Research suggests that urban minority children of low socioeconomic status endure disproportionately high asthma morbidity. Although traffic proximity has been associated with adverse respiratory health outcomes and the home environment has been extensively studied in children with asthma, many studies do not account for residential mobility or daily activity patterns (eg, school location), explains Marissa Hauptman, MD, MPH, FAAP. “Less is known about the combined impact of residential and school exposures, where children spend the majority of their day, on pediatric asthma,” she adds.

For a research article published in the Journal of Allergy & Clinical Immunology, Dr. Hauptman and colleagues theorized that a composite measurement accounting for both home and school exposure would be associated with worsened asthma morbidity. “We used spatial analysis methodology to analyze residential and school proximity to major roadways and pediatric asthma morbidity in the School Inner-City Asthma Study, a 5-year prospective cohort study of school-aged children with asthma attending urban public elementary schools in the northeastern US from 2008-2013,” notes Dr. Hauptman. Study participants had been followed approximately every 3 months over an academic year, and extensive longitudinal information was available on asthma symptoms, healthcare use, medication use and adherence, home and school allergic and environmental risk factors, environmental exposure measurements, allergen sensitization, skin and blood testing, and pulmonary function testing.

We found that proximity to major roadways—a composite measurement accounting for both home and school exposure and primarily driven by home proximity to major roadway—was associated with increased asthma symptoms, healthcare utilization, and poor asthma control.” Dr. Hauptman says. Indeed, at greater than a threshold of 100 m, children had 29% decreased odds of a symptom day during the previous 2 weeks for each 100-m increase in distance from a major roadway (odds ratio, 0.71) and were significantly less likely to have poor asthma control (odds ratio, 0.80).

“Our findings strengthen the literature that it is a child’s combined exposure to traffic proximity, both at home and school, that is associated with worsened asthma morbidity,” says Dr. Hauptman. “It is important for physicians to identify a child’s proximity to traffic, especially at the home environment, into their clinical decision making in managing and preventing acute asthma exacerbations.”