When it comes to PM2.5 pollution — tiny, grungy particles discharged into the air by factories, boilers and motor vehicles, which damage respiration — the Chinese government says 35 micrograms per cubic meter is a healthy maximum.
But over the weekend, Shenyang, an industrial city in northeastern China, endured PM2.5 readings that exceeded 1,000, even 1,400 micrograms, per cubic meter, at some measuring stations, according to Xinhua, the state news agency. Even for a country where chronic smog has inspired superlatives like “airpocalypse” and “crazy bad,” the numbers from Shenyang prompted a kind of awed revulsion.