Lanzhou, the capital of China's northwest Gansu province, has notoriously bad pollution due to high coal use for energy, heavy industrial emissions and its position in a valley that traps air, but also because of rising car use.

To help fight the problem, Lanzhou's mayor has told civil servants they will have to leave their cars at home and walk to work on days when the pollution problems are particularly bad, the China Daily said, citing local officials.

"We have suggested that civil servants walk to and from their offices on days when the pollution level is very high to reduce vehicle emission," the paper quoted Lu Zhaowen, a director with the city's Environment Protection Bureau, as saying.

The China Daily said Lanzhou was already regarded as one of the world's 10 most polluted cities and the problems had worsened this year despite environmental protection efforts put in place as far back as the 1980s.

One of the chief culprits is increasing automobile use, as is the case elsewhere in China.

The number of cars in Lanzhou -- a city of 3.1 million people -- reached 232,000 last year, 26 percent more than in 2005, the China Daily said.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.