The occurrence of premalignant changes of bronchial epithelium was studied in 56 symptom-free volunteers from the risk group of Czech and Moravian uranium miners (mean age 50.69 years, mean WLM 21.06) by the additional employment of the System of Autofluorescence Endoscopy (SAFE-1000 Pentax) to conventional white-light bronchoscopy, comparing results with those of bronchial biopsy histopathology examination. Histopathology using hematoxylin and eosin staining confirmed intraepithelial neoplasias in 15 areas in 10 persons. White-light bronchoscopy sensitivity was 21.05%, and specificity 93.7% which an autofluo- rescence sensitivity was 78.95%, and specificity 81.89%. 1 Working Level Month (WLM) = the absorption of latent energy of 2.08 x 10 -5 J/m 3 in one month (i.e. 170 working hours).

        Key words: autofluorescence bronchoscopy, bronchial (pre-)neoplasia, bronchogenic cancer, uranium miner