Title: Understanding the sources, atmospheric processes, health associations, and lung deposition of aerosol oxidative potential

Committee members: Dr. Rodney Weber, Dr. Armistead Russell, Dr. Nga Lee Ng, Dr. Gregory Huey, and Dr. Jim Mulholland

Abstract: Aerosol oxidative potential (OP), the ability of particulate matter (PM) to generate reactive oxygen species (ROS) in vivo, plays an important role in upsetting redox homeostasis, causing oxidative stress, and leading to adverse health effects. This dissertation presents a semi-automated system for quantifying OP using two widely used chemical measures, the dithiothreitol (DTT) and ascorbic acid (AA) assays, from aqueous extracts of ambient PM samples. The system was used to generate large dataset at urban, rural, road-side sites in southeast U.S. to investigate the spatiotemporal distributions, sources, atmospheric processes, and health associations of water-soluble OPDTT and OPAA of fine particles (PM2.5, with aerodynamic diameter smaller than 2.5 µm) as part of the Southeastern Center for Air Pollution & Epidemiology (SCAPE) project. Ambient size distributions of water-soluble OPDTT and OPAA at an urban and a road-side site collected using Micro-Orifice Uniform Deposit Impactors (MOUDIs) were consistent with the sources and atmospheric processes for both forms of OP from the SCAPE study. Ambient size distribution of water-insoluble fractions of OPDTT at the urban and road-side site was also measured and compared to water-soluble OPDTT in terms of major players, atmospheric processes, and deposition in the human respiratory system.