American Association for Aerosol Research - Abstract Submission

AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA

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Inflammatory Response to Chronic Exposure of Secondary Organic Aerosol

ARTHUR CHAN, Jianhuai Ye, Xiaomin Wang, Sepehr Salehi, Chung-Wai Chow, University of Toronto

     Abstract Number: 79
     Working Group: Health Related Aerosols

Abstract
Chronic lung diseases, such as asthma and chronic obstructive lung disease, are a significant cause of morbidity and mortality. Air pollutants not only exacerbate conditions of patients with pre-existing disease, but also lead to de novo disease development that is related to chronic cumulative exposures over time. Here we present work focused on studying the pulmonary response to low-dose chronic exposure. We developed a system to expose mice to laboratory-generated aerosol for 2 hours a day over a 2-week period. Characterization tests using fluorescent zinc silicate particles show uniform deposition in the lobes at ambient concentrations. For exposure experiments, we use secondary organic aerosol generated from photooxidation of naphthalene, a representative organic compound in engine exhaust. SOA from naphthalene has been shown in previous work to be highly redox active, and to produce significant levels of reactive oxygen species. The amount and composition of the pollutant mixture are reproducible across many days of exposure. The chemical composition of particles is monitored using GC/MS, and we focus on measuring the concentrations of quinones, which are known redox active compounds. Gas-phase species are selectively removed in some exposures using a honeycomb charcoal denuder, such that mice are exposed to particles only. Results from preliminary experiments will evaluate the physiological response (respiratory mechanics) and inflammatory and immune response (production of inflammatory mediators) from this chronic exposure setup. The difference in responses between particle-only and gas and particle exposures are studied to identify physical mechanisms by which pollutants are delivered.