Impact of Multiple HVAC Systems on Indoor Air VOC and Radon Concentrations from Vapor Intrusion During Seasonal Usage

Subsurface contamination can migrate upward into overlying buildings, exposing the buildings’ inhabitants to contaminants that can cause detrimental health effects. This phenomenon is known as vapor intrusion (VI). When evaluating a building for VI, one must understand that seasonal and short-term v...

Full description

Saved in:
Bibliographic Details
Main Authors: John H. Zimmerman, Alan Williams, Brian Schumacher, Christopher Lutes, Rohit Warrier, Brian Cosky, Ben Thompson, Chase W. Holton, Kate Bronstein
Format: Article
Language:English
Published: MDPI AG 2025-03-01
Series:Atmosphere
Subjects:
Online Access:https://www.mdpi.com/2073-4433/16/4/378
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849712118833610752
author John H. Zimmerman
Alan Williams
Brian Schumacher
Christopher Lutes
Rohit Warrier
Brian Cosky
Ben Thompson
Chase W. Holton
Kate Bronstein
author_facet John H. Zimmerman
Alan Williams
Brian Schumacher
Christopher Lutes
Rohit Warrier
Brian Cosky
Ben Thompson
Chase W. Holton
Kate Bronstein
author_sort John H. Zimmerman
collection DOAJ
description Subsurface contamination can migrate upward into overlying buildings, exposing the buildings’ inhabitants to contaminants that can cause detrimental health effects. This phenomenon is known as vapor intrusion (VI). When evaluating a building for VI, one must understand that seasonal and short-term variability are significant factors in determining the reasonable maximum exposure (RME) to the occupants. RME is a semi-quantitative term that refers to the lower portion of the high end of the exposure distribution—conceptually, above the 90th percentile exposure but less than the 98th percentile exposure. Samples were collected between December 2020 and April 2022 at six non-residential commercial buildings in Fairbanks, Alaska. The types of samples collected included indoor air (IA); outdoor air; subslab soil gas; soil gas; indoor radon; differential pressure; indoor and outdoor temperature; heating, ventilation, and air conditioning (HVAC) parameters; and other environmental factors. The buildings in close proximity to the volatile organic compound (VOC) source/release points presented less variability in indoor air concentrations of trichloroethylene (TCE) and tetrachloroethylene (PCE) compared to the buildings farther down gradient in the contaminated groundwater plume. The VOC data pattern for the source area buildings shows an outdoor air temperature-dominated behavior for indoor air concentrations in the summer season. HVAC system operations had less influence on long-term indoor air concentration trends than environmental factors, which is supported by similar indoor air concentration patterns independent of location within the plume. The use of soil temperature and indoor/outdoor temperatures as indicators and tracers (I&Ts) across the plume as predictors of the sampling period could produce a good estimation of the RME for the building occupants. These results, which show the use of soil temperature and indoor/outdoor temperatures as I&Ts, will help advance investigative methods for evaluation of VI in similar settings and thereby improve the protection of human health in indoor environments.
format Article
id doaj-art-08d9d3707bba45c6bb97bd4c358c6d4c
institution DOAJ
issn 2073-4433
language English
publishDate 2025-03-01
publisher MDPI AG
record_format Article
series Atmosphere
spelling doaj-art-08d9d3707bba45c6bb97bd4c358c6d4c2025-08-20T03:14:23ZengMDPI AGAtmosphere2073-44332025-03-0116437810.3390/atmos16040378Impact of Multiple HVAC Systems on Indoor Air VOC and Radon Concentrations from Vapor Intrusion During Seasonal UsageJohn H. Zimmerman0Alan Williams1Brian Schumacher2Christopher Lutes3Rohit Warrier4Brian Cosky5Ben Thompson6Chase W. Holton7Kate Bronstein8Office of Research and Development, U.S. Environmental Protection Agency, 109 TW Alexander Dr., P.O. Box 12055, Research Triangle Park, Durham, NC 27711, USAOffice of Research and Development, U.S. Environmental Protection Agency, 109 TW Alexander Dr., P.O. Box 12055, Research Triangle Park, Durham, NC 27711, USAOffice of Research and Development, U.S. Environmental Protection Agency, 960 College Station Road, Athens, GA 30605, USAJacobs, 1999 Bryan Street, Suite 1200, Dallas, TX 75201, USAGSI Environmental Inc., 13949 W. Colfax, No. 210, Lakewood, CO 80401, USAJacobs, 1999 Bryan Street, Suite 1200, Dallas, TX 75201, USAJacobs, 1999 Bryan Street, Suite 1200, Dallas, TX 75201, USARTI International, 3040 E. Cornwallis Rd., Research Triangle Park, Durham, NC 27709, USAGSI Environmental Inc., 13949 W. Colfax, No. 210, Lakewood, CO 