Clinical and HRCT screening of heavily asbestos-exposed workers

To characterize asbestosis today and to clarify the indications for high-resolution computed tomography (HRCT) in the surveillance of heavily exposed workers.

Six hundred and twenty-seven workers were screened and HRCT findings were classified and divided in two groups: pulmonary fibrosis (n = 86) and no fibrosis (n = 541).

Most (65/86 = 76%) of the detected fibrosis cases were mild. The magnitude of asbestos exposure showed an unexpected inverse relation with fibrosis. In multivariate analyses, age, forced expiratory volume in 1 s/forced vital capacity ratio, and poor diffusing capacity were associated with HRCT fibrosis, but asbestos exposure was not.

Asbestosis seems to be characterized by mild fibrosis today even in heavily exposed workers. To avoid radiation exposure in HRCT, age and lung function data may be used only to a limited extent to select imaging candidates. Selection and recollection biases may distort the relation between asbestos exposure and fibrosis.