Infants living near stop and go bus and truck traffic have significantly higher rates of wheezing, a common symptom of asthma, according to new research published in the August 2005 Journal of Allergy & Clinical Immunology (JACI). The JACI is the peer-reviewed, scientific journal of the American Academy of Allergy, Asthma and Immunology (AAAAI).
Patrick H. Ryan, MS, and colleagues from the University of Cincinnati tracked the respiratory health of 622 infants living near three traffic conditions: highway traffic, ‘stop and go’ traffic, and areas unexposed to major roads or bus routes. The children were all enrolled in the Cincinnati Childhood Allergy and Air Pollution Study. Researchers defined a ‘stop and go’ traffic area as being within 100 meters (approximately 100 yards) of a bus or state route with a posted speed limit of 50 mph or less.
Results of the four-year study suggest that the type of traffic and distance from it, not just the volume of traffic, are associated with wheezing in children. Previous air pollution studies have not addressed these factors in children.
Researchers found:
Infants living within 100 meters of ‘stop and go’ traffic wheezed twice as often as those living within 400 meters of interstates, and more than three times as often as infants living in unexposed areas.
African American infants living near ‘stop and go’ traffic experienced the highest wheezing rates at 25%.
This is the first epidemiologic study to examine the risk of wheezing in infants younger than one year who are exposed to varying types and amounts of city traffic. The study demonstrated that even within a city environment, the risk of wheezing varies with the type of distance and traffic.