80401, USASubsurface contamination can migrate upward into overlying buildings, exposing the buildings’ inhabitants to contaminants that can cause detrimental health effects. This phenomenon is known as vapor intrusion (VI). When evaluating a building for VI, one must understand that seasonal and short-term variability are significant factors in determining the reasonable maximum exposure (RME) to the occupants. RME is a semi-quantitative term that refers to the lower portion of the high end of the exposure distribution—conceptually, above the 90th percentile exposure but less than the 98th percentile exposure. Samples were collected between December 2020 and April 2022 at six non-residential commercial buildings in Fairbanks, Alaska. The types of samples collected included indoor air (IA); outdoor air; subslab soil gas; soil gas; indoor radon; differential pressure; indoor and outdoor temperature; heating, ventilation, and air conditioning (HVAC) parameters; and other environmental factors. The buildings in close proximity to the volatile organic compound (VOC) source/release points presented less variability in indoor air concentrations of trichloroethylene (TCE) and tetrachloroethylene (PCE) compared to the buildings farther down gradient in the contaminated groundwater plume. The VOC data pattern for the source area buildings shows an outdoor air temperature-dominated behavior for indoor air concentrations in the summer season. HVAC system operations had less influence on long-term indoor air concentration trends than environmental factors, which is supported by similar indoor air concentration patterns independent of location within the plume. The use of soil temperature and indoor/outdoor temperatures as indicators and tracers (I&Ts) across the plume as predictors of the sampling period could produce a good estimation of the RME for the building occupants. These results, which show the use of soil temperature and indoor/outdoor temperatures as I&Ts, will help advance investigative methods for evaluation of VI in similar settings and thereby improve the protection of human health in indoor environments.https://www.mdpi.com/2073-4433/16/4/378reasonable maximum exposureindicators and tracerssubslab soil gasvapor intrusionpassive samplingvolatile organic compounds
spellingShingle John H. Zimmerman
Alan Williams
Brian Schumacher
Christopher Lutes
Rohit Warrier
Brian Cosky
Ben Thompson
Chase W. Holton
Kate Bronstein
Impact of Multiple HVAC Systems on Indoor Air VOC and Radon Concentrations from Vapor Intrusion During Seasonal Usage
Atmosphere
reasonable maximum exposure
indicators and tracers
subslab soil gas
vapor intrusion
passive sampling
volatile organic compounds
title Impact of Multiple HVAC Systems on Indoor Air VOC and Radon Concentrations from Vapor Intrusion During Seasonal Usage
title_full Impact of Multiple HVAC Systems on Indoor Air VOC and Radon Concentrations from Vapor Intrusion During Seasonal Usage
title_fullStr Impact of Multiple HVAC Systems on Indoor Air VOC and Radon Concentrations from Vapor Intrusion During Seasonal Usage
title_full_unstemmed Impact of Multiple HVAC Systems on Indoor Air VOC and Radon Concentrations from Vapor Intrusion During Seasonal Usage
title_short Impact of Multiple HVAC Systems on Indoor Air VOC and Radon Concentrations from Vapor Intrusion During Seasonal Usage
title_sort impact of multiple hvac systems on indoor air voc and radon concentrations from vapor intrusion during seasonal usage
topic reasonable maximum exposure
indicators and tracers
subslab soil gas
vapor intrusion
passive sampling
volatile organic compounds
url https://www.mdpi.com/2073-4433/16/4/378
work_keys_str_mv AT johnhzimmerman impactofmultiplehvacsystemsonindoorairvocandradonconcentrationsfromvaporintrusionduringseasonalusage
AT alanwilliams impactofmultiplehvacsystemsonindoorairvocandradonconcentrationsfromvaporintrusionduringseasonalusage
AT brianschumacher impactofmultiplehvacsystemsonindoorairvocandradonconcentrationsfromvaporintrusionduringseasonalusage
AT christopherlutes impactofmultiplehvacsystemsonindoorairvocandradonconcentrationsfromvaporintrusionduringseasonalusage
AT rohitwarrier impactofmultiplehvacsystemsonindoorairvocandradonconcentrationsfromvaporintrusionduringseasonalusage
AT briancosky impactofmultiplehvacsystemsonindoorairvocandradonconcentrationsfromvaporintrusionduringseasonalusage
AT benthompson impactofmultiplehvacsystemsonindoorairvocandradonconcentrationsfromvaporintrusionduringseasonalusage
AT chasewholton impactofmultiplehvacsystemsonindoorairvocandradonconcentrationsfromvaporintrusionduringseasonalusage
AT katebronstein impactofmultiplehvacsystemsonindoorairvocandradonconcentrationsfromvaporintrusionduringseasonalusage