Diesel exhaust is a major source of combustion particles that contribute to poor air quality nationwide. Since almost all school buses are operated with diesel engines, diesel engine exhaust can thus also be a source of concern, specifically with regard to exposure to children. Diesel particulate matter (DPM) is a complex and unhealthy mixture of inorganic and organic carbon particles with adhered toxic substances and metals. The purpose of the study was to investigate the causes of school bus self-pollution and to document in-cabin diesel particulate matter exposures in buses retrofit with a variety of available particulate matter emissions control combinations. This is one of the first studies to report on the in-cabin benefits of retrofit technology. To date, our testing has been conducted on school bus fleets in three U.S. cities – Chicago, IL and Atlanta, GA in 2003 and in Ann Arbor, MI in 2004.
Where do the authors work, and what are their areas of expertise? Note any other publications by the authors with relevance to the 6Cities project.
L. Bruce Hill is a Clean Air Task Force Investigator. Neil J Zimmerman is an Associate Professor at Purdue University, he is interested in indoor air quality. James Gooch, a research assistant for the Clean Air Task Force
What are the main findings or arguments presented in the article or report?
They find diesel emissions are at elevated levels inside diesel school bus cabins due to the buses own emissions. They also found that the drop-off locations at schools have elevated air pollutants.
Describe at least three ways that the argument is supported.
Their study utilizes continuous monitoring techniques
What three (or more) quotes capture the message of the article or report?
"Tailpipes and crankcase emissions were the dominant sources affecting cabin air quality
on school buses tested in this study. Clearly, both emissions sources need to be
addressed in order to provide clean air for riders of conventional school buses.
On residential bus routes in suburban Atlanta, urban Chicago and suburban Ann Arbor
there were few external diesel sources contributing to particulate matter levels on the bus.
Instead build up occurred at bus stops. Emissions were found to typically enter the tested
school buses through the front door causing attendant increases in cabin particulate matter levels."
"This study also presents some of the first data showing that a DPF retrofit combined with a closed crankcase filtration device (Spiracle) effectively eliminates all detectable particulate matter self-pollution in the cabin of school buses--including PM2.5, ultrafine particulate matter, black carbon and PAH."
"Pollutants behind the conventional bus rapidly reached high levels suggesting that when queued buses leave a school they may strongly influence the air quality in the bus behind them (Figure 48). Simulated drop-off tests suggest that the ULSD-DPF combination (with or without the Spiracle) would eliminate measurable ultra-fine particle and PM2.5 pollution at drop-off time. Furthermore this retrofit combination would also protect cabin air quality when buses are following each other upon leaving a school or bus lot."
What were the methods, tools and/or data used to produce the claims or arguments made in the article or report?
Various monitors were installed to the buses to detect different types of pollutants, and each of the devices was calibrated to the area before being installed to check for bias.
How (if at all) are health disparities or other equity issues addressed in the article or report?
The bus routes examined in the study were in both urban and suburban environments, but that was really the only distinction made as this was not the focus of the study.
Where has this article or report been referenced or discussed? (In some journals, you can see this in a sidebar.)
This is an older study, and was referenced in many similar studies that followed it. Because of the susceptibility of children to air pollution, this is a very important issue. I chose to review this article because Philadelphia's diesel difference project referenced it.
Can you learn anything from the article or report’s bibliography that tells us something about how the article or report was produced?
Their report had a comprehensive comparison of air pollution monitors to be used in the busses, and based on their bibliography, they did a lot of research to determine what would be the most appropriate.
What three points, details or references from the text did you follow up on to advance your understanding of how air pollution science has been produced and used in governance and education in different settings?
These additional articles were interesting to browse through and all relate to the diesel and school bus issue.
- Full citation and abstract?
School Bus Particulate Matter Study, Clean Air Task Force, Inc, January 2005Diesel exhaust is a major source of combustion particles that contribute to poor air quality nationwide. Since almost all school buses are operated with diesel engines, diesel engine exhaust can thus also be a source of concern, specifically with regard to exposure to children. Diesel particulate matter (DPM) is a complex and unhealthy mixture of inorganic and organic carbon particles with adhered toxic substances and metals. The purpose of the study was to investigate the causes of school bus self-pollution and to document in-cabin diesel particulate matter exposures in buses retrofit with a variety of available particulate matter emissions control combinations. This is one of the first studies to report on the in-cabin benefits of retrofit technology. To date, our testing has been conducted on school bus fleets in three U.S. cities – Chicago, IL and Atlanta, GA in 2003 and in Ann Arbor, MI in 2004.
- Where do the authors work, and what are their areas of expertise? Note any other publications by the authors with relevance to the 6Cities project.
L. Bruce Hill is a Clean Air Task Force Investigator.Neil J Zimmerman is an Associate Professor at Purdue University, he is interested in indoor air quality.
James Gooch, a research assistant for the Clean Air Task Force
- What are the main findings or arguments presented in the article or report?
They find diesel emissions are at elevated levels inside diesel school bus cabins due to the buses own emissions. They also found that the drop-off locations at schools have elevated air pollutants."Tailpipes and crankcase emissions were the dominant sources affecting cabin air quality
on school buses tested in this study. Clearly, both emissions sources need to be
addressed in order to provide clean air for riders of conventional school buses.
On residential bus routes in suburban Atlanta, urban Chicago and suburban Ann Arbor
there were few external diesel sources contributing to particulate matter levels on the bus.
Instead build up occurred at bus stops. Emissions were found to typically enter the tested
school buses through the front door causing attendant increases in cabin particulate matter levels."
"This study also presents some of the first data showing that a DPF retrofit combined with
a closed crankcase filtration device (Spiracle) effectively eliminates all detectable
particulate matter self-pollution in the cabin of school buses--including PM2.5, ultrafine
particulate matter, black carbon and PAH."
"Pollutants behind the conventional bus rapidly reached high
levels suggesting that when queued buses leave a school they may strongly influence the
air quality in the bus behind them (Figure 48). Simulated drop-off tests suggest that the ULSD-DPF
combination (with or without the Spiracle) would eliminate measurable ultra-fine particle and PM2.5
pollution at drop-off time. Furthermore this retrofit combination would also protect cabin air quality
when buses are following each other upon leaving a school or bus lot."
- What were the methods, tools and/or data used to produce the claims or arguments made in the article or report?
Various monitors were installed to the buses to detect different types of pollutants, and each of the devices was calibrated to the area before being installed to check for bias.- How (if at all) are health disparities or other equity issues addressed in the article or report?
The bus routes examined in the study were in both urban and suburban environments, but that was really the only distinction made as this was not the focus of the study.- Where has this article or report been referenced or discussed? (In some journals, you can see this in a sidebar.)
This is an older study, and was referenced in many similar studies that followed it. Because of the susceptibility of children to air pollution, this is a very important issue. I chose to review this article because Philadelphia's diesel difference project referenced it.- Can you learn anything from the article or report’s bibliography that tells us something about how the article or report was produced?
Their report had a comprehensive comparison of air pollution monitors to be used in the busses, and based on their bibliography, they did a lot of research to determine what would be the most appropriate.- What three points, details or references from the text did you follow up on to advance your understanding of how air pollution science has been produced and used in governance and education in different settings?
These additional articles were interesting to browse through and all relate to the diesel and school bus issue.