Abstract View
Modeling Indoor Aerosol Dynamics during HOMEChem
SAMEER PATEL, Sumit Sankhyan, Donghyun Rim, Atila Novoselac, Delphine K. Farmer, Marina Vance, University of Colorado Boulder
Abstract Number: 430
Working Group: Indoor Aerosols
Abstract
In the US, people spend about 90% of their time indoors, and indoor PM2.5 exposure has been estimated to account for more than a quarter of fine particulate matter (PM) mortality burden. We conducted a field study titled HOMEChem (House Observations of Microbial and Environmental Chemistry) to comprehensively characterize the indoor chemistry of a three-bedroom, two-bathroom 110 m2 manufactured test house while everyday activities such as cooking, cleaning, human occupancy, and opening doors and windows were performed.1 Our previous work provided an overview of indoor concentrations of PM (~1 nm – 20 µm) observed during HOMEChem.2
Modeling of indoor PM emissions provides insights into PM formation rate, transport, and fate which might facilitate the development of mitigation strategies to reduce personal exposure. The present work focuses on an aerosol dynamics model including coagulation, wall depositions, and other sources and sinks of particles (4-500 nm) to (1) calculate deposition characteristic of the test house, (2) calculate activity-wise emission rates or source strength, (3) attribute PM loss to different sinks (deposition and exfiltration). We also performed a sensitivity analysis to assess the effects of house parameters on indoor concentrations, and therefore, personal exposure. Model results show coagulation and deposition as the major factors contributing to the decay of PM number concentrations. Exfiltration accounted for less than 30% of the particle losses. Sensitivity analysis results indicate that while increasing the air exchange rate (AER) reduces indoor PM mass concentration, the PM number concentration increases at higher AERs.
[1] Farmer et al. (2019), Environmental Science: Processes & Impacts, 21(8), 1280-1300.
[2] Patel et al. (2020), Environmental Science & Technology, 54, 7107-7116.