Photos: Fog or smog? Pollution at dangerous levels in China
73075099
Credit: Getty Images
BEIJING, CHINA - JANUARY 29: A men wearing the mask rides a bicycle on the street 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: Deadly Joplin tornado remembered 2 years later
Photos: Severe storms slam St. Louis area
Peek Inside: Stan Musial's $1.8M Ladue home for sale
Photos: Business district severely damaged in Mt. Olive
Photos: Dozens killed in mile-wide Oklahoma tornado
Photos: Oklahoma tornado damage