Researchers find benefits of clean air on fetal growth

By NewsGram Staff Writer

Women breathing high levels of pollution during the last month of pregnancy are more likely to give birth to babies with significantly lower weight as compared to an unexposed woman. A study of the effects of the air-quality controls, introduced during the 2008 Beijing Olympics, brings out the revelation.

Scientists involved in the study said that the temporary pollution regulations imposed on Beijing during 2008 Olympics had a measurable and positive effects on the weight of babies born to mothers who were 8-months pregnant at that time.

It is the first time when a study is able to indicate the harmful effects of air pollution on development of fetus in the womb while specifying the importance of clean air for fetal growth.

During 2008 Olympics, the Chinese government had imposed stringent curbs on vehicles and industry to minimize the impact of city's high levels of air pollution on competing athletes. It was during this time when almost 84,000 births to mothers living in four urban districts of Beijing before, during and after the 2008 Olympics, were analyzed.

The study found that women who were in the eighth month of their pregnancy benefited most from the significantly "cleaner" air in the Chinese capital. The babies born to them were on average 23 grams heavier than the babies born to similar women in 2007 and 2009, when air pollution controls were not as severe.

David Rich, an epidemiologist at the University of Rochester Medical Centre in New York, and lead author of the study published in the journal Environmental Health Perspectives, said, "This is the first study to show that when air pollution levels go down during the 8th month of pregnancy, we see an increase in birth weight."

Just before the Olympics, the Chinese government took many steps to bring down the high pollution level in the capital. They prohibited traffic, closed factories and even seeded clouds to make it rain. These measures together led to 60% reduction in sulfur dioxide, 48% reduction in carbon monoxide, 43% reduction in nitrogen dioxide and a reduction in the number of particles in the air smaller than 2.5 microns, which have the capability to enter the blood stream through the lungs.

"The results of this study demonstrate a clear association between changes in air pollutant concentrations and birth weight. These findings not only illustrate one of the many significant health consequences of pollution, but also demonstrate that this phenomenon can be reversed," said Dr. Rich.

"While Beijing's pollution is particularly noteworthy, many of the world's other cities face similar air-quality problems. This study shows that pollution controls – even short-term ones – can have positive public health benefits," said Junfeng Zhang, a researcher at Duke University in North Carolina, who led the study.