Cancer morbidity in iron and steel workers in Korea

BACKGROUND: In the iron and steel industry, workers are potentially exposed to a number of carcinogens and are involved in a number of processes of a hazardous nature. The cancer morbidity of iron and steel workers from modern plants in a developing country is described. METHODS: Cancer morbidity at two Korean iron and steel complexes was analyzed using Poisson regression methods. Work histories were merged with the national cancer registry for 44,974 workers who were followed from 1988-2001. RESULTS: Four hundred sixty-four cancers, in 1% of the population, were diagnosed over 14 years. Based on national cancer rates, the cohort exhibited a healthy worker effect for all cancer (SIR = 0.87, 95% CI = 0.79-0.95) reflecting relative good health, particularly for lung cancer (SIR = 0.58, 95% CI = 0. 04-0.82), stomach cancer (SIR = 0.78, 95% CI = 0.64-0.93), and liver cancer (SIR = 0.83, 95% CI = 0.68-1.01). Lung cancer morbidity was significantly elevated at the affiliated plants versus the parent plants (SRR = 2.35, 95% CI = 1.07-4.92), and all-cancer morbidity was significantly elevated for maintenance workers compared to office and production workers (SRR = 1.27, 95% CI = 1.00-1.60). Lymphohematopoietic cancer incidence was higher in the coke plants (SRR = 3.46, 95% CI = 1.02-8.91) and stomach cancer incidence was higher in the maintenance departments (SRR = 1.66, 95% CI = 1.05-2.56). CONCLUSIONS: This recent steelworker cohort exhibits possible excess cancer morbidity in some processing areas. Further follow-up of this cohort and alternate study designs such as case-control study will be needed to elucidate the relationship of exposure and health risks of iron and steel workers.