Study Finds Air Pollution Exposure at Schools Linked to Childhood Asthma Development
by Meghan LewitLiving near major highways has been linked to childhood asthma, but a new study led by researchers at the Keck School of Medicine of the University of Southern California suggests that traffic-related pollution near schools is also contributing to the development of asthma in kids.
The researchers found that the risk of developing asthma due to exposure at school was comparable to that of children whose exposure occurred primarily at home, even though time spent at school only accounted for about one third of waking hours. Children in schools located in high-traffic environments had a 45 percent increased risk of developing asthma. The study appears in the journal Environmental Health Perspectives.
The study drew upon data from the Children’s Health Study, a longitudinal study designed to investigate the chronic effects of air pollution on respiratory health. Using a cohort of kindergarten and first grade children who were asthma-free when they entered the study, researchers examined the relationship of local traffic around schools and homes to diagnosis of new onset asthma that occurred during three years of follow-up.
Researchers found 120 cases of new asthma. The risk associated with traffic-related pollution exposure at schools was almost as high as for residential exposure, and combined exposure accounting for time spent at home and at school had a slightly larger effect.
Although children spend less time at school than at home, physical education and other activities that take place at school may increase ventilation rates and the dose of pollutants getting into the lungs, notes lead author Rob McConnell, MD, professor of Preventive Medicine at the Keck School of Medicine of USC. Traffic-related pollutant levels may also be higher during the morning hours when children are arriving at school.
This article was originally published in Coping® with Allergies & Asthma magazine, July/August 2010.