AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Changes in Black Carbon Outdoors and Indoors at Near-Roadway Schools in Las Vegas: 2008 to 2013
Steven G. Brown, LYLE CHINKIN, Paul Roberts, David Vaughn, Sonoma Technology, Inc
Abstract Number: 422 Working Group: Urban Aerosols
Abstract Ambient concentrations of black carbon (BC) at three schools adjacent to highway US 95 in Las Vegas, Nevada, decreased between 2008 and 2013. The total traffic volume, volume of large vehicles such as diesel trucks, and vehicle speeds on US 95 remained similar between the two years, however, indicating that emissions per vehicle and/or background BC concentrations decreased between 2008 and 2013. Vehicle emissions in the U.S. have been trending downward, suggesting much of the decrease in ambient BC may be due to decreased emissions in the vehicle fleet. Indoor concentrations at all three schools were much lower than ambient concentrations. Filtration efficiencies of the heating, ventilation, and air conditioning systems at two schools were similarly high (greater than 90% efficiency) between 2008 and 2013; at one school, doors were left open more frequently in 2013, leading to higher indoor BC concentrations and correspondingly lower calculated filter efficiencies.