Silica Exposure and Cardiovascular, Cerebrovascular, and Respiratory Morbidity in a Cohort of Male Swedish Iron Foundry Workers

OBJECTIVE: We present quantitative exposure-response data on silica exposure in male Swedish iron foundry workers for cardiovascular, cerebrovascular, and respiratory morbidity. METHODS: This research is a cohort study of 2063 male Swedish iron foundry workers. From the Swedish National Patient Registers, data on morbidity incidence were retrieved. A historical measurement database of 1667 respirable silica exposure measurements from 10 Swedish iron foundries was used to calculate the cumulative exposure dose for each worker. RESULTS: Increased morbidity risk for the whole group of foundry workers was determined for ischemic heart disease, cerebrovascular disease, chronic obstructive pulmonary disease (COPD), bronchitis, and pneumonia. In addition, an increased risk for COPD at cumulative silica exposures ranging from 0.11 to 0.84 mg/m(3) year is presented. CONCLUSIONS: The study presents a significantly increased COPD risk at cumulative silica exposures below the Swedish occupational exposure limit.