Los Angeles air cleaner, kids’ lungs stronger, study finds

Since the mid-1940s, widely known has been the Los Angeles area’s notorious polluted-air problem.

Though that scourge in the region hasn’t completely gone away, conditions have nonetheless improved. Imposed federal, state and local rules are partly responsible for L.A.-area air improvement. So, too, as a contributing factor, was the downturn in the economy, beginning in 2007 as a result of the Great Recession. Information in a Mar. 4, 2015 University of Southern California (USC) news release titled: “L.A. Story: Cleaner Air, Healthier Kids,” bears this out.

In addition to the better-air news in the release, mentioned also is a two-decades-long USC study, a study in which more than 2,000 Los Angeles-area students in three separate cohorts (cohort 1: 1994-1998; cohort 2: 1997-2001; and cohort 3: 2007-2011) took part. Study participants’ lungs were tested for both size and strength. In the final analysis and very, very simply stated, the youngest of the children studied had the greatest gains in terms of lung development and lung function.

“‘We saw pretty substantial improvements in lung function development in our most recent cohort of children,’ said lead author W. James Gauderman, professor of preventive medicine at the Keck School of Medicine of USC, noting this was the first good news from the long-running study,” declared the doctor in the release. There is much more on this below.

The study

“The University of Southern California Children’s Health Study measured lung development between the ages of 11 and 15 and found large gains for children studied from 2007 to 2011, compared to children of the same age in the same communities from 1994-98 and 1997-2001,” as information in the news release made clear.

Lung function was tested a minimum of three times per student. Participants were not tested every year but every other year. Students participating received their first test either near or at age 11. Testing concluded when students were near or at age 15. A spirometer was used to measure both the size and strength of lungs. The time to complete each test took only a second. All according to release information presented.

Pollutants of concern

“Combined exposure to two harmful pollutants, nitrogen dioxide (NO2) and particulate matter of diameter under 2.5 microns (PM2.5), fell approximately 40 percent for the third cohort of 2007-2011 compared to the first cohort of 1994-98. The study followed children from Long Beach, Mira Loma, Riverside, San Dimas and Upland.” It should as well be noted that among the study findings, there was no significant change evident among the three cohorts regarding the incidence of asthma.

Also according to information presented in the release, for the 11-to-15-year-old students in the 2007-2011 cohort who were exposed to reduced NO₂ levels, their lung growth was 10 percent greater than those in the 1994-1998 cohort inhaling NO₂ levels that were higher.

Findings and observations

“The percentage of children in the study with abnormally low lung function at age 15 dropped from nearly 8 percent for the 1994-98 cohort, to 6.3 percent in 1997-2001, to just 3.6 percent for children followed between 2007 and 2011.”

The gains, although favorable, are not absolute. Should the condition of air in Los Angeles and environs deteriorate, any gains made could be erased.

“‘We have to maintain the same sort of level of effort to keep the levels of air pollution down,’” in no uncertain terms emphasized Frank Gilliland, Keck School of Medicine, Hastings Professor of Medicine and the study’s senior author. Gilliland expressed also that with the ongoing drought, a rise in particulate matter pollution can be expected.

The broader view, of course, is: what was found as a result of this study being conducted could well be relevant for areas beyond L.A.

Image above: U.S. National Institutes of Health: National Heart, Lung and Blood Institute

Note: It was stated in an earlier version of this article that: “Lung function was tested a minimum of three times per year per student.” The article has been modified and now includes the corrected text.

Published by Alan Kandel