Dimensional microscopic analysis of asbestos bundles released into atmosphere from an asbestos-cement roof

This study was conducted in an industrial location including a building covered by a 2500 m2 ACM (asbestos-cement roof). The atmospheric settling dust sampling was performed for 26 days with a method first proposed by Chiappino et al. in 1999 [1]. This method captures dust by microscopic slides covered with an appropriate adhesive film. The sampling instruments were arranged, in groups of three, in five different positions from the asbestos-cement source (Table 1), in order to define possible morphological differences between amphiboles and chrysotile, as well as qualitatively evaluate the mass influence on the sedimentation process. The analysis was carried out in phase contrast optical microscopy, using the dispersion staining method, to facilitate qualitative discrimination of asbestos minerals.