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Beijing Babies Show the Importance of Clean Air

The Chinese government's pollution-cutting efforts for the 2008 Olympics improved birth weights in the city, a new study finds.
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(Photo: randomix/Flickr)

(Photo: randomix/Flickr)

Call it a baby bump. A new study has found that mothers in Beijing who were pregnant during the 2008 Olympics gave birth to babies who were slightly heavier than babies gestated before or after the sporting event. How can the Olympics affect a baby's weight, you ask? Because Beijing cut its air pollution drastically in preparation for the event—and it appears the change benefitted its tiniest citizens.

The new study's results fall in line with many experiments conducted over the past two decades showing that mothers who live in places with more severe air pollution tend to give birth to smaller, lighter babies. The Beijing study provides a fascinating example of this effect at work during one of the world's best-known pollution-cutting efforts. It also underscores the wide-ranging effects clean-air regulation can have. Most smaller babies grow up to be indistinguishable from their heavier peers, but, as a group, they're at higher risk for illness and developmental problems.

Restrictions made concentrations of different air pollutants fall by up to 59 percent.

During the summer of 2008, Beijing raised emissions standards on cars, allowed cars to drive only every other day (there were days for even- and odd-numbered license plates), re-located or temporarily closed nearby factories, and temporarily halted construction projects. (Some of those measures lasted beyond the Olympics.) The restrictions made concentrations of different air pollutants fall by up to 59 percent, past researchers reported. That drop in air pollution, it turns out, made for some healthier youngsters.

To conduct this newly published study, researchers from the United States and Beijing analyzed data from over 83,000 women who were pregnant during the summers of 2007, 2008, and 2009. Those who were in their last month of pregnancy during the summer of 2008 birthed babies who were, on average, a little less than an ounce heavier than those who were eight months pregnant in 2007 or 2009. That's not a lot bigger—the normal range for baby birth weight spans five-and-a-half pounds to 10 pounds, or 160 ounces. Still, the effect was statistically significant and appeared in Beijing babies with moms across all ages and education levels.

Some benefits of improving air pollution are obvious, such as clearer skies. But it's important to remember that air pollution can have seemingly invisible effects too—and to consider what it's worth to clean our air.

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