Posted Oct. 6, 2010
The results are in for a new biodiesel versus diesel exhaust exposure study. The study, Biodiesel versus Diesel: A Pilot Study Comparing Exhaust Exposures for Employees at a Rural Municipal Facility, indicates "that B20 use dramatically reduces work area respirable particle and formaldehyde levels compared with petroleum diesel." Performed by Keene State College of New Hampshire at a recycling center, the work was aimed at combining established industrial hygiene and environmental air monitoring methods to evaluate diesel and biodiesel blend exposure profiles in an occupational setting utilizing nonroad diesel equipment. "Overall," the study stated, "this suggests that biodiesel blends reduce worker exposure to and health risk from petroleum diesel exhaust."
The team of researchers that completed the study used the same facility equipment and alternated between diesel fuel and a B20 blend, measuring the equipment cabin and the perimeter of the work area for known toxins such as benzene, 1,3-butadiene and formaldehyde. During the process, the researchers noted two areas of difficulty in the testing approach, "limited measurements of existing human exposure and difficulty developing techniques to identify a unique signature that distinguishes diesel exhaust from background air pollution." The techniques used to measure for pollutants involved a high-sensitivity real time light scattering monitor called a Haz-Dust EPAM-5000 along with various filters. For sampling days, "researchers and students performed equipment calibrations before and after sampling, positioned the equipment in the same locations, and regularly performed operational checks on all of the equipment."
Four pieces of equipment were in the study, a large front-end loader, a small front-end loader, a skid steer and a propane-powered forklift, and the same employees operated the equipment for the duration. The facility consisted of a single, large building with one large bay door and no mechanical ventilation. "Although biodiesel may hold promise for reducing exposure to PM and carbonyls, more comprehensive biodiesel data are needed to determine if these reductions are replicable and statistically significant," the study notes. However, while the study states that diesel effects are still somewhat unknown, "Biodiesel may offer immediate, nationwide risk reduction opportunities, even as the debate regarding the level of health risk posed by diesel continues."
The research team was made up of several members from Keene State College including: Nora Traviss and Brett Amy Thelen of the Department of Environmental Studies, Jaime Kathryn Ingalls of the Department of Safety Studies and Melinda Dawn Treadwell of the Department of Professional and Graduate Studies. To view the study, click
here.