Beijing smog

A woman wearing a protective mask against smog poses for photos at the Temple of Heaven Park in Beijing.

Traffic stretches into the gloom and a lone man walks along an overpass amid heavy air pollution in Beijing.

Beijingers brave the toxic elements on a pedestrian bridge over a road shrouded in smog.

People wearing masks to protect against the air pollution walk past the Turret of the Forbidden City in Beijing.

A couple wearing face masks practice martial arts at the Temple of Heaven in Beijing.

A woman wearing a face mask walks along an elevated walkway amid heavy air pollution in Beijing.

People wearing masks to protect themselves from pollutants in the air enter a pedestrian tunnel in Beijing.

Tiananmen Square under a smog on Dec. 1, 2015, in Beijing.

A woman wearing a mask to protect herself from pollutants walks past office buildings shrouded with pollution haze in Beijing.

A man wearing a mask walks past office buildings shrouded in smog in Beijing.

Visitors, some wearing masks to protect themselves from pollutants, share a light moment as they take a selfie at the Jingshan Park on a polluted day in Beijing.

Commuters wearing protective masks wait for buses at a bus stand on a polluted day in Beijing.

A woman with her child sitting on her bicycle crosses the street outside a school in Beijing. Beijing’s education authorities ordered all of the city’s primary and middle school students indoors as China’s weather observatory issued smog alerts.

A woman carries her child as both wear protective masks while waiting at a bus stop outside a school in Beijing.

A Chinese man wears a mask as protection from the pollution as he stands in the Forbidden City during a day of high pollution in Beijing.

A woman wearing a mask practices roller blading at Olympic Park during heavy smog in Beijing.

Smog is seen on a day of high pollution at the Temple of Heaven park in Beijing.

A paramilitary police officer stands guard near Tiananmen Gate shrouded with heavy pollution and fog in Beijing.