title: Relationship between vapor intrusion and human exposure to trichloroethylene.
abstract: Trichloroethylene (TCE) in groundwater has the potential to volatilize through soil into indoor air where it can be inhaled. The purpose of this study was to determine whether individuals living above TCE-contaminated groundwater are exposed to TCE through vapor intrusion. We examined associations between TCE concentrations in various environmental media and TCE concentrations in residents. For this assessment, indoor air, outdoor air, soil gas, and tap water samples were collected in and around 36 randomly selected homes; blood samples were collected from 63 residents of these homes. Additionally, a completed exposure survey was collected from each participant. Environmental and blood samples were analyzed for TCE. Mixed model multiple linear regression analyses were performed to determine associations between TCE in residents' blood and TCE in indoor air, outdoor air, and soil gas. Blood TCE concentrations were above the limit of quantitation (LOQ; ≥ 0.012 µg L(-1)) in 17.5% of the blood samples. Of the 36 homes, 54.3%, 47.2%, and >84% had detectable concentrations of TCE in indoor air, outdoor air, and soil gas, respectively. Both indoor air and soil gas concentrations were statistically significantly positively associated with participants' blood concentrations (P = 0.0002 and P = 0.04, respectively). Geometric mean blood concentrations of residents from homes with indoor air concentrations of >1.6 µg m(-3) were approximately 50 times higher than geometric mean blood TCE concentrations in participants from homes with no detectable TCE in indoor air (P < .0001; 95% CI 10.4-236.4). This study confirms the occurrence of vapor intrusion and demonstrates the magnitude of exposure from vapor intrusion of TCE in a residential setting.
authors.affiliation: a Environmental Epidemiology and Disease Registries Section , Texas Department of State Health Services , Austin , Texas , USA.
authors.forename: Natalie P
authors.initials: NP
authors.lastname: Archer
authors.affiliation: a Environmental Epidemiology and Disease Registries Section , Texas Department of State Health Services , Austin , Texas , USA.
authors.forename: Carrie M
authors.initials: CM
authors.lastname: Bradford
authors.affiliation: a Environmental Epidemiology and Disease Registries Section , Texas Department of State Health Services , Austin , Texas , USA.
authors.forename: John F
authors.initials: JF
authors.lastname: Villanacci
authors.affiliation: b Center for Energy and Environmental Resources , The University of Texas at Austin , Austin , Texas , USA.
authors.forename: Neil E
authors.initials: NE
authors.lastname: Crain
authors.affiliation: c Department of Civil , Architectural and Environmental Engineering , The University of Texas at Austin , Austin , Texas , USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Corsi
authors.affiliation: d National Center for Environmental Health , Division of Laboratory Sciences , The Centers for Disease Control and Prevention , Atlanta , Georgia , USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Chambers
authors.affiliation: e Division of Community Health Investigations , Agency for Toxic Substances and Disease Registry , Atlanta , Georgia , USA.
authors.forename: Tonia
authors.initials: T
authors.lastname: Burk
authors.affiliation: d National Center for Environmental Health , Division of Laboratory Sciences , The Centers for Disease Control and Prevention , Atlanta , Georgia , USA.
authors.forename: Benjamin C
authors.initials: BC
authors.lastname: Blount
mesh_terms: D000328:Adult; D016902:Air Pollution, Indoor / Q000032:analysis; D004781:Environmental Exposure / Q000032:analysis*; D005191:Family Characteristics; D005260:Female; D005740:Gases / Q000737:chemistry; D060587:Groundwater / Q000737:chemistry; D006801:Humans; D057230:Limit of Detection; D008297:Male; D012987:Soil / Q000737:chemistry; D014241:Trichloroethylene / Q000032:analysis* / Q000097:blood; D014835:Volatilization; D014867:Water / Q000737:chemistry
chemical_list: D005740:Gases; D012987:Soil; D014867:Water; D014241:Trichloroethylene
keywords: Groundwater plume; indoor air exposure; soil gas exposure; trichloroethylene; vapor intrusion; volatile organic compounds