Floor tile installation as a source of asbestos exposure.

Asphalt or vinyl-asbestos floor tile contains fifteen to twenty-five per cent asbestos, but the numeral fibers are firmly embedded in the binding material. Installation of these tiles would, therefore, seem to be an unlikely source of a hazardous dust exposure. Case reports of two installers of floor tile, one with biopsy-proved mesothelioma and another with extensive pleural calcifications are presented. Both workers had frequently sanded asphalt and vinyl tile floors prior to installation of new floor covering. An investigation of the work process revealed that under simulated conditions of work, asbestos dust concentrations as large as 1.3 fibers per ml were found in air samples passed through membrane filters worn by a person engaged in sanding vinyl asbestos. Characteristic asbestos fibers were seen in electron photomicrographs of these samples. These findings suggest that before the tile sanding procedure is performed adequate respiratory protection should be provided or alternate, available install...