Students dressed in Ao Dai on the way to school, Cai Be, Vietnam, Indochina, Southeast Asia, Asia

A road sweeper wears a face mask against the awful air pollution in Harbin city in Northern China, Heilongjiang Province, China, Asia

Cyclists in Beijing wearing smog masks to help protect against the awful air pollution, Beijing, China, Asia

People wear face masks against the awful air pollution in Suihua city in Northern China, Asia

A cyclist wears a face mask against the awful air pollution in Harbin city, Heilongjiang, Northern China, Asia

Road sweepers wear a face masks against the awful air pollution in Harbin city, Heilongjiang, Northern China, Asia

People wear face masks against the awful air pollution in Suihua city, Heilongjiang, Northern China, Asia

Road sweepers on bicycles wear face masks against the awful air pollution in Suihua city, Heilongjiang, Northern China, Asia

Road sweepers wear a face masks against the awful air pollution in Harbin city, Heilongjiang, Northern China, Asia

Road sweepers on bicycles wear face masks against the awful air pollution in Suihua city, Heilongjiang, Northern China, Asia

People wear face masks against the awful air pollution in Suihua city in Northern China, Asia

Person wearing mask in smoke

Naked Caucasian woman breathing on man wearing pollution mask

Smog in the streets of Pangkalanbun, Central-Kalimantan, Borneo, Indonesia