An Ultrastructural Study of Particulate Matter and Ferruginous Bodies in the Sputum from Former Asbestos Workers

Abstract

Limited data exist concerning the ultrastructural assessment of the particulate content of sputum from occupationally exposed individuals. These assessments along with cytopathological screening provide valuable information about the current lung clearance patterns of these individuals.Sputum samples were collected from nine former asbestos workers who were selected because their cytopathological history included the presence of ferruginous bodies. A portion of each sample not needed for cytopathologic screening was utilized in the present study. Some of this material was fixed, embedded, and sectioned for electron microscopy, while a separate portion of the material was digested and collected on a Nuclepore filter. Energy dispersive analysis was used in assessing inorganic matter in both preparations as well as defining the core composition of the ferruginous bodies.The ultrastructural studies of the macrophage--ferruginous body interactions revealed abundant fibrillar elements (Fig. 1) in the subplasmalemmal zone of the macrophages. The extracellular boundary consisted of a halo of finegrained material separating the cell membrane from the dense ferruginous material.