Thanks to the 2008 Beijing Olympics, China may find another generation of star athletes on its hand. No, it's not thanks to the facilities or the experience of bringing together the world's best athletes in its large port-city-rather it has everything to do with the pollution around the event. Researchers are aware of the fact that high levels of air pollution can significantly impact fetal growth and development, and when it comes to air pollution few nations are quite as bad as China. But with the arrival of the 2008 Beijing Olympics and mandates reducing pollution levels courtesy of the Chinese government, researchers were given the perfect setup for a case study. And what they happened to find is that children born from mothers pregnant during the games had higher birth weights than those born before or after the games.

In the months leading to the summer Olympics of 2008, the Chinese government launched aggressive measures to improve Beijing's notoriously poor air quality-measures that relaxed greatly shortly after the games. So though the air was only better for a short while, mothers pregnant during the "natural experiment" found that their children had a greater chance of survival and fewer health risks by developing better and having a larger birth weight.

"The results of this study demonstrate a clear association between changes in air pollutant concentrations and birth weight" lead author of the new study published this week in the journal Environmental Health Perspectives, David Q. Rich says. "These findings not only illustrate one of the many significant health consequences of pollution, but also demonstrate that this phenomenon can be reversed."

Analyzing information from 83,672 term births between 2007 and 2009, the researchers found that on average babies born during the time of the Olympics weighed 23 grams more than the babies exposed to pollution. And though the study's researcher still do not widely understand the biological mechanism by which pollution causes lower birth weights their study suggests that air pollutants may interfere with end-stage development occurring in late pregnancy, when the development of the nervous, musculoskeletal and cardiovascular systems accelerates. The researchers believe that these pollutants could play the role of many factors causing maternal inflammation, altered placental function, and reduced nutrient delivery to the developing fetus.

"While Beijing's pollution is particularly noteworthy, many of the world's other cities face similar air quality problems" coauthor of the study, Junfeng Zhang says. "This study shows that pollution controls-even short-term ones-can have positive public health benefits."

And it's one benefit that could give rise to a whole generation of new Olympic athletes, big enough to dominate all of their polluted competitors.