Photo taken on Oct. 13, 2016 shows buildings shrouded in smog in Beijing, capital of China, Oct. 13, 2016. A blue alert for air pollution was issued on Thursday in Beijing. (Xinhua/Xing Guangli)
Photo taken on Oct. 13, 2016 shows buildings shrouded in smog in Beijing, capital of China, Oct. 13, 2016. A blue alert for air pollution was issued on Thursday in Beijing. (Xinhua/Xing Guangli)