Air Quality Regulation Improved Children's Lung Health

A 20-year analysis of children in southern CA showed increased regulation of pollutants — resulting in an improvement in air quality — has led to an improvement in their lung function and development.

Led by W. James Gauderman, professor of preventive medicine at the Keck School of Medicine of the University of Southern California (USC), the team measured lung function of 2,120 children from the ages of 11 to 15.

The participants were separated into three cohorts. The first were fourth-grade students who were included in 1992—1993; the second were also fourth-grade students that were analyzed in 1995–1996; the third were kindergarten and first-grade students in which were monitored in 2002–2003. Due to limitations which prevented widespread pulmonary testing, only results from 5 CA communities were included for their report.

The study, which also measured the air quality in these 5 communities, found both male and female participants — regardless of asthma prevalence — had improved lung function and lung growth.

“Regional air quality has improved dramatically over the course of the Children’s Health Study with respect to some pollutants,” they wrote in the March 5 issue of the New England Journal of Medicine (NEJM). Specifically, the team identified significant decreases in PM2.5 and nitrogen dioxide in the included communities.

Moreover, the authors noted lung growth from 11 to 15 improved 10 percent in children exposed to lower levels in 2007-2011 than 1994-1998. Specifically, the mean forced expiratory volume (FEV1) in girls went from 2274 ml at 11 years of age to 3150 ml at 15 years of age; in boys, the mean FEV1 was 2311 ml at 11 years of age and 3831 ml at 15 years of age. Similar improvements were noted in both boys’ and girls’ forced vital capacity (FVC).

“The proportions of children with clinically low FEV1 (defined as <80% of the predicted value) at 15 years of age declined significantly, from 7.9% to 6.3% to 3.6% across the three periods, as the air quality improved (P=0.001),” the authors wrote.

Based on their analysis, the investigators attributed the improvements in lung functions to decreases in nitrogen dioxide exposure and particulate matter of diameter under 2.5 microns (PM2.5) of up to 40% occurring from 2007-11.

“Our results suggest that better air quality in the future will lead to even better lung health,” Gauderman said in a news release.

Gauderman also cautioned that the study’s results shouldn’t make anyone “complacent,” since air quality should continue to be a priority with an increase of vehicles on the roads.