Up in the air

The National Stadium, the main venue for the 2008 Olympics, is shrouded in smog in Beijing, China.  (Michael Reynolds / EPA)

A cyclist and a bus pass by the high rise buildings shrouded in a haze of smog, in Beijing, China.  (Andy Wong / Associated Press)

Delegates arrive for the meeting of the National People’s Congress as smog engulfs Tiananmen Square in Beijing, China.  (Peter Parks / AFP/Getty Images)

Traffic clogged roads and thick smog fill the Central Business District (CBD) in Beijing, China.  (Adrian Bradshaw / EPA)