10th International Aerosol Conference September 2 - September 7, 2018 America's Center Convention Complex St. Louis, Missouri, USA
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Characterization of Electrophilic and Oxidative Potential of Atmospheric Carbonyls
JIN CHEN, Stacy Chen, Cody Cullen, C.M. Sabbir Ahmed, Ying-Hsuan Lin, University of California, Riverside
Abstract Number: 1611 Working Group: Aerosols and Health - Connecting the Dots
Abstract Ambient particulate matter (PM) is a prominent environmental risk factor associated with adverse human health effects such as asthma, cancer, and chronic obstructive pulmonary disease. PM represents a complex mixture consisting of numerous individual compounds, including carbonyls, which play a crucial role in atmospheric oxidation processes. Owing to the complex nature of atmospheric PM, currently a comprehensive understanding of molecular composition and toxicity of individual aerosol components is lacking. Sources of atmospheric carbonyls include direct emissions from cooking, cigarette smoke, and fuel combustion, or they can be generated through atmospheric degradation of volatile organic compound precursors. Upon exposure, some carbonyls such as unsaturated aldehydes are strong electrophiles that can react with thiol antioxidants and protein residues to induce inflammation and cellular oxidative stress. In this study, we calculate the global electrophilicity of atmospherically relevant carbonyls with computational chemistry approaches to estimate their chemical reactivity. Dithiothreitol (DTT) activity, a commonly used measure for PM oxidative potential, is assessed as a surrogate of biological activity. The reaction products of carbonyls with DTT are characterized using gas and liquid chromatography-mass spectrometry based methods to understand reaction pathways. The potential of using global electrophilicity as a descriptor for carbonyl reactivity in PM and toxicity screening will be discussed.