Scientists have long known that polluted air is bad for the lungs of children, and resulting health problems can plague them for the rest of their lives. While common sense might intuitively lead someone to the conclusion that better air quality would improve the health of children, no one apparently actually quantified that—until now.

A new study published in the New England Journal of Medicine found for the first that respiratory function in Southern California kids 11 to 15 years old improved over the past 17 years as government regulations at state and federal levels dramatically reduced pollution in the region.

Researchers at the University of Southern California (USC) used measurements of the breathing capacity of 2,120 schoolchildren during three periods, 1994-1998, 1997-2001 and 2007-2011, and charted the results against pollution levels. During that time, the Los Angeles Basin experienced a 50% decline in fine particulates associated with vehicle exhaust and 35% drop in nitrogen dioxide levels.

The number of kids with abnormally low lung function (80% of normal) dropped from 7.9% in the first group to 6.3% in the second and 3.6% in the third. Lung growth grew 10% during the same period. The benefits were felt equally by boys and girls and across racial and ethnic backgrounds.

“It is an environmental success story in a very complex urban area,” James Gauderman, the study’s lead author, told the Orange County Register. He attributed the gains to the 1970 Clean Air Act and the subsequent legislation and regulations it inspired.

Information for the report was drawn from the Children’s Health Study, an ongoing research project at USC that tracks more than 11,000 Southern California children. This report covered kids in Riverside, Jurupa Valley, Upland, San Dimas and Long Beach.   

The Los Angeles Times said that previous studies have established that better air increases the life expectancy of adults and provides them with other health benefits but the USC study is the first to prove it helps kids. That’s not to say there weren’t a few hints. A study in 2001 showed that kids who moved away from polluted areas showed increased lung function.

Both the L.A. Times and the New York Times implied that the research findings could play a significant role in reshaping future pollution standards, although perhaps not the hearts and minds of polluters. Diane Katz, a research fellow at the conservative Heritage Foundation, told the N.Y. Times, “The study doesn’t say anything about regulation. We don’t know what would have happened if we had had less burdensome regulation.”

–Ken Broder

To Learn More:

Children’s Lung Health Improves as Air Pollution Is Reduced, Study Says (by Jan Hoffman, New York Times)

Cleaner Air Is Linked to Stronger Lungs in Southern California Children (by Tony Barboza, Los Angeles Times)

Children's Health, Local Air Improve In Tandem (by David Danelski, Orange County Register)

Association of Improved Air Quality with Lung Development in Children (New England Journal of Medicine)