Electron microscope characteristics of inhaled chrysotile asbestos fibre

Abstract

Pooley, F. D. (1972).Brit. J. industr. Med.,29, 146-153. Electron microscope characteristics of inhaled chrysotile asbestos fibre. Specimens from 300 lungs have been examined under the electron microscope to determine the morphology and diffraction characteristics of any chrysotile asbestos they contained. In 120 cases, material was prepared by alkali digestion and the residual dust was examined. In all cases standard 6-micron histological slides were partially ashed before the residue was transferred to the electron microscope grids. Of the 300 specimens examined, 20 came from men with prolonged industrial exposure to chrysotile, 87 from cases of mesothelioma, and the remainder from control groups drawn from rural and industrial populations. Chrysotile fibres were readily identified by the characteristic polycrystalline diffraction pattern. The hollow appearance of the single fibres and their shape and arrangement also help in the identification. Specimens from men without industrial exposure contained either single short fibres or aggregates scattered throughout the lungs. In specimens from industrially exposed men, fibres were very numerous and found as strands of single fibres mainly grouped together in discrete locations. Ferruginous bodies were found rarely and only on straight fibre bundles of over several micrometers in length.

Electron Microscopical Investigation of Asbestos Fibers

“…Chrysotile fibers tend to consist of bundles of fibrils which are often curvilinear with splayed ends. These features have been reported in the literature Environmental Health Perspectives (17) Figure 5A.…”

“…These features are relatively well defined and have been cited in the literature previously (8,17,20). As chrysotile asbestos is progressively deformed by electron bombardment, its characteristic electron diffraction pattern changes.…”

Semiquantitative Chemical Analysis of Asbestos Fibers and Clay Minerals with an Analytical Electron Microscope

“…They showed that the intensity ratio of a characteristic peak to the intensity of the continuum provides a measure for the concentration of an element, which is independent of the film thickness. Literature exists on application of the analytical electron microscope to environmental and tissue samples whose volumes of less than 1/xm 3 (Langer et al, 1971(Langer et al, , 1974Pooley, 1972Pooley, , 1976Henderson et al, 1973;Rubin and Maggiore, 1974); but few of these investigations have determined chemical components quantitatively for silicate minerals, especially submicron particles.…”

Determination of inorganic fiber density in human lung tissue by scanning electron microscopy after low temperature ashing.

“…However, some authors relate fiber number to tissue volume (cm: l ) (3) or to fiber weight (16). EspeciaHy, specification of fiber number per unit volume must be quite tedious, and -the risk of introdudng errors is high.…”