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Asbestos Human Health Risk Assessments, Libby Sister Sites

U.S. Environmental Protection Agency, Region 4, under contract to JM Waller, Inc.
LOCATION: MULTIPLE LOCATIONS - Southeastern U.S.

OVERVIEW

• Site soil, air, and dust impacted by asbestos.
• Conducted Human Health Risk Assessments following the EPA Framework for Investigating Asbestos-Contaminated Superfund Sites.
• Activity based air sampling, as well as, soil and dust sampling and meteorological data were used to evaluate risks to local residents.

DESCRIPTION

Avatar Environmental has a significant amount of work experience at asbestos contaminated sites. Our experience includes the initial site investigation, the design and implementation of sampling activities, and the development of human health risk assessments (HHRAs). Avatar Environmental is managing and performing multiple HHRAs for potential exposure to asbestos at 14 sites located in EPA Region 4 following the 2008 EPA Framework for Investigating Asbestos-Contaminated Superfund Sites in consultation with EPA Region 4 risk assessors. In addition to the work currently being performed for EPA in Region 4, Avatar performed an asbestos HHRA at the Big Text Site located within EPA Region 6 in San Antonio, TX. This HHRA, which was conducted with EPA risk assessors from Region 6 and other EPA Regions, was one of the first HHRAs developed using the Framework Document. Additional asbestos risk assessment work is also being done in Region 3 at the Borit Site in Ambler, PA. The goal of the HHRAs is to determine whether a potential health risk exists to local residents and current or future workers to assist in the decision making on site cleanup options.

These sites have historically been associated with industrial activity, including the operation of vermiculite exfoliation plants. Many of these plants have processed raw vermiculite ore, contaminated with amphibole asbestos, mined from Libby, Montana.

These asbestos HHRAs are being performed due to EPA concerns that the previously used 1% in soil threshold of asbestos sites might not be health protective, especially at amphibole asbestos sites.

Sampling has indicated that asbestos contamination exists in the soil, air, and dust (inside buildings) at some of these sites.

Risks are being estimated using activity based air sampling (ABS) from on-site activities such as raking, sweeping, bicycling, etc., and are being reported as Phase Contrast Microscopy equivalents or PCMe. Other results are also evaluated, including stationary air samples, soil and dust (inside on-site buildings) sample results. Meteorological data was collected and considered in these assessments.

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