The dust storms are not just in Beijing and neighbouring towns; it is a geological phenomenon which has been happening on a geological time-scale, over millions of years. All of the North China Plain, home to many many millions of people, is a result of silt land blowing from the dry Asian inland - Gobi Desert - and then being washed down by the Yellow River, forming an alluvial plain.
The dust storms are not nice, but they are not really man-made, although man's actions may have worsened them a little (and now man is trying to help out a little bit, although once again, what you can do about is quite small in scale).