Project at a Glance

Title: Probing the intrinsic ability of particles to generate reactive oxygen species and the effect of physiologically relevant solutes

Principal Investigator / Author(s): Paulson, Suzanne E.

Contractor: UC Los Angeles

Contract Number: 10-314

Research Program Area: Atmospheric Processes

Topic Areas: Chemistry & Reactivity


Determining the ‘causative agents’ in particulate matter (PM) that are responsible for damaging health is the subject of increasing research activity but many questions remain. A scientific consensus has emerged that oxidative stress mediated by reactive oxygen species (ROS) is a major mechanism by which PM contributes to illnesses and mortality. Freshly collected ambient particles are able to generate significant amounts of ROS. This work was aimed at understanding the components in PM responsible for ROS formation under physiological conditions and the role of two important ROS: hydrogen peroxide (H2O2) and hydroxyl radical (•OH). Measurements of aerosols in the field were complemented by laboratory studies of ROS generation by metals and organics in PM. The detailed analysis of organics and metals from field samples identified the attribution of those components and sources most responsible for ROS activity to their sources, particularly copper from motor-vehicle braking and humic-like substances from biomass-burning. The results are expected to enable the development of PM controls that target the sources that are most responsible for the toxicity of PM.

For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753

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