ALJAZEERA: Choking smog all but shut down one of northeastern China’s largest cities Monday, forcing schools to suspend classes, snarling traffic and closing the airport in the country’s first major air-pollution crisis of this fall and winter.
Smog — a mixture of atmospheric pollutants, including car exhaust and factory emissions — is measured on an air-quality index measuring PM2.5, or particulate matter less than 2.5 micrometers in diameter. A level above 300 is considered hazardous, and the World Health Organization recommends a daily level of no more than 20.
In some parts of Harbin, the gritty capital of northeastern Heilongjiang province and home to some 11 million people, readings reached 1,000… (more)
