The whole town of Lanzhou is overlaid by a visible lay of pollution from automobile traffic and factories activity using coal. Here housings in the centertown.
Lanzhou, in the Gansu province is the most polluted cities of China and in the world's top ten for atmospheric pollution due to human activity. The town is situated between two hills along the Yellow River and the polluted clouds remain blocked over the town. The sky is most of the time hidden by the pollution.