AdvertisementOpinionIn China, Pollution Fears Are Both Literal And MetaphoricalJanuary 18, 2017Jeffrey Wasserstrom, Benjamin van RooijfacebookEmailFace masks were placed on stone monkeys at the Beijing Zoo on Dec. 19 to protest heavy air pollution in northeast China. A week earlier, riot police cracked down after artists put similar masks on human figures in Chengdu. (AFP/Getty Images)