![A woman wearing a mask walks to a subway station in Beijing amid the air pollution [File: Andy Wong/AP]](https://i0.wp.com/www.aljazeera.com/mritems/imagecache/mbdxxlarge/mritems/Images/2017/12/23/cd24d131a1ce4b2791a8ee8e1af6034b_18.jpg "China's killer smog rolls in")
A woman wearing a mask walks to a subway station in Beijing amid the air pollution [File: Andy Wong/AP]
Beijing, China – During the cold and bitter winter season in Beijing – capital of the People’s Republic of China – it is common to find people walking the streets with masks covering their faces.
Je Seung Lee 