Tree Sampling as a Method to Assess Vapor Intrusion Potential at a Site Characterized by VOC-Contaminated Groundwater and Soil
Vapor intrusion (VI) by volatile organic compounds (VOCs) in the built environment presents a threat to human health. Traditional VI assessments are often time-, cost-, and labor-intensive; whereas traditional subsurface methods sample a relatively small volume in the subsurface and are difficult to collect within and near structures. Trees could provide a similar subsurface sample where roots act as the "sampler' and are already onsite. Regression models were developed to assess the relation between PCE concentrations in over 500 tree-core samples with PCE concentrations in over 50 groundwater and 1000 soil samples collected from a tetrachloroethylene- (PCE-) contaminated Superfund site and analyzed using gas chromatography. Results indicate that in planta concentrations are significantly and positively related to PCE concentrations in groundwater samples collected at depths less than 20 m (adjusted R2 values greater than 0.80) and in soil samples (adjusted R2 values greater than 0.90). Results indicate that a 30 cm diameter tree characterizes soil concentrations at depths less than 6 m over an area of 700-1600 m2, the volume of a typical basement. These findings indicate that tree sampling may be an appropriate method to detect contamination at shallow depths at sites with VI.
J. L. Wilson et al., "Tree Sampling as a Method to Assess Vapor Intrusion Potential at a Site Characterized by VOC-Contaminated Groundwater and Soil," Environmental Science and Technology, vol. 51, no. 18, pp. 10369-10378, American Chemical Society (ACS), Aug 2017.
The definitive version is available at https://doi.org/10.1021/acs.est.7b02667
Mathematics and Statistics
Civil, Architectural and Environmental Engineering
Keywords and Phrases
Forestry; Gas chromatography; Groundwater; Groundwater pollution; Health risks; Mercury (metal); Regression analysis; Soil surveys; Soils; Volatile organic compounds; Built environment; Contaminated groundwater; Labor intensive; Regression model; Soil concentrations; Subsurface methods; Superfund sites; Tetrachloroethylenes; Soil pollution; Ground water; Volatile organic compounds; Concentration (composition); Sampling; Site characterization; Soil pollution; Superfund; Trees; Vaporization; Article; Concentration (parameters); Vapor; Water pollution; Chemistry; Environmental monitoring; Humans; Soil
International Standard Serial Number (ISSN)
Article - Journal
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