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In this Saturday, Nov. 28, 2015, file photo, people wearing face masks walk across Tiananmen Square on a day with poor air quality in Beijing. Air pollution in Beijing reached hazardous levels on Saturday as smog engulfed large parts of the country despite efforts to clean up the foul air.
In this Saturday, Nov. 28, 2015, file photo, people wearing face masks walk across Tiananmen Square on a day with poor air quality in Beijing. Air pollution in Beijing reached hazardous levels on Saturday as smog engulfed large parts of the country despite efforts to clean up the foul air.

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    Beijing issues first red alert for pollution

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Beijing issues first red alert for pollution

CNN Senior Meteorologist Chad Myers explains why Beijing raised its haze warning signal to red.

Beijing issues first red alert for pollution

CNN Senior Meteorologist Chad Myers explains why Beijing raised its haze warning signal to red.