Smog thick enough to cancel flights hits Beijing

  Obscenely high pollution levels shrouded eastern China for the second time in about two weeks Tuesday, forcing airlines in Beijing and elsewhere to cancel flights because of poor visibility and prompting government warnings for residents to stay indoors. The outlines of buildings in the capital receded into a white mist as pedestrians donned face masks to guard against the thick, caustic air, which stranded passengers during the first week of the country's peak, six-week period for travel surrounding the Chinese New Year on Feb. 10.
The U.S. Embassy reported a peak level of PM2.5 - 1 of the worst pollutants - at 526 micrograms per cubic meter, or "beyond index," and more than 20 times higher than World Health Organization safety levels over a 24-hour period.