Downtown Lanzhou on an average pollution day. Pollution regularly exceeds the hazardous level by 100-200%. The hazardous level being when Mexico City bans the use of cars. This never happens in Lanzhou.

Mask sellers on the street risk arrest as they sell their wares illegally. Plastic flowers decorate the sidewalk, the only flowers that grow in Lanzhou.

Workers return home after a day in the factory, smog rests over the city, visibility is no more than 20 meters

A labourer breaks concrete to reuse the metal supports. In the background an iron factory pours out smoke, hidden in the mountains from the eyes of the authorities.

Citizens exercise in the early morning. The Chinese healthy lifestyle is threatened by the continuous smog.

A child waits for his mother clad in the essential mask as a husband and wife make dumplings on the street.

Cyclists brave the daily pollution in downtown Lanzhou.

The hussle and bussle of street life in Lanzhou, with the ever present mask.

Girls write on the windows outside their electricity factory in Lanzhou.

Citizens of Lanzhou exercise in the evening in Dongfanhong square. The local government encourages it use to counter balance the effect of pollution.

A smoke cloud hangs over Lanzhou, China's most polluted city. Coal fires most of the electricity generators in China

A child feasts on western food in KFC, downtown Lanzhou. Western culture has increased the pressure to consume and as a result pressures to produce are increasing pollution.

Workers from the factories return to their homes in the countryside after two months away from home. Western culture has increased the pressure to consume and as a result pressures to produce are increasing pollution. Countryside people can supplement their income by working in the factories in Lanzhou.

The view out of a Beijing Taxi. Pollution limits the view. Beijing has three times lower levels of pollution than Lanzhou.