Sampling and Analysis of Asbestos Fibers on Filter Media to Support Exposure Assessments: Scoping Effort

摘要

Methods for the analysis of asbestos and other fibers in air, water, dust, and bulk materials are reviewed and summarized. Techniques commonly used for analysis of these fibers include phase contrast microscopy, polarized light microscopy, x-ray diffraction spectrometry, scanning electron microscopy, and transmission electron microscopy. The principles of qualitative and quantitative analysis for each technique are reviewed. Fiber counting protocols for each method are also described. Fibers are typically identified by their chemical and physical properties and distinguished by measurement of their length, width (or diameter) and the ratio of their length to width. Collection media for aerosols of fibers are usually membrane filters of polycarbonate or mixed cellulose ester. Pore sizes usually range from 0.4 to 1.2 mm. Data comparing the relative efficiency of each filter type and pore size is sparse. Experiments to determine the relative efficiency for these filters are proposed.