Incidence of cancer among ferrochromium and ferrosilicon workers.

ABSTRACT The results are presented of a study of the overall mortality and the incidence of cancer in male workers producing ferrosilicon and ferrochromium. Although the study included all present and retired workers employed in the factory for more than one year from 1928 until 1977 inclusive, the incidence of cancer in those 976 workers who started work before 1 January 1960 was studied in particular. Both the overall mortality and the incidence of cancer for all sites were lower than expected when compared with the national expected figures. Nine cases of lung cancer were found in the total population—seven in the ferrochromium subpopulation against expected rates of 3·1 and 1·8 when using national and local expected rates respectively as reference, and less than one expected case when using an internal reference population. A 1·5 O/E ratio was found for prostatic cancer in the whole study population. The results indicate that the increased incidence of lung cancer in the ferrochromium group has a causal relationship to occupational exposure. Perforation of the nasal septum was found in two present ferrochromium workers, and hexavalent chromium was found in the working atmosphere at the ferrochromium arc-furnaces during an industrial hygiene survey carried out in 1975. It is therefore concluded that the raised incidence of lung cancer is partly due to exposure to chromates. The results do not support the suggestion that exposure to chromic compounds entails a cancer hazard similar to that of exposure to hexavalent chromium compounds.