Woman wearing mask in Beijing
Andy Wong/AP Photo
In this Feb. 21, 2017 photo, a woman wearing a mask walks to a subway station during the evening rush hour in Beijing. Yet the city’s average reading of the tiny particulate matter PM2.5 - considered a good gauge of air pollution - is still seven times what the World Health Organization considers safe. A group of Chinese lawyers is suing the governments of Beijing and its surrounding areas for not doing enough to get rid of the smog.