Mortality in a cohort of cement workers in a plant of Central Italy

Workers of cement production are exposed to alkaline dust with irritant effects on the respiratory system. Most previous studies have examined workers in cement/asbestos factories, but there is limited information of the effects of exposures to Portland cement alone. The present study examines the effects of cement dust in a cohort of Portland cement workers through the analyses of their mortality records. Using the records of a cement plant, we reconstructed the work history of all 748 male employees between 1956 and 2006. SMRs were computed for overall mortality and for specific causes of death for the cohort compared with the reference population. The analysis was also performed by subdividing the cohort in low- and high-exposure groups on the basis of the task of the worker and the length of his exposure. The overall mortality of the cohort (SMR = 0.87) as well as the mortality from all cancers (SMR = 0.64) and from cancers of the respiratory system (SMR = 0.56) was significantly lower compared to the reference population. Workers of the cement plant with higher exposures did not have an increased mortality risk from any cause. The only significantly elevated risk observed among these workers was for cancer of the respiratory system (SMR = 2.86), exclusively in the small subgroup of 39 workers with previous exposure to a cement/asbestos plant. Portland cement workers had a statistically significant reduced risk of overall mortality and of all cancers mortality probably due to the healthy workers effect. The study confirmed an increased risk of respiratory system cancer only in the subgroup with previous work exposure in a cement/asbestos plant.