ASBESTOS, ASBESTOSIS, PLEURAL PLAQUES AND LUNG-CANCER

Inhalation of asbestos fibers increases the risk of bronchial carcinom a. It has been claimed that asbestosis is a necessary prerequisite for the malignancy, but epidemiologic studies usually do not have enough statistical strength to prove that asbestos-exposed patients without a sbestosis are without risk. Several recent studies do actually indicat e that there is a risk for such patients. In addition, case-referent s tudies of patients with lung cancer show an attributable risk for asbe stos of 6% to 23%, which is much higher than the actual occurrence of asbestosis among these patients. Thus there is an increasing body of e vidence that, at low exposure levels, asbestos produces a slight incre ase in the relative risk of lung cancer even in the absence of asbesto sis. Consequently, all exposure to asbestos must be minimized.