Asbestos Versus Nonasbestos Fibers

Abstract

To classify usefully fibrous dusts inhaled by urban populations, it is suggested that they be categorized initially as asbestos or nonasbestos fibers. This would supply information sufficient for statistical significance and reduce analytical requirements, saving time and money. The ultramicroscopic criteria of asbestos fibers are ends which have profiles characterized by step-like interruptions up or down from each other, as seen at a magnification of 20,000 or 25,000 X under the electron microscope, and a surface view (scanning electron microscope at the same magnification) characterized by parallel longitudinal lines that delineate the fibrils. The ultramicroscopic criteria of nonasbestos fibers viewed at 20,000 or 25,000 X magnification are ends which have uninterrupted linear profiles, and a surface view devoid of longitudinal parallel lines.