Pollution worried Olympians in 2008 but China managed to cut pollution levels in Beijing in half for the world's assembly of athletes.

Research now suggests that Chinese officials may have dodged a bullet as Mother Nature contributed to about half of the clean up efforts through rains and winds that cleaned up the skies.

In addition to the emission controls, the weather was very important in reducing pollution, atmospheric chemist Xiaohong Liu at the Department of Energy's Pacific Northwest National laboratory, said in a statement. You can see the rain washing pollution out of the sky and wind transporting it away from the area.

The results came out in the Dec. 12 issue of the journal Atmospheric Chemistry and Physics.

Chinese officials aggressively sought to reduce pollution by restricting driving, halting manufacturing and relocating heavily polluting industries.

However, the atmospheric scientists found that the pollution dropped a week and a half before and after the games, likely due to weather patterns.

They got very lucky. There were strong storms right before the Olympics, Liu said.

Winds blew much of the pollution south.

The area we looked at is about 50 miles south. This suggests that emission controls need to be on a regional scale rather than just a local scale, Liu said.

Chinese and U.S. government grants paid for the research.

Researchers next plan to research the reverse: How pollution affects weather patterns throughout China.