Biodiesel and Petroleum Diesel: Exposure Profiles and Public Health Consequences
Junior Investigator and Project Leader
Nora Traviss, Ph.D.
Assistant Professor, Environmental Studies
School of Sciences and Social Sciences
Keene State College
There is growing interest in the use of biodiesel to replace petroleum diesel fuel as biodiesel has been suggested to pose less risk to human health and the environment. While there is a considerable body of evidence on the negative health effects of petroleum diesel exhaust (DE) exposure, including recent studies associating occupational DE exposure with lung cancer, there has been little research examining the effects switching to biodiesel may have on worker health and the local environment. A number of tailpipe emissions studies have indicated biodiesel use reduces emissions of carbon monoxide, particulate matter, and total hydrocarbons; however real world exposure studies characterizing biodiesel use in nonroad heavy duty engines are nearly absent from the literature. Despite a paucity of human exposure and health effects research, in 2011 U.S. biodiesel production volume exceeded 900 million gallons. Initial research in our laboratory demonstrated use of a 20% biodiesel/80% petroleum diesel (B20) blend reduced airborne fine particulate matter (PM2.5) exposure concentrations by approximately 60%. Exposure to fine particulate matter is well associated with acute and chronic cardiopulmonary effects, so this observed PM2.5 reduction is promising. Conversely, B20 use demonstrated a 370% increase in organic carbon concentrations; however, the PM composition was not characterized. More recent research has focused on comprehensively evaluating exposure profiles from newer engines and developing methods to more fully characterize biodiesel PM's physical properties (size and shape), chemical composition, and the associated biological responses in lung epithelial cells. Changes in particle size and morphology are critically important to understand biodiesel's overall impact on public health, as smaller particle diameter/increased surface area would be undesirable characteristics. Understanding chemical composition informs our understanding of PM toxicity. Two additional novel aspects of this research include a focus on undergraduate student researchers, as Keene State is mainly an undergraduate institution, as well as the study of combustion of biodiesel made from waste grease feedstock, a relatively understudied area. In summary, this project characterizes diesel/biodiesel occupational and environmental exposure profiles in an application utilizing heavy-duty nonroad diesel engines, with a focus on fine and quasi-ultrafine particulate matter exposure. Measurement of 'real world' exposures provides valuable data to evaluate potential health risks to workers and the local public, and is often a weak link in the risk assessment process. We are investigating the hypotheses that use of biodiesel will result in significant reductions in total PM2.5 mass; significant differences in particle size and shape; and significant decreases in toxic organic carbon species (PAH's & nitro-PAH's). Our collaborations with colleagues from Dartmouth College, the National Renewable Energy Laboratories, and the University of Vermont have provided Keene State researchers and students from multiple majors important access to state of the art instrumentation and learning experiences, including student presentation of scientific results at regional and national conferences.
Melissa Lombard, PhD
Undergraduate Student Researchers at Keene State College (2008 - 2012)
Kyle Barnett, Alissa Couturier, Greg Goupil, Ryan Hall, Ben Lazich, Peter Kersker, Dan O' Brien, Anthony Santa Fe, Dustin Sciacca, Melissa Sweeney, Austin Mills, Alison Dreyfuss, Megan Ferm, Kristin Bissonnette, Taylor Barnes, Alison Asmus, Joe Frechette, Drew Grandmont, Sam Guimaraes, Jeff Pelkey, Connor Tyrell.
Traviss, N., Thelen, B.A., Ingalls, J. and Treadwell, M. 2010. Biodiesel vs. Diesel: A Pilot Study Examining Exhaust Exposures for Employees at a Rural Municipal Facility. Journal of the Air and Waste Management Association, 60: 1026-1033.
Traviss, N., Thelen, B.A., Ingalls, J, Treadwell, M. 2012. Evaluation of biodiesel's impact on real-world occupational and environmental particulate matter exposures at a municipal facility in Keene, NH. Air Quality and Atmospheric Health, 5 (1): 101-114.
Traviss, N. 2012. Breathing Easier? The known impacts of biodiesel on air quality. Biofuels 3 (3): 285-291.