For an introduction to the problem, and to anyone who hasn't lived in a severely air polluted city, I highly recommend the documentary Under the Dome, released

For an introduction to the problem, and to anyone who hasn't lived in a severely air polluted city, I highly recommend the documentary Under the Dome, released earlier this year and later banned in China: https://www.youtube.com/watch?v=T6X2uwlQGQM https://www.youtube.com/watch?v=T6X2uwlQGQM