July 28, 2008—Less than two weeks before the Olympics, heavy smog in Beijing has Chinese officials blaming natural factors, such as fog. But others say athletes "have reason to be concerned."
Welcome to the National Geographic video player.
You need the latest Flash Player version from Abode and a JavaScript enabled browser to view this site. Please click here to download the free flash player.
© 1996-2009 National Geographic Society. All rights reserved.