Photos: Fog or smog? Pollution at dangerous levels in China
73075062
Credit: Getty Images
BEIJING, CHINA - JANUARY 29: Beijing residents wearing the mask ride amid fog during severe pollution on January 29, 2013 in Beijing, China. The 4th dense fog envelops Beijing with pollution at hazardous levels in January. (Photo by Feng Li/Getty Images)
Other Slideshows
Photos: Parts of St. Louis area flooded after storms
Photos: Shark attack off Texas beach
Photos: St. Louis Zoo debuts baby lemurs
Photos: Pope Francis blesses Harley-Davidsons
Photos: Four-legged Spurs fans show their pride
Photos: Erin Brady, of Connecticut, wins Miss USA
