AAAR 37th Annual Conference October 14 - October 18, 2019 Oregon Convention Center Portland, Oregon, USA
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Indoor Abundance of Semivolatile Organic Compounds under Dynamic Aerosol Conditions
DAVID LUNDERBERG, Kasper Kristensen, Yilin Tian, Caleb Arata, Yingjun Liu, Pawel Misztal, William Nazaroff, Allen Goldstein, University of California, Berkeley
Abstract Number: 409 Working Group: The Air We Breathe: Indoor Aerosol Sources and Chemistry
Abstract The chemical composition of indoor environments is not fully understood; nor are the processes and emission sources controlling that composition. Implementing high-time resolution measurements of airborne organics in residential environments can contribute to a better understanding of the dynamic processes affecting the air we breathe. Semivolatile thermal desorption aerosol gas chromatography (SV-TAG) quantifies the speciated abundance and gas-particle phase-partitioning of compounds with vapor pressures between ~C14 and ~C30 alkanes at hourly time-resolution. We present data acquired by SV-TAG during two separate field campaigns that investigated residential indoor air under controlled conditions (HOMEChem campaign: manufactured test house in Austin, Texas) and normal-occupancy conditions (H2 campaign: single-family residence in Orinda, California).
The indoor airborne composition of semivolatile organic compounds (SVOCs) is chemically complex, with significant contributions from outdoor air, indoor building materials, and occupant-driven perturbations. Because SVOCs exist in multiple phases throughout a residence, including in dust, in surface films, in airborne particulate matter, and in the gas-phase, changes in aerosol properties can induce shifts in partitioning, including in the relative abundance of species that are surface-sorbed rather than airborne. Outdoor infiltration of particulate matter and emissions from cooking events can introduce airborne particles into the indoor environment. The impact of these aerosol sources on SVOC partitioning phenomena was studied during the HOMEChem and H2 campaigns. Analysis of vacant periods, when particles are expected to be of primarily of outdoor origin, were compared against periods influenced by indoor cooking events. During the HOMEChem campaign, concentration enhancements of SVOCs from cooking events consisted of gas- and particle-phase species directly attributable to the cooking process and by lower-volatility species related to primary emissions from building materials.