Human lung cancer and hexavalent chromium exposure.
OBJECTIVE: Workers chronically exposed to hexavalent chromium have higher incidence of lung cancer. Our study investigates incidence of lung cancer types, age at onset of the disease and survival time among chromium exposed workers (smelters, tapers, crane operators) in comparison to non-exposed persons.
METHODS: 64 chromium exposed workers and 104 male controls with diagnosed lung cancer were analysed. The average exposure time among workers was 16.71 +/- 10.02 (S.D.) years (range 1- 41 years).
RESULTS: Chromium exposure significantly decreases the age at the onset of the disease by 3.51 years (62.20 +/- 9.08 years in exposed group and 65.71 +/- 10.50 years in control; P=0.018). Small cell lung carcinoma (SCLC) forms 25.0 % of all cases in chromium exposed workers and 16.34% in non exposed individuals. No correlation was found between the age at the diseases onset and time of exposure. The mean survival time in exposed group was 9.03 +/- 12.73 month, in control 12.14 +/- 21.94 month, but this difference was not significant (P=0.473).
CONCLUSION: Occupational exposure to chromium was identified as an important risk factor of lung cancer, decreasing the age at the diseases onset. Higher percentage of SCLC was found in chromium exposed individuals....