The Science Journal of the American Association for Respiratory Care

2010 OPEN FORUM Abstracts


Kathleen Hernlen, Randall Baker; Department of Respiratory Therapy, Medical College of Georgia, Augusta, GA

Background Since children spend 24% of their week in schools, school Indoor Air Quality (IAQ) may influence respiratory health. The EPA designates bus interiors as indoor environments that may pose a risk through exposure to diesel particulates. Approximately 22,000 students (66.61%) in the Richmond County school system are transported by bus each day. In a previous study, we found significant increases in respirable particulates in bus loading zones. The purpose of this study was to assess the exposure to particulates inside of a school bus during daily routes. Methods Permission from the Richmond County Board of Education was obtained to assess particle counts inside of buses during daily routes in August, 2009. The transportation manager assigned buses and routes for the collection of data. Four of the buses had exhaust emitted from the rear of the bus, while three had exhaust vented to the side of the bus. Measurements were made in a total of seven buses that varied in years from 1995 – 2008. The routes included high and low traffic areas. Particulates (.3- 5.0 um) were assessed using a Met One 237B Portable Airborne Particle Counter stationed at the front of the bus. Counts were taken every minute for 5 minutes followed by a one minute break. Investigators noted specific events during the ride including, stopping at traffic lights, loading/unloading of students, idling, road construction, and the detection of diesel fumes inside the bus. Results Table 1 shows the percent increase in particulates inside buses during common events on routine daily bus routes: Conclusions Particle counts increased up to 20% in buses during common events regardless of the bus’s age. Both internal and external factors appeared to contribute to increased particulate counts. The greatest increases were observed when buses stopped at traffic lights, when students were loading or unloading both on routes and in school bus zones, and when traveling through road construction sites. Further measurements in a more controlled environment may better determine the cause of changes in particulates during routine bus routes. Sponsored Research - Georgia Department of Human Resources, East Central Health District Table 1: Increases Particle Counts Inside School Buses