Cardiovascular disease mortality among British asbestos workers (1971-2005)

Objectives Asbestos is an inflammatory agent, and there is evidence that inflammatory processes are involved in the development of cardiovascular disease. Whether asbestos is a risk factor for cardiovascular disease has not been established. The objective of this study was to investigate cardiovascular disease mortality in a large cohort of workers occupationally exposed to asbestos. Methods Cardiovascular disease mortality in a cohort of 98 912 asbestos workers, with median follow-up of 19 years, was analysed. Unadjusted and smoking-adjusted standardised mortality ratios (SMRs) were calculated. The association between indicators of asbestos exposure and mortality was analysed with Poisson regression models, for deaths occurring during the period 1971-2005. Results Altogether 15 557 deaths from all causes, 1053 deaths from cerebrovascular disease and 4185 deaths from ischaemic heart disease (IHD) occurred during follow-up. There was statistically significant excess mortality from cerebrovascular disease (SMR: men 1.63, women 2.04) and IHD (SMR: men 1.39, women 1.89). Job and birth cohort were associated with the risk of cerebrovascular and IHD mortality in the Poisson regression model including sex, age, smoking status, job, cohort and duration of exposure. For IHD only, duration of exposure was also statistically significant in this model. Conclusions Cerebrovascular and IHD mortality was significantly higher among these asbestos workers than in the general population and within the cohort mortality was associated with indicators of asbestos exposure. These findings provide some evidence that occupational exposure to asbestos was associated with cardiovascular disease mortality in this group of workers.