Abstract View
Chemical and Cellular Superoxide Generation by Secondary Organic Aerosols in Epithelial Lining Fluid
TING FANG, Jinlai Wei, Jessica Monterrosa Mena, Michael Kleinman, Manabu Shiraiwa, University of California, Irvine
Abstract Number: 215
Working Group: Health-Related Aerosols
Abstract
Inhaled particulate matter (PM) produces reactive oxygen species (ROS), such as superoxide radical (O2-), which have been implicated in the initiation and development of lung inflammation and cardiovascular diseases. PM can trigger release of superoxide in epithelial lining fluid through redox reactions or can induce macrophages to generate superoxide biologically after they phagocytize particles. However, the relative importance of the source of the PM on chemically and biologically generated ROS is poorly understood. Very little is known, especially, about the role of secondary organic aerosols (SOA) from specific sources in the generation of superoxide. In this study, SOA particles were generated from specific volatile organic compounds including isoprene, toluene, and naphthalene by hydroxyl radical oxidation using a Potential Aerosol Mass (PAM) chamber. Superoxide generation by SOA from aqueous redox chemistry was measured using an Electron Paramagnetic Resonance spectrometer coupled with a spin trapping technique. For cellular superoxide release, RAW 264.7 macrophage cells were incubated with SOA particles on 96-well cell culture plates at physiologically relevant conditions and the production of superoxide was monitored over 2 hours using a calibrated chemiluminescence assay. The total amount of O2- generated from macrophages was compared to that from SOA aqueous chemistry. Dose-response curves were used to compare the role of different SOA on superoxide production. Preliminary results suggest that isoprene SOA generates more superoxide compared to other types of SOA.