Dynamics of Residential Indoor Gas- and Particle-Phase Water-Soluble Organic Carbon: Measurements During the CASA Experiment

Published

October 4, 2024

Author(s)

Marc Webb, Glenn Morrison, Karsten Baumann, Jienan Li, Jenna Ditto, Han Huynh, Jie Yu, Kathryn Mayer, Marina Vance, Delphine Farmer, Jonathan Abbatt, Dustin Poppendieck, Barbara Turpin

Abstract

Previous time-integrated (2 h to 4 h) measurements show that total gas-phase water-soluble organic carbon (WSOCg) is 10 to 20 times higher inside homes compared to outside. However, concentration dynamics of WSOCg and total particle phase WSOC (WSOCp)—are not well understood. During the Chemical Assessment of Surfaces and Air (CASA) experiment, we measured concentration dynamics of WSOCg and WSOCp inside a residential test facility in the house background and during scripted activities. A total organic carbon (TOC) analyzer pulled alternately from a particle-into-liquid sampler (PILS) or a mist chamber (MC). WSOCg concentrations (215 ± 29 μg-C m−3) were generally 36× higher than WSOCp (6 ± 3 μg-C m−3) and 20× higher than outdoor levels. A building-specific emission factor (Ef) of 31 mg-C h−1 maintained the relatively high house WSOCg background, which was dominated by ethanol (46 μg-C m−3 to 82 μg-C m−3). When we opened the windows, WSOCg decayed slower (2.8 h−1) than the air change rate (21.2 h−1) and Ef increased (243 mg-C h−1). The response (increased Ef) suggests WSOCg concentrations are regulated by large near surface reservoirs rather than diffusion through surface materials. Cooking and ozone addition had a small impact on WSOC, whereas surface cleaning, volatile organic compound (VOC) additions, or wood smoke injections had significant impacts on WSOC concentrations. WSOCg concentration decay rates from these activities (0.4 h−1 to 4.0 h−1) were greater than the normal operating 0.24 h−1 air change rate, which is consistent with an important role for surface removal.

Citation

Environmental Science: Processes and Impacts

Volume

27

Pub Type

Journals

Download Paper

https://doi.org/10.1039/D4EM00340C

Local Download

Keywords

Acid, Base, Indoor Air

Citation

Webb, M. , Morrison, G. , Baumann, K. , Li, J. , Ditto, J. , Huynh, H. , Yu, J. , Mayer, K. , Vance, M. , Farmer, D. , Abbatt, J. , Poppendieck, D. and Turpin, B. (2024), Dynamics of Residential Indoor Gas- and Particle-Phase Water-Soluble Organic Carbon: Measurements During the CASA Experiment, Environmental Science: Processes and Impacts, [online], https://doi.org/10.1039/D4EM00340C, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958157 (Accessed October 27, 2025)