Analytical performance issues. Two different methods, three different variations, four different sources: what bulk asbestos PLM method is your laboratory using? Part 2

Our plain-English summary of Analytical performance issues. Two different methods, three different variations, four different sources: what bulk asbestos PLM method is your laboratory using? Part 2, by D.B. McGrath, D.R. Van Orden, R.M. Howard, et al (Journal of Occupational and Environmental Hygiene, 2010).

The study

• Authors: D.B. McGrath, D.R. Van Orden, R.M. Howard, P. Guerrero, S.C. Davis
• Journal: Journal of Occupational and Environmental Hygiene
• Published: 2010;7(9):D65-8
• Read it: PubMed · Publisher

In plain English

This was the second part of a two-part column, not a scientific study. The authors discussed which polarized light microscopy (PLM) method US laboratories use to measure asbestos in bulk materials under the EPA asbestos NESHAP and AHERA regulations. They stated that only one method is legally binding. In their account, EPA's 1993 method was never adopted through rulemaking, yet EPA and the laboratory accreditation program NVLAP have promoted it since 1994. According to the authors, the binding method averages asbestos content across all layers of a multi-layered material. The 1993 method instead treats a material as regulated if any single layer exceeds one percent asbestos. They described a federal prosecution of San Diego Gas & Electric over the removal of multi-layered coal tar pipe coating. They reported that the court ruled all of the government's test evidence inadmissible and that the case was dismissed in October 2009. The authors concluded that laboratories need to consider returning to the binding method. They noted that this method does not say how layer results should be averaged.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Regulatory and legal commentary (journal column), Part 2 of a two-part series; not an epidemiological or laboratory study
• Who was studied: No human or animal population. The column discusses US bulk asbestos PLM test methods, EPA guidance, laboratories accredited through NVLAP, and the federal prosecution of San Diego Gas & Electric Company (SDG&E), 2006 to 2009
• Exposure: Measurement of asbestos content in bulk materials, especially multi-layered materials such as coal tar pipe coating, relative to the one percent regulatory threshold; no fiber types named
• Main results:
  • The authors stated that EPA never adopted its 1993 test method as a formal rule.
  • According to the authors, the binding 1990 method averages asbestos content across all layers of a multi-layered material. The 1993 method asks whether any single layer exceeds one percent asbestos.
  • The authors reported that NVLAP has directed accredited laboratories since August 1994 to use EPA's latest method revision, which in their account means the non-binding 1993 method.
  • In the SDG&E case, the authors reported that in November 2006 the court dismissed all asbestos NESHAP counts of the indictment.
  • The authors reported that, at the 2007 trial, the defense showed asbestos content below one percent when the binding test method was followed. A new trial was later granted.
  • The authors reported that on August 31, 2009 the trial court ruled all of the government's evidence (27 samples offered) inadmissible, and that the case was dismissed on October 6, 2009.
  • The authors stated that the court found volumetric averaging consistent with the binding method. They also stated that the method itself does not specify how layers should be combined.
• The authors' conclusion: The authors concluded that only one test method is mandated by law under NESHAP and AHERA, and that laboratories need to consider returning to it, including reporting averaged results for multi-layered samples.

Related studies

• Two different methods, three different variations, four different sources: what bulk asbestos PLM method is your laboratory using? Part 1 — D.B. McGrath, D.R. Van Orden, et al. (2010)
• Analysis of the analytical performance of laboratories participating in two major U.S. bulk asbestos proficiency testing programs — B.W. Harvey, W.G. Winstead (2008)
• An air quality data analysis system for interrelating effects, standards, and needed source reductions: Part 13--Applying the EPA Proposed Guidelines for Carcinogen Risk Assessment to a set of asbestos lung cancer mortality data — R.I. Larsen (2003)
• Risk assessment of asbestos containing materials in a deteriorated dwelling area using four different methods — Y.L. Zhang, H.S. Byeon, et al. (2021)
• Morphologic and immunocytochemical performances of effusion cell blocks prepared using 3 different methods — X. Jing, Q.K. Li, et al. (2013)
• Development of a method for the determination of low contents of asbestos fibres in bulk material — T. Schneider, L.S. Davies, et al. (1998)

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