Methods: 40 patients referred with occupational history were included. For 24 of them SEM analysis was done in induced sputum (IS) together with questionnaires and in 11 among them the SEM analysis was done both from lung tissue (TS) and IS. In addition 11 lung biopsies from patients with occupational history were scanned by SEM and compared to 10 biopsies from patients with no occupational history.