Near-Road Traffic-Related Air Pollution: Resuspended PM_2.5 from Highways and Arterials

Recent studies suggest that the transportation sector is a major contributor to fine particulate matter (PM_2.5) in urban areas. A growing body of literature indicates PM_2.5 exposure can lead to adverse health effects, and that PM_2.5 concentrations are often elevated close to roadways. The transportation sector produces PM_2.5 emissions from combustion, brake wear, tire wear, and resuspended dust. Traffic-related resuspended dust is particulate matter, previously deposited on the surface of roadways that becomes resuspended into the air by the movement of traffic. The objective of this study was to use regulatory guidelines to model the contribution of resuspended dust to near-road traffic-related PM_2.5 concentrations. The U.S. Environmental Protection Agency (EPA) guidelines for quantitative hotspot analysis were used to predict traffic-related PM_2.5 concentrations for a small network in Dallas, Texas. Results show that the inclusion of resuspended dust in the emission and dispersion modeling chain increases prediction of near-road PM_2.5 concentrations by up to 74%. The results also suggest elevated PM_2.5 concentrations near arterial roads. Our results are discussed in the context of human exposure to traffic-related air pollution.