[Mortality of chromium plating workers in Japan--a 16-year follow-up study]

Health hazards due to exposure to chromium in the chromium plating industry has been documented in only a few epidemiological studies. A prospective cohort study was conducted to examine the health hazards of chromium plating with a follow-up period of over sixteen years. Subjects were 1193 male metal platers in the small-scale chromium plating plants in Tokyo. They were divided into a chromium plater subgroup (n = 623) and non-chromium plater subgroup (n = 567) and were followed up from October 1976 through December 1992. The 95% confidence interval (95%CI) of the standardized mortality ratio (SMR) was used to evaluate statistical significance. In the chromium plating subgroup, the risk of chronic hepatitis or liver cirrhosis was significantly elevated (SMR 2.34; 95%CI 1.17-4.19) and a trend toward statistical significance was seen for the risk of lung cancer (SMR 1.18; 95%CI 0.99-3.04). No significantly elevated risk was seen in the non-chromium plating subgroup. We concluded that, as the number of disease-specific deaths was small, further follow-up is necessary.