Days of heavy smog shrouding swathes of northern China pushed pollution to more than 20 times recommended limits on October 10, despite government promises to tackle environmental blight. Visibility dropped dramatically as measures of small pollutant particles known as PM2.5, which can embed themselves deep in the lungs, reached more than 500 micrograms per cubic metre in parts of Hebei, a province bordering Beijing. The WHO's recommended daily maximum average exposure is 25.
In the capital buildings were obscured by a thick haze, with PM2.5 levels in the city staying above 300 micrograms per cubic metre since October 08 afternoon and authorities issuing an "orange" alert.
"It's very worrying, the main worry is my health," said a 28-year-old marketing worker surnamed Hu, carrying an anti-smog mask decorated with a pink pig's nose as she walked in central Beijing. Levels were beginning to drop on October 10 afternoon but China has for years been hit by heavy air pollution, caused by enormous use of coal to generate electricity to power a booming economy, and more vehicles on the roads.
Public discontent about the environment has grown, leading the government to declare a "war on pollution" and vow to cut coal use in some areas.
Nonetheless poor air quality has persisted with officials continuing to focus on economic growth, and lax enforcement of environmental regulations remains rife.
"The Beijing government must do what it can," the government-run China Daily newspaper said in an editorial. Otherwise, it said, "the mayor's promises will turn out to be empty words".
The pollution - which also hit areas hundreds of kilometres from Beijing - comes as the capital hosts a Brazil-Argentina football friendly and cycling's Tour of Beijing.