Measurements of mobile source particulate emissions in a highway tunnel

Recent studies have linked atmospheric fine particulate matter (PM2.5) with human health effects. In many urban areas, mobile sources are the dominant source Of PM2.5. Dynamometer studies have also implicated diesel engines as being a significant source of ultrafine particles. In order to characterise particulate emissions from in-use vehicles, we performed an on-road study of emissions from vehicles operating in the Tuscarora Mountain Tunnel along the Pennsylvania Turnpike. As part of this study we obtained chemically speciated, size-segregated PM emission rates, particle size distributions, chemically speciated profiles of diesel emissions for use in source apportionment studies, a comparison with years past how much improvement there has actually been in diesel particulate emission rates, and measurements of particulate emission rates from light-duty gasoline vehicles to evaluate the relative significance of this source. This paper describes the experimental methods and presents the preliminary results of the on-road particulate emissions measurements.