According to reports, pollution and smog grounded traffic in parts of China on January 23, 2013.
Government warnings were issued for residents to stay indoors in Beijing.
PM2.5 one of the worst pollutants was measured at 526 micrograms per cubic metre, or “beyond index”, and more than 20 times higher than World Health Organisation safety levels over a 24-hour period, and visibility levels were measured at less than 100m in some areas of eastern China.
Flights cancelled:
Zhengzhou = 100 flights
Beijing = 33 flights
Qindao = 20 flights
Jinan = 13 flights