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

Details

• Journal Article:
  Environmental Science: Processes & Impacts
• Personal Author:
  Webb, Marc ; Morrison, Glenn C. ; Baumann, Karsten ; Li, Jienan ; Ditto, Jenna C. ; Huynh, Han H. ; Yu, Jie ; Mayer, Kathryn ; Mael, Liora ; Vance, Marina E. ; Farmer, Delphine K. ; Abbatt, Jonathan ; Poppendieck, Dustin ; Turpin, Barbara J.
• Description:
  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.
• Subjects:
  Air Pollution, Indoor Carbon Occupational Health Particulate Matter Safety Volatile Organic Compounds
• Keywords:
  Indoor environments; Indoor air pollution; Carbon; Gases; Particle aerodynamics; Emission sources; Volatile organic compounds; VOCs; Ventilation; Sampling methods; Aerosol particles
• Source:
  Environ Sci Process Impacts 2025 Jun; 27(6):1535-1550
• ISSN:
  2050-7887
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  North Carolina ; Colorado ; Maryland ; Atlanta Region [OSHA] ; Denver Region [OSHA] ; Philadelphia Region [OSHA]
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Pages in Document:
  16 pdf pages
• Volume:
  27
• NIOSHTIC Number:
  nn:20071426
• Contact Point Address:
  Barbara J. Turpin, Department of Environmental Sciences and Engineering, Gillings School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
• Email:
  bjturpin@email.unc.edu
• CAS Registry Number:
  Carbon (CAS RN 7440-44-0)
• Federal Fiscal Year:
  2025
• Performing Organization:
  University of North Carolina, Chapel Hill
• Peer Reviewed:
  True
• Start Date:
  20050701
• End Date:
  20270630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:0860974b518bf196230d03db64fbab2e9b6001f48821c0fd4cf67ddd66b2999b56879da7afefbdd786715ef8952b180a4d416651d3463b1d1de81bf9c9c8f74c
• Download URL:
  https://stacks.cdc.gov/view/cdc/259025/cdc_259025_DS1.pdf
• File Type:
  [PDF - 1.39 MB ]