Dusty??? Beijing is not isolated! China is not isolated! It will be influenced by so many countries and factors. I think it should be considered as a global problem if you think Beijing is so dusty. Everyone should stop destroying our globe instead of blaming a certain place or certain people. :)
Beijing is very close to the Gobi desert. Each Spring, yellow sand blows into Beijing from the Gobi desert, coating everything with small particulates. This is only one reason Beijing is dusty. Another reason is pollutants from industry and automobiles.
Beijing locates on the north of China, near to the Mongolia. Compared to London, I think Beijing is ok. just some windy days in Spring. and it has beautiful and sunshine summer.