Beijing all smogged up with air pollution

Polluted air in Beijing reached unhealthy levels Thursday morning for the second time in a week, reports the South China Morning Post.

Airborne particles small enough to enter the lungs and blood, a.k.a. PM2.5, hit levels of 502 micrograms per cubic metre, surpassing the maximum of 500 on the US embassy air quality monitor.

The World Health Organization recommends levels of 25 or less.

Beijing authorities ordered a yellow haze warning to advise citizens to limit outdoor activity, after its environmental experts recorded severely polluted air conditions.

The airport cancelled 14 flights, including 10 international ones, and four city highways were partially closed.

Some residents posted photos on social media channels to illustrate the worsening air quality:

Neighbouring cities, such as Baoding and Shijiazhuang, also reported similar high levels of pollution.

Beijing has seen chronic air pollution problems for several weeks.

Related: Beijing air pollution hits catastrophic heights

Front page image: Hung Chung Chih /