AAAR 33rd Annual Conference
October 20 - October 24, 2014
Rosen Shingle Creek
Orlando, Florida, USA
Abstract View
The Effects of Atmospheric Oxidation on the Levels of Aerosol Reactive Oxygen Species
JONATHAN ABBATT, University of Toronto
Abstract Number: 456 Working Group: Linking Aerosols with Public Health in a Changing World
Abstract The term reactive oxygen species (ROS) is used to collectively describe species that are potentially good oxidants. Whereas it is believed that ROS are important in affecting the oxidant balance within the body, it is not known the degree to which atmospheric processing of aerosol before inhalation affects the abilities of particles to give rise to ROS. This talk will focus primarily on the ability of particulate matter to participate in redox cycling reactions which oxidize reduced aqueous species, such as anti-oxidants. Our group has been exploring how atmospheric oxidation gives rise to redox-active products in secondary organic aerosol formed from gas phase precursors (i.e. naphthalene, two-stroke engine exhaust) and from particulate precursors (i.e. diesel exhaust). The diesel black carbon results are intriguing because they illustrate that the majority of the redox-cycling ability is associated with the particle and not with small soluble species, and that redox abilities increase with simulated atmospheric oxidation. Such black carbon (“soot”) particles are known to translocate through the body, potentially allowing oxidative stress effects to be felt beyond the pulmonary system. A second topic is the level of peroxide species formed within particles through oxidation chemistry, focusing on their abundance in secondary organic aerosol. Overall, there is the need to better understand the fundamental chemistry generating ROS, so that a mechanistic connection of potential health effects can be made to atmospheric chemistry.