Beijing pollution drops, ahead of Games

Strict traffic controls that Beijing imposed during a summit with African leaders last November produced a significant drop in pollution, a positive sign for the city8217;s Olympic planning, according to a recently released study.

The researchers from Harvard University and the Royal Netherlands Meteorological Institute studied satellite data and found that levels of NOx, a class of nitrogen oxides thought to contribute to global warming, fell 40 percent from normal during the summit. The drop was larger and more rapid than expected, the researchers wrote in their findings, published in the April 28 issue of Geophysical Research Letters, a journal of the American Geophysical Union.

Beijing8217;s normally gridlocked streets and smog-choked skies are among the leading concerns as the city prepares to host the 2008 Olympics.

City authorities used some persuasion to get an estimated 800,000 of the city8217;s 2.8 million vehicles off the road. The result was nearly a week of smooth traffic and low pollution.