Abstract View
Impact of Indoor Physicochemical Phenomena on Volatile Chemical Products' Emissions from Indoor Spaces
AMIRASHKAN ASKARI, Arthur W. H. Chan, University of Toronto
Abstract Number: 155
Working Group: Indoor Aerosols
Abstract
The decrease in emissions from fossil fuel combustion sources, especially from the traffic sector, due to mitigation policies implemented during the recent decades has led to increasing relative importance from other sources. Among these emerging sources, Volatile Chemical Products (VCPs) of petrochemical origin are significant contributors to anthropogenic emissions, especially in urban regions. Further to the adverse effect of VCP emissions on ambient air quality, recent works have also provided evidence of the potential of VCP emissions to act as precursors for secondary pollutants like tropospheric ozone and secondary organic aerosol. Although a significant fraction of VCP emissions occurs within indoor spaces like residential and commercial buildings, the effects of indoor processes on their eventual emission into the ambient atmosphere are unknown. In this study, we modelled the effect of indoor gas-phase chemistry and partitioning to indoor surfaces in an unsteady-state framework to shed light on the attenuations/modifications which occur for indoor VCP emissions before they migrate outdoors. We construct a VCP emission inventory for Canada, as a typical developed country, utilizing a bottom-up approach. The differential potency of VCP emissions as pollutant precursors after being processed by indoor phenomena is also covered. The inventory estimations are constrained using building air handler samples and data provided by National Air Surveillance Program (NAPS). While more than 50% of the indoor VCP emissions are prone to gas-phase chemistry, the rate of the reactions is often negligible in comparison with the ventilation rate. Moreover, Partitioning to indoor surfaces is shown to act as a strong reservoir for some of the less volatile species which could keep the species retained within indoor surfaces for up to about 400 days before they migrate outdoors. Overall, our study highlights the importance of indoor physicochemical phenomena on VCP emissions into the atmosphere.