Authors: B.K. Ku, G. Deye, L.A. Turkevich
Affilation: NIOSH, United States
Pages: 166 - 169
Keywords: glass fiber, fiber length, aerosol, mesh screens, alignment, electric field
Length classification of airborne fibers, including carbon nanotubes/nanofibers, is a fundamental technology important for toxicology studies of these materials. Fiber toxicity appears to depend on fiber concentration, dimensions (diameter and length) and durability in the lungs. Recently, the National Institute for Occupational Safety and Health (NIOSH) has published a Roadmap for research of asbestos fibers and other elongate mineral particles (EMPs) (NIOSH, 2011). An underlying theme is that, in order to better understand the toxicity of fibers, it is necessary to develop methods for classifying fibers by length so as to enable toxicology studies to directly test length as a salient parameter. Researchers have used a variety of approaches to separate fibers by length; Spurny et al. (1979) used liquid sedimentation, and Baron and colleagues (Baron et al., 1994; Deye et al., 1999) developed a dielectrophoresis-based fiber length classifier (FLC). Several studies were conducted using a screen as a low-pass filter for length classification (Spurny et al., 1979; Myojo, 1999). Considering the promise of using screens, but the heretofore limited quantitative results, we have explored the use of screens (housed in asbestos sampling cassettes) as a length separation method of airborne fibers in the micrometer size range. Fiber alignment in an electric field was also investigated as a way to improve screen collection.
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