Visibility shrank to less than half a football field and small-particle pollution soared to a record 40 times higher than an international safety standard in one northern Chinese city as the region entered its high-smog season.
At least 40 flights to destinations in southern China and Beijing among others were canceled or postponed at Harbin's Taiping International Airport on Monday morning.
The choking smog shut city of 11 million people forcing schools to suspend classes, snarling traffic and closing the airport in the country's first major air pollution crisis of the winter.
The manager for US jazz singer Patti Austen, meanwhile, said the singer had canceled a concert in Beijing because of an asthma attack likely linked to pollution.
Winter typically brings the worst air pollution to northern China because of a combination of weather conditions and an increase in the burning of coal for homes and municipal heating systems, which usually start on a specific date.
For the northern city of Harbin, the city's heating systems kicked in yesterday, and today visibility there was less than 50 meters, according to state media. "I couldn't see anything outside the window of my apartment, and I thought it was snowing," said Wu Kai, 33, a housewife and mother of a baby boy, said in a telephone interview from Harbin.
"Then I realized it wasn't snow. I have not seen the sun for a long time." She said her husband went to work in a mask, that he could barely see a few meters ahead of him and that his usual bus had stopped running. "It's scary, too dangerous. How could people drive or walk on such a dayIJ"