A community campaign in which bus drivers and parents turned off their vehicles while waiting to drop off and pick up kids at school resulted in significant reductions in traffic-related air pollution.

The anti-idling campaign was conducted during the fall and winter of 2010-2011 and led by Cincinnati Children’s researcher Patrick Ryan, PhD, of the Division of Biostatistics and Epidemiology.  Ryan and his colleagues studied outdoor air quality at four Cincinnati Public Schools before and after initiating the anti-idling campaign. They sampled pollutants before buses and automobiles arrived in the morning and again after they left in the afternoon.  The researchers also took samples of air at four sites in the communities surrounding the schools.

Prior to the campaign, the air quality measurements exceeded community background levels at three of four schools.  The differences were greatest at the school with the most buses.

Following the campaign, the researchers again measured air quality.  At the school with the most buses (39), background levels of particulate matter had decreased 76 percent and elemental carbon decreased 63 percent. 

The campaign included:

  • An educational program for school bus drivers and parents, followed by an anti-idling pledge 
  • Anti-idling signs near school drop-off and pick-up zones 
  • Student and staff assemblies regarding air quality 
  • A student-led movie 
  • Monitoring of idling activity 

The study involved Cincinnati Children’s, Cincinnati Public Schools, the Cincinnati Health Department and the University of Cincinnati Department of Environmental Health. 

A full report of the project can be found online in the journal Environmental Science Processes and Impacts, published by The Royal Society of Chemistry.

“Anti-idling campaigns are frequently attempted to improve air quality, but until now, no one has evaluated how effective they are,” says Ryan, lead author on the study. “The results of this study demonstrate, for the first time, that not idling is a simple and effective policy that can improve air quality at schools, especially schools with a large number of buses.”