New | Worst smog of the year leaves Beijing choking as US embassy’s air quality reading hits 545

Beijing is choking in its worst smog so far this year, with air pollution at hazardous levels and the reading at the US embassy hitting as high as 545 on Thursday afternoon.

An air quality index (AQI) reading of more than 300 is considered “hazardous”. Anything beyond 200 is “very unhealthy”. The United States embassy measures PM2.5 particulates as an indication of the air quality at its compound in Chaoyang district.

The average AQI reading released by the Beijing Environmental Protection Bureau was slightly lower at 430, which is still considered “seriously polluted”. Residents were advised to don face masks and avoid outdoor activities.

Thursday was the first seriously polluted day of the year, but strong winds and a cold front starting on Friday morning are expected to disperse the smog, the Legal Evening News reported.

But on Thursday, the yellow pollution alert – the third highest in a four-tier system – remained in place amid stagnant, humid air in most parts of the capital, according to the Beijing Meteorological Bureau. The yellow alert had been hoisted since Saturday evening.

Pollution – albeit less severe – was also expected to blanket Tianjin, Hebei, large parts of Shanxi in the west, and parts of Sichuan. Hunan, Yunnan and Guangdong were also likely to experience “dense fog” that would limit visibility.