AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Diesel Particulate Matter and Coal Dust from Trains
DAN JAFFE, Jon Hee, Francisco Gabela, Juliane L. Fry, Benjamin Ayres, Makoto Kelp, University of Washington, Bothell, WA, USA
Abstract Number: 423 Working Group: Aerosol Exposure
Abstract We have examined the emissions of diesel particulate matter (DPM) and coal dust from trains in the Columbia River Gorge (CRG) of Washington State. This was in response to several proposals to substantially increase rail shipments of coal from the Powder River Basin through the Pacific Northwest enroute to Asia. To support this work we raised funds directly from the public via the crowd-funding platform Experiment.com. In the 2014 measurement campaign, we measured PM1, PM2.5, CO2, and black carbon (BC), along with videos to identify the train type and speed.
During the two-month period, we identified 293 freight trains and 74 coal trains that gave a PM2.5 enhancement of more than 3.0 μg/m3. We found an average PM2.5 enhancements of 8.8 and 16.7 μg/m3, respectively, for freight and coal trains. For most freight trains (52%), and a smaller fraction of coal trains (11%), we found a good correlation between PM2.5 and CO2. Using this correlation, we calculated a mean DPM emission factor (EF) of 1.2 gm/kg fuel consumed, with an uncertainty of 20%. For four coal trains, the videos revealed large plumes of coal dust emanating from the uncovered coal cars. These trains also had the highest peak PM2.5 concentrations recorded during our study (53–232 µg/m3). Trains with visible coal dust were observed for 5.4% of all coal trains, but 10.3% when the effective wind speed was greater than 90 km/h. We also found that nearly all coal trains emit coal dust based on several indicators.
Our results demonstrate that, on average, passage of a diesel powered open-top coal train result in nearly twice as much respirable PM2.5 compared to passage of a diesel-powered freight train. Our work also shows the substantial interest of the public in legitimate investigations on important environmental issues.