Growing up in Southern California exposes you to air pollution at an early age. I recall smog being a regular problem during school. So while we were never had the pleasure of experiencing snow days, we had our own Southern Californian version, which were known as “smog days.” Unfortunately, on smog days, we didn’t have the good fortune to stay at home and play in the snow; we had to be at school. We just weren’t allowed to play outside for fear of the health consequences.

It now appears that those consequences may have been more severe than any of us realized. In fact researchers have determined that attending a school near heavy traffic zones, where air quality is poor, increases a child’s risks for asthma as much as when a child actually lives in heavy traffic zones.

The findings, published in the journal Environmental Health Perspectives, suggest that pollution from traffic near schools can have a significant and detrimental effect on the health of a child’s lungs, resulting in a 45% increased risk for asthma. This rate is comparable to the risk when exposure to pollution occurs at home, even though children only spend about one-third of their waking hours at school.

To arrive at their conclusions, researchers turned to the Children’s Health Study (CHS), a three-year study that was undertaken to gain a better understanding of the chronic effects of air pollution on a child’s health. Looking at nearly 2,500 students in kindergarten and first grade who were asthma-free at the beginning of the study, scientists tracked the respiratory health of these students over the course of the study.

The relationship between air quality and the level of traffic was based on the proximity of home and school to high traffic zones, traffic volume, and local weather conditions. The effects of exposure to air pollution at school were then compared with levels of exposure at home. By the end of the study, 120 new cases of asthma were diagnosed, and based on this number, it was determined that risk for contracting asthma at school was nearly as high as the risks associated with living in a high traffic area, and the combined effect was even higher.

The reasons for this high level of exposure may be due to the fact that at school, physical education programs result in a high level of activity outside. This correlation is especially significant during regular school hours, which in the morning coincides with heavy rush hour traffic. And though some states (including California) prohibit schools from being located within 500 feet of a highway, schools can be in the vicinity of busy streets where traffic levels are extremely high.

Scientists hope that findings will lead to an increased awareness by policymakers to help reduce childhood exposure to air pollution, which can lead to respiratory problems that include asthma.

Asthma is in fact the most common childhood illness in children who grow up in industrialized nations, and a strong link exists between the condition and exposure to air pollution.

If you suspect that your child is suffering from asthma, speak with your pediatrician. If you have concerns about your child’s exposure to pollution at school, speak with the school administrators. For more information about asthma, visit the website for the U.S. Department of Health and Human Services, and the Asthma and Allergy Foundation of America.