In the latest smog-related health scare in China, officials in Shanghai on Friday ordered schoolchildren to stay indoors, halted all construction and even delayed flights in and out of the city, which has been enveloped in a thick blanket of haze, reducing visibility in places to less than 150 feet.

NPR's Frank Langfitt reports from Shanghai that the commercial capital's Air Quality Index soared above 500 for the first time ever, according to government sensors. He says officials described the readings as "beyond index" — in layman's terms, off-the-charts awful.

The government, Langfitt says, blamed the gray, soupy skies on the usual culprits: vehicle exhaust, coal burning power plants and a lack of wind.

"I feel like I'm living in clouds of smog," Zheng Qiaoyun, a local resident who kept her 6-month-old son at home, was quoted by The Associated Press as saying. "I have a headache, I'm coughing, and it's hard to breathe on my way to my office."

It's been a recurring consequence of China's rapid growth and almost nonexistent environmental regulations.

As we reported almost a year ago, Beijing had its own "airpocalypse" with off-the-charts pollution readings that were 25 times what would be considered safe in the U.S.

As NPR's Louisa Lim reported at the time:

"China is choking on its own breakneck development, with thousands of new cars taking to the road every day. This year, the pollution has been exacerbated by weather patterns, combined with an unusually cold spell."

The event prompted state-run China Daily to declare the country's major cities "barely suitable for living."

In August, we reported that the smog problem had gotten so bad that "to placate camera-clicking tourists unable to get those iconic shots of the skyscraper-studded waterfront, Hong Kong has set up a panoramic backdrop with clear, blue skies."

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