Characterization and variability of pollutant concentrations for the Las Vegas implementation of the national near-road mobile source air toxics study

A summary of a field study conducted in Las Vegas, NV, from middle of December 2008 through middle of December 2009 is presented to determine criteria pollutant concentrations and variations in concentrations as a function of distance from the highway and to establish relationships between MSAT concentrations as related to highway traffic flows including traffic count, vehicle types and speeds, and meteorological conditions such as wind speed and wind direction. Concentration gradients were observed for gaseous pollutants and black carbon associated with distance from roadway. Elevated concentrations of measured pollutant were directly proportional with traffic volume, as indicated by average hourly traffic counts. Effect of wind speed appeared to be a factor with regard to concentration gradient, e.g., dilution effect. Preliminary results of this study provided indications that highway vehicle emissions impact near-road air quality. Known highway vehicle pollutants such as CO, carbon black, NO, and PM2.5 have elevated concentrations in a near-road environment and decrease as one moves away from the road. Additional analysis of the data is needed to more accurately assess the effect of wind speed as well as other near-road effects. This is an abstract of a paper presented at the 103rd AWMA Annual Conference and Exhibition (Calgary, Alberta, Canada 6/22-25/2010).

Duke Scholars

Author Daniel Vallero Civil and Environmental Engineering