AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
Abstract View
A Comprehensive Assessment of the Spatiotemporal Variability of Oxidative Potential of Ambient PM2.5 in Midwest U.S. using a Semi-Automated Multi-Endpoint ROS-Activity Analyzer (SAMERA)
HAORAN YU, Joseph Puthussery, Yixiang Wang, Vishal Verma, University of Illinois Urbana-Champaign
Abstract Number: 225 Working Group: From Aerosol Dosimetry and Toxicology to Health
Abstract The capability of ambient fine particles to generate reactive oxygen species (ROS) (referred to as the oxidative potential or OP) has been associated with myriad health effects on human. Many chemical assay protocols have been developed to simulate different mechanisms of PM2.5-catalyzed ROS generation, yet no consensus has been reached in selecting the most relevant method. In this study, a semi-automated multi-endpoint ROS-activity analyzer (SAMERA), which integrates five commonly used OP assay endpoints [ascorbic acid (AA) and glutathione (GSH) consumption in surrogate lung fluid (SLF), dithiothreitol (DTT) consumption and •OH generation in SLF and DTT] has been developed and employed in a large-scale spatial sampling. We collected 72 h integrated ambient PM2.5 samples from four urban sites and a rural site in Midwest U.S. region (including Illinois, Missouri and Indiana states) in May 2018 – May 2019, as a part of the MidWest Campaign (MWC) project. We are currently analyzing the OP of these ambient PM2.5 filter samples by SAMERA system, to assess the seasonal and spatial variabilities of OP compared to PM2.5 mass. We will also analyze these filters for the various chemical components such as HULIS, organic and elemental carbon, metals and inorganic ions. The correlations among different OP endpoints and with the chemical composition in different seasons and sites will also be presented. This study accommodates the most comprehensive list of the OP indices in a single investigation, which will be applied on a very large number of PM samples collected from an extensive spatial scale.