Studies of bronchogenic carcinoma among chromate workers

On high incidence of lung cancer in the workers of the chromate industry that was located near Sapporo city was already reported. Further studies of these patients, epidemiologically and pathologically, revealed following distinct points. 1) The latent period of occurence of bronchogenic carcinoma, i. e., from beginning of chromate exposure to detection of lung cancer, measured 21.9 years on average, which was ca. 7 years longer than the reported average. 2) Histological examination of the lung revealed squamous cell carcinoma in 4 cases and oat cell carcinoma in 3 cases. No cases of adeno carcinoma were detected. 3) Primary lesions of bronchogenic carcinoma were at the left upper bronchus in one case, at the left lower lobe bronchus in remaining 6 cases. No peripheral lesion was not seen.