In a study published May 21, 2013 in Environmental Health Perspectives, a team led by Nicholas Newman, DO, MS, director of the Pediatric Environmental Health and Lead Clinic at Cincinnati Children’s, reported that children exposed to high levels of traffic-related air pollution (TRAP) during their first year of life were more likely to have “at risk” scores for hyperactivity by age 7.
The study followed children enrolled in the Cincinnati Childhood Allergy and Air Pollution Study.  They were born in the Cincinnati metropolitan area between 2001 and 2003 and were selected based on family history of allergy and proximity to a major highway or bus route. They were followed from infancy to age 7, at which time parents completed a behavioral questionnaire and reported on symptoms including hyperactivity, attention problems, aggression, conduct problems and atypical behavior.

Of 762 children initially enrolled in the study, 576 completed the tasks necessary for inclusion in the final analysis. Results showed that children exposed to the highest amount of TRAP during the first year of life were more likely to have hyperactivity scores in the "at risk” range. “At risk” means that children should be monitored for the development of clinically important symptoms.

Newman says "several biological mechanisms” could explain the connection between TRAP and hyperactive behaviors, including direct toxicity to the brain.  Investigators at Cincinnati Children’s are currently working to better understand these mechanisms.

He notes that studies have shown that approximately 11 percent of the US population lives within 100 meters (328 ft.) of a four-lane highway and that 40 percent of children attend school within 400 meters of a major highway.

"Traffic-related air pollution is one of many factors associated with changes in neurodevelopment,” Newman says, “but it is one that is potentially preventable.”

Newman’s research was carried out in collaboration with the University of Cincinnati College of Medicine’s Department of Environmental Health.