Title: Measurements of oxidative capacity of combustion generated nanoparticles

Speaker: Professor Zoran Ristovski  
                  ILAQH, Queensland University of Technology,
                  Brisbane, Australia

Time: 10:00--11:00 a.m   Sep 4, 2014

Location:  Room 301, Old Geoscience Building
Abstract:  Particulate pollution has been widely recognised as an important risk factor to human health. Oxidative stress caused by generation of free radicals and related reactive oxygen species (ROS) at the sites of deposition has been proposed as a mechanism for many of the adverse health outcomes associated with exposure to particulate matter (PM). For a rapid screening of the oxidative potential of PM, cell-free assays are needed. An in-house methodology for assessing PM-related ROS activity has been developed. A profluorescent nitroxide probe, BPEAnit, was used to measure the oxidative potential of combustion generated aerosols and the probe proved to be sufficiently robust and sensitive enough to provide reliable and rapid estimates of the oxidative potential of PM. The technique was applied on particles produced by a number of different combustion sources (i.e cigarette smoke, wood smoke and various diesel engines and fuels). The oxidative potential per PM mass significantly varies for different combustion sources as well as the type of fuel used and combustion conditions. There was a strong correlation between the organic fraction (especially the oxygenated organic fraction for diesel PM) of particles and the oxidative potential measured by the PFN assay, which clearly highlights the importance of organic species in particle-induced toxicity. The research work sheds a light onto new aspects of diesel particulate emissions that should be taken into account when establishing relevant metrics for health implications of emissions from various future fuels.

Short Bio: Professor Ristovski is an atmospheric scientist with almost 20 years of experience in the general area of airborne particle pollution working at QUT. His main areas of interest are in the characterisation of vehicle emission related nanoparticles, their physical and chemical properties, transport in the atmosphere as well as their toxicity. He has conducted a number of projects in this area both for the Australian government as well as private industry. He has extensively published in the area with over 100 journal publications that have attracted over 2000 citations (h-index of 28). He is a recipient of a number of grants both from the Australian government and industry (over $6 million in total).