technogeekagain: your dust mask probably isn’t designed to filter out PM1/2.5/10 although, of course, I can’t be sure about that - perhaps you have a special or versatile mask. I think the masks that most folks are wearing there are (or should be) filtering out those very small particles. The following link has a little review of various masks from 3M and other companies - some local to that part of the world - that make masks specifically designed to deal with heavy levels of pollution.
http://www.theworldofchinese.com/2013/04/whered-you-get-that-mask/
