Background: Most studies on asbestos-related diseases describe the associations between exposure and disease and the factors influencing that association. It is recognized that there is a long latency period between exposure and disease, but the health status of affected individuals after long-term non-exposure is uncertain.
Objectives: To describe the changes in pulmonary function tests (PFTs) and computed tomographic imaging of the thorax over a 15 year period after cessation of exposure to asbestos in a cohort of Israeli power plant workers.
Methods: Israeli power plant workers whose PFTs and thoracic CT imaging between 1993 and 1998 revealed asbestos-related disease underwent a second clinical, functional and imaging evaluation up to 15 years later. The two sets of results were compared.
Results: Of the original cohort of 59 males, 35 were still alive and 18 of them agreed to take part in the current study. The mean length of their exposure was 30 +/- 10.06 years (range 7-43 years). Comparison of the initial and follow-up examination findings revealed a significant increase in calcification of the pleural plaques (from 37% to 66%, P = 0.008) and a deterioration in PFT results (P= 0.04). Of the 24 men who died, malignant disease was the cause of death in 53%, mostly in sites other than the respiratory system.
Conclusions: PFTs declined and CT findings worsened in subjects who were formerly exposed to asbestos and had not been exposed to it for over a decade. Continued monitoring of individuals exposed to asbestos, even decades after the cessation of exposure, is recommended.