Air exchange rates and alternative vapor entry pathways to inform vapor intrusion exposure risk assessments

Rivka Reichman, Mohammadyousef Roghani, Evan J. Willett, Elham Shirazi, Kelly G. Pennell

Research output: Contribution to journalReview articlepeer-review

8 Scopus citations


Vapor intrusion (VI) is a term used to describe indoor air (IA) contamination that occurs due to the migration of chemical vapors in the soil and groundwater. The overall vapor transport process depends on several factors such as contaminant source characteristics, subsurface conditions, building characteristics, and general site conditions. However, the classic VI conceptual model does not adequately account for the physics of airflow around and inside a building and does not account for chemical emissions from alternative preferential pathways (e.g. sewers and other utility connections) into IA spaces. This mini-review provides information about recent research related to building air exchange rates (AERs) and alternative pathways to improve the accuracy of VI exposure risk assessment practices. First, results from a recently published AER study for residential homes across the United States (US) are presented and compared to AERs recommended by the US Environmental Protection Agency (USEPA). The comparison shows considerable differences in AERs when season, location, building age, and other factors are considered. These differences could directly impact VI assessments by influencing IA concentration measurements. Second, a conceptual model for sewer gas entry into buildings is presented and a summary of published field studies is reported. The results of the field studies suggest that alternative pathways for vapors to enter indoor spaces warrant consideration. Ultimately, the information presented in this mini-review can be incorporated into a multiple-lines-of-evidence approach for assessing site-specific VI exposure risks.

Original languageEnglish
Pages (from-to)27-33
Number of pages7
JournalReviews on Environmental Health
Issue number1-2
StatePublished - Mar 1 2017

Bibliographical note

Publisher Copyright:
© 2017 Walter de Gruyter GmbH, Berlin/Boston.


  • hazardous waste
  • indoor air
  • vapor intrusion
  • volatile organic compounds

ASJC Scopus subject areas

  • Health(social science)
  • Pollution
  • Public Health, Environmental and Occupational Health


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