title: Evaluation of vapor intrusion using controlled building pressure.
abstract: The use of measured volatile organic chemical (VOC) concentrations in indoor air to evaluate vapor intrusion is complicated by (i) indoor sources of the same VOCs and (ii) temporal variability in vapor intrusion. This study evaluated the efficacy of utilizing induced negative and positive building pressure conditions during a vapor intrusion investigation program to provide an improved understanding of the potential for vapor intrusion. Pressure control was achieved in five of six buildings where the investigation program was tested. For these five buildings, the induced pressure differences were sufficient to control the flow of soil gas through the building foundation. A comparison of VOC concentrations in indoor air measured during the negative and positive pressure test conditions was sufficient to determine whether vapor intrusion was the primary source of VOCs in indoor air at these buildings. The study results indicate that sampling under controlled building pressure can help minimize ambiguity caused by both indoor sources of VOCs and temporal variability in vapor intrusion.
authors.affiliation: GSI Environmental Inc., Houston, Texas, USA. temchugh@gsi-net.com
authors.forename: Thomas E
authors.initials: TE
authors.lastname: McHugh
authors.forename: Lila
authors.initials: L
authors.lastname: Beckley
authors.forename: Danielle
authors.initials: D
authors.lastname: Bailey
authors.forename: Kyle
authors.initials: K
authors.lastname: Gorder
authors.forename: Erik
authors.initials: E
authors.lastname: Dettenmaier
authors.forename: Ignacio
authors.initials: I
authors.lastname: Rivera-Duarte
authors.forename: Samuel
authors.initials: S
authors.lastname: Brock
authors.forename: Ian C
authors.initials: IC
authors.lastname: MacGregor
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D011312:Pressure; D055549:Volatile Organic Compounds / Q000032:analysis*
chemical_list: D055549:Volatile Organic Compounds