This image is from wikimedia commons (https://commons.wikimedia.org/wiki/File:LA_smog_masks.jpg).

It's ~1954 and shows people wearing gas masks to protect themselves from the LA (Los Angeles) smog. During the 50s and 60s in LA the accumulated air pollution from gasoline cars was so bad that it caused peoples nostrils and lungs to burn.

Basically what Beijing is going through now.

Ironically, this is a meeting of the "Optimists Club".