In this March 21, 2018 photo smog and fog rise from the Chelyabinsk Electrometallurgical Plant in Chelyabinsk, Russia. Residents of Chelyabinsk are expressing worry over industrial pollution after heavy smog enveloped the Ural Mountains city this month and remained for two weeks. On Sunday, Dec. 23, 2018 about 700 protesters braved temperatures of –20 degrees Celsius (–4 degrees Fahrenheit) to demand cleaner air. (Photo by Dmitry Balakiev/AP Photo)
