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Environmental Asbestos Assessment Manual Superfund Method for the Determination of Asbestos in Ambient Air Part 2: Technical Background Document
Citation:
Chatfield, E. J. AND D. W. Berman. Environmental Asbestos Assessment Manual Superfund Method for the Determination of Asbestos in Ambient Air Part 2: Technical Background Document. U.S. Environmental Protection Agency, Washington, DC, EPA/540/2-90/005b (NTIS 90-274291), 1990.
Impact/Purpose:
to inform the public
Description:
A sampling and analysis method for the determination of asbestos in air is presented in Part 1 of this report, under separate cover. This method is designed specifically to provide results suitable for supporting risk assessments at Superfund sites, although it is applicable to a wide range of ambient air situations. Considerations addressed during the development of the method are presented in this companion technical background document. Also, in the interest of facilitating the use and interpretation of analytical results derived from the method presented in Part 1, recommended procedures for manipulating such data as part of a site evaluation are provided in Section 7 of this document. Asbestos presents a complex challenge to investigators evaluating risks at Superfund sites. Unlike the majority of other chemicals frequently monitored at hazardous wastes sites, asbestos exposures can not be adequately characterized by a single concentration parameter. This is because the different size ranges of airborne asbestos particles, even when they are of the same mineral variety, exhibit different dose/response relationships. Thus a more accurate characterization of asbestos exposure is that arising from a family of substances•independently contributing to toxicity rather than that of exposure to a single chemical. Therefore, proper characterization of asbestos exposure requires that the relative contributions from each of the many components of exposure be defined. . .-. Existing equipment and methods used to measure asbestos are limited in their ability to fully characterize asbestos exposures. In addition, the toxicity of asbestos is currently a subject of .scientific debate. Consequently, monitoring asbestos in a manner that satisfies the needs of a risk assessment requires innovations that tax the limits of available technology. Several variations were considered during development and the method presented in Part 1 of this report represents a workable compromise among several technical constraints. The purpose for documenting the data and assumptions used to develop the method proposed in Part 1 is to facilitate critical evaluation while highlighting the needs for additional research and for better documentation of existing analytical results. Considerations addressed in this report that have been documented in the literature are cited accordingly. Considerations that remain largely a subject of conjecture are also noted. Due to the current level of interest and activity provoked by asbestos, further improvements in asbestos sampling, analysis, and evaluation are anticipated.