The term "asbestosis" usually has been applied to a disease characterized by diffuse pulmonary interstitial fibrosis. It was often associated with a significant adverse impact on the individual. A review of case definitions employed in published research studies shows stability of the criteria for asbestosis case definitions over the past decade. Nevertheless, additional modalities have been suggested for the early diagnosis of asbestosis. It is probable that the significance of such abnormalities may be different from that of usual asbestosis, and there is therefore a need to carefully define the manner in which the terms are used. Additional anomalies way be seen in asbestos-exposed individuals including small airway physiologic abnormality, pathologic evidence of inflammation near the airways, positive gallium scan, abnormal lung compliance, exercise test abnormalities, CAT scan findings, and highresolution CAT scan findings.