnings about high air pollution out here.
Because we came in August, the fall weather was splendid and clear air.
However, since the winter and spring winds came and blew the stuff down from China, there hasn't been a day that doesn't look like the ghost movie mentioned above.
Worse, because I run twice a day, I have inhaled a lot of air here and have developed an upper respiratory blockage that hasn't subsided for three months despite two different doctors and lots of natural therapy.
I am horrified to hear myself sound exactly like a lot of the locals who are constantly hacking and coughing.
I am also worried cause I had asthma as a kid and am now experiencing similar symptoms and the constant tickle of phlegm in my throat.
To any and all expats thinking of moving here with kids: THINK TWICE AND THRICE. ASTHMA HAS BEEN LINKED TO AIR QUALITY AND IF YOU WANT YOU're CHILDREN TO COUGH AND HACK LIKE A BUNCH OF LOCAL FISHERMEN, THIS MAY BE THE RIGHT PLACE FOR YOU.
PLEASE KNOW THAT I was one of the expats who ignored all warnings but now have a chest condition and have taken to wearing a mask. If you think I'm paranoid, just take a train ride through HK and listen to how many locals have coughs and phlegm problems.
It's a sad reality, but the air quality has declined in the past ten years and it's mostly China's fault.
They won't stop and don't be surprised. After all, that's why they're called a repressive regime, right?