Abnormal alveolar macrophage morphology Dust particle inclusion in alveolar macrophages Accumulation of inhaled, nondigestable particles in macrophages. This can be recognized in May-Grunwald-Giemsa routine stains. Rarey and for special indications, BAL can be further analyzed to identify and quantify dust exposure. X-ray microprobe analysis identified particles which related to the known exposures, superimposed on a background of other particles related to smoking (kaolinite and mica) or to the general environment (silicon, titanium, and iron). Inhaled dust can follow in fibrous tissue and scarring which follow in impaired lung function.