| Title: | Creation of a Sub-slab Soil Gas Cloud by an Indoor Air Source and Its Dissipation Following Source Removal |
| Author(s): | Holton C; Guo Y; Luo H; Dahlen P; Gorder K; Dettenmaier E; Johnson PC; |
| Address: | "School of Sustainable Engineering and the Built Environment, Ira A. Fulton Schools of Engineering , Arizona State University , Tempe , Arizona 85287 , United States. Chevron Energy Technology Company , 1200 Smith Street , Houston , Texas 77002 , United States. Hill Air Force Base , 7290 Weiner Street , Building 383, Hill Air Force Base , Utah 84056 , United States. Department of Civil and Environmental Engineering , Colorado School of Mines , Golden , Colorado 80401 , United States" |
| ISSN/ISBN: | 1520-5851 (Electronic) 0013-936X (Linking) |
| Abstract: | "It is accepted that indoor sources of volatile organic compounds can confound vapor intrusion (VI) pathway assessment. When they are discovered during pre-sampling inspection, indoor sources are removed and air sampling is delayed, with the assumption that a few hours to a few days are sufficient for indoor source impacts to dissipate. This assumption was tested through the controlled release of SF(6) and its monitoring in indoor air and soil gas at a study house over 2 years. Results show that indoor sources generate subsurface soil gas clouds as a result of fluctuating direction in the exchange between soil gas and indoor air and that it may take days to weeks under natural conditions for a soil gas cloud beneath a building to dissipate following indoor source removal. The data also reveal temporal variability in indoor air and soil gas concentrations, long-term seasonal patterns, and dissipation of soil gas clouds over days to weeks following source removal. Preliminary modeling results for similar conditions are consistent field observations. If representative of other sites, these results suggest that a typical 1-3 day waiting period following indoor source removal may not be sufficient to avoid confounding data and erroneous conclusions regarding VI occurrence" |
| Keywords: | "*Air Pollutants *Air Pollution, Indoor Gases Soil *Volatile Organic Compounds;" |
| Notes: | "MedlineHolton, Chase Guo, Yuanming Luo, Hong Dahlen, Paul Gorder, Kyle Dettenmaier, Erik Johnson, Paul C eng Research Support, U.S. Gov't, Non-P.H.S. 2018/08/19 Environ Sci Technol. 2018 Sep 18; 52(18):10637-10646. doi: 10.1021/acs.est.8b01188. Epub 2018 Aug 29" |
