An analysis program for occupational cohort mortality and update cancer risk in copper miners

Author has developed a computer analysis system to deal with data from occupational follow-up studies, including: (1) input and administration of data; (2) calculation of person-years at risk and follow-up rate; (3) standardised mortality ratios for all cause-of-death categories; (4) the differences and trends of the cancer risks among subcategories defined by variables such as year and age at death, year and age at start of exposure, duration of exposure and time since first exposure, and job titles; and (5) life expectancy analysis. It is explained and applied in an updated cohort of copper miners. The computed results showed that the SMR for all cancer was elevated to 129 (95% CI 117-142). The SMR increased with calendar periods and a higher risk of cancer deaths was found in the miners employed in the 1950s. The miners who were exposed at a younger age had more chance of developing cancer. The risk of cancer deaths increased with the time since first exposure and more strongly with the duration of exposure. The SMR of cancer in underground miners reached up to 137 significantly. All analysis suggests that the occupational exposure (possibly silica dust) could be considered as a risk factor of cancer among the copper miners. The analysis of life expectancy indicated that deaths from circulatory system disease shorten more life expectancy for the miners.