Grim new record for China

The air pollution reading in Shenyang on Monday was possibly the worst since China started monitoring and publishing PM 2.5 data. Photo / AP

Toxic particle reading off the chart as smog thickens and cold weather kicks in.

Fairyland or doomsday? asked China's state-backed newswire. Sure looks like doomsday.

Walking the line between cluelessness and dark comedy, Xinhua's English-language Twitter account on Monday called global attention to what may be the worst air pollution reading since China started monitoring and publishing PM 2.5 data, or the density of toxic particles, in 2013.

The thick, toxic air shrouded the city of Shenyang for much of the weekend, turning day to smoggy night and severely limiting visibility. Photographs from the city show buildings enveloped by airborne grit and commuters caught in an otherworldly, grey haze.

Data released by the Shenyang Environmental Protection Agency showed the density of toxic particles - PM 2.5 - was more than 1000 micrograms per cubic metre. (The World Health Organisation says a reading of 25, on average, over 24 hours, is safe.) Local officials said the pollution-levels topped 1200. Xinhua put the figure at 1400. The United States Consulate in Shenyang, which publishes regular updates, registered the air as "beyond", meaning, off the chart.

China's pollution problem is not new. But despite some signs of hope, air pollution continues to plague much of the country, particularly the northeast.

One recent study, published in the journal PLOS One, found that air pollution is linked to about one in six premature deaths, killing 1.6 million Chinese a year.

In China, PM 2.5 levels tend to peak during the winter months, and local officials linked the pollution in Shenyang to the fact that city recently switched on the heat.

But the advent of winter - and the start of heating season - comes as no surprise, which led many Chinese to question why officials did not do more to prevent the seasonal surge.

On Chinese social media, people vented about the even-worse-than-usual weather, worrying about the prospect of lung cancer and lamenting the limits of the state response. "Waiting for the wind to change is how the Government deals with air pollution," one person wrote.

China's leaders say they share the concern and have vowed, repeatedly, to wage war on bad air. In November last year, as China welcomed world leaders to an Apec summit, President Xi Jinping conceded that he checked pollution readings every day.

"These days the first thing I have been doing after getting up in the morning is check how Beijing's air quality is and hope there is less smog so that all these guests from distant places will feel more comfortable," he said in a televised speech.

His team managed to clear the air for visiting dignitaries.

Not so in Shenyang.