In this Tuesday, May 7, 2013 photo, visitors to Tiananmen Gate wear masks during a day of heavy pollution in Beijing. Air pollution significantly shortens people’s life expectancy, according to a

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In this Tuesday, May 7, 2013 photo, visitors to Tiananmen Gate wear masks during a day of heavy pollution in Beijing. Air pollution significantly shortens people’s life expectancy, according to a study published Tuesday that says bad air shortened the lives of 500 million people in north China by an average of more than five years. (AP Photo/Ng Han Guan) less 

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Associated Press
Tue, Jul 9, 2013 2:23 PM EDT