MORTALITY OF ITALIAN LEAD SMELTER WORKERS

Objectives The purpose of this study was to evaluate the health conseq uences of employment in the lead-smelting industry. Methods A mortalit y study of 1388 workers and laborers in production and maintenance dep artments was conducted in an Italian lead-smelting plant. The vital st atus of cohort members was determined from 1950 to 1992. Standardized mortality ratios were calculated for specific causes of death on the b asis of national and regional reference rates. The relative risk for s elected causes of death was also modeled as a function of age, calenda r period, latency, and duration of employment with Poisson regression analysis. Results A significant 4.5-fold excess mortality from pneumoc oniosis and other diseases of the respiratory system was observed, but the risk of pneumoconiosis did not show a significant trend by durati on of employment. Mortality from all cancers, stomach cancer, and lung cancer was lower than expected. The standardized mortality ratios for genitourinary diseases and kidney cancer were not significantly eleva ted, but the Poisson regression analysis showed that both risks increa sed significantly by duration of employment. Conclusions These finding s provide limited evidence that long-term employment in lead-smelting plants increases the risk of genitourinary diseases and kidney cancer. The observed increase in mortality from pneumoconiosis and other dise ases of the respiratory system was more likely related to silica expos ure in other workplaces. No excess risk of stomach cancer and lung can cer was observed in this cohort.