Temporal Patterns of Exposure to Asbestos and Risk of Asbestosis

Objective: The aim of the study was to assess the risk of asbestosis death based on the temporal pattern of exposure to asbestos. Methods: We followed up a cohort of asbestos textile workers, employed in 1946 to 1984, until November 2013. We measured the duration of the employment, the time since last employment (TSLE), the age, and the year of first employment. Hazard ratios (HR) were estimated through multivariable Cox regression models. Results: We observed 51 asbestosis deaths among 1823 workers. The HR of asbestosis death increased with exposure duration (HR 2.4 for ≥15 years compared with <5 years, P trend=0.014) and declined with TSLE (HR 0.3 for ≥25 compared with <5 years, P=0.004). The risk of asbestosis mortality strongly declined for exposure starting after 1968. Conclusions: The risk of asbestosis death strongly declines in the decades after cessation of the exposure.