Toxicological Assessment of Particulate Emissions From the Exhaust of Old and New Model Heavy- and Light-Duty Vehicles

The primary objective of this project is to develop an improved understanding of the factors affecting the toxicology of particulate exhaust emissions. Diesel particulate matter is a known carcinogen, and particulate exhaust emissions from both light-duty and heavy-duty vehicles are toxic. In this project, we aim to take advantage of extensive existing particulate exhaust emission samples collected in dynamometer facilities of heavy-duty diesel and light-duty vehicles using a variety of driving cycles, emission controls and fuels. These samples have been collected under existing research programs funded by the Southern California Particle Center through grants from the California Air Resources Board as well as on-going international research collaborations between our Particle Center and European Union (EU) investigators. Emission controls range from none through compliance with the 2007 and 2010 EPA standards. Physical characterization as well as some chemical characterization of the California samples has already been completed. This project will allow chemical analyses on more samples - principally those from our European collaborators - to be completed as well as biologically-based toxicological assessment of all the available samples. These data, in combination with knowledge of the physical exhaust emission properties, emission control level and driving cycle will permit us to gain insight to the expected toxicological impacts of changes in the vehicle fleet and planned emission control strategies. Further these results will provide the ability to evaluate the effect of fleet turn-over on the air quality impacts in the Los Angeles basin from the heavy-duty diesel vehicles engaged in goods movement.