Frequency, sensitivity and specificity of roentgenographic features of slight and moderate asbestos-related respiratory diseases.

The possibility of early detection of asbestos-related respiratory diseases was examined on the basis of four x-ray abnormalities, namely, pulmonary fibrosis, pleural plaque, diffuse pleural thickening and diaphragmatic calcification, in a group of workers exposed to chrysotile asbestos. The frequency of these phenomena was compared to the unexposed control group of similar distribution of number, sex and age. Besides the pleural plaques, which had a high specificity, the combination of minor x-ray abnormalities proved to be most characteristic of exposure to asbestos. The more frequent one of the abnormalities, the less specificity it had to asbestos exposure.