Proximity to Traffic, Air Toxic Exposures and the Development of Asthma in Children

The Mickey Leland National Urban Air Toxics Research Center has funded Dr. Woskie to examine how traffic related air toxics are associated with changes in respiratory symptoms and exhaled nitric oxide, a marker of airway inflammation, in children. The project uses a repeated measures design to study sibling pairs where the older sibling is asthmatic and the younger pre-school sibling is at high risk of developing asthma. To examine the role of traffic, a gradient of exposures will be achieved by selecting sibling pairs whose geocoded locations represent a range of traffic proximity/traffic volume categories.

Sibling pairs will be identified and recruited using a large Central Massachusetts group practice / HMO, the Fallon Clinic. For each child in the sibling pair, the field team will conduct 2 home visits over a 1 year period (one in the heating season and one in the non-heating season) to collect health (exhaled NO and symptom questionnaire) and exposure data (personal exposures to volatile air toxics (benzene, toluene, ethylbenzene, xylenes, formaldehyde, acetaldehyde and acrolein). In addition, exposures to criteria air pollutants will be collected from 2 Massachusetts Department of Environmental Protection (MADEP) centralized monitoring sites to control for confounding. Exposure-response analysis will be conducted to examine associations between exhaled nitric oxide, symptoms and subject location relative to roadways categorized by traffic patterns as well as by various exposure metrics for the air toxics, while controlling for potential confounders including indoor allergens, weather, and criteria air pollutants. This study will evaluate how distance from roadways may result in gradients of volatile air toxic exposures that may increase asthma risk in children.