What happens if we find high levels of contaminants?
This project does not end with the data collection, we will work with project participants and the community in understanding and interpreting the results, which may call for additional testing, guidance finding remediation resources, or possibly sharing results with local regulators.
While many tests may come back positive for the presence of a contaminant, its concentration determines whether or not action is recommended. For example, if a test sample indicates a level of radon that could greatly increase the risk to a person’s health (e.g., 4 picocuries per liter or 4 pCi/L or higher), the EPA recommends a repeat test. When a repeat test indicates radon levels at or above 4 pCi/L, the EPA recommends that the homeowner install a radon mitigation system to reduce radon levels in the home to less than 2 pCi/L [1].
For PERC, studies have generally found background levels of PERC in homes to be between .03 and 9.5 micrograms per cubic meter [2]. By contrast the 'residential action level', as defined by the Colorado Department of Public Health and the Environment (CDPHE) is 41.7 micrograms per cubic meter [3]. This 'residential action level' is the point at which we would recommend additional testing and investigations into the precise source. For example, in addition to the possibility of PERC contamination in soil and groundwater, various household products such as certain glues, metal degreasers, automotive products, cleaning products, aerosols, and paint removers contain PCE. Additionally, clothes that have been dry-cleaned may release PERC vapors.
Actions can be taken to reduce both radon and PERC to safer levels in homes and businesses. For example, the installation of radon or vapor intrusion mitigation systems will vent any contaminants originating from vapor intrusion into the outdoor air [4]. These systems often cost between $800 and $1,200 to install but may be higher depending on the house’s size, construction, and other considerations.
The CDPHE has compiled a list of agencies and programs that can assist homeowners with limited and low incomes in meeting radon mitigation costs through low interest loans and grants [5]. The project team is currently investigating which of these resources may work best for study participants.
Sources:
[1] http://www.epa.gov/radon/pubs/citguide.html
[2] Response, Emergency, and U S Environmental Protection Agency. 2011. “Background Indoor Air Concentrations of Volatile Organic Compounds in North American Residences ( 1990 – 2005 ): A Compilation of Statistics for Assessing Vapor Intrusion.” Environmental Protection, no. June.
[3] Washington, D C. 2009. “Hazardous Materials and Waste Management Division Air Screening Concentrations Table” I (January): 7–10.
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