Lung cancer mortality update and prevalence of smoking among copper miners and smelters

Abstract

Objectives: The aim of this investigation was to study the cancer mortality of Chinese copper miners and smelters further, with particular reference to that from lung cancer, and smoking prevalence. Methods: From an earlier follow-up (1970-1985) of the mortality of the two cohorts, all new death cases registered since 1985 were recorded, and the mortality analysis was extended through 1992. A questionnaire survey of smoking habits was carried out in three samples, randomly chosen from the copper miners (N = 1125), smelters (N = 603), and local residents (N = 1517) of Tongling city. Results: Lung cancer was significantly increased among the copper miners [standardized mortality ratio (SMR) 152, 95% confidence interval (95% CI) 123-187], but not among the copper smelters (SMR 102, 95% CI 53-178). Smoking was more prevalent among copper miners than among local male residents (71.7 versus 64.3%, P < 0.001), whereas among the smelters it was significantly less prevalent (57.4 versus 64.3%, P < 0.005). Similar patterns were found for the average number of cigarettes smoked daily among the miners (21.6 ± 7.2), smelters (15 ± 7.1), and local male residents (19.2 ± 7.3). Conclusions: In addition to occupational exposures, cigarette smoking may partly play a role in influencing mortality from lung cancer among Chinese copper miners and smelters.