April 2015

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Cleaner Air Tied to Healthier Lungs in Kids

As air quality improved in a once-smoggy region of California, lung function also improved in children during a critical period of growth and development. The findings point to the potential long-term effects of air quality on human health.

Air pollution has been linked to a wide range of health problems, including breathing difficulties, cardiovascular disease, and even death. In Southern California—long known for its high levels of air pollution—public policies have helped to improve air quality over the past few decades.

NIH-supported scientists took a closer look at the link between better air quality and breathing in 11- to 15-year-old kids. Those ages are especially important to long-term lung function, because that’s when lungs undergo rapid development. The researchers looked at data from 3 different groups of children taken during the time periods 1994–1998, 1997–2001, and 2007–2011. More than 2,100 kids participated.

The researchers found that as levels of air pollution declined, lung function development improved. Improvements were seen in both boys and girls, in children with and without asthma, and in children of different racial/ethnic backgrounds.

The proportion of kids with clinically low lung function at age 15 also dropped as the air got cleaner. Across the 3 time periods, the proportion with low lung function fell from about 8% to 6% to less than 4%.

“We expect that our results are relevant for areas outside Southern California. Improved health was most strongly linked to reduced levels of nitrogen dioxide and particulate matter—pollutants that are elevated in any urban environment,” says research team leader Dr. W. James Gauderman of the University of Southern California.