BEIJING - China's government on Wednesday took emergency measures to combat smog that has encased Beijing, which the Communist Party has hailed as a showcase capital, in brown and gray soot. The measures include temporarily shutting down more than 100 factories and ordering one-third of government vehicles off the streets.

The effort came on the second straight day of air that is rated "hazardous" by the standards of the U.S. Environmental Protection Agency. That rating means people should not venture outdoors at all.

Beijing has writhed this month in the grip of the most polluted air on recent record. The surge in pollution, which is happening across northern China, has angered residents and led the state news media to report more openly on air-quality problems. Officials have also begun acknowledging the severity of the air pollution. Xinhua, the state news agency, reported that Wang Anshun, the newly appointed mayor of Beijing, said on Monday that the government had come up with a preliminary plan to curb the pollution. "I hope we can have blue skies, clean water, less traffic and a more balanced education system," Wang told municipal legislators.

Wang also told lawmakers that "the current environmental problems are worrisome." He said the number of vehicles in Beijing should be allowed to increase, but slowly. The Xinhua report said there were an estimated 5.18 million vehicles in Beijing, compared with 3.13 million in early 2008.

In the past three decades, China has adopted a growth-at-any-cost attitude to build its economy, and the resulting environmental damage is now widespread and severe.

NEW YORK TIMES