Study: Bus Riders Exposed to High Levels of Exhaust

By Jessica L. Tonn — May 10, 2005 1 min read

An abstract of the report, “Vehicle Self-Pollution Intake Fraction: Children’s Exposure to School Bus Emissions,” is available from the April 2005 issue of Environmental Science and Technology.

A child commuting to school on a school bus breathes in seven to 70 times more exhaust emissions from his or her bus alone than the typical resident breathes in from all school buses combined, a study concludes.

The study—conducted by researchers at the University of California, Berkeley, and the University of California, Los Angeles, and published in the April 15 issue of the journal Environmental Science and Technology—found that older buses deliver more pollution to passengers’ lungs than newer models.

A student traveling on a bus built in the early 1970s will have a 70 percent higher 24-hour inhalation intake of diesel particulate matter than a student who travels by car. Riding on a bus built in the 1990s reduces the higher 24-hour intake to 34 percent.

Breathing diesel exhaust has been linked to bronchitis and asthma in childhood, and to lung cancer in long-term scenarios, according to Julian D. Marshall, a doctoral student in air quality engineering at Berkeley and one of the study’s authors.