Oxidative potential of particulate matter collected at sites that differ in local emission sources

Background: The capacity of particulate matter (PM) to oxidise target molecules, defined as its oxidative potential (OP), has been proposed as a biologically more relevant metric than PM mass . Different assays exist for measuring OP and little is known about how different PM characteristics or sources contribute to the different measures of OP. Aim: To assess the OP of PM collected at sites with different local emission sources and to study the correlation with chemical composition for different measurement methods for OP. Methods: Within the framework of the RAPTES study (Risks of Airborne Particles-a Toxicological Epidemiological hybrid Study) PM2.5 and PM10 was sampled at 5 different sites: an underground train station, an animal farm, 2 different traffic sites and an urban background site in the Netherlands. Three a-cellular assays; dithiothreitol (OPDTT), electron spin resonance (OPESR) of hydroxyl radical generation, and ascorbate acid depletion (OPAA) were used to characterise the OP of PM. Result...