Air pollution is associated with chronic respiratory health problems in children. A new study examined whether decreases in air pollution levels are associated with significant reductions in respiratory symptoms in children.

Researchers from the University of Southern California followed over 4,600 children in eight Southern California communities across three different time periods from 1993-2012. In addition to monitoring air quality, they also looked at children with and without asthma, and whether they reported respiratory symptoms like bronchitis, congestion, phlegm production, or a daily cough for three months in a row, during the previous year.

Along with significant improvements in air pollution levels, the authors found a decrease in reported respiratory symptoms in children both with and without asthma. Respiratory symptoms decreased by 32 percent in children with asthma and 21 percent in children without.

Click here to read the publication in JAMA, Journal of the American Medical Association.