Children’s lung health improves with decreasing air pollution
Research, supported in part by NIEHS, shows that decreases in ambient air pollution in Southern California were associated with significant reductions in respiratory symptoms in children with and without asthma.
Since 1992, air pollution reduction policies and strategies have significantly improved air quality across Southern California. To find out how these improvements affected lung health, the researchers examined data from a total of 4,602 children in eight Southern California communities. They were all part of the Southern California Children’s Health Study over three time periods — from 1993 to 2001, 1996 to 2004, or 2003 to 2012. Researchers tracked bronchitic symptoms, including presence of a daily cough for three or more consecutive months, congestion or phlegm not related to a cold, and inflammation of the mucous membranes.
The authors report that decreases in ambient concentrations of nitrogen dioxide, ozone, and two sizes of particulate matter — less than 10 microns and less than 2.5 microns — were associated with significant decreases in bronchitic symptoms in children with and without asthma. Children with asthma showed proportionally larger symptom reductions, which remained persistent through age 15. Communities with the highest improvements in air quality exhibited the largest reductions in bronchitic symptoms.
Although the study does not provide a causal link between air pollution reduction and improved bronchitic symptoms, the findings support the potential benefit of air pollution reduction on asthma control.
Citation: Berhane K, Chang CC, McConnell R, Gauderman WJ, Avol E, Rapapport E, Urman R, Lurmann F, Gilliland F. 2016. Association of changes in air quality with bronchitic symptoms in children in California, 1993-2012. JAMA 315(14):1491-1501.