Insights into vapour intrusion phenomena: Current outlook and preferential pathway scenario

Unnithan, Aravind and Bekele, Dawit Nega and Chadalavada, Sreenivasulu ORCID: and Naidu, Ravi (2021) Insights into vapour intrusion phenomena: Current outlook and preferential pathway scenario. Science of the Total Environment, 796:148885. pp. 1-16. ISSN 0048-9697


Vapour intrusion (VI) is the phenomenon by which volatile organic compounds (VOCs) migrate from the subsurface source through the soil and enter into the overlying buildings, affecting the indoor air quality and ultimately causing health hazards to the occupants. Health risk assessments associated with hydrocarbon contaminated sites and recommendations of site closure are often made by quantifying the VI risks using mathematical models known as ‘vapour intrusion models’ (VIM). In order to predict the health risk, various factors such as the lithological and geochemical conditions of the subsurface, environmental conditions, building operational conditions etc. are commonly evaluated using VIMs. Use of these models can overlook the role of preferential pathways like highly permeable subsurface layers and utility lines which act as the path of least resistance for vapour transport, which can increase the VI risks. The extensive networks of utility lines and sanitary sewer systems in urban areas can significantly exacerbate the uncertainty of VI investigations. The backfill materials like sand and gravel surrounding the utility lines can allow the vapours to easily pass through due to their high porosity as compared to natural formations. Hence, failure to understand the role of preferential pathways on the fate and transport of VOC in the vadose zone can result in more conservative predictions of indoor air vapour concentrations and wrong clean up approaches. This comprehensive review outlines the vapour transport mechanisms, factors influencing VI, VIMs and the role of preferential pathways in predicting indoor air vapour concentrations.

Statistics for USQ ePrint 46139
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Faculty/School / Institute/Centre: No Faculty
Faculty/School / Institute/Centre: No Faculty
Date Deposited: 15 Feb 2022 03:56
Last Modified: 16 Feb 2022 00:11
Uncontrolled Keywords: Preferential pathways; Transport mechanisms; Vapour intrusion; Vapour intrusion models
Fields of Research (2008): 05 Environmental Sciences > 0502 Environmental Science and Management > 050204 Environmental Impact Assessment
Fields of Research (2020): 41 ENVIRONMENTAL SCIENCES > 4104 Environmental management > 410402 Environmental assessment and monitoring
Identification Number or DOI:

Actions (login required)

View Item Archive Repository Staff Only