Former celebrity TV anchor Chai Jing, quit her job after her baby daughter was born with lung tumor, and after a year of rigorous investigation, launched this 1 hour 40 minutes documentary about China’s smog: what is smog? Where does it come from? What do we do from here? It is very powerful in many ways. English subtitles of the documentary is not available, but if you can, grab a Chinese friend and watch it with you.