AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Particulate Matter Oxidative Potential as an Additional Metric of Pollutant Exposure
ANGELA HUANG, Jandi Kim, Greg J. Evans, Scott Weichenthal, Krystal G. Pollitt, SOCAAR, University of Toronto
Abstract Number: 305 Working Group: Health Related Aerosols
Abstract Particulate matter (PM) is able to induce adverse health effects through an oxidative stress mechanism. PM is comprised of a complex mixture of chemical components. The composition of PM, which is dependent on the emission source, dictates its surface reactivity and is an important factor in determining particle toxicity. Whether these particles result in oxidative damage depends on the initial interactions between inhaled PM and the respiratory tract’s extracellular antioxidant network.
Experiments were conducted using particles collected from air quality monitoring sites across Canada and a lab-based concentrator used to collect size-fractionated urban ambient PM. The organic species, metals, and carbonaceous fraction of PM was determined. The oxidative potential, a measure of the capacity of pollutants to oxidize biological molecules, of PM samples was evaluated using a synthetic respiratory tract lung fluid. This chemical model of human respiratory tract lung fluid was comprised of antioxidants (ascorbate, glutathione and urate) at physiological concentrations. Antioxidant depletion was measured over 4 hours.
Composition related variability in the depletion of the antioxidants was observed. Antioxidant depletion and PM chemical composition correlation results will be discussed. Increased variability was observed across oxidative potential measurements as compared to PM mass. This enhanced variability may be related to PM composition and sources. Thus oxidative potential may be able to provide a valuable additional metric for use in of air pollution exposure studies.