One of Beijing's worst rounds of air pollution kept schoolchildren indoors and sent coughing residents to hospitals today.
The wave of pollution had peaked on Saturday with off-the-charts levels.
At the height of the smog authorities said readings for PM2.5 - particles small enough to penetrate the lungs - hit 993 micrograms/m3, almost 40 times the World Health Organisation limit.
They went down to levels around 350 micrograms today, but that was still way above the WHO safety levels of 25.
City authorities ordered many factories to scale back emissions and were spraying water at building sites to try to tamp down dust and dirt that worsen the noxious haze.
A government guided by common sense would respond to news that publicly owned Royal Mail has increased profits to £403 million by scrapping plans to flog off the service.