(Newser) – The northeastern Chinese city of Harbin, population 11 million, has virtually shut down today thanks to air pollution; the smog is so heavy in places that you can't see beyond about 30 feet. It's this bad: "We were all late for class today because we couldn't find the academic building," noted a microblog user. The pollution is measured using an index that tracks fine particles in the air: Readings of 300 are considered dangerous, and the WHO puts a healthy daily level at 20 or below—so it's no surprise that Harbin, where the figure hit 1,000 in some sections, has closed schools, bus routes, and its airport, Reuters reports.

Today's crisis was pinned on public heating systems that were turned on for the first time this winter, according to local news cited by the BBC. Harbin is not the only place dealing with the smog; other northeastern Chinese cities, including one two hours outside Beijing, are also facing serious pollution, and all the highways in Heilongjiang province are closed. The provinces of Jilin and Liaoning were also under red alerts for smog. Chinese leaders fear popular anger over the conditions, Reuters notes, especially amid reports that officials have found ways around the issue: They are said to make use of pricey home and office air purifiers. Meanwhile, air pollution was recently declared a carcinogen. (Read more air pollution stories.)

