Refractile particles are observed by light microscopy (LM) in alveolar lavaged macrophages from patients exhibiting clinical symptoms of asbestosis, silicosis and coal-miner's emphysema. However the elemental composition and location of these particles in the ultrastructure of the macrophages cannot be determined by LM. Elemental x-ray images obtained in the CAMECA MBX microprobe from large fields of whole air-dried macrophages have enabled investigators to correlate particle composition with disease. High resolution images of individual macrophages in ultrathin sections of epon embeded preparations obtained in the Hitachi H700H analytical electron microscope utilizing bright field (BF), energy dispersive x-ray (EDS) and electron energy loss (EELS) signals have revealed both elemental composition and ultrastructural location of the particles.
